diff options
| author | Dr. David Alan Gilbert <dgilbert@redhat.com> | 2014-12-12 11:13:38 +0000 |
|---|---|---|
| committer | Amit Shah <amit.shah@redhat.com> | 2014-12-16 17:47:36 +0530 |
| commit | 60fe637bf0e4d7989e21e50f52526444765c63b4 (patch) | |
| tree | b5dbcea1d25fe151e097cc1401cb19b64262401c /migration | |
| parent | d6d69731f5295e4c3bb0196f57e8848af28b705e (diff) | |
Start migrating migration code into a migration directory
The migration code now occupies a fair chunk of the top level .c
files, it seems time to give it it's own directory.
I've not touched:
arch_init.c - that's mostly RAM migration but has a few random other
bits
savevm.c - because it's built target specific
This is purely a code move; no code has changed.
- it fails checkpatch because of old violations, it feels safer
to keep this as purely a move and fix those at some mythical future
date.
The xbzrle and vmstate tests are now only run for softmmu builds
since they require files in the migrate/ directory which is only built
for softmmu.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Diffstat (limited to 'migration')
| -rw-r--r-- | migration/Makefile.objs | 10 | ||||
| -rw-r--r-- | migration/block-migration.c | 892 | ||||
| -rw-r--r-- | migration/migration-exec.c | 69 | ||||
| -rw-r--r-- | migration/migration-fd.c | 68 | ||||
| -rw-r--r-- | migration/migration-rdma.c | 3438 | ||||
| -rw-r--r-- | migration/migration-tcp.c | 103 | ||||
| -rw-r--r-- | migration/migration-unix.c | 103 | ||||
| -rw-r--r-- | migration/migration.c | 700 | ||||
| -rw-r--r-- | migration/qemu-file-stdio.c | 194 | ||||
| -rw-r--r-- | migration/qemu-file-unix.c | 223 | ||||
| -rw-r--r-- | migration/qemu-file.c | 995 | ||||
| -rw-r--r-- | migration/vmstate.c | 687 | ||||
| -rw-r--r-- | migration/xbzrle.c | 175 |
13 files changed, 7657 insertions, 0 deletions
diff --git a/migration/Makefile.objs b/migration/Makefile.objs new file mode 100644 index 0000000000..63dbe93447 --- /dev/null +++ b/migration/Makefile.objs @@ -0,0 +1,10 @@ +common-obj-y += migration.o migration-tcp.o +common-obj-y += vmstate.o +common-obj-y += qemu-file.o qemu-file-unix.o qemu-file-stdio.o +common-obj-$(CONFIG_RDMA) += migration-rdma.o +common-obj-y += xbzrle.o + +common-obj-$(CONFIG_POSIX) += migration-exec.o migration-unix.o migration-fd.o + +common-obj-y += block-migration.o + diff --git a/migration/block-migration.c b/migration/block-migration.c new file mode 100644 index 0000000000..74d9eb125c --- /dev/null +++ b/migration/block-migration.c @@ -0,0 +1,892 @@ +/* + * QEMU live block migration + * + * Copyright IBM, Corp. 2009 + * + * Authors: + * Liran Schour <lirans@il.ibm.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ + +#include "qemu-common.h" +#include "block/block.h" +#include "qemu/error-report.h" +#include "qemu/main-loop.h" +#include "hw/hw.h" +#include "qemu/queue.h" +#include "qemu/timer.h" +#include "migration/block.h" +#include "migration/migration.h" +#include "sysemu/blockdev.h" +#include <assert.h> + +#define BLOCK_SIZE (1 << 20) +#define BDRV_SECTORS_PER_DIRTY_CHUNK (BLOCK_SIZE >> BDRV_SECTOR_BITS) + +#define BLK_MIG_FLAG_DEVICE_BLOCK 0x01 +#define BLK_MIG_FLAG_EOS 0x02 +#define BLK_MIG_FLAG_PROGRESS 0x04 +#define BLK_MIG_FLAG_ZERO_BLOCK 0x08 + +#define MAX_IS_ALLOCATED_SEARCH 65536 + +//#define DEBUG_BLK_MIGRATION + +#ifdef DEBUG_BLK_MIGRATION +#define DPRINTF(fmt, ...) \ + do { printf("blk_migration: " fmt, ## __VA_ARGS__); } while (0) +#else +#define DPRINTF(fmt, ...) \ + do { } while (0) +#endif + +typedef struct BlkMigDevState { + /* Written during setup phase. Can be read without a lock. */ + BlockDriverState *bs; + int shared_base; + int64_t total_sectors; + QSIMPLEQ_ENTRY(BlkMigDevState) entry; + + /* Only used by migration thread. Does not need a lock. */ + int bulk_completed; + int64_t cur_sector; + int64_t cur_dirty; + + /* Protected by block migration lock. */ + unsigned long *aio_bitmap; + int64_t completed_sectors; + BdrvDirtyBitmap *dirty_bitmap; + Error *blocker; +} BlkMigDevState; + +typedef struct BlkMigBlock { + /* Only used by migration thread. */ + uint8_t *buf; + BlkMigDevState *bmds; + int64_t sector; + int nr_sectors; + struct iovec iov; + QEMUIOVector qiov; + BlockAIOCB *aiocb; + + /* Protected by block migration lock. */ + int ret; + QSIMPLEQ_ENTRY(BlkMigBlock) entry; +} BlkMigBlock; + +typedef struct BlkMigState { + /* Written during setup phase. Can be read without a lock. */ + int blk_enable; + int shared_base; + QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list; + int64_t total_sector_sum; + bool zero_blocks; + + /* Protected by lock. */ + QSIMPLEQ_HEAD(blk_list, BlkMigBlock) blk_list; + int submitted; + int read_done; + + /* Only used by migration thread. Does not need a lock. */ + int transferred; + int prev_progress; + int bulk_completed; + + /* Lock must be taken _inside_ the iothread lock. */ + QemuMutex lock; +} BlkMigState; + +static BlkMigState block_mig_state; + +static void blk_mig_lock(void) +{ + qemu_mutex_lock(&block_mig_state.lock); +} + +static void blk_mig_unlock(void) +{ + qemu_mutex_unlock(&block_mig_state.lock); +} + +/* Must run outside of the iothread lock during the bulk phase, + * or the VM will stall. + */ + +static void blk_send(QEMUFile *f, BlkMigBlock * blk) +{ + int len; + uint64_t flags = BLK_MIG_FLAG_DEVICE_BLOCK; + + if (block_mig_state.zero_blocks && + buffer_is_zero(blk->buf, BLOCK_SIZE)) { + flags |= BLK_MIG_FLAG_ZERO_BLOCK; + } + + /* sector number and flags */ + qemu_put_be64(f, (blk->sector << BDRV_SECTOR_BITS) + | flags); + + /* device name */ + len = strlen(bdrv_get_device_name(blk->bmds->bs)); + qemu_put_byte(f, len); + qemu_put_buffer(f, (uint8_t *)bdrv_get_device_name(blk->bmds->bs), len); + + /* if a block is zero we need to flush here since the network + * bandwidth is now a lot higher than the storage device bandwidth. + * thus if we queue zero blocks we slow down the migration */ + if (flags & BLK_MIG_FLAG_ZERO_BLOCK) { + qemu_fflush(f); + return; + } + + qemu_put_buffer(f, blk->buf, BLOCK_SIZE); +} + +int blk_mig_active(void) +{ + return !QSIMPLEQ_EMPTY(&block_mig_state.bmds_list); +} + +uint64_t blk_mig_bytes_transferred(void) +{ + BlkMigDevState *bmds; + uint64_t sum = 0; + + blk_mig_lock(); + QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { + sum += bmds->completed_sectors; + } + blk_mig_unlock(); + return sum << BDRV_SECTOR_BITS; +} + +uint64_t blk_mig_bytes_remaining(void) +{ + return blk_mig_bytes_total() - blk_mig_bytes_transferred(); +} + +uint64_t blk_mig_bytes_total(void) +{ + BlkMigDevState *bmds; + uint64_t sum = 0; + + QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { + sum += bmds->total_sectors; + } + return sum << BDRV_SECTOR_BITS; +} + + +/* Called with migration lock held. */ + +static int bmds_aio_inflight(BlkMigDevState *bmds, int64_t sector) +{ + int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK; + + if (sector < bdrv_nb_sectors(bmds->bs)) { + return !!(bmds->aio_bitmap[chunk / (sizeof(unsigned long) * 8)] & + (1UL << (chunk % (sizeof(unsigned long) * 8)))); + } else { + return 0; + } +} + +/* Called with migration lock held. */ + +static void bmds_set_aio_inflight(BlkMigDevState *bmds, int64_t sector_num, + int nb_sectors, int set) +{ + int64_t start, end; + unsigned long val, idx, bit; + + start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK; + end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK; + + for (; start <= end; start++) { + idx = start / (sizeof(unsigned long) * 8); + bit = start % (sizeof(unsigned long) * 8); + val = bmds->aio_bitmap[idx]; + if (set) { + val |= 1UL << bit; + } else { + val &= ~(1UL << bit); + } + bmds->aio_bitmap[idx] = val; + } +} + +static void alloc_aio_bitmap(BlkMigDevState *bmds) +{ + BlockDriverState *bs = bmds->bs; + int64_t bitmap_size; + + bitmap_size = bdrv_nb_sectors(bs) + BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1; + bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8; + + bmds->aio_bitmap = g_malloc0(bitmap_size); +} + +/* Never hold migration lock when yielding to the main loop! */ + +static void blk_mig_read_cb(void *opaque, int ret) +{ + BlkMigBlock *blk = opaque; + + blk_mig_lock(); + blk->ret = ret; + + QSIMPLEQ_INSERT_TAIL(&block_mig_state.blk_list, blk, entry); + bmds_set_aio_inflight(blk->bmds, blk->sector, blk->nr_sectors, 0); + + block_mig_state.submitted--; + block_mig_state.read_done++; + assert(block_mig_state.submitted >= 0); + blk_mig_unlock(); +} + +/* Called with no lock taken. */ + +static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds) +{ + int64_t total_sectors = bmds->total_sectors; + int64_t cur_sector = bmds->cur_sector; + BlockDriverState *bs = bmds->bs; + BlkMigBlock *blk; + int nr_sectors; + + if (bmds->shared_base) { + qemu_mutex_lock_iothread(); + while (cur_sector < total_sectors && + !bdrv_is_allocated(bs, cur_sector, MAX_IS_ALLOCATED_SEARCH, + &nr_sectors)) { + cur_sector += nr_sectors; + } + qemu_mutex_unlock_iothread(); + } + + if (cur_sector >= total_sectors) { + bmds->cur_sector = bmds->completed_sectors = total_sectors; + return 1; + } + + bmds->completed_sectors = cur_sector; + + cur_sector &= ~((int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK - 1); + + /* we are going to transfer a full block even if it is not allocated */ + nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK; + + if (total_sectors - cur_sector < BDRV_SECTORS_PER_DIRTY_CHUNK) { + nr_sectors = total_sectors - cur_sector; + } + + blk = g_new(BlkMigBlock, 1); + blk->buf = g_malloc(BLOCK_SIZE); + blk->bmds = bmds; + blk->sector = cur_sector; + blk->nr_sectors = nr_sectors; + + blk->iov.iov_base = blk->buf; + blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE; + qemu_iovec_init_external(&blk->qiov, &blk->iov, 1); + + blk_mig_lock(); + block_mig_state.submitted++; + blk_mig_unlock(); + + qemu_mutex_lock_iothread(); + blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov, + nr_sectors, blk_mig_read_cb, blk); + + bdrv_reset_dirty(bs, cur_sector, nr_sectors); + qemu_mutex_unlock_iothread(); + + bmds->cur_sector = cur_sector + nr_sectors; + return (bmds->cur_sector >= total_sectors); +} + +/* Called with iothread lock taken. */ + +static int set_dirty_tracking(void) +{ + BlkMigDevState *bmds; + int ret; + + QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { + bmds->dirty_bitmap = bdrv_create_dirty_bitmap(bmds->bs, BLOCK_SIZE, + NULL); + if (!bmds->dirty_bitmap) { + ret = -errno; + goto fail; + } + } + return 0; + +fail: + QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { + if (bmds->dirty_bitmap) { + bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap); + } + } + return ret; +} + +static void unset_dirty_tracking(void) +{ + BlkMigDevState *bmds; + + QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { + bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap); + } +} + +static void init_blk_migration(QEMUFile *f) +{ + BlockDriverState *bs; + BlkMigDevState *bmds; + int64_t sectors; + + block_mig_state.submitted = 0; + block_mig_state.read_done = 0; + block_mig_state.transferred = 0; + block_mig_state.total_sector_sum = 0; + block_mig_state.prev_progress = -1; + block_mig_state.bulk_completed = 0; + block_mig_state.zero_blocks = migrate_zero_blocks(); + + for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) { + if (bdrv_is_read_only(bs)) { + continue; + } + + sectors = bdrv_nb_sectors(bs); + if (sectors <= 0) { + return; + } + + bmds = g_new0(BlkMigDevState, 1); + bmds->bs = bs; + bmds->bulk_completed = 0; + bmds->total_sectors = sectors; + bmds->completed_sectors = 0; + bmds->shared_base = block_mig_state.shared_base; + alloc_aio_bitmap(bmds); + error_setg(&bmds->blocker, "block device is in use by migration"); + bdrv_op_block_all(bs, bmds->blocker); + bdrv_ref(bs); + + block_mig_state.total_sector_sum += sectors; + + if (bmds->shared_base) { + DPRINTF("Start migration for %s with shared base image\n", + bdrv_get_device_name(bs)); + } else { + DPRINTF("Start full migration for %s\n", bdrv_get_device_name(bs)); + } + + QSIMPLEQ_INSERT_TAIL(&block_mig_state.bmds_list, bmds, entry); + } +} + +/* Called with no lock taken. */ + +static int blk_mig_save_bulked_block(QEMUFile *f) +{ + int64_t completed_sector_sum = 0; + BlkMigDevState *bmds; + int progress; + int ret = 0; + + QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { + if (bmds->bulk_completed == 0) { + if (mig_save_device_bulk(f, bmds) == 1) { + /* completed bulk section for this device */ + bmds->bulk_completed = 1; + } + completed_sector_sum += bmds->completed_sectors; + ret = 1; + break; + } else { + completed_sector_sum += bmds->completed_sectors; + } + } + + if (block_mig_state.total_sector_sum != 0) { + progress = completed_sector_sum * 100 / + block_mig_state.total_sector_sum; + } else { + progress = 100; + } + if (progress != block_mig_state.prev_progress) { + block_mig_state.prev_progress = progress; + qemu_put_be64(f, (progress << BDRV_SECTOR_BITS) + | BLK_MIG_FLAG_PROGRESS); + DPRINTF("Completed %d %%\r", progress); + } + + return ret; +} + +static void blk_mig_reset_dirty_cursor(void) +{ + BlkMigDevState *bmds; + + QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { + bmds->cur_dirty = 0; + } +} + +/* Called with iothread lock taken. */ + +static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds, + int is_async) +{ + BlkMigBlock *blk; + int64_t total_sectors = bmds->total_sectors; + int64_t sector; + int nr_sectors; + int ret = -EIO; + + for (sector = bmds->cur_dirty; sector < bmds->total_sectors;) { + blk_mig_lock(); + if (bmds_aio_inflight(bmds, sector)) { + blk_mig_unlock(); + bdrv_drain_all(); + } else { + blk_mig_unlock(); + } + if (bdrv_get_dirty(bmds->bs, bmds->dirty_bitmap, sector)) { + + if (total_sectors - sector < BDRV_SECTORS_PER_DIRTY_CHUNK) { + nr_sectors = total_sectors - sector; + } else { + nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK; + } + blk = g_new(BlkMigBlock, 1); + blk->buf = g_malloc(BLOCK_SIZE); + blk->bmds = bmds; + blk->sector = sector; + blk->nr_sectors = nr_sectors; + + if (is_async) { + blk->iov.iov_base = blk->buf; + blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE; + qemu_iovec_init_external(&blk->qiov, &blk->iov, 1); + + blk->aiocb = bdrv_aio_readv(bmds->bs, sector, &blk->qiov, + nr_sectors, blk_mig_read_cb, blk); + + blk_mig_lock(); + block_mig_state.submitted++; + bmds_set_aio_inflight(bmds, sector, nr_sectors, 1); + blk_mig_unlock(); + } else { + ret = bdrv_read(bmds->bs, sector, blk->buf, nr_sectors); + if (ret < 0) { + goto error; + } + blk_send(f, blk); + + g_free(blk->buf); + g_free(blk); + } + + bdrv_reset_dirty(bmds->bs, sector, nr_sectors); + break; + } + sector += BDRV_SECTORS_PER_DIRTY_CHUNK; + bmds->cur_dirty = sector; + } + + return (bmds->cur_dirty >= bmds->total_sectors); + +error: + DPRINTF("Error reading sector %" PRId64 "\n", sector); + g_free(blk->buf); + g_free(blk); + return ret; +} + +/* Called with iothread lock taken. + * + * return value: + * 0: too much data for max_downtime + * 1: few enough data for max_downtime +*/ +static int blk_mig_save_dirty_block(QEMUFile *f, int is_async) +{ + BlkMigDevState *bmds; + int ret = 1; + + QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { + ret = mig_save_device_dirty(f, bmds, is_async); + if (ret <= 0) { + break; + } + } + + return ret; +} + +/* Called with no locks taken. */ + +static int flush_blks(QEMUFile *f) +{ + BlkMigBlock *blk; + int ret = 0; + + DPRINTF("%s Enter submitted %d read_done %d transferred %d\n", + __FUNCTION__, block_mig_state.submitted, block_mig_state.read_done, + block_mig_state.transferred); + + blk_mig_lock(); + while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) { + if (qemu_file_rate_limit(f)) { + break; + } + if (blk->ret < 0) { + ret = blk->ret; + break; + } + + QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry); + blk_mig_unlock(); + blk_send(f, blk); + blk_mig_lock(); + + g_free(blk->buf); + g_free(blk); + + block_mig_state.read_done--; + block_mig_state.transferred++; + assert(block_mig_state.read_done >= 0); + } + blk_mig_unlock(); + + DPRINTF("%s Exit submitted %d read_done %d transferred %d\n", __FUNCTION__, + block_mig_state.submitted, block_mig_state.read_done, + block_mig_state.transferred); + return ret; +} + +/* Called with iothread lock taken. */ + +static int64_t get_remaining_dirty(void) +{ + BlkMigDevState *bmds; + int64_t dirty = 0; + + QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { + dirty += bdrv_get_dirty_count(bmds->bs, bmds->dirty_bitmap); + } + + return dirty << BDRV_SECTOR_BITS; +} + +/* Called with iothread lock taken. */ + +static void blk_mig_cleanup(void) +{ + BlkMigDevState *bmds; + BlkMigBlock *blk; + + bdrv_drain_all(); + + unset_dirty_tracking(); + + blk_mig_lock(); + while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) { + QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry); + bdrv_op_unblock_all(bmds->bs, bmds->blocker); + error_free(bmds->blocker); + bdrv_unref(bmds->bs); + g_free(bmds->aio_bitmap); + g_free(bmds); + } + + while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) { + QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry); + g_free(blk->buf); + g_free(blk); + } + blk_mig_unlock(); +} + +static void block_migration_cancel(void *opaque) +{ + blk_mig_cleanup(); +} + +static int block_save_setup(QEMUFile *f, void *opaque) +{ + int ret; + + DPRINTF("Enter save live setup submitted %d transferred %d\n", + block_mig_state.submitted, block_mig_state.transferred); + + qemu_mutex_lock_iothread(); + init_blk_migration(f); + + /* start track dirty blocks */ + ret = set_dirty_tracking(); + + if (ret) { + qemu_mutex_unlock_iothread(); + return ret; + } + + qemu_mutex_unlock_iothread(); + + ret = flush_blks(f); + blk_mig_reset_dirty_cursor(); + qemu_put_be64(f, BLK_MIG_FLAG_EOS); + + return ret; +} + +static int block_save_iterate(QEMUFile *f, void *opaque) +{ + int ret; + int64_t last_ftell = qemu_ftell(f); + int64_t delta_ftell; + + DPRINTF("Enter save live iterate submitted %d transferred %d\n", + block_mig_state.submitted, block_mig_state.transferred); + + ret = flush_blks(f); + if (ret) { + return ret; + } + + blk_mig_reset_dirty_cursor(); + + /* control the rate of transfer */ + blk_mig_lock(); + while ((block_mig_state.submitted + + block_mig_state.read_done) * BLOCK_SIZE < + qemu_file_get_rate_limit(f)) { + blk_mig_unlock(); + if (block_mig_state.bulk_completed == 0) { + /* first finish the bulk phase */ + if (blk_mig_save_bulked_block(f) == 0) { + /* finished saving bulk on all devices */ + block_mig_state.bulk_completed = 1; + } + ret = 0; + } else { + /* Always called with iothread lock taken for + * simplicity, block_save_complete also calls it. + */ + qemu_mutex_lock_iothread(); + ret = blk_mig_save_dirty_block(f, 1); + qemu_mutex_unlock_iothread(); + } + if (ret < 0) { + return ret; + } + blk_mig_lock(); + if (ret != 0) { + /* no more dirty blocks */ + break; + } + } + blk_mig_unlock(); + + ret = flush_blks(f); + if (ret) { + return ret; + } + + qemu_put_be64(f, BLK_MIG_FLAG_EOS); + delta_ftell = qemu_ftell(f) - last_ftell; + if (delta_ftell > 0) { + return 1; + } else if (delta_ftell < 0) { + return -1; + } else { + return 0; + } +} + +/* Called with iothread lock taken. */ + +static int block_save_complete(QEMUFile *f, void *opaque) +{ + int ret; + + DPRINTF("Enter save live complete submitted %d transferred %d\n", + block_mig_state.submitted, block_mig_state.transferred); + + ret = flush_blks(f); + if (ret) { + return ret; + } + + blk_mig_reset_dirty_cursor(); + + /* we know for sure that save bulk is completed and + all async read completed */ + blk_mig_lock(); + assert(block_mig_state.submitted == 0); + blk_mig_unlock(); + + do { + ret = blk_mig_save_dirty_block(f, 0); + if (ret < 0) { + return ret; + } + } while (ret == 0); + + /* report completion */ + qemu_put_be64(f, (100 << BDRV_SECTOR_BITS) | BLK_MIG_FLAG_PROGRESS); + + DPRINTF("Block migration completed\n"); + + qemu_put_be64(f, BLK_MIG_FLAG_EOS); + + blk_mig_cleanup(); + return 0; +} + +static uint64_t block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size) +{ + /* Estimate pending number of bytes to send */ + uint64_t pending; + + qemu_mutex_lock_iothread(); + blk_mig_lock(); + pending = get_remaining_dirty() + + block_mig_state.submitted * BLOCK_SIZE + + block_mig_state.read_done * BLOCK_SIZE; + + /* Report at least one block pending during bulk phase */ + if (pending == 0 && !block_mig_state.bulk_completed) { + pending = BLOCK_SIZE; + } + blk_mig_unlock(); + qemu_mutex_unlock_iothread(); + + DPRINTF("Enter save live pending %" PRIu64 "\n", pending); + return pending; +} + +static int block_load(QEMUFile *f, void *opaque, int version_id) +{ + static int banner_printed; + int len, flags; + char device_name[256]; + int64_t addr; + BlockDriverState *bs, *bs_prev = NULL; + uint8_t *buf; + int64_t total_sectors = 0; + int nr_sectors; + int ret; + + do { + addr = qemu_get_be64(f); + + flags = addr & ~BDRV_SECTOR_MASK; + addr >>= BDRV_SECTOR_BITS; + + if (flags & BLK_MIG_FLAG_DEVICE_BLOCK) { + /* get device name */ + len = qemu_get_byte(f); + qemu_get_buffer(f, (uint8_t *)device_name, len); + device_name[len] = '\0'; + + bs = bdrv_find(device_name); + if (!bs) { + fprintf(stderr, "Error unknown block device %s\n", + device_name); + return -EINVAL; + } + + if (bs != bs_prev) { + bs_prev = bs; + total_sectors = bdrv_nb_sectors(bs); + if (total_sectors <= 0) { + error_report("Error getting length of block device %s", + device_name); + return -EINVAL; + } + } + + if (total_sectors - addr < BDRV_SECTORS_PER_DIRTY_CHUNK) { + nr_sectors = total_sectors - addr; + } else { + nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK; + } + + if (flags & BLK_MIG_FLAG_ZERO_BLOCK) { + ret = bdrv_write_zeroes(bs, addr, nr_sectors, + BDRV_REQ_MAY_UNMAP); + } else { + buf = g_malloc(BLOCK_SIZE); + qemu_get_buffer(f, buf, BLOCK_SIZE); + ret = bdrv_write(bs, addr, buf, nr_sectors); + g_free(buf); + } + + if (ret < 0) { + return ret; + } + } else if (flags & BLK_MIG_FLAG_PROGRESS) { + if (!banner_printed) { + printf("Receiving block device images\n"); + banner_printed = 1; + } + printf("Completed %d %%%c", (int)addr, + (addr == 100) ? '\n' : '\r'); + fflush(stdout); + } else if (!(flags & BLK_MIG_FLAG_EOS)) { + fprintf(stderr, "Unknown block migration flags: %#x\n", flags); + return -EINVAL; + } + ret = qemu_file_get_error(f); + if (ret != 0) { + return ret; + } + } while (!(flags & BLK_MIG_FLAG_EOS)); + + return 0; +} + +static void block_set_params(const MigrationParams *params, void *opaque) +{ + block_mig_state.blk_enable = params->blk; + block_mig_state.shared_base = params->shared; + + /* shared base means that blk_enable = 1 */ + block_mig_state.blk_enable |= params->shared; +} + +static bool block_is_active(void *opaque) +{ + return block_mig_state.blk_enable == 1; +} + +static SaveVMHandlers savevm_block_handlers = { + .set_params = block_set_params, + .save_live_setup = block_save_setup, + .save_live_iterate = block_save_iterate, + .save_live_complete = block_save_complete, + .save_live_pending = block_save_pending, + .load_state = block_load, + .cancel = block_migration_cancel, + .is_active = block_is_active, +}; + +void blk_mig_init(void) +{ + QSIMPLEQ_INIT(&block_mig_state.bmds_list); + QSIMPLEQ_INIT(&block_mig_state.blk_list); + qemu_mutex_init(&block_mig_state.lock); + + register_savevm_live(NULL, "block", 0, 1, &savevm_block_handlers, + &block_mig_state); +} diff --git a/migration/migration-exec.c b/migration/migration-exec.c new file mode 100644 index 0000000000..479024752f --- /dev/null +++ b/migration/migration-exec.c @@ -0,0 +1,69 @@ +/* + * QEMU live migration + * + * Copyright IBM, Corp. 2008 + * Copyright Dell MessageOne 2008 + * + * Authors: + * Anthony Liguori <aliguori@us.ibm.com> + * Charles Duffy <charles_duffy@messageone.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ + +#include "qemu-common.h" +#include "qemu/sockets.h" +#include "qemu/main-loop.h" +#include "migration/migration.h" +#include "migration/qemu-file.h" +#include "block/block.h" +#include <sys/types.h> +#include <sys/wait.h> + +//#define DEBUG_MIGRATION_EXEC + +#ifdef DEBUG_MIGRATION_EXEC +#define DPRINTF(fmt, ...) \ + do { printf("migration-exec: " fmt, ## __VA_ARGS__); } while (0) +#else +#define DPRINTF(fmt, ...) \ + do { } while (0) +#endif + +void exec_start_outgoing_migration(MigrationState *s, const char *command, Error **errp) +{ + s->file = qemu_popen_cmd(command, "w"); + if (s->file == NULL) { + error_setg_errno(errp, errno, "failed to popen the migration target"); + return; + } + + migrate_fd_connect(s); +} + +static void exec_accept_incoming_migration(void *opaque) +{ + QEMUFile *f = opaque; + + qemu_set_fd_handler2(qemu_get_fd(f), NULL, NULL, NULL, NULL); + process_incoming_migration(f); +} + +void exec_start_incoming_migration(const char *command, Error **errp) +{ + QEMUFile *f; + + DPRINTF("Attempting to start an incoming migration\n"); + f = qemu_popen_cmd(command, "r"); + if(f == NULL) { + error_setg_errno(errp, errno, "failed to popen the migration source"); + return; + } + + qemu_set_fd_handler2(qemu_get_fd(f), NULL, + exec_accept_incoming_migration, NULL, f); +} diff --git a/migration/migration-fd.c b/migration/migration-fd.c new file mode 100644 index 0000000000..d2e523af74 --- /dev/null +++ b/migration/migration-fd.c @@ -0,0 +1,68 @@ +/* + * QEMU live migration via generic fd + * + * Copyright Red Hat, Inc. 2009 + * + * Authors: + * Chris Lalancette <clalance@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ + +#include "qemu-common.h" +#include "qemu/main-loop.h" +#include "qemu/sockets.h" +#include "migration/migration.h" +#include "monitor/monitor.h" +#include "migration/qemu-file.h" +#include "block/block.h" + +//#define DEBUG_MIGRATION_FD + +#ifdef DEBUG_MIGRATION_FD +#define DPRINTF(fmt, ...) \ + do { printf("migration-fd: " fmt, ## __VA_ARGS__); } while (0) +#else +#define DPRINTF(fmt, ...) \ + do { } while (0) +#endif + +void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp) +{ + int fd = monitor_get_fd(cur_mon, fdname, errp); + if (fd == -1) { + return; + } + s->file = qemu_fdopen(fd, "wb"); + + migrate_fd_connect(s); +} + +static void fd_accept_incoming_migration(void *opaque) +{ + QEMUFile *f = opaque; + + qemu_set_fd_handler2(qemu_get_fd(f), NULL, NULL, NULL, NULL); + process_incoming_migration(f); +} + +void fd_start_incoming_migration(const char *infd, Error **errp) +{ + int fd; + QEMUFile *f; + + DPRINTF("Attempting to start an incoming migration via fd\n"); + + fd = strtol(infd, NULL, 0); + f = qemu_fdopen(fd, "rb"); + if(f == NULL) { + error_setg_errno(errp, errno, "failed to open the source descriptor"); + return; + } + + qemu_set_fd_handler2(fd, NULL, fd_accept_incoming_migration, NULL, f); +} diff --git a/migration/migration-rdma.c b/migration/migration-rdma.c new file mode 100644 index 0000000000..b32dbdfccd --- /dev/null +++ b/migration/migration-rdma.c @@ -0,0 +1,3438 @@ +/* + * RDMA protocol and interfaces + * + * Copyright IBM, Corp. 2010-2013 + * + * Authors: + * Michael R. Hines <mrhines@us.ibm.com> + * Jiuxing Liu <jl@us.ibm.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * later. See the COPYING file in the top-level directory. + * + */ +#include "qemu-common.h" +#include "migration/migration.h" +#include "migration/qemu-file.h" +#include "exec/cpu-common.h" +#include "qemu/main-loop.h" +#include "qemu/sockets.h" +#include "qemu/bitmap.h" +#include "block/coroutine.h" +#include <stdio.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <netdb.h> +#include <arpa/inet.h> +#include <string.h> +#include <rdma/rdma_cma.h> + +//#define DEBUG_RDMA +//#define DEBUG_RDMA_VERBOSE +//#define DEBUG_RDMA_REALLY_VERBOSE + +#ifdef DEBUG_RDMA +#define DPRINTF(fmt, ...) \ + do { printf("rdma: " fmt, ## __VA_ARGS__); } while (0) +#else +#define DPRINTF(fmt, ...) \ + do { } while (0) +#endif + +#ifdef DEBUG_RDMA_VERBOSE +#define DDPRINTF(fmt, ...) \ + do { printf("rdma: " fmt, ## __VA_ARGS__); } while (0) +#else +#define DDPRINTF(fmt, ...) \ + do { } while (0) +#endif + +#ifdef DEBUG_RDMA_REALLY_VERBOSE +#define DDDPRINTF(fmt, ...) \ + do { printf("rdma: " fmt, ## __VA_ARGS__); } while (0) +#else +#define DDDPRINTF(fmt, ...) \ + do { } while (0) +#endif + +/* + * Print and error on both the Monitor and the Log file. + */ +#define ERROR(errp, fmt, ...) \ + do { \ + fprintf(stderr, "RDMA ERROR: " fmt "\n", ## __VA_ARGS__); \ + if (errp && (*(errp) == NULL)) { \ + error_setg(errp, "RDMA ERROR: " fmt, ## __VA_ARGS__); \ + } \ + } while (0) + +#define RDMA_RESOLVE_TIMEOUT_MS 10000 + +/* Do not merge data if larger than this. */ +#define RDMA_MERGE_MAX (2 * 1024 * 1024) +#define RDMA_SIGNALED_SEND_MAX (RDMA_MERGE_MAX / 4096) + +#define RDMA_REG_CHUNK_SHIFT 20 /* 1 MB */ + +/* + * This is only for non-live state being migrated. + * Instead of RDMA_WRITE messages, we use RDMA_SEND + * messages for that state, which requires a different + * delivery design than main memory. + */ +#define RDMA_SEND_INCREMENT 32768 + +/* + * Maximum size infiniband SEND message + */ +#define RDMA_CONTROL_MAX_BUFFER (512 * 1024) +#define RDMA_CONTROL_MAX_COMMANDS_PER_MESSAGE 4096 + +#define RDMA_CONTROL_VERSION_CURRENT 1 +/* + * Capabilities for negotiation. + */ +#define RDMA_CAPABILITY_PIN_ALL 0x01 + +/* + * Add the other flags above to this list of known capabilities + * as they are introduced. + */ +static uint32_t known_capabilities = RDMA_CAPABILITY_PIN_ALL; + +#define CHECK_ERROR_STATE() \ + do { \ + if (rdma->error_state) { \ + if (!rdma->error_reported) { \ + fprintf(stderr, "RDMA is in an error state waiting migration" \ + " to abort!\n"); \ + rdma->error_reported = 1; \ + } \ + return rdma->error_state; \ + } \ + } while (0); + +/* + * A work request ID is 64-bits and we split up these bits + * into 3 parts: + * + * bits 0-15 : type of control message, 2^16 + * bits 16-29: ram block index, 2^14 + * bits 30-63: ram block chunk number, 2^34 + * + * The last two bit ranges are only used for RDMA writes, + * in order to track their completion and potentially + * also track unregistration status of the message. + */ +#define RDMA_WRID_TYPE_SHIFT 0UL +#define RDMA_WRID_BLOCK_SHIFT 16UL +#define RDMA_WRID_CHUNK_SHIFT 30UL + +#define RDMA_WRID_TYPE_MASK \ + ((1UL << RDMA_WRID_BLOCK_SHIFT) - 1UL) + +#define RDMA_WRID_BLOCK_MASK \ + (~RDMA_WRID_TYPE_MASK & ((1UL << RDMA_WRID_CHUNK_SHIFT) - 1UL)) + +#define RDMA_WRID_CHUNK_MASK (~RDMA_WRID_BLOCK_MASK & ~RDMA_WRID_TYPE_MASK) + +/* + * RDMA migration protocol: + * 1. RDMA Writes (data messages, i.e. RAM) + * 2. IB Send/Recv (control channel messages) + */ +enum { + RDMA_WRID_NONE = 0, + RDMA_WRID_RDMA_WRITE = 1, + RDMA_WRID_SEND_CONTROL = 2000, + RDMA_WRID_RECV_CONTROL = 4000, +}; + +const char *wrid_desc[] = { + [RDMA_WRID_NONE] = "NONE", + [RDMA_WRID_RDMA_WRITE] = "WRITE RDMA", + [RDMA_WRID_SEND_CONTROL] = "CONTROL SEND", + [RDMA_WRID_RECV_CONTROL] = "CONTROL RECV", +}; + +/* + * Work request IDs for IB SEND messages only (not RDMA writes). + * This is used by the migration protocol to transmit + * control messages (such as device state and registration commands) + * + * We could use more WRs, but we have enough for now. + */ +enum { + RDMA_WRID_READY = 0, + RDMA_WRID_DATA, + RDMA_WRID_CONTROL, + RDMA_WRID_MAX, +}; + +/* + * SEND/RECV IB Control Messages. + */ +enum { + RDMA_CONTROL_NONE = 0, + RDMA_CONTROL_ERROR, + RDMA_CONTROL_READY, /* ready to receive */ + RDMA_CONTROL_QEMU_FILE, /* QEMUFile-transmitted bytes */ + RDMA_CONTROL_RAM_BLOCKS_REQUEST, /* RAMBlock synchronization */ + RDMA_CONTROL_RAM_BLOCKS_RESULT, /* RAMBlock synchronization */ + RDMA_CONTROL_COMPRESS, /* page contains repeat values */ + RDMA_CONTROL_REGISTER_REQUEST, /* dynamic page registration */ + RDMA_CONTROL_REGISTER_RESULT, /* key to use after registration */ + RDMA_CONTROL_REGISTER_FINISHED, /* current iteration finished */ + RDMA_CONTROL_UNREGISTER_REQUEST, /* dynamic UN-registration */ + RDMA_CONTROL_UNREGISTER_FINISHED, /* unpinning finished */ +}; + +const char *control_desc[] = { + [RDMA_CONTROL_NONE] = "NONE", + [RDMA_CONTROL_ERROR] = "ERROR", + [RDMA_CONTROL_READY] = "READY", + [RDMA_CONTROL_QEMU_FILE] = "QEMU FILE", + [RDMA_CONTROL_RAM_BLOCKS_REQUEST] = "RAM BLOCKS REQUEST", + [RDMA_CONTROL_RAM_BLOCKS_RESULT] = "RAM BLOCKS RESULT", + [RDMA_CONTROL_COMPRESS] = "COMPRESS", + [RDMA_CONTROL_REGISTER_REQUEST] = "REGISTER REQUEST", + [RDMA_CONTROL_REGISTER_RESULT] = "REGISTER RESULT", + [RDMA_CONTROL_REGISTER_FINISHED] = "REGISTER FINISHED", + [RDMA_CONTROL_UNREGISTER_REQUEST] = "UNREGISTER REQUEST", + [RDMA_CONTROL_UNREGISTER_FINISHED] = "UNREGISTER FINISHED", +}; + +/* + * Memory and MR structures used to represent an IB Send/Recv work request. + * This is *not* used for RDMA writes, only IB Send/Recv. + */ +typedef struct { + uint8_t control[RDMA_CONTROL_MAX_BUFFER]; /* actual buffer to register */ + struct ibv_mr *control_mr; /* registration metadata */ + size_t control_len; /* length of the message */ + uint8_t *control_curr; /* start of unconsumed bytes */ +} RDMAWorkRequestData; + +/* + * Negotiate RDMA capabilities during connection-setup time. + */ +typedef struct { + uint32_t version; + uint32_t flags; +} RDMACapabilities; + +static void caps_to_network(RDMACapabilities *cap) +{ + cap->version = htonl(cap->version); + cap->flags = htonl(cap->flags); +} + +static void network_to_caps(RDMACapabilities *cap) +{ + cap->version = ntohl(cap->version); + cap->flags = ntohl(cap->flags); +} + +/* + * Representation of a RAMBlock from an RDMA perspective. + * This is not transmitted, only local. + * This and subsequent structures cannot be linked lists + * because we're using a single IB message to transmit + * the information. It's small anyway, so a list is overkill. + */ +typedef struct RDMALocalBlock { + uint8_t *local_host_addr; /* local virtual address */ + uint64_t remote_host_addr; /* remote virtual address */ + uint64_t offset; + uint64_t length; + struct ibv_mr **pmr; /* MRs for chunk-level registration */ + struct ibv_mr *mr; /* MR for non-chunk-level registration */ + uint32_t *remote_keys; /* rkeys for chunk-level registration */ + uint32_t remote_rkey; /* rkeys for non-chunk-level registration */ + int index; /* which block are we */ + bool is_ram_block; + int nb_chunks; + unsigned long *transit_bitmap; + unsigned long *unregister_bitmap; +} RDMALocalBlock; + +/* + * Also represents a RAMblock, but only on the dest. + * This gets transmitted by the dest during connection-time + * to the source VM and then is used to populate the + * corresponding RDMALocalBlock with + * the information needed to perform the actual RDMA. + */ +typedef struct QEMU_PACKED RDMARemoteBlock { + uint64_t remote_host_addr; + uint64_t offset; + uint64_t length; + uint32_t remote_rkey; + uint32_t padding; +} RDMARemoteBlock; + +static uint64_t htonll(uint64_t v) +{ + union { uint32_t lv[2]; uint64_t llv; } u; + u.lv[0] = htonl(v >> 32); + u.lv[1] = htonl(v & 0xFFFFFFFFULL); + return u.llv; +} + +static uint64_t ntohll(uint64_t v) { + union { uint32_t lv[2]; uint64_t llv; } u; + u.llv = v; + return ((uint64_t)ntohl(u.lv[0]) << 32) | (uint64_t) ntohl(u.lv[1]); +} + +static void remote_block_to_network(RDMARemoteBlock *rb) +{ + rb->remote_host_addr = htonll(rb->remote_host_addr); + rb->offset = htonll(rb->offset); + rb->length = htonll(rb->length); + rb->remote_rkey = htonl(rb->remote_rkey); +} + +static void network_to_remote_block(RDMARemoteBlock *rb) +{ + rb->remote_host_addr = ntohll(rb->remote_host_addr); + rb->offset = ntohll(rb->offset); + rb->length = ntohll(rb->length); + rb->remote_rkey = ntohl(rb->remote_rkey); +} + +/* + * Virtual address of the above structures used for transmitting + * the RAMBlock descriptions at connection-time. + * This structure is *not* transmitted. + */ +typedef struct RDMALocalBlocks { + int nb_blocks; + bool init; /* main memory init complete */ + RDMALocalBlock *block; +} RDMALocalBlocks; + +/* + * Main data structure for RDMA state. + * While there is only one copy of this structure being allocated right now, + * this is the place where one would start if you wanted to consider + * having more than one RDMA connection open at the same time. + */ +typedef struct RDMAContext { + char *host; + int port; + + RDMAWorkRequestData wr_data[RDMA_WRID_MAX]; + + /* + * This is used by *_exchange_send() to figure out whether or not + * the initial "READY" message has already been received or not. + * This is because other functions may potentially poll() and detect + * the READY message before send() does, in which case we need to + * know if it completed. + */ + int control_ready_expected; + + /* number of outstanding writes */ + int nb_sent; + + /* store info about current buffer so that we can + merge it with future sends */ + uint64_t current_addr; + uint64_t current_length; + /* index of ram block the current buffer belongs to */ + int current_index; + /* index of the chunk in the current ram block */ + int current_chunk; + + bool pin_all; + + /* + * infiniband-specific variables for opening the device + * and maintaining connection state and so forth. + * + * cm_id also has ibv_context, rdma_event_channel, and ibv_qp in + * cm_id->verbs, cm_id->channel, and cm_id->qp. + */ + struct rdma_cm_id *cm_id; /* connection manager ID */ + struct rdma_cm_id *listen_id; + bool connected; + + struct ibv_context *verbs; + struct rdma_event_channel *channel; + struct ibv_qp *qp; /* queue pair */ + struct ibv_comp_channel *comp_channel; /* completion channel */ + struct ibv_pd *pd; /* protection domain */ + struct ibv_cq *cq; /* completion queue */ + + /* + * If a previous write failed (perhaps because of a failed + * memory registration, then do not attempt any future work + * and remember the error state. + */ + int error_state; + int error_reported; + + /* + * Description of ram blocks used throughout the code. + */ + RDMALocalBlocks local_ram_blocks; + RDMARemoteBlock *block; + + /* + * Migration on *destination* started. + * Then use coroutine yield function. + * Source runs in a thread, so we don't care. + */ + int migration_started_on_destination; + + int total_registrations; + int total_writes; + + int unregister_current, unregister_next; + uint64_t unregistrations[RDMA_SIGNALED_SEND_MAX]; + + GHashTable *blockmap; +} RDMAContext; + +/* + * Interface to the rest of the migration call stack. + */ +typedef struct QEMUFileRDMA { + RDMAContext *rdma; + size_t len; + void *file; +} QEMUFileRDMA; + +/* + * Main structure for IB Send/Recv control messages. + * This gets prepended at the beginning of every Send/Recv. + */ +typedef struct QEMU_PACKED { + uint32_t len; /* Total length of data portion */ + uint32_t type; /* which control command to perform */ + uint32_t repeat; /* number of commands in data portion of same type */ + uint32_t padding; +} RDMAControlHeader; + +static void control_to_network(RDMAControlHeader *control) +{ + control->type = htonl(control->type); + control->len = htonl(control->len); + control->repeat = htonl(control->repeat); +} + +static void network_to_control(RDMAControlHeader *control) +{ + control->type = ntohl(control->type); + control->len = ntohl(control->len); + control->repeat = ntohl(control->repeat); +} + +/* + * Register a single Chunk. + * Information sent by the source VM to inform the dest + * to register an single chunk of memory before we can perform + * the actual RDMA operation. + */ +typedef struct QEMU_PACKED { + union QEMU_PACKED { + uint64_t current_addr; /* offset into the ramblock of the chunk */ + uint64_t chunk; /* chunk to lookup if unregistering */ + } key; + uint32_t current_index; /* which ramblock the chunk belongs to */ + uint32_t padding; + uint64_t chunks; /* how many sequential chunks to register */ +} RDMARegister; + +static void register_to_network(RDMARegister *reg) +{ + reg->key.current_addr = htonll(reg->key.current_addr); + reg->current_index = htonl(reg->current_index); + reg->chunks = htonll(reg->chunks); +} + +static void network_to_register(RDMARegister *reg) +{ + reg->key.current_addr = ntohll(reg->key.current_addr); + reg->current_index = ntohl(reg->current_index); + reg->chunks = ntohll(reg->chunks); +} + +typedef struct QEMU_PACKED { + uint32_t value; /* if zero, we will madvise() */ + uint32_t block_idx; /* which ram block index */ + uint64_t offset; /* where in the remote ramblock this chunk */ + uint64_t length; /* length of the chunk */ +} RDMACompress; + +static void compress_to_network(RDMACompress *comp) +{ + comp->value = htonl(comp->value); + comp->block_idx = htonl(comp->block_idx); + comp->offset = htonll(comp->offset); + comp->length = htonll(comp->length); +} + +static void network_to_compress(RDMACompress *comp) +{ + comp->value = ntohl(comp->value); + comp->block_idx = ntohl(comp->block_idx); + comp->offset = ntohll(comp->offset); + comp->length = ntohll(comp->length); +} + +/* + * The result of the dest's memory registration produces an "rkey" + * which the source VM must reference in order to perform + * the RDMA operation. + */ +typedef struct QEMU_PACKED { + uint32_t rkey; + uint32_t padding; + uint64_t host_addr; +} RDMARegisterResult; + +static void result_to_network(RDMARegisterResult *result) +{ + result->rkey = htonl(result->rkey); + result->host_addr = htonll(result->host_addr); +}; + +static void network_to_result(RDMARegisterResult *result) +{ + result->rkey = ntohl(result->rkey); + result->host_addr = ntohll(result->host_addr); +}; + +const char *print_wrid(int wrid); +static int qemu_rdma_exchange_send(RDMAContext *rdma, RDMAControlHeader *head, + uint8_t *data, RDMAControlHeader *resp, + int *resp_idx, + int (*callback)(RDMAContext *rdma)); + +static inline uint64_t ram_chunk_index(const uint8_t *start, + const uint8_t *host) +{ + return ((uintptr_t) host - (uintptr_t) start) >> RDMA_REG_CHUNK_SHIFT; +} + +static inline uint8_t *ram_chunk_start(const RDMALocalBlock *rdma_ram_block, + uint64_t i) +{ + return (uint8_t *) (((uintptr_t) rdma_ram_block->local_host_addr) + + (i << RDMA_REG_CHUNK_SHIFT)); +} + +static inline uint8_t *ram_chunk_end(const RDMALocalBlock *rdma_ram_block, + uint64_t i) +{ + uint8_t *result = ram_chunk_start(rdma_ram_block, i) + + (1UL << RDMA_REG_CHUNK_SHIFT); + + if (result > (rdma_ram_block->local_host_addr + rdma_ram_block->length)) { + result = rdma_ram_block->local_host_addr + rdma_ram_block->length; + } + + return result; +} + +static int __qemu_rdma_add_block(RDMAContext *rdma, void *host_addr, + ram_addr_t block_offset, uint64_t length) +{ + RDMALocalBlocks *local = &rdma->local_ram_blocks; + RDMALocalBlock *block = g_hash_table_lookup(rdma->blockmap, + (void *) block_offset); + RDMALocalBlock *old = local->block; + + assert(block == NULL); + + local->block = g_malloc0(sizeof(RDMALocalBlock) * (local->nb_blocks + 1)); + + if (local->nb_blocks) { + int x; + + for (x = 0; x < local->nb_blocks; x++) { + g_hash_table_remove(rdma->blockmap, (void *)old[x].offset); + g_hash_table_insert(rdma->blockmap, (void *)old[x].offset, + &local->block[x]); + } + memcpy(local->block, old, sizeof(RDMALocalBlock) * local->nb_blocks); + g_free(old); + } + + block = &local->block[local->nb_blocks]; + + block->local_host_addr = host_addr; + block->offset = block_offset; + block->length = length; + block->index = local->nb_blocks; + block->nb_chunks = ram_chunk_index(host_addr, host_addr + length) + 1UL; + block->transit_bitmap = bitmap_new(block->nb_chunks); + bitmap_clear(block->transit_bitmap, 0, block->nb_chunks); + block->unregister_bitmap = bitmap_new(block->nb_chunks); + bitmap_clear(block->unregister_bitmap, 0, block->nb_chunks); + block->remote_keys = g_malloc0(block->nb_chunks * sizeof(uint32_t)); + + block->is_ram_block = local->init ? false : true; + + g_hash_table_insert(rdma->blockmap, (void *) block_offset, block); + + DDPRINTF("Added Block: %d, addr: %" PRIu64 ", offset: %" PRIu64 + " length: %" PRIu64 " end: %" PRIu64 " bits %" PRIu64 " chunks %d\n", + local->nb_blocks, (uint64_t) block->local_host_addr, block->offset, + block->length, (uint64_t) (block->local_host_addr + block->length), + BITS_TO_LONGS(block->nb_chunks) * + sizeof(unsigned long) * 8, block->nb_chunks); + + local->nb_blocks++; + + return 0; +} + +/* + * Memory regions need to be registered with the device and queue pairs setup + * in advanced before the migration starts. This tells us where the RAM blocks + * are so that we can register them individually. + */ +static void qemu_rdma_init_one_block(void *host_addr, + ram_addr_t block_offset, ram_addr_t length, void *opaque) +{ + __qemu_rdma_add_block(opaque, host_addr, block_offset, length); +} + +/* + * Identify the RAMBlocks and their quantity. They will be references to + * identify chunk boundaries inside each RAMBlock and also be referenced + * during dynamic page registration. + */ +static int qemu_rdma_init_ram_blocks(RDMAContext *rdma) +{ + RDMALocalBlocks *local = &rdma->local_ram_blocks; + + assert(rdma->blockmap == NULL); + rdma->blockmap = g_hash_table_new(g_direct_hash, g_direct_equal); + memset(local, 0, sizeof *local); + qemu_ram_foreach_block(qemu_rdma_init_one_block, rdma); + DPRINTF("Allocated %d local ram block structures\n", local->nb_blocks); + rdma->block = (RDMARemoteBlock *) g_malloc0(sizeof(RDMARemoteBlock) * + rdma->local_ram_blocks.nb_blocks); + local->init = true; + return 0; +} + +static int __qemu_rdma_delete_block(RDMAContext *rdma, ram_addr_t block_offset) +{ + RDMALocalBlocks *local = &rdma->local_ram_blocks; + RDMALocalBlock *block = g_hash_table_lookup(rdma->blockmap, + (void *) block_offset); + RDMALocalBlock *old = local->block; + int x; + + assert(block); + + if (block->pmr) { + int j; + + for (j = 0; j < block->nb_chunks; j++) { + if (!block->pmr[j]) { + continue; + } + ibv_dereg_mr(block->pmr[j]); + rdma->total_registrations--; + } + g_free(block->pmr); + block->pmr = NULL; + } + + if (block->mr) { + ibv_dereg_mr(block->mr); + rdma->total_registrations--; + block->mr = NULL; + } + + g_free(block->transit_bitmap); + block->transit_bitmap = NULL; + + g_free(block->unregister_bitmap); + block->unregister_bitmap = NULL; + + g_free(block->remote_keys); + block->remote_keys = NULL; + + for (x = 0; x < local->nb_blocks; x++) { + g_hash_table_remove(rdma->blockmap, (void *)old[x].offset); + } + + if (local->nb_blocks > 1) { + + local->block = g_malloc0(sizeof(RDMALocalBlock) * + (local->nb_blocks - 1)); + + if (block->index) { + memcpy(local->block, old, sizeof(RDMALocalBlock) * block->index); + } + + if (block->index < (local->nb_blocks - 1)) { + memcpy(local->block + block->index, old + (block->index + 1), + sizeof(RDMALocalBlock) * + (local->nb_blocks - (block->index + 1))); + } + } else { + assert(block == local->block); + local->block = NULL; + } + + DDPRINTF("Deleted Block: %d, addr: %" PRIu64 ", offset: %" PRIu64 + " length: %" PRIu64 " end: %" PRIu64 " bits %" PRIu64 " chunks %d\n", + local->nb_blocks, (uint64_t) block->local_host_addr, block->offset, + block->length, (uint64_t) (block->local_host_addr + block->length), + BITS_TO_LONGS(block->nb_chunks) * + sizeof(unsigned long) * 8, block->nb_chunks); + + g_free(old); + + local->nb_blocks--; + + if (local->nb_blocks) { + for (x = 0; x < local->nb_blocks; x++) { + g_hash_table_insert(rdma->blockmap, (void *)local->block[x].offset, + &local->block[x]); + } + } + + return 0; +} + +/* + * Put in the log file which RDMA device was opened and the details + * associated with that device. + */ +static void qemu_rdma_dump_id(const char *who, struct ibv_context *verbs) +{ + struct ibv_port_attr port; + + if (ibv_query_port(verbs, 1, &port)) { + fprintf(stderr, "FAILED TO QUERY PORT INFORMATION!\n"); + return; + } + + printf("%s RDMA Device opened: kernel name %s " + "uverbs device name %s, " + "infiniband_verbs class device path %s, " + "infiniband class device path %s, " + "transport: (%d) %s\n", + who, + verbs->device->name, + verbs->device->dev_name, + verbs->device->dev_path, + verbs->device->ibdev_path, + port.link_layer, + (port.link_layer == IBV_LINK_LAYER_INFINIBAND) ? "Infiniband" : + ((port.link_layer == IBV_LINK_LAYER_ETHERNET) + ? "Ethernet" : "Unknown")); +} + +/* + * Put in the log file the RDMA gid addressing information, + * useful for folks who have trouble understanding the + * RDMA device hierarchy in the kernel. + */ +static void qemu_rdma_dump_gid(const char *who, struct rdma_cm_id *id) +{ + char sgid[33]; + char dgid[33]; + inet_ntop(AF_INET6, &id->route.addr.addr.ibaddr.sgid, sgid, sizeof sgid); + inet_ntop(AF_INET6, &id->route.addr.addr.ibaddr.dgid, dgid, sizeof dgid); + DPRINTF("%s Source GID: %s, Dest GID: %s\n", who, sgid, dgid); +} + +/* + * As of now, IPv6 over RoCE / iWARP is not supported by linux. + * We will try the next addrinfo struct, and fail if there are + * no other valid addresses to bind against. + * + * If user is listening on '[::]', then we will not have a opened a device + * yet and have no way of verifying if the device is RoCE or not. + * + * In this case, the source VM will throw an error for ALL types of + * connections (both IPv4 and IPv6) if the destination machine does not have + * a regular infiniband network available for use. + * + * The only way to guarantee that an error is thrown for broken kernels is + * for the management software to choose a *specific* interface at bind time + * and validate what time of hardware it is. + * + * Unfortunately, this puts the user in a fix: + * + * If the source VM connects with an IPv4 address without knowing that the + * destination has bound to '[::]' the migration will unconditionally fail + * unless the management software is explicitly listening on the the IPv4 + * address while using a RoCE-based device. + * + * If the source VM connects with an IPv6 address, then we're OK because we can + * throw an error on the source (and similarly on the destination). + * + * But in mixed environments, this will be broken for a while until it is fixed + * inside linux. + * + * We do provide a *tiny* bit of help in this function: We can list all of the + * devices in the system and check to see if all the devices are RoCE or + * Infiniband. + * + * If we detect that we have a *pure* RoCE environment, then we can safely + * thrown an error even if the management software has specified '[::]' as the + * bind address. + * + * However, if there is are multiple hetergeneous devices, then we cannot make + * this assumption and the user just has to be sure they know what they are + * doing. + * + * Patches are being reviewed on linux-rdma. + */ +static int qemu_rdma_broken_ipv6_kernel(Error **errp, struct ibv_context *verbs) +{ + struct ibv_port_attr port_attr; + + /* This bug only exists in linux, to our knowledge. */ +#ifdef CONFIG_LINUX + + /* + * Verbs are only NULL if management has bound to '[::]'. + * + * Let's iterate through all the devices and see if there any pure IB + * devices (non-ethernet). + * + * If not, then we can safely proceed with the migration. + * Otherwise, there are no guarantees until the bug is fixed in linux. + */ + if (!verbs) { + int num_devices, x; + struct ibv_device ** dev_list = ibv_get_device_list(&num_devices); + bool roce_found = false; + bool ib_found = false; + + for (x = 0; x < num_devices; x++) { + verbs = ibv_open_device(dev_list[x]); + + if (ibv_query_port(verbs, 1, &port_attr)) { + ibv_close_device(verbs); + ERROR(errp, "Could not query initial IB port"); + return -EINVAL; + } + + if (port_attr.link_layer == IBV_LINK_LAYER_INFINIBAND) { + ib_found = true; + } else if (port_attr.link_layer == IBV_LINK_LAYER_ETHERNET) { + roce_found = true; + } + + ibv_close_device(verbs); + + } + + if (roce_found) { + if (ib_found) { + fprintf(stderr, "WARN: migrations may fail:" + " IPv6 over RoCE / iWARP in linux" + " is broken. But since you appear to have a" + " mixed RoCE / IB environment, be sure to only" + " migrate over the IB fabric until the kernel " + " fixes the bug.\n"); + } else { + ERROR(errp, "You only have RoCE / iWARP devices in your systems" + " and your management software has specified '[::]'" + ", but IPv6 over RoCE / iWARP is not supported in Linux."); + return -ENONET; + } + } + + return 0; + } + + /* + * If we have a verbs context, that means that some other than '[::]' was + * used by the management software for binding. In which case we can actually + * warn the user about a potential broken kernel; + */ + + /* IB ports start with 1, not 0 */ + if (ibv_query_port(verbs, 1, &port_attr)) { + ERROR(errp, "Could not query initial IB port"); + return -EINVAL; + } + + if (port_attr.link_layer == IBV_LINK_LAYER_ETHERNET) { + ERROR(errp, "Linux kernel's RoCE / iWARP does not support IPv6 " + "(but patches on linux-rdma in progress)"); + return -ENONET; + } + +#endif + + return 0; +} + +/* + * Figure out which RDMA device corresponds to the requested IP hostname + * Also create the initial connection manager identifiers for opening + * the connection. + */ +static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp) +{ + int ret; + struct rdma_addrinfo *res; + char port_str[16]; + struct rdma_cm_event *cm_event; + char ip[40] = "unknown"; + struct rdma_addrinfo *e; + + if (rdma->host == NULL || !strcmp(rdma->host, "")) { + ERROR(errp, "RDMA hostname has not been set"); + return -EINVAL; + } + + /* create CM channel */ + rdma->channel = rdma_create_event_channel(); + if (!rdma->channel) { + ERROR(errp, "could not create CM channel"); + return -EINVAL; + } + + /* create CM id */ + ret = rdma_create_id(rdma->channel, &rdma->cm_id, NULL, RDMA_PS_TCP); + if (ret) { + ERROR(errp, "could not create channel id"); + goto err_resolve_create_id; + } + + snprintf(port_str, 16, "%d", rdma->port); + port_str[15] = '\0'; + + ret = rdma_getaddrinfo(rdma->host, port_str, NULL, &res); + if (ret < 0) { + ERROR(errp, "could not rdma_getaddrinfo address %s", rdma->host); + goto err_resolve_get_addr; + } + + for (e = res; e != NULL; e = e->ai_next) { + inet_ntop(e->ai_family, + &((struct sockaddr_in *) e->ai_dst_addr)->sin_addr, ip, sizeof ip); + DPRINTF("Trying %s => %s\n", rdma->host, ip); + + ret = rdma_resolve_addr(rdma->cm_id, NULL, e->ai_dst_addr, + RDMA_RESOLVE_TIMEOUT_MS); + if (!ret) { + if (e->ai_family == AF_INET6) { + ret = qemu_rdma_broken_ipv6_kernel(errp, rdma->cm_id->verbs); + if (ret) { + continue; + } + } + goto route; + } + } + + ERROR(errp, "could not resolve address %s", rdma->host); + goto err_resolve_get_addr; + +route: + qemu_rdma_dump_gid("source_resolve_addr", rdma->cm_id); + + ret = rdma_get_cm_event(rdma->channel, &cm_event); + if (ret) { + ERROR(errp, "could not perform event_addr_resolved"); + goto err_resolve_get_addr; + } + + if (cm_event->event != RDMA_CM_EVENT_ADDR_RESOLVED) { + ERROR(errp, "result not equal to event_addr_resolved %s", + rdma_event_str(cm_event->event)); + perror("rdma_resolve_addr"); + rdma_ack_cm_event(cm_event); + ret = -EINVAL; + goto err_resolve_get_addr; + } + rdma_ack_cm_event(cm_event); + + /* resolve route */ + ret = rdma_resolve_route(rdma->cm_id, RDMA_RESOLVE_TIMEOUT_MS); + if (ret) { + ERROR(errp, "could not resolve rdma route"); + goto err_resolve_get_addr; + } + + ret = rdma_get_cm_event(rdma->channel, &cm_event); + if (ret) { + ERROR(errp, "could not perform event_route_resolved"); + goto err_resolve_get_addr; + } + if (cm_event->event != RDMA_CM_EVENT_ROUTE_RESOLVED) { + ERROR(errp, "result not equal to event_route_resolved: %s", + rdma_event_str(cm_event->event)); + rdma_ack_cm_event(cm_event); + ret = -EINVAL; + goto err_resolve_get_addr; + } + rdma_ack_cm_event(cm_event); + rdma->verbs = rdma->cm_id->verbs; + qemu_rdma_dump_id("source_resolve_host", rdma->cm_id->verbs); + qemu_rdma_dump_gid("source_resolve_host", rdma->cm_id); + return 0; + +err_resolve_get_addr: + rdma_destroy_id(rdma->cm_id); + rdma->cm_id = NULL; +err_resolve_create_id: + rdma_destroy_event_channel(rdma->channel); + rdma->channel = NULL; + return ret; +} + +/* + * Create protection domain and completion queues + */ +static int qemu_rdma_alloc_pd_cq(RDMAContext *rdma) +{ + /* allocate pd */ + rdma->pd = ibv_alloc_pd(rdma->verbs); + if (!rdma->pd) { + fprintf(stderr, "failed to allocate protection domain\n"); + return -1; + } + + /* create completion channel */ + rdma->comp_channel = ibv_create_comp_channel(rdma->verbs); + if (!rdma->comp_channel) { + fprintf(stderr, "failed to allocate completion channel\n"); + goto err_alloc_pd_cq; + } + + /* + * Completion queue can be filled by both read and write work requests, + * so must reflect the sum of both possible queue sizes. + */ + rdma->cq = ibv_create_cq(rdma->verbs, (RDMA_SIGNALED_SEND_MAX * 3), + NULL, rdma->comp_channel, 0); + if (!rdma->cq) { + fprintf(stderr, "failed to allocate completion queue\n"); + goto err_alloc_pd_cq; + } + + return 0; + +err_alloc_pd_cq: + if (rdma->pd) { + ibv_dealloc_pd(rdma->pd); + } + if (rdma->comp_channel) { + ibv_destroy_comp_channel(rdma->comp_channel); + } + rdma->pd = NULL; + rdma->comp_channel = NULL; + return -1; + +} + +/* + * Create queue pairs. + */ +static int qemu_rdma_alloc_qp(RDMAContext *rdma) +{ + struct ibv_qp_init_attr attr = { 0 }; + int ret; + + attr.cap.max_send_wr = RDMA_SIGNALED_SEND_MAX; + attr.cap.max_recv_wr = 3; + attr.cap.max_send_sge = 1; + attr.cap.max_recv_sge = 1; + attr.send_cq = rdma->cq; + attr.recv_cq = rdma->cq; + attr.qp_type = IBV_QPT_RC; + + ret = rdma_create_qp(rdma->cm_id, rdma->pd, &attr); + if (ret) { + return -1; + } + + rdma->qp = rdma->cm_id->qp; + return 0; +} + +static int qemu_rdma_reg_whole_ram_blocks(RDMAContext *rdma) +{ + int i; + RDMALocalBlocks *local = &rdma->local_ram_blocks; + + for (i = 0; i < local->nb_blocks; i++) { + local->block[i].mr = + ibv_reg_mr(rdma->pd, + local->block[i].local_host_addr, + local->block[i].length, + IBV_ACCESS_LOCAL_WRITE | + IBV_ACCESS_REMOTE_WRITE + ); + if (!local->block[i].mr) { + perror("Failed to register local dest ram block!\n"); + break; + } + rdma->total_registrations++; + } + + if (i >= local->nb_blocks) { + return 0; + } + + for (i--; i >= 0; i--) { + ibv_dereg_mr(local->block[i].mr); + rdma->total_registrations--; + } + + return -1; + +} + +/* + * Find the ram block that corresponds to the page requested to be + * transmitted by QEMU. + * + * Once the block is found, also identify which 'chunk' within that + * block that the page belongs to. + * + * This search cannot fail or the migration will fail. + */ +static int qemu_rdma_search_ram_block(RDMAContext *rdma, + uint64_t block_offset, + uint64_t offset, + uint64_t length, + uint64_t *block_index, + uint64_t *chunk_index) +{ + uint64_t current_addr = block_offset + offset; + RDMALocalBlock *block = g_hash_table_lookup(rdma->blockmap, + (void *) block_offset); + assert(block); + assert(current_addr >= block->offset); + assert((current_addr + length) <= (block->offset + block->length)); + + *block_index = block->index; + *chunk_index = ram_chunk_index(block->local_host_addr, + block->local_host_addr + (current_addr - block->offset)); + + return 0; +} + +/* + * Register a chunk with IB. If the chunk was already registered + * previously, then skip. + * + * Also return the keys associated with the registration needed + * to perform the actual RDMA operation. + */ +static int qemu_rdma_register_and_get_keys(RDMAContext *rdma, + RDMALocalBlock *block, uint8_t *host_addr, + uint32_t *lkey, uint32_t *rkey, int chunk, + uint8_t *chunk_start, uint8_t *chunk_end) +{ + if (block->mr) { + if (lkey) { + *lkey = block->mr->lkey; + } + if (rkey) { + *rkey = block->mr->rkey; + } + return 0; + } + + /* allocate memory to store chunk MRs */ + if (!block->pmr) { + block->pmr = g_malloc0(block->nb_chunks * sizeof(struct ibv_mr *)); + if (!block->pmr) { + return -1; + } + } + + /* + * If 'rkey', then we're the destination, so grant access to the source. + * + * If 'lkey', then we're the source VM, so grant access only to ourselves. + */ + if (!block->pmr[chunk]) { + uint64_t len = chunk_end - chunk_start; + + DDPRINTF("Registering %" PRIu64 " bytes @ %p\n", + len, chunk_start); + + block->pmr[chunk] = ibv_reg_mr(rdma->pd, + chunk_start, len, + (rkey ? (IBV_ACCESS_LOCAL_WRITE | + IBV_ACCESS_REMOTE_WRITE) : 0)); + + if (!block->pmr[chunk]) { + perror("Failed to register chunk!"); + fprintf(stderr, "Chunk details: block: %d chunk index %d" + " start %" PRIu64 " end %" PRIu64 " host %" PRIu64 + " local %" PRIu64 " registrations: %d\n", + block->index, chunk, (uint64_t) chunk_start, + (uint64_t) chunk_end, (uint64_t) host_addr, + (uint64_t) block->local_host_addr, + rdma->total_registrations); + return -1; + } + rdma->total_registrations++; + } + + if (lkey) { + *lkey = block->pmr[chunk]->lkey; + } + if (rkey) { + *rkey = block->pmr[chunk]->rkey; + } + return 0; +} + +/* + * Register (at connection time) the memory used for control + * channel messages. + */ +static int qemu_rdma_reg_control(RDMAContext *rdma, int idx) +{ + rdma->wr_data[idx].control_mr = ibv_reg_mr(rdma->pd, + rdma->wr_data[idx].control, RDMA_CONTROL_MAX_BUFFER, + IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE); + if (rdma->wr_data[idx].control_mr) { + rdma->total_registrations++; + return 0; + } + fprintf(stderr, "qemu_rdma_reg_control failed!\n"); + return -1; +} + +const char *print_wrid(int wrid) +{ + if (wrid >= RDMA_WRID_RECV_CONTROL) { + return wrid_desc[RDMA_WRID_RECV_CONTROL]; + } + return wrid_desc[wrid]; +} + +/* + * RDMA requires memory registration (mlock/pinning), but this is not good for + * overcommitment. + * + * In preparation for the future where LRU information or workload-specific + * writable writable working set memory access behavior is available to QEMU + * it would be nice to have in place the ability to UN-register/UN-pin + * particular memory regions from the RDMA hardware when it is determine that + * those regions of memory will likely not be accessed again in the near future. + * + * While we do not yet have such information right now, the following + * compile-time option allows us to perform a non-optimized version of this + * behavior. + * + * By uncommenting this option, you will cause *all* RDMA transfers to be + * unregistered immediately after the transfer completes on both sides of the + * connection. This has no effect in 'rdma-pin-all' mode, only regular mode. + * + * This will have a terrible impact on migration performance, so until future + * workload information or LRU information is available, do not attempt to use + * this feature except for basic testing. + */ +//#define RDMA_UNREGISTRATION_EXAMPLE + +/* + * Perform a non-optimized memory unregistration after every transfer + * for demonsration purposes, only if pin-all is not requested. + * + * Potential optimizations: + * 1. Start a new thread to run this function continuously + - for bit clearing + - and for receipt of unregister messages + * 2. Use an LRU. + * 3. Use workload hints. + */ +static int qemu_rdma_unregister_waiting(RDMAContext *rdma) +{ + while (rdma->unregistrations[rdma->unregister_current]) { + int ret; + uint64_t wr_id = rdma->unregistrations[rdma->unregister_current]; + uint64_t chunk = + (wr_id & RDMA_WRID_CHUNK_MASK) >> RDMA_WRID_CHUNK_SHIFT; + uint64_t index = + (wr_id & RDMA_WRID_BLOCK_MASK) >> RDMA_WRID_BLOCK_SHIFT; + RDMALocalBlock *block = + &(rdma->local_ram_blocks.block[index]); + RDMARegister reg = { .current_index = index }; + RDMAControlHeader resp = { .type = RDMA_CONTROL_UNREGISTER_FINISHED, + }; + RDMAControlHeader head = { .len = sizeof(RDMARegister), + .type = RDMA_CONTROL_UNREGISTER_REQUEST, + .repeat = 1, + }; + + DDPRINTF("Processing unregister for chunk: %" PRIu64 + " at position %d\n", chunk, rdma->unregister_current); + + rdma->unregistrations[rdma->unregister_current] = 0; + rdma->unregister_current++; + + if (rdma->unregister_current == RDMA_SIGNALED_SEND_MAX) { + rdma->unregister_current = 0; + } + + + /* + * Unregistration is speculative (because migration is single-threaded + * and we cannot break the protocol's inifinband message ordering). + * Thus, if the memory is currently being used for transmission, + * then abort the attempt to unregister and try again + * later the next time a completion is received for this memory. + */ + clear_bit(chunk, block->unregister_bitmap); + + if (test_bit(chunk, block->transit_bitmap)) { + DDPRINTF("Cannot unregister inflight chunk: %" PRIu64 "\n", chunk); + continue; + } + + DDPRINTF("Sending unregister for chunk: %" PRIu64 "\n", chunk); + + ret = ibv_dereg_mr(block->pmr[chunk]); + block->pmr[chunk] = NULL; + block->remote_keys[chunk] = 0; + + if (ret != 0) { + perror("unregistration chunk failed"); + return -ret; + } + rdma->total_registrations--; + + reg.key.chunk = chunk; + register_to_network(®); + ret = qemu_rdma_exchange_send(rdma, &head, (uint8_t *) ®, + &resp, NULL, NULL); + if (ret < 0) { + return ret; + } + + DDPRINTF("Unregister for chunk: %" PRIu64 " complete.\n", chunk); + } + + return 0; +} + +static uint64_t qemu_rdma_make_wrid(uint64_t wr_id, uint64_t index, + uint64_t chunk) +{ + uint64_t result = wr_id & RDMA_WRID_TYPE_MASK; + + result |= (index << RDMA_WRID_BLOCK_SHIFT); + result |= (chunk << RDMA_WRID_CHUNK_SHIFT); + + return result; +} + +/* + * Set bit for unregistration in the next iteration. + * We cannot transmit right here, but will unpin later. + */ +static void qemu_rdma_signal_unregister(RDMAContext *rdma, uint64_t index, + uint64_t chunk, uint64_t wr_id) +{ + if (rdma->unregistrations[rdma->unregister_next] != 0) { + fprintf(stderr, "rdma migration: queue is full!\n"); + } else { + RDMALocalBlock *block = &(rdma->local_ram_blocks.block[index]); + + if (!test_and_set_bit(chunk, block->unregister_bitmap)) { + DDPRINTF("Appending unregister chunk %" PRIu64 + " at position %d\n", chunk, rdma->unregister_next); + + rdma->unregistrations[rdma->unregister_next++] = + qemu_rdma_make_wrid(wr_id, index, chunk); + + if (rdma->unregister_next == RDMA_SIGNALED_SEND_MAX) { + rdma->unregister_next = 0; + } + } else { + DDPRINTF("Unregister chunk %" PRIu64 " already in queue.\n", + chunk); + } + } +} + +/* + * Consult the connection manager to see a work request + * (of any kind) has completed. + * Return the work request ID that completed. + */ +static uint64_t qemu_rdma_poll(RDMAContext *rdma, uint64_t *wr_id_out, + uint32_t *byte_len) +{ + int ret; + struct ibv_wc wc; + uint64_t wr_id; + + ret = ibv_poll_cq(rdma->cq, 1, &wc); + + if (!ret) { + *wr_id_out = RDMA_WRID_NONE; + return 0; + } + + if (ret < 0) { + fprintf(stderr, "ibv_poll_cq return %d!\n", ret); + return ret; + } + + wr_id = wc.wr_id & RDMA_WRID_TYPE_MASK; + + if (wc.status != IBV_WC_SUCCESS) { + fprintf(stderr, "ibv_poll_cq wc.status=%d %s!\n", + wc.status, ibv_wc_status_str(wc.status)); + fprintf(stderr, "ibv_poll_cq wrid=%s!\n", wrid_desc[wr_id]); + + return -1; + } + + if (rdma->control_ready_expected && + (wr_id >= RDMA_WRID_RECV_CONTROL)) { + DDDPRINTF("completion %s #%" PRId64 " received (%" PRId64 ")" + " left %d\n", wrid_desc[RDMA_WRID_RECV_CONTROL], + wr_id - RDMA_WRID_RECV_CONTROL, wr_id, rdma->nb_sent); + rdma->control_ready_expected = 0; + } + + if (wr_id == RDMA_WRID_RDMA_WRITE) { + uint64_t chunk = + (wc.wr_id & RDMA_WRID_CHUNK_MASK) >> RDMA_WRID_CHUNK_SHIFT; + uint64_t index = + (wc.wr_id & RDMA_WRID_BLOCK_MASK) >> RDMA_WRID_BLOCK_SHIFT; + RDMALocalBlock *block = &(rdma->local_ram_blocks.block[index]); + + DDDPRINTF("completions %s (%" PRId64 ") left %d, " + "block %" PRIu64 ", chunk: %" PRIu64 " %p %p\n", + print_wrid(wr_id), wr_id, rdma->nb_sent, index, chunk, + block->local_host_addr, (void *)block->remote_host_addr); + + clear_bit(chunk, block->transit_bitmap); + + if (rdma->nb_sent > 0) { + rdma->nb_sent--; + } + + if (!rdma->pin_all) { + /* + * FYI: If one wanted to signal a specific chunk to be unregistered + * using LRU or workload-specific information, this is the function + * you would call to do so. That chunk would then get asynchronously + * unregistered later. + */ +#ifdef RDMA_UNREGISTRATION_EXAMPLE + qemu_rdma_signal_unregister(rdma, index, chunk, wc.wr_id); +#endif + } + } else { + DDDPRINTF("other completion %s (%" PRId64 ") received left %d\n", + print_wrid(wr_id), wr_id, rdma->nb_sent); + } + + *wr_id_out = wc.wr_id; + if (byte_len) { + *byte_len = wc.byte_len; + } + + return 0; +} + +/* + * Block until the next work request has completed. + * + * First poll to see if a work request has already completed, + * otherwise block. + * + * If we encounter completed work requests for IDs other than + * the one we're interested in, then that's generally an error. + * + * The only exception is actual RDMA Write completions. These + * completions only need to be recorded, but do not actually + * need further processing. + */ +static int qemu_rdma_block_for_wrid(RDMAContext *rdma, int wrid_requested, + uint32_t *byte_len) +{ + int num_cq_events = 0, ret = 0; + struct ibv_cq *cq; + void *cq_ctx; + uint64_t wr_id = RDMA_WRID_NONE, wr_id_in; + + if (ibv_req_notify_cq(rdma->cq, 0)) { + return -1; + } + /* poll cq first */ + while (wr_id != wrid_requested) { + ret = qemu_rdma_poll(rdma, &wr_id_in, byte_len); + if (ret < 0) { + return ret; + } + + wr_id = wr_id_in & RDMA_WRID_TYPE_MASK; + + if (wr_id == RDMA_WRID_NONE) { + break; + } + if (wr_id != wrid_requested) { + DDDPRINTF("A Wanted wrid %s (%d) but got %s (%" PRIu64 ")\n", + print_wrid(wrid_requested), + wrid_requested, print_wrid(wr_id), wr_id); + } + } + + if (wr_id == wrid_requested) { + return 0; + } + + while (1) { + /* + * Coroutine doesn't start until process_incoming_migration() + * so don't yield unless we know we're running inside of a coroutine. + */ + if (rdma->migration_started_on_destination) { + yield_until_fd_readable(rdma->comp_channel->fd); + } + + if (ibv_get_cq_event(rdma->comp_channel, &cq, &cq_ctx)) { + perror("ibv_get_cq_event"); + goto err_block_for_wrid; + } + + num_cq_events++; + + if (ibv_req_notify_cq(cq, 0)) { + goto err_block_for_wrid; + } + + while (wr_id != wrid_requested) { + ret = qemu_rdma_poll(rdma, &wr_id_in, byte_len); + if (ret < 0) { + goto err_block_for_wrid; + } + + wr_id = wr_id_in & RDMA_WRID_TYPE_MASK; + + if (wr_id == RDMA_WRID_NONE) { + break; + } + if (wr_id != wrid_requested) { + DDDPRINTF("B Wanted wrid %s (%d) but got %s (%" PRIu64 ")\n", + print_wrid(wrid_requested), wrid_requested, + print_wrid(wr_id), wr_id); + } + } + + if (wr_id == wrid_requested) { + goto success_block_for_wrid; + } + } + +success_block_for_wrid: + if (num_cq_events) { + ibv_ack_cq_events(cq, num_cq_events); + } + return 0; + +err_block_for_wrid: + if (num_cq_events) { + ibv_ack_cq_events(cq, num_cq_events); + } + return ret; +} + +/* + * Post a SEND message work request for the control channel + * containing some data and block until the post completes. + */ +static int qemu_rdma_post_send_control(RDMAContext *rdma, uint8_t *buf, + RDMAControlHeader *head) +{ + int ret = 0; + RDMAWorkRequestData *wr = &rdma->wr_data[RDMA_WRID_CONTROL]; + struct ibv_send_wr *bad_wr; + struct ibv_sge sge = { + .addr = (uint64_t)(wr->control), + .length = head->len + sizeof(RDMAControlHeader), + .lkey = wr->control_mr->lkey, + }; + struct ibv_send_wr send_wr = { + .wr_id = RDMA_WRID_SEND_CONTROL, + .opcode = IBV_WR_SEND, + .send_flags = IBV_SEND_SIGNALED, + .sg_list = &sge, + .num_sge = 1, + }; + + DDDPRINTF("CONTROL: sending %s..\n", control_desc[head->type]); + + /* + * We don't actually need to do a memcpy() in here if we used + * the "sge" properly, but since we're only sending control messages + * (not RAM in a performance-critical path), then its OK for now. + * + * The copy makes the RDMAControlHeader simpler to manipulate + * for the time being. + */ + assert(head->len <= RDMA_CONTROL_MAX_BUFFER - sizeof(*head)); + memcpy(wr->control, head, sizeof(RDMAControlHeader)); + control_to_network((void *) wr->control); + + if (buf) { + memcpy(wr->control + sizeof(RDMAControlHeader), buf, head->len); + } + + + ret = ibv_post_send(rdma->qp, &send_wr, &bad_wr); + + if (ret > 0) { + fprintf(stderr, "Failed to use post IB SEND for control!\n"); + return -ret; + } + + ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_SEND_CONTROL, NULL); + if (ret < 0) { + fprintf(stderr, "rdma migration: send polling control error!\n"); + } + + return ret; +} + +/* + * Post a RECV work request in anticipation of some future receipt + * of data on the control channel. + */ +static int qemu_rdma_post_recv_control(RDMAContext *rdma, int idx) +{ + struct ibv_recv_wr *bad_wr; + struct ibv_sge sge = { + .addr = (uint64_t)(rdma->wr_data[idx].control), + .length = RDMA_CONTROL_MAX_BUFFER, + .lkey = rdma->wr_data[idx].control_mr->lkey, + }; + + struct ibv_recv_wr recv_wr = { + .wr_id = RDMA_WRID_RECV_CONTROL + idx, + .sg_list = &sge, + .num_sge = 1, + }; + + + if (ibv_post_recv(rdma->qp, &recv_wr, &bad_wr)) { + return -1; + } + + return 0; +} + +/* + * Block and wait for a RECV control channel message to arrive. + */ +static int qemu_rdma_exchange_get_response(RDMAContext *rdma, + RDMAControlHeader *head, int expecting, int idx) +{ + uint32_t byte_len; + int ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RECV_CONTROL + idx, + &byte_len); + + if (ret < 0) { + fprintf(stderr, "rdma migration: recv polling control error!\n"); + return ret; + } + + network_to_control((void *) rdma->wr_data[idx].control); + memcpy(head, rdma->wr_data[idx].control, sizeof(RDMAControlHeader)); + + DDDPRINTF("CONTROL: %s receiving...\n", control_desc[expecting]); + + if (expecting == RDMA_CONTROL_NONE) { + DDDPRINTF("Surprise: got %s (%d)\n", + control_desc[head->type], head->type); + } else if (head->type != expecting || head->type == RDMA_CONTROL_ERROR) { + fprintf(stderr, "Was expecting a %s (%d) control message" + ", but got: %s (%d), length: %d\n", + control_desc[expecting], expecting, + control_desc[head->type], head->type, head->len); + return -EIO; + } + if (head->len > RDMA_CONTROL_MAX_BUFFER - sizeof(*head)) { + fprintf(stderr, "too long length: %d\n", head->len); + return -EINVAL; + } + if (sizeof(*head) + head->len != byte_len) { + fprintf(stderr, "Malformed length: %d byte_len %d\n", + head->len, byte_len); + return -EINVAL; + } + + return 0; +} + +/* + * When a RECV work request has completed, the work request's + * buffer is pointed at the header. + * + * This will advance the pointer to the data portion + * of the control message of the work request's buffer that + * was populated after the work request finished. + */ +static void qemu_rdma_move_header(RDMAContext *rdma, int idx, + RDMAControlHeader *head) +{ + rdma->wr_data[idx].control_len = head->len; + rdma->wr_data[idx].control_curr = + rdma->wr_data[idx].control + sizeof(RDMAControlHeader); +} + +/* + * This is an 'atomic' high-level operation to deliver a single, unified + * control-channel message. + * + * Additionally, if the user is expecting some kind of reply to this message, + * they can request a 'resp' response message be filled in by posting an + * additional work request on behalf of the user and waiting for an additional + * completion. + * + * The extra (optional) response is used during registration to us from having + * to perform an *additional* exchange of message just to provide a response by + * instead piggy-backing on the acknowledgement. + */ +static int qemu_rdma_exchange_send(RDMAContext *rdma, RDMAControlHeader *head, + uint8_t *data, RDMAControlHeader *resp, + int *resp_idx, + int (*callback)(RDMAContext *rdma)) +{ + int ret = 0; + + /* + * Wait until the dest is ready before attempting to deliver the message + * by waiting for a READY message. + */ + if (rdma->control_ready_expected) { + RDMAControlHeader resp; + ret = qemu_rdma_exchange_get_response(rdma, + &resp, RDMA_CONTROL_READY, RDMA_WRID_READY); + if (ret < 0) { + return ret; + } + } + + /* + * If the user is expecting a response, post a WR in anticipation of it. + */ + if (resp) { + ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_DATA); + if (ret) { + fprintf(stderr, "rdma migration: error posting" + " extra control recv for anticipated result!"); + return ret; + } + } + + /* + * Post a WR to replace the one we just consumed for the READY message. + */ + ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY); + if (ret) { + fprintf(stderr, "rdma migration: error posting first control recv!"); + return ret; + } + + /* + * Deliver the control message that was requested. + */ + ret = qemu_rdma_post_send_control(rdma, data, head); + + if (ret < 0) { + fprintf(stderr, "Failed to send control buffer!\n"); + return ret; + } + + /* + * If we're expecting a response, block and wait for it. + */ + if (resp) { + if (callback) { + DDPRINTF("Issuing callback before receiving response...\n"); + ret = callback(rdma); + if (ret < 0) { + return ret; + } + } + + DDPRINTF("Waiting for response %s\n", control_desc[resp->type]); + ret = qemu_rdma_exchange_get_response(rdma, resp, + resp->type, RDMA_WRID_DATA); + + if (ret < 0) { + return ret; + } + + qemu_rdma_move_header(rdma, RDMA_WRID_DATA, resp); + if (resp_idx) { + *resp_idx = RDMA_WRID_DATA; + } + DDPRINTF("Response %s received.\n", control_desc[resp->type]); + } + + rdma->control_ready_expected = 1; + + return 0; +} + +/* + * This is an 'atomic' high-level operation to receive a single, unified + * control-channel message. + */ +static int qemu_rdma_exchange_recv(RDMAContext *rdma, RDMAControlHeader *head, + int expecting) +{ + RDMAControlHeader ready = { + .len = 0, + .type = RDMA_CONTROL_READY, + .repeat = 1, + }; + int ret; + + /* + * Inform the source that we're ready to receive a message. + */ + ret = qemu_rdma_post_send_control(rdma, NULL, &ready); + + if (ret < 0) { + fprintf(stderr, "Failed to send control buffer!\n"); + return ret; + } + + /* + * Block and wait for the message. + */ + ret = qemu_rdma_exchange_get_response(rdma, head, + expecting, RDMA_WRID_READY); + + if (ret < 0) { + return ret; + } + + qemu_rdma_move_header(rdma, RDMA_WRID_READY, head); + + /* + * Post a new RECV work request to replace the one we just consumed. + */ + ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY); + if (ret) { + fprintf(stderr, "rdma migration: error posting second control recv!"); + return ret; + } + + return 0; +} + +/* + * Write an actual chunk of memory using RDMA. + * + * If we're using dynamic registration on the dest-side, we have to + * send a registration command first. + */ +static int qemu_rdma_write_one(QEMUFile *f, RDMAContext *rdma, + int current_index, uint64_t current_addr, + uint64_t length) +{ + struct ibv_sge sge; + struct ibv_send_wr send_wr = { 0 }; + struct ibv_send_wr *bad_wr; + int reg_result_idx, ret, count = 0; + uint64_t chunk, chunks; + uint8_t *chunk_start, *chunk_end; + RDMALocalBlock *block = &(rdma->local_ram_blocks.block[current_index]); + RDMARegister reg; + RDMARegisterResult *reg_result; + RDMAControlHeader resp = { .type = RDMA_CONTROL_REGISTER_RESULT }; + RDMAControlHeader head = { .len = sizeof(RDMARegister), + .type = RDMA_CONTROL_REGISTER_REQUEST, + .repeat = 1, + }; + +retry: + sge.addr = (uint64_t)(block->local_host_addr + + (current_addr - block->offset)); + sge.length = length; + + chunk = ram_chunk_index(block->local_host_addr, (uint8_t *) sge.addr); + chunk_start = ram_chunk_start(block, chunk); + + if (block->is_ram_block) { + chunks = length / (1UL << RDMA_REG_CHUNK_SHIFT); + + if (chunks && ((length % (1UL << RDMA_REG_CHUNK_SHIFT)) == 0)) { + chunks--; + } + } else { + chunks = block->length / (1UL << RDMA_REG_CHUNK_SHIFT); + + if (chunks && ((block->length % (1UL << RDMA_REG_CHUNK_SHIFT)) == 0)) { + chunks--; + } + } + + DDPRINTF("Writing %" PRIu64 " chunks, (%" PRIu64 " MB)\n", + chunks + 1, (chunks + 1) * (1UL << RDMA_REG_CHUNK_SHIFT) / 1024 / 1024); + + chunk_end = ram_chunk_end(block, chunk + chunks); + + if (!rdma->pin_all) { +#ifdef RDMA_UNREGISTRATION_EXAMPLE + qemu_rdma_unregister_waiting(rdma); +#endif + } + + while (test_bit(chunk, block->transit_bitmap)) { + (void)count; + DDPRINTF("(%d) Not clobbering: block: %d chunk %" PRIu64 + " current %" PRIu64 " len %" PRIu64 " %d %d\n", + count++, current_index, chunk, + sge.addr, length, rdma->nb_sent, block->nb_chunks); + + ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RDMA_WRITE, NULL); + + if (ret < 0) { + fprintf(stderr, "Failed to Wait for previous write to complete " + "block %d chunk %" PRIu64 + " current %" PRIu64 " len %" PRIu64 " %d\n", + current_index, chunk, sge.addr, length, rdma->nb_sent); + return ret; + } + } + + if (!rdma->pin_all || !block->is_ram_block) { + if (!block->remote_keys[chunk]) { + /* + * This chunk has not yet been registered, so first check to see + * if the entire chunk is zero. If so, tell the other size to + * memset() + madvise() the entire chunk without RDMA. + */ + + if (can_use_buffer_find_nonzero_offset((void *)sge.addr, length) + && buffer_find_nonzero_offset((void *)sge.addr, + length) == length) { + RDMACompress comp = { + .offset = current_addr, + .value = 0, + .block_idx = current_index, + .length = length, + }; + + head.len = sizeof(comp); + head.type = RDMA_CONTROL_COMPRESS; + + DDPRINTF("Entire chunk is zero, sending compress: %" + PRIu64 " for %d " + "bytes, index: %d, offset: %" PRId64 "...\n", + chunk, sge.length, current_index, current_addr); + + compress_to_network(&comp); + ret = qemu_rdma_exchange_send(rdma, &head, + (uint8_t *) &comp, NULL, NULL, NULL); + + if (ret < 0) { + return -EIO; + } + + acct_update_position(f, sge.length, true); + + return 1; + } + + /* + * Otherwise, tell other side to register. + */ + reg.current_index = current_index; + if (block->is_ram_block) { + reg.key.current_addr = current_addr; + } else { + reg.key.chunk = chunk; + } + reg.chunks = chunks; + + DDPRINTF("Sending registration request chunk %" PRIu64 " for %d " + "bytes, index: %d, offset: %" PRId64 "...\n", + chunk, sge.length, current_index, current_addr); + + register_to_network(®); + ret = qemu_rdma_exchange_send(rdma, &head, (uint8_t *) ®, + &resp, ®_result_idx, NULL); + if (ret < 0) { + return ret; + } + + /* try to overlap this single registration with the one we sent. */ + if (qemu_rdma_register_and_get_keys(rdma, block, + (uint8_t *) sge.addr, + &sge.lkey, NULL, chunk, + chunk_start, chunk_end)) { + fprintf(stderr, "cannot get lkey!\n"); + return -EINVAL; + } + + reg_result = (RDMARegisterResult *) + rdma->wr_data[reg_result_idx].control_curr; + + network_to_result(reg_result); + + DDPRINTF("Received registration result:" + " my key: %x their key %x, chunk %" PRIu64 "\n", + block->remote_keys[chunk], reg_result->rkey, chunk); + + block->remote_keys[chunk] = reg_result->rkey; + block->remote_host_addr = reg_result->host_addr; + } else { + /* already registered before */ + if (qemu_rdma_register_and_get_keys(rdma, block, + (uint8_t *)sge.addr, + &sge.lkey, NULL, chunk, + chunk_start, chunk_end)) { + fprintf(stderr, "cannot get lkey!\n"); + return -EINVAL; + } + } + + send_wr.wr.rdma.rkey = block->remote_keys[chunk]; + } else { + send_wr.wr.rdma.rkey = block->remote_rkey; + + if (qemu_rdma_register_and_get_keys(rdma, block, (uint8_t *)sge.addr, + &sge.lkey, NULL, chunk, + chunk_start, chunk_end)) { + fprintf(stderr, "cannot get lkey!\n"); + return -EINVAL; + } + } + + /* + * Encode the ram block index and chunk within this wrid. + * We will use this information at the time of completion + * to figure out which bitmap to check against and then which + * chunk in the bitmap to look for. + */ + send_wr.wr_id = qemu_rdma_make_wrid(RDMA_WRID_RDMA_WRITE, + current_index, chunk); + + send_wr.opcode = IBV_WR_RDMA_WRITE; + send_wr.send_flags = IBV_SEND_SIGNALED; + send_wr.sg_list = &sge; + send_wr.num_sge = 1; + send_wr.wr.rdma.remote_addr = block->remote_host_addr + + (current_addr - block->offset); + + DDDPRINTF("Posting chunk: %" PRIu64 ", addr: %lx" + " remote: %lx, bytes %" PRIu32 "\n", + chunk, sge.addr, send_wr.wr.rdma.remote_addr, + sge.length); + + /* + * ibv_post_send() does not return negative error numbers, + * per the specification they are positive - no idea why. + */ + ret = ibv_post_send(rdma->qp, &send_wr, &bad_wr); + + if (ret == ENOMEM) { + DDPRINTF("send queue is full. wait a little....\n"); + ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RDMA_WRITE, NULL); + if (ret < 0) { + fprintf(stderr, "rdma migration: failed to make " + "room in full send queue! %d\n", ret); + return ret; + } + + goto retry; + + } else if (ret > 0) { + perror("rdma migration: post rdma write failed"); + return -ret; + } + + set_bit(chunk, block->transit_bitmap); + acct_update_position(f, sge.length, false); + rdma->total_writes++; + + return 0; +} + +/* + * Push out any unwritten RDMA operations. + * + * We support sending out multiple chunks at the same time. + * Not all of them need to get signaled in the completion queue. + */ +static int qemu_rdma_write_flush(QEMUFile *f, RDMAContext *rdma) +{ + int ret; + + if (!rdma->current_length) { + return 0; + } + + ret = qemu_rdma_write_one(f, rdma, + rdma->current_index, rdma->current_addr, rdma->current_length); + + if (ret < 0) { + return ret; + } + + if (ret == 0) { + rdma->nb_sent++; + DDDPRINTF("sent total: %d\n", rdma->nb_sent); + } + + rdma->current_length = 0; + rdma->current_addr = 0; + + return 0; +} + +static inline int qemu_rdma_buffer_mergable(RDMAContext *rdma, + uint64_t offset, uint64_t len) +{ + RDMALocalBlock *block; + uint8_t *host_addr; + uint8_t *chunk_end; + + if (rdma->current_index < 0) { + return 0; + } + + if (rdma->current_chunk < 0) { + return 0; + } + + block = &(rdma->local_ram_blocks.block[rdma->current_index]); + host_addr = block->local_host_addr + (offset - block->offset); + chunk_end = ram_chunk_end(block, rdma->current_chunk); + + if (rdma->current_length == 0) { + return 0; + } + + /* + * Only merge into chunk sequentially. + */ + if (offset != (rdma->current_addr + rdma->current_length)) { + return 0; + } + + if (offset < block->offset) { + return 0; + } + + if ((offset + len) > (block->offset + block->length)) { + return 0; + } + + if ((host_addr + len) > chunk_end) { + return 0; + } + + return 1; +} + +/* + * We're not actually writing here, but doing three things: + * + * 1. Identify the chunk the buffer belongs to. + * 2. If the chunk is full or the buffer doesn't belong to the current + * chunk, then start a new chunk and flush() the old chunk. + * 3. To keep the hardware busy, we also group chunks into batches + * and only require that a batch gets acknowledged in the completion + * qeueue instead of each individual chunk. + */ +static int qemu_rdma_write(QEMUFile *f, RDMAContext *rdma, + uint64_t block_offset, uint64_t offset, + uint64_t len) +{ + uint64_t current_addr = block_offset + offset; + uint64_t index = rdma->current_index; + uint64_t chunk = rdma->current_chunk; + int ret; + + /* If we cannot merge it, we flush the current buffer first. */ + if (!qemu_rdma_buffer_mergable(rdma, current_addr, len)) { + ret = qemu_rdma_write_flush(f, rdma); + if (ret) { + return ret; + } + rdma->current_length = 0; + rdma->current_addr = current_addr; + + ret = qemu_rdma_search_ram_block(rdma, block_offset, + offset, len, &index, &chunk); + if (ret) { + fprintf(stderr, "ram block search failed\n"); + return ret; + } + rdma->current_index = index; + rdma->current_chunk = chunk; + } + + /* merge it */ + rdma->current_length += len; + + /* flush it if buffer is too large */ + if (rdma->current_length >= RDMA_MERGE_MAX) { + return qemu_rdma_write_flush(f, rdma); + } + + return 0; +} + +static void qemu_rdma_cleanup(RDMAContext *rdma) +{ + struct rdma_cm_event *cm_event; + int ret, idx; + + if (rdma->cm_id && rdma->connected) { + if (rdma->error_state) { + RDMAControlHeader head = { .len = 0, + .type = RDMA_CONTROL_ERROR, + .repeat = 1, + }; + fprintf(stderr, "Early error. Sending error.\n"); + qemu_rdma_post_send_control(rdma, NULL, &head); + } + + ret = rdma_disconnect(rdma->cm_id); + if (!ret) { + DDPRINTF("waiting for disconnect\n"); + ret = rdma_get_cm_event(rdma->channel, &cm_event); + if (!ret) { + rdma_ack_cm_event(cm_event); + } + } + DDPRINTF("Disconnected.\n"); + rdma->connected = false; + } + + g_free(rdma->block); + rdma->block = NULL; + + for (idx = 0; idx < RDMA_WRID_MAX; idx++) { + if (rdma->wr_data[idx].control_mr) { + rdma->total_registrations--; + ibv_dereg_mr(rdma->wr_data[idx].control_mr); + } + rdma->wr_data[idx].control_mr = NULL; + } + + if (rdma->local_ram_blocks.block) { + while (rdma->local_ram_blocks.nb_blocks) { + __qemu_rdma_delete_block(rdma, + rdma->local_ram_blocks.block->offset); + } + } + + if (rdma->cq) { + ibv_destroy_cq(rdma->cq); + rdma->cq = NULL; + } + if (rdma->comp_channel) { + ibv_destroy_comp_channel(rdma->comp_channel); + rdma->comp_channel = NULL; + } + if (rdma->pd) { + ibv_dealloc_pd(rdma->pd); + rdma->pd = NULL; + } + if (rdma->listen_id) { + rdma_destroy_id(rdma->listen_id); + rdma->listen_id = NULL; + } + if (rdma->cm_id) { + if (rdma->qp) { + rdma_destroy_qp(rdma->cm_id); + rdma->qp = NULL; + } + rdma_destroy_id(rdma->cm_id); + rdma->cm_id = NULL; + } + if (rdma->channel) { + rdma_destroy_event_channel(rdma->channel); + rdma->channel = NULL; + } + g_free(rdma->host); + rdma->host = NULL; +} + + +static int qemu_rdma_source_init(RDMAContext *rdma, Error **errp, bool pin_all) +{ + int ret, idx; + Error *local_err = NULL, **temp = &local_err; + + /* + * Will be validated against destination's actual capabilities + * after the connect() completes. + */ + rdma->pin_all = pin_all; + + ret = qemu_rdma_resolve_host(rdma, temp); + if (ret) { + goto err_rdma_source_init; + } + + ret = qemu_rdma_alloc_pd_cq(rdma); + if (ret) { + ERROR(temp, "rdma migration: error allocating pd and cq! Your mlock()" + " limits may be too low. Please check $ ulimit -a # and " + "search for 'ulimit -l' in the output"); + goto err_rdma_source_init; + } + + ret = qemu_rdma_alloc_qp(rdma); + if (ret) { + ERROR(temp, "rdma migration: error allocating qp!"); + goto err_rdma_source_init; + } + + ret = qemu_rdma_init_ram_blocks(rdma); + if (ret) { + ERROR(temp, "rdma migration: error initializing ram blocks!"); + goto err_rdma_source_init; + } + + for (idx = 0; idx < RDMA_WRID_MAX; idx++) { + ret = qemu_rdma_reg_control(rdma, idx); + if (ret) { + ERROR(temp, "rdma migration: error registering %d control!", + idx); + goto err_rdma_source_init; + } + } + + return 0; + +err_rdma_source_init: + error_propagate(errp, local_err); + qemu_rdma_cleanup(rdma); + return -1; +} + +static int qemu_rdma_connect(RDMAContext *rdma, Error **errp) +{ + RDMACapabilities cap = { + .version = RDMA_CONTROL_VERSION_CURRENT, + .flags = 0, + }; + struct rdma_conn_param conn_param = { .initiator_depth = 2, + .retry_count = 5, + .private_data = &cap, + .private_data_len = sizeof(cap), + }; + struct rdma_cm_event *cm_event; + int ret; + + /* + * Only negotiate the capability with destination if the user + * on the source first requested the capability. + */ + if (rdma->pin_all) { + DPRINTF("Server pin-all memory requested.\n"); + cap.flags |= RDMA_CAPABILITY_PIN_ALL; + } + + caps_to_network(&cap); + + ret = rdma_connect(rdma->cm_id, &conn_param); + if (ret) { + perror("rdma_connect"); + ERROR(errp, "connecting to destination!"); + rdma_destroy_id(rdma->cm_id); + rdma->cm_id = NULL; + goto err_rdma_source_connect; + } + + ret = rdma_get_cm_event(rdma->channel, &cm_event); + if (ret) { + perror("rdma_get_cm_event after rdma_connect"); + ERROR(errp, "connecting to destination!"); + rdma_ack_cm_event(cm_event); + rdma_destroy_id(rdma->cm_id); + rdma->cm_id = NULL; + goto err_rdma_source_connect; + } + + if (cm_event->event != RDMA_CM_EVENT_ESTABLISHED) { + perror("rdma_get_cm_event != EVENT_ESTABLISHED after rdma_connect"); + ERROR(errp, "connecting to destination!"); + rdma_ack_cm_event(cm_event); + rdma_destroy_id(rdma->cm_id); + rdma->cm_id = NULL; + goto err_rdma_source_connect; + } + rdma->connected = true; + + memcpy(&cap, cm_event->param.conn.private_data, sizeof(cap)); + network_to_caps(&cap); + + /* + * Verify that the *requested* capabilities are supported by the destination + * and disable them otherwise. + */ + if (rdma->pin_all && !(cap.flags & RDMA_CAPABILITY_PIN_ALL)) { + ERROR(errp, "Server cannot support pinning all memory. " + "Will register memory dynamically."); + rdma->pin_all = false; + } + + DPRINTF("Pin all memory: %s\n", rdma->pin_all ? "enabled" : "disabled"); + + rdma_ack_cm_event(cm_event); + + ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY); + if (ret) { + ERROR(errp, "posting second control recv!"); + goto err_rdma_source_connect; + } + + rdma->control_ready_expected = 1; + rdma->nb_sent = 0; + return 0; + +err_rdma_source_connect: + qemu_rdma_cleanup(rdma); + return -1; +} + +static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp) +{ + int ret = -EINVAL, idx; + struct rdma_cm_id *listen_id; + char ip[40] = "unknown"; + struct rdma_addrinfo *res; + char port_str[16]; + + for (idx = 0; idx < RDMA_WRID_MAX; idx++) { + rdma->wr_data[idx].control_len = 0; + rdma->wr_data[idx].control_curr = NULL; + } + + if (rdma->host == NULL) { + ERROR(errp, "RDMA host is not set!"); + rdma->error_state = -EINVAL; + return -1; + } + /* create CM channel */ + rdma->channel = rdma_create_event_channel(); + if (!rdma->channel) { + ERROR(errp, "could not create rdma event channel"); + rdma->error_state = -EINVAL; + return -1; + } + + /* create CM id */ + ret = rdma_create_id(rdma->channel, &listen_id, NULL, RDMA_PS_TCP); + if (ret) { + ERROR(errp, "could not create cm_id!"); + goto err_dest_init_create_listen_id; + } + + snprintf(port_str, 16, "%d", rdma->port); + port_str[15] = '\0'; + + if (rdma->host && strcmp("", rdma->host)) { + struct rdma_addrinfo *e; + + ret = rdma_getaddrinfo(rdma->host, port_str, NULL, &res); + if (ret < 0) { + ERROR(errp, "could not rdma_getaddrinfo address %s", rdma->host); + goto err_dest_init_bind_addr; + } + + for (e = res; e != NULL; e = e->ai_next) { + inet_ntop(e->ai_family, + &((struct sockaddr_in *) e->ai_dst_addr)->sin_addr, ip, sizeof ip); + DPRINTF("Trying %s => %s\n", rdma->host, ip); + ret = rdma_bind_addr(listen_id, e->ai_dst_addr); + if (!ret) { + if (e->ai_family == AF_INET6) { + ret = qemu_rdma_broken_ipv6_kernel(errp, listen_id->verbs); + if (ret) { + continue; + } + } + + goto listen; + } + } + + ERROR(errp, "Error: could not rdma_bind_addr!"); + goto err_dest_init_bind_addr; + } else { + ERROR(errp, "migration host and port not specified!"); + ret = -EINVAL; + goto err_dest_init_bind_addr; + } +listen: + + rdma->listen_id = listen_id; + qemu_rdma_dump_gid("dest_init", listen_id); + return 0; + +err_dest_init_bind_addr: + rdma_destroy_id(listen_id); +err_dest_init_create_listen_id: + rdma_destroy_event_channel(rdma->channel); + rdma->channel = NULL; + rdma->error_state = ret; + return ret; + +} + +static void *qemu_rdma_data_init(const char *host_port, Error **errp) +{ + RDMAContext *rdma = NULL; + InetSocketAddress *addr; + + if (host_port) { + rdma = g_malloc0(sizeof(RDMAContext)); + memset(rdma, 0, sizeof(RDMAContext)); + rdma->current_index = -1; + rdma->current_chunk = -1; + + addr = inet_parse(host_port, NULL); + if (addr != NULL) { + rdma->port = atoi(addr->port); + rdma->host = g_strdup(addr->host); + } else { + ERROR(errp, "bad RDMA migration address '%s'", host_port); + g_free(rdma); + rdma = NULL; + } + + qapi_free_InetSocketAddress(addr); + } + + return rdma; +} + +/* + * QEMUFile interface to the control channel. + * SEND messages for control only. + * VM's ram is handled with regular RDMA messages. + */ +static int qemu_rdma_put_buffer(void *opaque, const uint8_t *buf, + int64_t pos, int size) +{ + QEMUFileRDMA *r = opaque; + QEMUFile *f = r->file; + RDMAContext *rdma = r->rdma; + size_t remaining = size; + uint8_t * data = (void *) buf; + int ret; + + CHECK_ERROR_STATE(); + + /* + * Push out any writes that + * we're queued up for VM's ram. + */ + ret = qemu_rdma_write_flush(f, rdma); + if (ret < 0) { + rdma->error_state = ret; + return ret; + } + + while (remaining) { + RDMAControlHeader head; + + r->len = MIN(remaining, RDMA_SEND_INCREMENT); + remaining -= r->len; + + head.len = r->len; + head.type = RDMA_CONTROL_QEMU_FILE; + + ret = qemu_rdma_exchange_send(rdma, &head, data, NULL, NULL, NULL); + + if (ret < 0) { + rdma->error_state = ret; + return ret; + } + + data += r->len; + } + + return size; +} + +static size_t qemu_rdma_fill(RDMAContext *rdma, uint8_t *buf, + int size, int idx) +{ + size_t len = 0; + + if (rdma->wr_data[idx].control_len) { + DDDPRINTF("RDMA %" PRId64 " of %d bytes already in buffer\n", + rdma->wr_data[idx].control_len, size); + + len = MIN(size, rdma->wr_data[idx].control_len); + memcpy(buf, rdma->wr_data[idx].control_curr, len); + rdma->wr_data[idx].control_curr += len; + rdma->wr_data[idx].control_len -= len; + } + + return len; +} + +/* + * QEMUFile interface to the control channel. + * RDMA links don't use bytestreams, so we have to + * return bytes to QEMUFile opportunistically. + */ +static int qemu_rdma_get_buffer(void *opaque, uint8_t *buf, + int64_t pos, int size) +{ + QEMUFileRDMA *r = opaque; + RDMAContext *rdma = r->rdma; + RDMAControlHeader head; + int ret = 0; + + CHECK_ERROR_STATE(); + + /* + * First, we hold on to the last SEND message we + * were given and dish out the bytes until we run + * out of bytes. + */ + r->len = qemu_rdma_fill(r->rdma, buf, size, 0); + if (r->len) { + return r->len; + } + + /* + * Once we run out, we block and wait for another + * SEND message to arrive. + */ + ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_QEMU_FILE); + + if (ret < 0) { + rdma->error_state = ret; + return ret; + } + + /* + * SEND was received with new bytes, now try again. + */ + return qemu_rdma_fill(r->rdma, buf, size, 0); +} + +/* + * Block until all the outstanding chunks have been delivered by the hardware. + */ +static int qemu_rdma_drain_cq(QEMUFile *f, RDMAContext *rdma) +{ + int ret; + + if (qemu_rdma_write_flush(f, rdma) < 0) { + return -EIO; + } + + while (rdma->nb_sent) { + ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RDMA_WRITE, NULL); + if (ret < 0) { + fprintf(stderr, "rdma migration: complete polling error!\n"); + return -EIO; + } + } + + qemu_rdma_unregister_waiting(rdma); + + return 0; +} + +static int qemu_rdma_close(void *opaque) +{ + DPRINTF("Shutting down connection.\n"); + QEMUFileRDMA *r = opaque; + if (r->rdma) { + qemu_rdma_cleanup(r->rdma); + g_free(r->rdma); + } + g_free(r); + return 0; +} + +/* + * Parameters: + * @offset == 0 : + * This means that 'block_offset' is a full virtual address that does not + * belong to a RAMBlock of the virtual machine and instead + * represents a private malloc'd memory area that the caller wishes to + * transfer. + * + * @offset != 0 : + * Offset is an offset to be added to block_offset and used + * to also lookup the corresponding RAMBlock. + * + * @size > 0 : + * Initiate an transfer this size. + * + * @size == 0 : + * A 'hint' or 'advice' that means that we wish to speculatively + * and asynchronously unregister this memory. In this case, there is no + * guarantee that the unregister will actually happen, for example, + * if the memory is being actively transmitted. Additionally, the memory + * may be re-registered at any future time if a write within the same + * chunk was requested again, even if you attempted to unregister it + * here. + * + * @size < 0 : TODO, not yet supported + * Unregister the memory NOW. This means that the caller does not + * expect there to be any future RDMA transfers and we just want to clean + * things up. This is used in case the upper layer owns the memory and + * cannot wait for qemu_fclose() to occur. + * + * @bytes_sent : User-specificed pointer to indicate how many bytes were + * sent. Usually, this will not be more than a few bytes of + * the protocol because most transfers are sent asynchronously. + */ +static size_t qemu_rdma_save_page(QEMUFile *f, void *opaque, + ram_addr_t block_offset, ram_addr_t offset, + size_t size, int *bytes_sent) +{ + QEMUFileRDMA *rfile = opaque; + RDMAContext *rdma = rfile->rdma; + int ret; + + CHECK_ERROR_STATE(); + + qemu_fflush(f); + + if (size > 0) { + /* + * Add this page to the current 'chunk'. If the chunk + * is full, or the page doen't belong to the current chunk, + * an actual RDMA write will occur and a new chunk will be formed. + */ + ret = qemu_rdma_write(f, rdma, block_offset, offset, size); + if (ret < 0) { + fprintf(stderr, "rdma migration: write error! %d\n", ret); + goto err; + } + + /* + * We always return 1 bytes because the RDMA + * protocol is completely asynchronous. We do not yet know + * whether an identified chunk is zero or not because we're + * waiting for other pages to potentially be merged with + * the current chunk. So, we have to call qemu_update_position() + * later on when the actual write occurs. + */ + if (bytes_sent) { + *bytes_sent = 1; + } + } else { + uint64_t index, chunk; + + /* TODO: Change QEMUFileOps prototype to be signed: size_t => long + if (size < 0) { + ret = qemu_rdma_drain_cq(f, rdma); + if (ret < 0) { + fprintf(stderr, "rdma: failed to synchronously drain" + " completion queue before unregistration.\n"); + goto err; + } + } + */ + + ret = qemu_rdma_search_ram_block(rdma, block_offset, + offset, size, &index, &chunk); + + if (ret) { + fprintf(stderr, "ram block search failed\n"); + goto err; + } + + qemu_rdma_signal_unregister(rdma, index, chunk, 0); + + /* + * TODO: Synchronous, guaranteed unregistration (should not occur during + * fast-path). Otherwise, unregisters will process on the next call to + * qemu_rdma_drain_cq() + if (size < 0) { + qemu_rdma_unregister_waiting(rdma); + } + */ + } + + /* + * Drain the Completion Queue if possible, but do not block, + * just poll. + * + * If nothing to poll, the end of the iteration will do this + * again to make sure we don't overflow the request queue. + */ + while (1) { + uint64_t wr_id, wr_id_in; + int ret = qemu_rdma_poll(rdma, &wr_id_in, NULL); + if (ret < 0) { + fprintf(stderr, "rdma migration: polling error! %d\n", ret); + goto err; + } + + wr_id = wr_id_in & RDMA_WRID_TYPE_MASK; + + if (wr_id == RDMA_WRID_NONE) { + break; + } + } + + return RAM_SAVE_CONTROL_DELAYED; +err: + rdma->error_state = ret; + return ret; +} + +static int qemu_rdma_accept(RDMAContext *rdma) +{ + RDMACapabilities cap; + struct rdma_conn_param conn_param = { + .responder_resources = 2, + .private_data = &cap, + .private_data_len = sizeof(cap), + }; + struct rdma_cm_event *cm_event; + struct ibv_context *verbs; + int ret = -EINVAL; + int idx; + + ret = rdma_get_cm_event(rdma->channel, &cm_event); + if (ret) { + goto err_rdma_dest_wait; + } + + if (cm_event->event != RDMA_CM_EVENT_CONNECT_REQUEST) { + rdma_ack_cm_event(cm_event); + goto err_rdma_dest_wait; + } + + memcpy(&cap, cm_event->param.conn.private_data, sizeof(cap)); + + network_to_caps(&cap); + + if (cap.version < 1 || cap.version > RDMA_CONTROL_VERSION_CURRENT) { + fprintf(stderr, "Unknown source RDMA version: %d, bailing...\n", + cap.version); + rdma_ack_cm_event(cm_event); + goto err_rdma_dest_wait; + } + + /* + * Respond with only the capabilities this version of QEMU knows about. + */ + cap.flags &= known_capabilities; + + /* + * Enable the ones that we do know about. + * Add other checks here as new ones are introduced. + */ + if (cap.flags & RDMA_CAPABILITY_PIN_ALL) { + rdma->pin_all = true; + } + + rdma->cm_id = cm_event->id; + verbs = cm_event->id->verbs; + + rdma_ack_cm_event(cm_event); + + DPRINTF("Memory pin all: %s\n", rdma->pin_all ? "enabled" : "disabled"); + + caps_to_network(&cap); + + DPRINTF("verbs context after listen: %p\n", verbs); + + if (!rdma->verbs) { + rdma->verbs = verbs; + } else if (rdma->verbs != verbs) { + fprintf(stderr, "ibv context not matching %p, %p!\n", + rdma->verbs, verbs); + goto err_rdma_dest_wait; + } + + qemu_rdma_dump_id("dest_init", verbs); + + ret = qemu_rdma_alloc_pd_cq(rdma); + if (ret) { + fprintf(stderr, "rdma migration: error allocating pd and cq!\n"); + goto err_rdma_dest_wait; + } + + ret = qemu_rdma_alloc_qp(rdma); + if (ret) { + fprintf(stderr, "rdma migration: error allocating qp!\n"); + goto err_rdma_dest_wait; + } + + ret = qemu_rdma_init_ram_blocks(rdma); + if (ret) { + fprintf(stderr, "rdma migration: error initializing ram blocks!\n"); + goto err_rdma_dest_wait; + } + + for (idx = 0; idx < RDMA_WRID_MAX; idx++) { + ret = qemu_rdma_reg_control(rdma, idx); + if (ret) { + fprintf(stderr, "rdma: error registering %d control!\n", idx); + goto err_rdma_dest_wait; + } + } + + qemu_set_fd_handler2(rdma->channel->fd, NULL, NULL, NULL, NULL); + + ret = rdma_accept(rdma->cm_id, &conn_param); + if (ret) { + fprintf(stderr, "rdma_accept returns %d!\n", ret); + goto err_rdma_dest_wait; + } + + ret = rdma_get_cm_event(rdma->channel, &cm_event); + if (ret) { + fprintf(stderr, "rdma_accept get_cm_event failed %d!\n", ret); + goto err_rdma_dest_wait; + } + + if (cm_event->event != RDMA_CM_EVENT_ESTABLISHED) { + fprintf(stderr, "rdma_accept not event established!\n"); + rdma_ack_cm_event(cm_event); + goto err_rdma_dest_wait; + } + + rdma_ack_cm_event(cm_event); + rdma->connected = true; + + ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY); + if (ret) { + fprintf(stderr, "rdma migration: error posting second control recv!\n"); + goto err_rdma_dest_wait; + } + + qemu_rdma_dump_gid("dest_connect", rdma->cm_id); + + return 0; + +err_rdma_dest_wait: + rdma->error_state = ret; + qemu_rdma_cleanup(rdma); + return ret; +} + +/* + * During each iteration of the migration, we listen for instructions + * by the source VM to perform dynamic page registrations before they + * can perform RDMA operations. + * + * We respond with the 'rkey'. + * + * Keep doing this until the source tells us to stop. + */ +static int qemu_rdma_registration_handle(QEMUFile *f, void *opaque, + uint64_t flags) +{ + RDMAControlHeader reg_resp = { .len = sizeof(RDMARegisterResult), + .type = RDMA_CONTROL_REGISTER_RESULT, + .repeat = 0, + }; + RDMAControlHeader unreg_resp = { .len = 0, + .type = RDMA_CONTROL_UNREGISTER_FINISHED, + .repeat = 0, + }; + RDMAControlHeader blocks = { .type = RDMA_CONTROL_RAM_BLOCKS_RESULT, + .repeat = 1 }; + QEMUFileRDMA *rfile = opaque; + RDMAContext *rdma = rfile->rdma; + RDMALocalBlocks *local = &rdma->local_ram_blocks; + RDMAControlHeader head; + RDMARegister *reg, *registers; + RDMACompress *comp; + RDMARegisterResult *reg_result; + static RDMARegisterResult results[RDMA_CONTROL_MAX_COMMANDS_PER_MESSAGE]; + RDMALocalBlock *block; + void *host_addr; + int ret = 0; + int idx = 0; + int count = 0; + int i = 0; + + CHECK_ERROR_STATE(); + + do { + DDDPRINTF("Waiting for next request %" PRIu64 "...\n", flags); + + ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_NONE); + + if (ret < 0) { + break; + } + + if (head.repeat > RDMA_CONTROL_MAX_COMMANDS_PER_MESSAGE) { + fprintf(stderr, "rdma: Too many requests in this message (%d)." + "Bailing.\n", head.repeat); + ret = -EIO; + break; + } + + switch (head.type) { + case RDMA_CONTROL_COMPRESS: + comp = (RDMACompress *) rdma->wr_data[idx].control_curr; + network_to_compress(comp); + + DDPRINTF("Zapping zero chunk: %" PRId64 + " bytes, index %d, offset %" PRId64 "\n", + comp->length, comp->block_idx, comp->offset); + block = &(rdma->local_ram_blocks.block[comp->block_idx]); + + host_addr = block->local_host_addr + + (comp->offset - block->offset); + + ram_handle_compressed(host_addr, comp->value, comp->length); + break; + + case RDMA_CONTROL_REGISTER_FINISHED: + DDDPRINTF("Current registrations complete.\n"); + goto out; + + case RDMA_CONTROL_RAM_BLOCKS_REQUEST: + DPRINTF("Initial setup info requested.\n"); + + if (rdma->pin_all) { + ret = qemu_rdma_reg_whole_ram_blocks(rdma); + if (ret) { + fprintf(stderr, "rdma migration: error dest " + "registering ram blocks!\n"); + goto out; + } + } + + /* + * Dest uses this to prepare to transmit the RAMBlock descriptions + * to the source VM after connection setup. + * Both sides use the "remote" structure to communicate and update + * their "local" descriptions with what was sent. + */ + for (i = 0; i < local->nb_blocks; i++) { + rdma->block[i].remote_host_addr = + (uint64_t)(local->block[i].local_host_addr); + + if (rdma->pin_all) { + rdma->block[i].remote_rkey = local->block[i].mr->rkey; + } + + rdma->block[i].offset = local->block[i].offset; + rdma->block[i].length = local->block[i].length; + + remote_block_to_network(&rdma->block[i]); + } + + blocks.len = rdma->local_ram_blocks.nb_blocks + * sizeof(RDMARemoteBlock); + + + ret = qemu_rdma_post_send_control(rdma, + (uint8_t *) rdma->block, &blocks); + + if (ret < 0) { + fprintf(stderr, "rdma migration: error sending remote info!\n"); + goto out; + } + + break; + case RDMA_CONTROL_REGISTER_REQUEST: + DDPRINTF("There are %d registration requests\n", head.repeat); + + reg_resp.repeat = head.repeat; + registers = (RDMARegister *) rdma->wr_data[idx].control_curr; + + for (count = 0; count < head.repeat; count++) { + uint64_t chunk; + uint8_t *chunk_start, *chunk_end; + + reg = ®isters[count]; + network_to_register(reg); + + reg_result = &results[count]; + + DDPRINTF("Registration request (%d): index %d, current_addr %" + PRIu64 " chunks: %" PRIu64 "\n", count, + reg->current_index, reg->key.current_addr, reg->chunks); + + block = &(rdma->local_ram_blocks.block[reg->current_index]); + if (block->is_ram_block) { + host_addr = (block->local_host_addr + + (reg->key.current_addr - block->offset)); + chunk = ram_chunk_index(block->local_host_addr, + (uint8_t *) host_addr); + } else { + chunk = reg->key.chunk; + host_addr = block->local_host_addr + + (reg->key.chunk * (1UL << RDMA_REG_CHUNK_SHIFT)); + } + chunk_start = ram_chunk_start(block, chunk); + chunk_end = ram_chunk_end(block, chunk + reg->chunks); + if (qemu_rdma_register_and_get_keys(rdma, block, + (uint8_t *)host_addr, NULL, ®_result->rkey, + chunk, chunk_start, chunk_end)) { + fprintf(stderr, "cannot get rkey!\n"); + ret = -EINVAL; + goto out; + } + + reg_result->host_addr = (uint64_t) block->local_host_addr; + + DDPRINTF("Registered rkey for this request: %x\n", + reg_result->rkey); + + result_to_network(reg_result); + } + + ret = qemu_rdma_post_send_control(rdma, + (uint8_t *) results, ®_resp); + + if (ret < 0) { + fprintf(stderr, "Failed to send control buffer!\n"); + goto out; + } + break; + case RDMA_CONTROL_UNREGISTER_REQUEST: + DDPRINTF("There are %d unregistration requests\n", head.repeat); + unreg_resp.repeat = head.repeat; + registers = (RDMARegister *) rdma->wr_data[idx].control_curr; + + for (count = 0; count < head.repeat; count++) { + reg = ®isters[count]; + network_to_register(reg); + + DDPRINTF("Unregistration request (%d): " + " index %d, chunk %" PRIu64 "\n", + count, reg->current_index, reg->key.chunk); + + block = &(rdma->local_ram_blocks.block[reg->current_index]); + + ret = ibv_dereg_mr(block->pmr[reg->key.chunk]); + block->pmr[reg->key.chunk] = NULL; + + if (ret != 0) { + perror("rdma unregistration chunk failed"); + ret = -ret; + goto out; + } + + rdma->total_registrations--; + + DDPRINTF("Unregistered chunk %" PRIu64 " successfully.\n", + reg->key.chunk); + } + + ret = qemu_rdma_post_send_control(rdma, NULL, &unreg_resp); + + if (ret < 0) { + fprintf(stderr, "Failed to send control buffer!\n"); + goto out; + } + break; + case RDMA_CONTROL_REGISTER_RESULT: + fprintf(stderr, "Invalid RESULT message at dest.\n"); + ret = -EIO; + goto out; + default: + fprintf(stderr, "Unknown control message %s\n", + control_desc[head.type]); + ret = -EIO; + goto out; + } + } while (1); +out: + if (ret < 0) { + rdma->error_state = ret; + } + return ret; +} + +static int qemu_rdma_registration_start(QEMUFile *f, void *opaque, + uint64_t flags) +{ + QEMUFileRDMA *rfile = opaque; + RDMAContext *rdma = rfile->rdma; + + CHECK_ERROR_STATE(); + + DDDPRINTF("start section: %" PRIu64 "\n", flags); + qemu_put_be64(f, RAM_SAVE_FLAG_HOOK); + qemu_fflush(f); + + return 0; +} + +/* + * Inform dest that dynamic registrations are done for now. + * First, flush writes, if any. + */ +static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque, + uint64_t flags) +{ + Error *local_err = NULL, **errp = &local_err; + QEMUFileRDMA *rfile = opaque; + RDMAContext *rdma = rfile->rdma; + RDMAControlHeader head = { .len = 0, .repeat = 1 }; + int ret = 0; + + CHECK_ERROR_STATE(); + + qemu_fflush(f); + ret = qemu_rdma_drain_cq(f, rdma); + + if (ret < 0) { + goto err; + } + + if (flags == RAM_CONTROL_SETUP) { + RDMAControlHeader resp = {.type = RDMA_CONTROL_RAM_BLOCKS_RESULT }; + RDMALocalBlocks *local = &rdma->local_ram_blocks; + int reg_result_idx, i, j, nb_remote_blocks; + + head.type = RDMA_CONTROL_RAM_BLOCKS_REQUEST; + DPRINTF("Sending registration setup for ram blocks...\n"); + + /* + * Make sure that we parallelize the pinning on both sides. + * For very large guests, doing this serially takes a really + * long time, so we have to 'interleave' the pinning locally + * with the control messages by performing the pinning on this + * side before we receive the control response from the other + * side that the pinning has completed. + */ + ret = qemu_rdma_exchange_send(rdma, &head, NULL, &resp, + ®_result_idx, rdma->pin_all ? + qemu_rdma_reg_whole_ram_blocks : NULL); + if (ret < 0) { + ERROR(errp, "receiving remote info!"); + return ret; + } + + nb_remote_blocks = resp.len / sizeof(RDMARemoteBlock); + + /* + * The protocol uses two different sets of rkeys (mutually exclusive): + * 1. One key to represent the virtual address of the entire ram block. + * (dynamic chunk registration disabled - pin everything with one rkey.) + * 2. One to represent individual chunks within a ram block. + * (dynamic chunk registration enabled - pin individual chunks.) + * + * Once the capability is successfully negotiated, the destination transmits + * the keys to use (or sends them later) including the virtual addresses + * and then propagates the remote ram block descriptions to his local copy. + */ + + if (local->nb_blocks != nb_remote_blocks) { + ERROR(errp, "ram blocks mismatch #1! " + "Your QEMU command line parameters are probably " + "not identical on both the source and destination."); + return -EINVAL; + } + + qemu_rdma_move_header(rdma, reg_result_idx, &resp); + memcpy(rdma->block, + rdma->wr_data[reg_result_idx].control_curr, resp.len); + for (i = 0; i < nb_remote_blocks; i++) { + network_to_remote_block(&rdma->block[i]); + + /* search local ram blocks */ + for (j = 0; j < local->nb_blocks; j++) { + if (rdma->block[i].offset != local->block[j].offset) { + continue; + } + + if (rdma->block[i].length != local->block[j].length) { + ERROR(errp, "ram blocks mismatch #2! " + "Your QEMU command line parameters are probably " + "not identical on both the source and destination."); + return -EINVAL; + } + local->block[j].remote_host_addr = + rdma->block[i].remote_host_addr; + local->block[j].remote_rkey = rdma->block[i].remote_rkey; + break; + } + + if (j >= local->nb_blocks) { + ERROR(errp, "ram blocks mismatch #3! " + "Your QEMU command line parameters are probably " + "not identical on both the source and destination."); + return -EINVAL; + } + } + } + + DDDPRINTF("Sending registration finish %" PRIu64 "...\n", flags); + + head.type = RDMA_CONTROL_REGISTER_FINISHED; + ret = qemu_rdma_exchange_send(rdma, &head, NULL, NULL, NULL, NULL); + + if (ret < 0) { + goto err; + } + + return 0; +err: + rdma->error_state = ret; + return ret; +} + +static int qemu_rdma_get_fd(void *opaque) +{ + QEMUFileRDMA *rfile = opaque; + RDMAContext *rdma = rfile->rdma; + + return rdma->comp_channel->fd; +} + +const QEMUFileOps rdma_read_ops = { + .get_buffer = qemu_rdma_get_buffer, + .get_fd = qemu_rdma_get_fd, + .close = qemu_rdma_close, + .hook_ram_load = qemu_rdma_registration_handle, +}; + +const QEMUFileOps rdma_write_ops = { + .put_buffer = qemu_rdma_put_buffer, + .close = qemu_rdma_close, + .before_ram_iterate = qemu_rdma_registration_start, + .after_ram_iterate = qemu_rdma_registration_stop, + .save_page = qemu_rdma_save_page, +}; + +static void *qemu_fopen_rdma(RDMAContext *rdma, const char *mode) +{ + QEMUFileRDMA *r = g_malloc0(sizeof(QEMUFileRDMA)); + + if (qemu_file_mode_is_not_valid(mode)) { + return NULL; + } + + r->rdma = rdma; + + if (mode[0] == 'w') { + r->file = qemu_fopen_ops(r, &rdma_write_ops); + } else { + r->file = qemu_fopen_ops(r, &rdma_read_ops); + } + + return r->file; +} + +static void rdma_accept_incoming_migration(void *opaque) +{ + RDMAContext *rdma = opaque; + int ret; + QEMUFile *f; + Error *local_err = NULL, **errp = &local_err; + + DPRINTF("Accepting rdma connection...\n"); + ret = qemu_rdma_accept(rdma); + + if (ret) { + ERROR(errp, "RDMA Migration initialization failed!"); + return; + } + + DPRINTF("Accepted migration\n"); + + f = qemu_fopen_rdma(rdma, "rb"); + if (f == NULL) { + ERROR(errp, "could not qemu_fopen_rdma!"); + qemu_rdma_cleanup(rdma); + return; + } + + rdma->migration_started_on_destination = 1; + process_incoming_migration(f); +} + +void rdma_start_incoming_migration(const char *host_port, Error **errp) +{ + int ret; + RDMAContext *rdma; + Error *local_err = NULL; + + DPRINTF("Starting RDMA-based incoming migration\n"); + rdma = qemu_rdma_data_init(host_port, &local_err); + + if (rdma == NULL) { + goto err; + } + + ret = qemu_rdma_dest_init(rdma, &local_err); + + if (ret) { + goto err; + } + + DPRINTF("qemu_rdma_dest_init success\n"); + + ret = rdma_listen(rdma->listen_id, 5); + + if (ret) { + ERROR(errp, "listening on socket!"); + goto err; + } + + DPRINTF("rdma_listen success\n"); + + qemu_set_fd_handler2(rdma->channel->fd, NULL, + rdma_accept_incoming_migration, NULL, + (void *)(intptr_t) rdma); + return; +err: + error_propagate(errp, local_err); + g_free(rdma); +} + +void rdma_start_outgoing_migration(void *opaque, + const char *host_port, Error **errp) +{ + MigrationState *s = opaque; + Error *local_err = NULL, **temp = &local_err; + RDMAContext *rdma = qemu_rdma_data_init(host_port, &local_err); + int ret = 0; + + if (rdma == NULL) { + ERROR(temp, "Failed to initialize RDMA data structures! %d", ret); + goto err; + } + + ret = qemu_rdma_source_init(rdma, &local_err, + s->enabled_capabilities[MIGRATION_CAPABILITY_RDMA_PIN_ALL]); + + if (ret) { + goto err; + } + + DPRINTF("qemu_rdma_source_init success\n"); + ret = qemu_rdma_connect(rdma, &local_err); + + if (ret) { + goto err; + } + + DPRINTF("qemu_rdma_source_connect success\n"); + + s->file = qemu_fopen_rdma(rdma, "wb"); + migrate_fd_connect(s); + return; +err: + error_propagate(errp, local_err); + g_free(rdma); + migrate_fd_error(s); +} diff --git a/migration/migration-tcp.c b/migration/migration-tcp.c new file mode 100644 index 0000000000..91c9cf381e --- /dev/null +++ b/migration/migration-tcp.c @@ -0,0 +1,103 @@ +/* + * QEMU live migration + * + * Copyright IBM, Corp. 2008 + * + * Authors: + * Anthony Liguori <aliguori@us.ibm.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ + +#include <string.h> + +#include "qemu-common.h" +#include "qemu/error-report.h" +#include "qemu/sockets.h" +#include "migration/migration.h" +#include "migration/qemu-file.h" +#include "block/block.h" +#include "qemu/main-loop.h" + +//#define DEBUG_MIGRATION_TCP + +#ifdef DEBUG_MIGRATION_TCP +#define DPRINTF(fmt, ...) \ + do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0) +#else +#define DPRINTF(fmt, ...) \ + do { } while (0) +#endif + +static void tcp_wait_for_connect(int fd, Error *err, void *opaque) +{ + MigrationState *s = opaque; + + if (fd < 0) { + DPRINTF("migrate connect error: %s\n", error_get_pretty(err)); + s->file = NULL; + migrate_fd_error(s); + } else { + DPRINTF("migrate connect success\n"); + s->file = qemu_fopen_socket(fd, "wb"); + migrate_fd_connect(s); + } +} + +void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp) +{ + inet_nonblocking_connect(host_port, tcp_wait_for_connect, s, errp); +} + +static void tcp_accept_incoming_migration(void *opaque) +{ + struct sockaddr_in addr; + socklen_t addrlen = sizeof(addr); + int s = (intptr_t)opaque; + QEMUFile *f; + int c, err; + + do { + c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen); + err = socket_error(); + } while (c < 0 && err == EINTR); + qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL); + closesocket(s); + + DPRINTF("accepted migration\n"); + + if (c < 0) { + error_report("could not accept migration connection (%s)", + strerror(err)); + return; + } + + f = qemu_fopen_socket(c, "rb"); + if (f == NULL) { + error_report("could not qemu_fopen socket"); + goto out; + } + + process_incoming_migration(f); + return; + +out: + closesocket(c); +} + +void tcp_start_incoming_migration(const char *host_port, Error **errp) +{ + int s; + + s = inet_listen(host_port, NULL, 256, SOCK_STREAM, 0, errp); + if (s < 0) { + return; + } + + qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL, + (void *)(intptr_t)s); +} diff --git a/migration/migration-unix.c b/migration/migration-unix.c new file mode 100644 index 0000000000..1cdadfbc83 --- /dev/null +++ b/migration/migration-unix.c @@ -0,0 +1,103 @@ +/* + * QEMU live migration via Unix Domain Sockets + * + * Copyright Red Hat, Inc. 2009 + * + * Authors: + * Chris Lalancette <clalance@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ + +#include <string.h> + +#include "qemu-common.h" +#include "qemu/error-report.h" +#include "qemu/sockets.h" +#include "qemu/main-loop.h" +#include "migration/migration.h" +#include "migration/qemu-file.h" +#include "block/block.h" + +//#define DEBUG_MIGRATION_UNIX + +#ifdef DEBUG_MIGRATION_UNIX +#define DPRINTF(fmt, ...) \ + do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0) +#else +#define DPRINTF(fmt, ...) \ + do { } while (0) +#endif + +static void unix_wait_for_connect(int fd, Error *err, void *opaque) +{ + MigrationState *s = opaque; + + if (fd < 0) { + DPRINTF("migrate connect error: %s\n", error_get_pretty(err)); + s->file = NULL; + migrate_fd_error(s); + } else { + DPRINTF("migrate connect success\n"); + s->file = qemu_fopen_socket(fd, "wb"); + migrate_fd_connect(s); + } +} + +void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp) +{ + unix_nonblocking_connect(path, unix_wait_for_connect, s, errp); +} + +static void unix_accept_incoming_migration(void *opaque) +{ + struct sockaddr_un addr; + socklen_t addrlen = sizeof(addr); + int s = (intptr_t)opaque; + QEMUFile *f; + int c, err; + + do { + c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen); + err = errno; + } while (c < 0 && err == EINTR); + qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL); + close(s); + + DPRINTF("accepted migration\n"); + + if (c < 0) { + error_report("could not accept migration connection (%s)", + strerror(err)); + return; + } + + f = qemu_fopen_socket(c, "rb"); + if (f == NULL) { + error_report("could not qemu_fopen socket"); + goto out; + } + + process_incoming_migration(f); + return; + +out: + close(c); +} + +void unix_start_incoming_migration(const char *path, Error **errp) +{ + int s; + + s = unix_listen(path, NULL, 0, errp); + if (s < 0) { + return; + } + + qemu_set_fd_handler2(s, NULL, unix_accept_incoming_migration, NULL, + (void *)(intptr_t)s); +} diff --git a/migration/migration.c b/migration/migration.c new file mode 100644 index 0000000000..c49a05a165 --- /dev/null +++ b/migration/migration.c @@ -0,0 +1,700 @@ +/* + * QEMU live migration + * + * Copyright IBM, Corp. 2008 + * + * Authors: + * Anthony Liguori <aliguori@us.ibm.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ + +#include "qemu-common.h" +#include "qemu/main-loop.h" +#include "migration/migration.h" +#include "monitor/monitor.h" +#include "migration/qemu-file.h" +#include "sysemu/sysemu.h" +#include "block/block.h" +#include "qemu/sockets.h" +#include "migration/block.h" +#include "qemu/thread.h" +#include "qmp-commands.h" +#include "trace.h" + +enum { + MIG_STATE_ERROR = -1, + MIG_STATE_NONE, + MIG_STATE_SETUP, + MIG_STATE_CANCELLING, + MIG_STATE_CANCELLED, + MIG_STATE_ACTIVE, + MIG_STATE_COMPLETED, +}; + +#define MAX_THROTTLE (32 << 20) /* Migration speed throttling */ + +/* Amount of time to allocate to each "chunk" of bandwidth-throttled + * data. */ +#define BUFFER_DELAY 100 +#define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY) + +/* Migration XBZRLE default cache size */ +#define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024) + +static NotifierList migration_state_notifiers = + NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); + +/* When we add fault tolerance, we could have several + migrations at once. For now we don't need to add + dynamic creation of migration */ + +MigrationState *migrate_get_current(void) +{ + static MigrationState current_migration = { + .state = MIG_STATE_NONE, + .bandwidth_limit = MAX_THROTTLE, + .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE, + .mbps = -1, + }; + + return ¤t_migration; +} + +void qemu_start_incoming_migration(const char *uri, Error **errp) +{ + const char *p; + + if (strstart(uri, "tcp:", &p)) + tcp_start_incoming_migration(p, errp); +#ifdef CONFIG_RDMA + else if (strstart(uri, "rdma:", &p)) + rdma_start_incoming_migration(p, errp); +#endif +#if !defined(WIN32) + else if (strstart(uri, "exec:", &p)) + exec_start_incoming_migration(p, errp); + else if (strstart(uri, "unix:", &p)) + unix_start_incoming_migration(p, errp); + else if (strstart(uri, "fd:", &p)) + fd_start_incoming_migration(p, errp); +#endif + else { + error_setg(errp, "unknown migration protocol: %s", uri); + } +} + +static void process_incoming_migration_co(void *opaque) +{ + QEMUFile *f = opaque; + Error *local_err = NULL; + int ret; + + ret = qemu_loadvm_state(f); + qemu_fclose(f); + free_xbzrle_decoded_buf(); + if (ret < 0) { + error_report("load of migration failed: %s", strerror(-ret)); + exit(EXIT_FAILURE); + } + qemu_announce_self(); + + /* Make sure all file formats flush their mutable metadata */ + bdrv_invalidate_cache_all(&local_err); + if (local_err) { + qerror_report_err(local_err); + error_free(local_err); + exit(EXIT_FAILURE); + } + + if (autostart) { + vm_start(); + } else { + runstate_set(RUN_STATE_PAUSED); + } +} + +void process_incoming_migration(QEMUFile *f) +{ + Coroutine *co = qemu_coroutine_create(process_incoming_migration_co); + int fd = qemu_get_fd(f); + + assert(fd != -1); + qemu_set_nonblock(fd); + qemu_coroutine_enter(co, f); +} + +/* amount of nanoseconds we are willing to wait for migration to be down. + * the choice of nanoseconds is because it is the maximum resolution that + * get_clock() can achieve. It is an internal measure. All user-visible + * units must be in seconds */ +static uint64_t max_downtime = 300000000; + +uint64_t migrate_max_downtime(void) +{ + return max_downtime; +} + +MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp) +{ + MigrationCapabilityStatusList *head = NULL; + MigrationCapabilityStatusList *caps; + MigrationState *s = migrate_get_current(); + int i; + + caps = NULL; /* silence compiler warning */ + for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) { + if (head == NULL) { + head = g_malloc0(sizeof(*caps)); + caps = head; + } else { + caps->next = g_malloc0(sizeof(*caps)); + caps = caps->next; + } + caps->value = + g_malloc(sizeof(*caps->value)); + caps->value->capability = i; + caps->value->state = s->enabled_capabilities[i]; + } + + return head; +} + +static void get_xbzrle_cache_stats(MigrationInfo *info) +{ + if (migrate_use_xbzrle()) { + info->has_xbzrle_cache = true; + info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache)); + info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size(); + info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred(); + info->xbzrle_cache->pages = xbzrle_mig_pages_transferred(); + info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss(); + info->xbzrle_cache->cache_miss_rate = xbzrle_mig_cache_miss_rate(); + info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow(); + } +} + +MigrationInfo *qmp_query_migrate(Error **errp) +{ + MigrationInfo *info = g_malloc0(sizeof(*info)); + MigrationState *s = migrate_get_current(); + + switch (s->state) { + case MIG_STATE_NONE: + /* no migration has happened ever */ + break; + case MIG_STATE_SETUP: + info->has_status = true; + info->status = g_strdup("setup"); + info->has_total_time = false; + break; + case MIG_STATE_ACTIVE: + case MIG_STATE_CANCELLING: + info->has_status = true; + info->status = g_strdup("active"); + info->has_total_time = true; + info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + - s->total_time; + info->has_expected_downtime = true; + info->expected_downtime = s->expected_downtime; + info->has_setup_time = true; + info->setup_time = s->setup_time; + + info->has_ram = true; + info->ram = g_malloc0(sizeof(*info->ram)); + info->ram->transferred = ram_bytes_transferred(); + info->ram->remaining = ram_bytes_remaining(); + info->ram->total = ram_bytes_total(); + info->ram->duplicate = dup_mig_pages_transferred(); + info->ram->skipped = skipped_mig_pages_transferred(); + info->ram->normal = norm_mig_pages_transferred(); + info->ram->normal_bytes = norm_mig_bytes_transferred(); + info->ram->dirty_pages_rate = s->dirty_pages_rate; + info->ram->mbps = s->mbps; + info->ram->dirty_sync_count = s->dirty_sync_count; + + if (blk_mig_active()) { + info->has_disk = true; + info->disk = g_malloc0(sizeof(*info->disk)); + info->disk->transferred = blk_mig_bytes_transferred(); + info->disk->remaining = blk_mig_bytes_remaining(); + info->disk->total = blk_mig_bytes_total(); + } + + get_xbzrle_cache_stats(info); + break; + case MIG_STATE_COMPLETED: + get_xbzrle_cache_stats(info); + + info->has_status = true; + info->status = g_strdup("completed"); + info->has_total_time = true; + info->total_time = s->total_time; + info->has_downtime = true; + info->downtime = s->downtime; + info->has_setup_time = true; + info->setup_time = s->setup_time; + + info->has_ram = true; + info->ram = g_malloc0(sizeof(*info->ram)); + info->ram->transferred = ram_bytes_transferred(); + info->ram->remaining = 0; + info->ram->total = ram_bytes_total(); + info->ram->duplicate = dup_mig_pages_transferred(); + info->ram->skipped = skipped_mig_pages_transferred(); + info->ram->normal = norm_mig_pages_transferred(); + info->ram->normal_bytes = norm_mig_bytes_transferred(); + info->ram->mbps = s->mbps; + info->ram->dirty_sync_count = s->dirty_sync_count; + break; + case MIG_STATE_ERROR: + info->has_status = true; + info->status = g_strdup("failed"); + break; + case MIG_STATE_CANCELLED: + info->has_status = true; + info->status = g_strdup("cancelled"); + break; + } + + return info; +} + +void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, + Error **errp) +{ + MigrationState *s = migrate_get_current(); + MigrationCapabilityStatusList *cap; + + if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP) { + error_set(errp, QERR_MIGRATION_ACTIVE); + return; + } + + for (cap = params; cap; cap = cap->next) { + s->enabled_capabilities[cap->value->capability] = cap->value->state; + } +} + +/* shared migration helpers */ + +static void migrate_set_state(MigrationState *s, int old_state, int new_state) +{ + if (atomic_cmpxchg(&s->state, old_state, new_state) == new_state) { + trace_migrate_set_state(new_state); + } +} + +static void migrate_fd_cleanup(void *opaque) +{ + MigrationState *s = opaque; + + qemu_bh_delete(s->cleanup_bh); + s->cleanup_bh = NULL; + + if (s->file) { + trace_migrate_fd_cleanup(); + qemu_mutex_unlock_iothread(); + qemu_thread_join(&s->thread); + qemu_mutex_lock_iothread(); + + qemu_fclose(s->file); + s->file = NULL; + } + + assert(s->state != MIG_STATE_ACTIVE); + + if (s->state != MIG_STATE_COMPLETED) { + qemu_savevm_state_cancel(); + if (s->state == MIG_STATE_CANCELLING) { + migrate_set_state(s, MIG_STATE_CANCELLING, MIG_STATE_CANCELLED); + } + } + + notifier_list_notify(&migration_state_notifiers, s); +} + +void migrate_fd_error(MigrationState *s) +{ + trace_migrate_fd_error(); + assert(s->file == NULL); + s->state = MIG_STATE_ERROR; + trace_migrate_set_state(MIG_STATE_ERROR); + notifier_list_notify(&migration_state_notifiers, s); +} + +static void migrate_fd_cancel(MigrationState *s) +{ + int old_state ; + trace_migrate_fd_cancel(); + + do { + old_state = s->state; + if (old_state != MIG_STATE_SETUP && old_state != MIG_STATE_ACTIVE) { + break; + } + migrate_set_state(s, old_state, MIG_STATE_CANCELLING); + } while (s->state != MIG_STATE_CANCELLING); +} + +void add_migration_state_change_notifier(Notifier *notify) +{ + notifier_list_add(&migration_state_notifiers, notify); +} + +void remove_migration_state_change_notifier(Notifier *notify) +{ + notifier_remove(notify); +} + +bool migration_in_setup(MigrationState *s) +{ + return s->state == MIG_STATE_SETUP; +} + +bool migration_has_finished(MigrationState *s) +{ + return s->state == MIG_STATE_COMPLETED; +} + +bool migration_has_failed(MigrationState *s) +{ + return (s->state == MIG_STATE_CANCELLED || + s->state == MIG_STATE_ERROR); +} + +static MigrationState *migrate_init(const MigrationParams *params) +{ + MigrationState *s = migrate_get_current(); + int64_t bandwidth_limit = s->bandwidth_limit; + bool enabled_capabilities[MIGRATION_CAPABILITY_MAX]; + int64_t xbzrle_cache_size = s->xbzrle_cache_size; + + memcpy(enabled_capabilities, s->enabled_capabilities, + sizeof(enabled_capabilities)); + + memset(s, 0, sizeof(*s)); + s->params = *params; + memcpy(s->enabled_capabilities, enabled_capabilities, + sizeof(enabled_capabilities)); + s->xbzrle_cache_size = xbzrle_cache_size; + + s->bandwidth_limit = bandwidth_limit; + s->state = MIG_STATE_SETUP; + trace_migrate_set_state(MIG_STATE_SETUP); + + s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + return s; +} + +static GSList *migration_blockers; + +void migrate_add_blocker(Error *reason) +{ + migration_blockers = g_slist_prepend(migration_blockers, reason); +} + +void migrate_del_blocker(Error *reason) +{ + migration_blockers = g_slist_remove(migration_blockers, reason); +} + +void qmp_migrate(const char *uri, bool has_blk, bool blk, + bool has_inc, bool inc, bool has_detach, bool detach, + Error **errp) +{ + Error *local_err = NULL; + MigrationState *s = migrate_get_current(); + MigrationParams params; + const char *p; + + params.blk = has_blk && blk; + params.shared = has_inc && inc; + + if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP || + s->state == MIG_STATE_CANCELLING) { + error_set(errp, QERR_MIGRATION_ACTIVE); + return; + } + + if (runstate_check(RUN_STATE_INMIGRATE)) { + error_setg(errp, "Guest is waiting for an incoming migration"); + return; + } + + if (qemu_savevm_state_blocked(errp)) { + return; + } + + if (migration_blockers) { + *errp = error_copy(migration_blockers->data); + return; + } + + s = migrate_init(¶ms); + + if (strstart(uri, "tcp:", &p)) { + tcp_start_outgoing_migration(s, p, &local_err); +#ifdef CONFIG_RDMA + } else if (strstart(uri, "rdma:", &p)) { + rdma_start_outgoing_migration(s, p, &local_err); +#endif +#if !defined(WIN32) + } else if (strstart(uri, "exec:", &p)) { + exec_start_outgoing_migration(s, p, &local_err); + } else if (strstart(uri, "unix:", &p)) { + unix_start_outgoing_migration(s, p, &local_err); + } else if (strstart(uri, "fd:", &p)) { + fd_start_outgoing_migration(s, p, &local_err); +#endif + } else { + error_set(errp, QERR_INVALID_PARAMETER_VALUE, "uri", "a valid migration protocol"); + s->state = MIG_STATE_ERROR; + return; + } + + if (local_err) { + migrate_fd_error(s); + error_propagate(errp, local_err); + return; + } +} + +void qmp_migrate_cancel(Error **errp) +{ + migrate_fd_cancel(migrate_get_current()); +} + +void qmp_migrate_set_cache_size(int64_t value, Error **errp) +{ + MigrationState *s = migrate_get_current(); + int64_t new_size; + + /* Check for truncation */ + if (value != (size_t)value) { + error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", + "exceeding address space"); + return; + } + + /* Cache should not be larger than guest ram size */ + if (value > ram_bytes_total()) { + error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", + "exceeds guest ram size "); + return; + } + + new_size = xbzrle_cache_resize(value); + if (new_size < 0) { + error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", + "is smaller than page size"); + return; + } + + s->xbzrle_cache_size = new_size; +} + +int64_t qmp_query_migrate_cache_size(Error **errp) +{ + return migrate_xbzrle_cache_size(); +} + +void qmp_migrate_set_speed(int64_t value, Error **errp) +{ + MigrationState *s; + + if (value < 0) { + value = 0; + } + if (value > SIZE_MAX) { + value = SIZE_MAX; + } + + s = migrate_get_current(); + s->bandwidth_limit = value; + if (s->file) { + qemu_file_set_rate_limit(s->file, s->bandwidth_limit / XFER_LIMIT_RATIO); + } +} + +void qmp_migrate_set_downtime(double value, Error **errp) +{ + value *= 1e9; + value = MAX(0, MIN(UINT64_MAX, value)); + max_downtime = (uint64_t)value; +} + +bool migrate_rdma_pin_all(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_RDMA_PIN_ALL]; +} + +bool migrate_auto_converge(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE]; +} + +bool migrate_zero_blocks(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS]; +} + +int migrate_use_xbzrle(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE]; +} + +int64_t migrate_xbzrle_cache_size(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->xbzrle_cache_size; +} + +/* migration thread support */ + +static void *migration_thread(void *opaque) +{ + MigrationState *s = opaque; + int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST); + int64_t initial_bytes = 0; + int64_t max_size = 0; + int64_t start_time = initial_time; + bool old_vm_running = false; + + qemu_savevm_state_begin(s->file, &s->params); + + s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start; + migrate_set_state(s, MIG_STATE_SETUP, MIG_STATE_ACTIVE); + + while (s->state == MIG_STATE_ACTIVE) { + int64_t current_time; + uint64_t pending_size; + + if (!qemu_file_rate_limit(s->file)) { + pending_size = qemu_savevm_state_pending(s->file, max_size); + trace_migrate_pending(pending_size, max_size); + if (pending_size && pending_size >= max_size) { + qemu_savevm_state_iterate(s->file); + } else { + int ret; + + qemu_mutex_lock_iothread(); + start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); + old_vm_running = runstate_is_running(); + + ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); + if (ret >= 0) { + qemu_file_set_rate_limit(s->file, INT64_MAX); + qemu_savevm_state_complete(s->file); + } + qemu_mutex_unlock_iothread(); + + if (ret < 0) { + migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR); + break; + } + + if (!qemu_file_get_error(s->file)) { + migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_COMPLETED); + break; + } + } + } + + if (qemu_file_get_error(s->file)) { + migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR); + break; + } + current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + if (current_time >= initial_time + BUFFER_DELAY) { + uint64_t transferred_bytes = qemu_ftell(s->file) - initial_bytes; + uint64_t time_spent = current_time - initial_time; + double bandwidth = transferred_bytes / time_spent; + max_size = bandwidth * migrate_max_downtime() / 1000000; + + s->mbps = time_spent ? (((double) transferred_bytes * 8.0) / + ((double) time_spent / 1000.0)) / 1000.0 / 1000.0 : -1; + + trace_migrate_transferred(transferred_bytes, time_spent, + bandwidth, max_size); + /* if we haven't sent anything, we don't want to recalculate + 10000 is a small enough number for our purposes */ + if (s->dirty_bytes_rate && transferred_bytes > 10000) { + s->expected_downtime = s->dirty_bytes_rate / bandwidth; + } + + qemu_file_reset_rate_limit(s->file); + initial_time = current_time; + initial_bytes = qemu_ftell(s->file); + } + if (qemu_file_rate_limit(s->file)) { + /* usleep expects microseconds */ + g_usleep((initial_time + BUFFER_DELAY - current_time)*1000); + } + } + + qemu_mutex_lock_iothread(); + if (s->state == MIG_STATE_COMPLETED) { + int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + uint64_t transferred_bytes = qemu_ftell(s->file); + s->total_time = end_time - s->total_time; + s->downtime = end_time - start_time; + if (s->total_time) { + s->mbps = (((double) transferred_bytes * 8.0) / + ((double) s->total_time)) / 1000; + } + runstate_set(RUN_STATE_POSTMIGRATE); + } else { + if (old_vm_running) { + vm_start(); + } + } + qemu_bh_schedule(s->cleanup_bh); + qemu_mutex_unlock_iothread(); + + return NULL; +} + +void migrate_fd_connect(MigrationState *s) +{ + s->state = MIG_STATE_SETUP; + trace_migrate_set_state(MIG_STATE_SETUP); + + /* This is a best 1st approximation. ns to ms */ + s->expected_downtime = max_downtime/1000000; + s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s); + + qemu_file_set_rate_limit(s->file, + s->bandwidth_limit / XFER_LIMIT_RATIO); + + /* Notify before starting migration thread */ + notifier_list_notify(&migration_state_notifiers, s); + + qemu_thread_create(&s->thread, "migration", migration_thread, s, + QEMU_THREAD_JOINABLE); +} diff --git a/migration/qemu-file-stdio.c b/migration/qemu-file-stdio.c new file mode 100644 index 0000000000..285068b303 --- /dev/null +++ b/migration/qemu-file-stdio.c @@ -0,0 +1,194 @@ +/* + * QEMU System Emulator + * + * Copyright (c) 2003-2008 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +#include "qemu-common.h" +#include "block/coroutine.h" +#include "migration/qemu-file.h" + +typedef struct QEMUFileStdio { + FILE *stdio_file; + QEMUFile *file; +} QEMUFileStdio; + +static int stdio_get_fd(void *opaque) +{ + QEMUFileStdio *s = opaque; + + return fileno(s->stdio_file); +} + +static int stdio_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, + int size) +{ + QEMUFileStdio *s = opaque; + int res; + + res = fwrite(buf, 1, size, s->stdio_file); + + if (res != size) { + return -errno; + } + return res; +} + +static int stdio_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size) +{ + QEMUFileStdio *s = opaque; + FILE *fp = s->stdio_file; + int bytes; + + for (;;) { + clearerr(fp); + bytes = fread(buf, 1, size, fp); + if (bytes != 0 || !ferror(fp)) { + break; + } + if (errno == EAGAIN) { + yield_until_fd_readable(fileno(fp)); + } else if (errno != EINTR) { + break; + } + } + return bytes; +} + +static int stdio_pclose(void *opaque) +{ + QEMUFileStdio *s = opaque; + int ret; + ret = pclose(s->stdio_file); + if (ret == -1) { + ret = -errno; + } else if (!WIFEXITED(ret) || WEXITSTATUS(ret) != 0) { + /* close succeeded, but non-zero exit code: */ + ret = -EIO; /* fake errno value */ + } + g_free(s); + return ret; +} + +static int stdio_fclose(void *opaque) +{ + QEMUFileStdio *s = opaque; + int ret = 0; + + if (qemu_file_is_writable(s->file)) { + int fd = fileno(s->stdio_file); + struct stat st; + + ret = fstat(fd, &st); + if (ret == 0 && S_ISREG(st.st_mode)) { + /* + * If the file handle is a regular file make sure the + * data is flushed to disk before signaling success. + */ + ret = fsync(fd); + if (ret != 0) { + ret = -errno; + return ret; + } + } + } + if (fclose(s->stdio_file) == EOF) { + ret = -errno; + } + g_free(s); + return ret; +} + +static const QEMUFileOps stdio_pipe_read_ops = { + .get_fd = stdio_get_fd, + .get_buffer = stdio_get_buffer, + .close = stdio_pclose +}; + +static const QEMUFileOps stdio_pipe_write_ops = { + .get_fd = stdio_get_fd, + .put_buffer = stdio_put_buffer, + .close = stdio_pclose +}; + +QEMUFile *qemu_popen_cmd(const char *command, const char *mode) +{ + FILE *stdio_file; + QEMUFileStdio *s; + + if (mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || mode[1] != 0) { + fprintf(stderr, "qemu_popen: Argument validity check failed\n"); + return NULL; + } + + stdio_file = popen(command, mode); + if (stdio_file == NULL) { + return NULL; + } + + s = g_malloc0(sizeof(QEMUFileStdio)); + + s->stdio_file = stdio_file; + + if (mode[0] == 'r') { + s->file = qemu_fopen_ops(s, &stdio_pipe_read_ops); + } else { + s->file = qemu_fopen_ops(s, &stdio_pipe_write_ops); + } + return s->file; +} + +static const QEMUFileOps stdio_file_read_ops = { + .get_fd = stdio_get_fd, + .get_buffer = stdio_get_buffer, + .close = stdio_fclose +}; + +static const QEMUFileOps stdio_file_write_ops = { + .get_fd = stdio_get_fd, + .put_buffer = stdio_put_buffer, + .close = stdio_fclose +}; + +QEMUFile *qemu_fopen(const char *filename, const char *mode) +{ + QEMUFileStdio *s; + + if (qemu_file_mode_is_not_valid(mode)) { + return NULL; + } + + s = g_malloc0(sizeof(QEMUFileStdio)); + + s->stdio_file = fopen(filename, mode); + if (!s->stdio_file) { + goto fail; + } + + if (mode[0] == 'w') { + s->file = qemu_fopen_ops(s, &stdio_file_write_ops); + } else { + s->file = qemu_fopen_ops(s, &stdio_file_read_ops); + } + return s->file; +fail: + g_free(s); + return NULL; +} diff --git a/migration/qemu-file-unix.c b/migration/qemu-file-unix.c new file mode 100644 index 0000000000..9682396d97 --- /dev/null +++ b/migration/qemu-file-unix.c @@ -0,0 +1,223 @@ +/* + * QEMU System Emulator + * + * Copyright (c) 2003-2008 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +#include "qemu-common.h" +#include "qemu/iov.h" +#include "qemu/sockets.h" +#include "block/coroutine.h" +#include "migration/qemu-file.h" + +typedef struct QEMUFileSocket { + int fd; + QEMUFile *file; +} QEMUFileSocket; + +static ssize_t socket_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, + int64_t pos) +{ + QEMUFileSocket *s = opaque; + ssize_t len; + ssize_t size = iov_size(iov, iovcnt); + + len = iov_send(s->fd, iov, iovcnt, 0, size); + if (len < size) { + len = -socket_error(); + } + return len; +} + +static int socket_get_fd(void *opaque) +{ + QEMUFileSocket *s = opaque; + + return s->fd; +} + +static int socket_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size) +{ + QEMUFileSocket *s = opaque; + ssize_t len; + + for (;;) { + len = qemu_recv(s->fd, buf, size, 0); + if (len != -1) { + break; + } + if (socket_error() == EAGAIN) { + yield_until_fd_readable(s->fd); + } else if (socket_error() != EINTR) { + break; + } + } + + if (len == -1) { + len = -socket_error(); + } + return len; +} + +static int socket_close(void *opaque) +{ + QEMUFileSocket *s = opaque; + closesocket(s->fd); + g_free(s); + return 0; +} + +static ssize_t unix_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, + int64_t pos) +{ + QEMUFileSocket *s = opaque; + ssize_t len, offset; + ssize_t size = iov_size(iov, iovcnt); + ssize_t total = 0; + + assert(iovcnt > 0); + offset = 0; + while (size > 0) { + /* Find the next start position; skip all full-sized vector elements */ + while (offset >= iov[0].iov_len) { + offset -= iov[0].iov_len; + iov++, iovcnt--; + } + + /* skip `offset' bytes from the (now) first element, undo it on exit */ + assert(iovcnt > 0); + iov[0].iov_base += offset; + iov[0].iov_len -= offset; + + do { + len = writev(s->fd, iov, iovcnt); + } while (len == -1 && errno == EINTR); + if (len == -1) { + return -errno; + } + + /* Undo the changes above */ + iov[0].iov_base -= offset; + iov[0].iov_len += offset; + + /* Prepare for the next iteration */ + offset += len; + total += len; + size -= len; + } + + return total; +} + +static int unix_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size) +{ + QEMUFileSocket *s = opaque; + ssize_t len; + + for (;;) { + len = read(s->fd, buf, size); + if (len != -1) { + break; + } + if (errno == EAGAIN) { + yield_until_fd_readable(s->fd); + } else if (errno != EINTR) { + break; + } + } + + if (len == -1) { + len = -errno; + } + return len; +} + +static int unix_close(void *opaque) +{ + QEMUFileSocket *s = opaque; + close(s->fd); + g_free(s); + return 0; +} + +static const QEMUFileOps unix_read_ops = { + .get_fd = socket_get_fd, + .get_buffer = unix_get_buffer, + .close = unix_close +}; + +static const QEMUFileOps unix_write_ops = { + .get_fd = socket_get_fd, + .writev_buffer = unix_writev_buffer, + .close = unix_close +}; + +QEMUFile *qemu_fdopen(int fd, const char *mode) +{ + QEMUFileSocket *s; + + if (mode == NULL || + (mode[0] != 'r' && mode[0] != 'w') || + mode[1] != 'b' || mode[2] != 0) { + fprintf(stderr, "qemu_fdopen: Argument validity check failed\n"); + return NULL; + } + + s = g_malloc0(sizeof(QEMUFileSocket)); + s->fd = fd; + + if (mode[0] == 'r') { + s->file = qemu_fopen_ops(s, &unix_read_ops); + } else { + s->file = qemu_fopen_ops(s, &unix_write_ops); + } + return s->file; +} + +static const QEMUFileOps socket_read_ops = { + .get_fd = socket_get_fd, + .get_buffer = socket_get_buffer, + .close = socket_close +}; + +static const QEMUFileOps socket_write_ops = { + .get_fd = socket_get_fd, + .writev_buffer = socket_writev_buffer, + .close = socket_close +}; + +QEMUFile *qemu_fopen_socket(int fd, const char *mode) +{ + QEMUFileSocket *s; + + if (qemu_file_mode_is_not_valid(mode)) { + return NULL; + } + + s = g_malloc0(sizeof(QEMUFileSocket)); + s->fd = fd; + if (mode[0] == 'w') { + qemu_set_block(s->fd); + s->file = qemu_fopen_ops(s, &socket_write_ops); + } else { + s->file = qemu_fopen_ops(s, &socket_read_ops); + } + return s->file; +} diff --git a/migration/qemu-file.c b/migration/qemu-file.c new file mode 100644 index 0000000000..f938e36fe8 --- /dev/null +++ b/migration/qemu-file.c @@ -0,0 +1,995 @@ +/* + * QEMU System Emulator + * + * Copyright (c) 2003-2008 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +#include "qemu-common.h" +#include "qemu/iov.h" +#include "qemu/sockets.h" +#include "block/coroutine.h" +#include "migration/migration.h" +#include "migration/qemu-file.h" +#include "trace.h" + +#define IO_BUF_SIZE 32768 +#define MAX_IOV_SIZE MIN(IOV_MAX, 64) + +struct QEMUFile { + const QEMUFileOps *ops; + void *opaque; + + int64_t bytes_xfer; + int64_t xfer_limit; + + int64_t pos; /* start of buffer when writing, end of buffer + when reading */ + int buf_index; + int buf_size; /* 0 when writing */ + uint8_t buf[IO_BUF_SIZE]; + + struct iovec iov[MAX_IOV_SIZE]; + unsigned int iovcnt; + + int last_error; +}; + +bool qemu_file_mode_is_not_valid(const char *mode) +{ + if (mode == NULL || + (mode[0] != 'r' && mode[0] != 'w') || + mode[1] != 'b' || mode[2] != 0) { + fprintf(stderr, "qemu_fopen: Argument validity check failed\n"); + return true; + } + + return false; +} + +QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops) +{ + QEMUFile *f; + + f = g_malloc0(sizeof(QEMUFile)); + + f->opaque = opaque; + f->ops = ops; + return f; +} + +/* + * Get last error for stream f + * + * Return negative error value if there has been an error on previous + * operations, return 0 if no error happened. + * + */ +int qemu_file_get_error(QEMUFile *f) +{ + return f->last_error; +} + +void qemu_file_set_error(QEMUFile *f, int ret) +{ + if (f->last_error == 0) { + f->last_error = ret; + } +} + +bool qemu_file_is_writable(QEMUFile *f) +{ + return f->ops->writev_buffer || f->ops->put_buffer; +} + +/** + * Flushes QEMUFile buffer + * + * If there is writev_buffer QEMUFileOps it uses it otherwise uses + * put_buffer ops. + */ +void qemu_fflush(QEMUFile *f) +{ + ssize_t ret = 0; + + if (!qemu_file_is_writable(f)) { + return; + } + + if (f->ops->writev_buffer) { + if (f->iovcnt > 0) { + ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, f->pos); + } + } else { + if (f->buf_index > 0) { + ret = f->ops->put_buffer(f->opaque, f->buf, f->pos, f->buf_index); + } + } + if (ret >= 0) { + f->pos += ret; + } + f->buf_index = 0; + f->iovcnt = 0; + if (ret < 0) { + qemu_file_set_error(f, ret); + } +} + +void ram_control_before_iterate(QEMUFile *f, uint64_t flags) +{ + int ret = 0; + + if (f->ops->before_ram_iterate) { + ret = f->ops->before_ram_iterate(f, f->opaque, flags); + if (ret < 0) { + qemu_file_set_error(f, ret); + } + } +} + +void ram_control_after_iterate(QEMUFile *f, uint64_t flags) +{ + int ret = 0; + + if (f->ops->after_ram_iterate) { + ret = f->ops->after_ram_iterate(f, f->opaque, flags); + if (ret < 0) { + qemu_file_set_error(f, ret); + } + } +} + +void ram_control_load_hook(QEMUFile *f, uint64_t flags) +{ + int ret = -EINVAL; + + if (f->ops->hook_ram_load) { + ret = f->ops->hook_ram_load(f, f->opaque, flags); + if (ret < 0) { + qemu_file_set_error(f, ret); + } + } else { + qemu_file_set_error(f, ret); + } +} + +size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset, + ram_addr_t offset, size_t size, int *bytes_sent) +{ + if (f->ops->save_page) { + int ret = f->ops->save_page(f, f->opaque, block_offset, + offset, size, bytes_sent); + + if (ret != RAM_SAVE_CONTROL_DELAYED) { + if (bytes_sent && *bytes_sent > 0) { + qemu_update_position(f, *bytes_sent); + } else if (ret < 0) { + qemu_file_set_error(f, ret); + } + } + + return ret; + } + + return RAM_SAVE_CONTROL_NOT_SUPP; +} + +/* + * Attempt to fill the buffer from the underlying file + * Returns the number of bytes read, or negative value for an error. + * + * Note that it can return a partially full buffer even in a not error/not EOF + * case if the underlying file descriptor gives a short read, and that can + * happen even on a blocking fd. + */ +static ssize_t qemu_fill_buffer(QEMUFile *f) +{ + int len; + int pending; + + assert(!qemu_file_is_writable(f)); + + pending = f->buf_size - f->buf_index; + if (pending > 0) { + memmove(f->buf, f->buf + f->buf_index, pending); + } + f->buf_index = 0; + f->buf_size = pending; + + len = f->ops->get_buffer(f->opaque, f->buf + pending, f->pos, + IO_BUF_SIZE - pending); + if (len > 0) { + f->buf_size += len; + f->pos += len; + } else if (len == 0) { + qemu_file_set_error(f, -EIO); + } else if (len != -EAGAIN) { + qemu_file_set_error(f, len); + } + + return len; +} + +int qemu_get_fd(QEMUFile *f) +{ + if (f->ops->get_fd) { + return f->ops->get_fd(f->opaque); + } + return -1; +} + +void qemu_update_position(QEMUFile *f, size_t size) +{ + f->pos += size; +} + +/** Closes the file + * + * Returns negative error value if any error happened on previous operations or + * while closing the file. Returns 0 or positive number on success. + * + * The meaning of return value on success depends on the specific backend + * being used. + */ +int qemu_fclose(QEMUFile *f) +{ + int ret; + qemu_fflush(f); + ret = qemu_file_get_error(f); + + if (f->ops->close) { + int ret2 = f->ops->close(f->opaque); + if (ret >= 0) { + ret = ret2; + } + } + /* If any error was spotted before closing, we should report it + * instead of the close() return value. + */ + if (f->last_error) { + ret = f->last_error; + } + g_free(f); + trace_qemu_file_fclose(); + return ret; +} + +static void add_to_iovec(QEMUFile *f, const uint8_t *buf, int size) +{ + /* check for adjacent buffer and coalesce them */ + if (f->iovcnt > 0 && buf == f->iov[f->iovcnt - 1].iov_base + + f->iov[f->iovcnt - 1].iov_len) { + f->iov[f->iovcnt - 1].iov_len += size; + } else { + f->iov[f->iovcnt].iov_base = (uint8_t *)buf; + f->iov[f->iovcnt++].iov_len = size; + } + + if (f->iovcnt >= MAX_IOV_SIZE) { + qemu_fflush(f); + } +} + +void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, int size) +{ + if (!f->ops->writev_buffer) { + qemu_put_buffer(f, buf, size); + return; + } + + if (f->last_error) { + return; + } + + f->bytes_xfer += size; + add_to_iovec(f, buf, size); +} + +void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size) +{ + int l; + + if (f->last_error) { + return; + } + + while (size > 0) { + l = IO_BUF_SIZE - f->buf_index; + if (l > size) { + l = size; + } + memcpy(f->buf + f->buf_index, buf, l); + f->bytes_xfer += l; + if (f->ops->writev_buffer) { + add_to_iovec(f, f->buf + f->buf_index, l); + } + f->buf_index += l; + if (f->buf_index == IO_BUF_SIZE) { + qemu_fflush(f); + } + if (qemu_file_get_error(f)) { + break; + } + buf += l; + size -= l; + } +} + +void qemu_put_byte(QEMUFile *f, int v) +{ + if (f->last_error) { + return; + } + + f->buf[f->buf_index] = v; + f->bytes_xfer++; + if (f->ops->writev_buffer) { + add_to_iovec(f, f->buf + f->buf_index, 1); + } + f->buf_index++; + if (f->buf_index == IO_BUF_SIZE) { + qemu_fflush(f); + } +} + +void qemu_file_skip(QEMUFile *f, int size) +{ + if (f->buf_index + size <= f->buf_size) { + f->buf_index += size; + } +} + +/* + * Read 'size' bytes from file (at 'offset') into buf without moving the + * pointer. + * + * It will return size bytes unless there was an error, in which case it will + * return as many as it managed to read (assuming blocking fd's which + * all current QEMUFile are) + */ +int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset) +{ + int pending; + int index; + + assert(!qemu_file_is_writable(f)); + assert(offset < IO_BUF_SIZE); + assert(size <= IO_BUF_SIZE - offset); + + /* The 1st byte to read from */ + index = f->buf_index + offset; + /* The number of available bytes starting at index */ + pending = f->buf_size - index; + + /* + * qemu_fill_buffer might return just a few bytes, even when there isn't + * an error, so loop collecting them until we get enough. + */ + while (pending < size) { + int received = qemu_fill_buffer(f); + + if (received <= 0) { + break; + } + + index = f->buf_index + offset; + pending = f->buf_size - index; + } + + if (pending <= 0) { + return 0; + } + if (size > pending) { + size = pending; + } + + memcpy(buf, f->buf + index, size); + return size; +} + +/* + * Read 'size' bytes of data from the file into buf. + * 'size' can be larger than the internal buffer. + * + * It will return size bytes unless there was an error, in which case it will + * return as many as it managed to read (assuming blocking fd's which + * all current QEMUFile are) + */ +int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size) +{ + int pending = size; + int done = 0; + + while (pending > 0) { + int res; + + res = qemu_peek_buffer(f, buf, MIN(pending, IO_BUF_SIZE), 0); + if (res == 0) { + return done; + } + qemu_file_skip(f, res); + buf += res; + pending -= res; + done += res; + } + return done; +} + +/* + * Peeks a single byte from the buffer; this isn't guaranteed to work if + * offset leaves a gap after the previous read/peeked data. + */ +int qemu_peek_byte(QEMUFile *f, int offset) +{ + int index = f->buf_index + offset; + + assert(!qemu_file_is_writable(f)); + assert(offset < IO_BUF_SIZE); + + if (index >= f->buf_size) { + qemu_fill_buffer(f); + index = f->buf_index + offset; + if (index >= f->buf_size) { + return 0; + } + } + return f->buf[index]; +} + +int qemu_get_byte(QEMUFile *f) +{ + int result; + + result = qemu_peek_byte(f, 0); + qemu_file_skip(f, 1); + return result; +} + +int64_t qemu_ftell(QEMUFile *f) +{ + qemu_fflush(f); + return f->pos; +} + +int qemu_file_rate_limit(QEMUFile *f) +{ + if (qemu_file_get_error(f)) { + return 1; + } + if (f->xfer_limit > 0 && f->bytes_xfer > f->xfer_limit) { + return 1; + } + return 0; +} + +int64_t qemu_file_get_rate_limit(QEMUFile *f) +{ + return f->xfer_limit; +} + +void qemu_file_set_rate_limit(QEMUFile *f, int64_t limit) +{ + f->xfer_limit = limit; +} + +void qemu_file_reset_rate_limit(QEMUFile *f) +{ + f->bytes_xfer = 0; +} + +void qemu_put_be16(QEMUFile *f, unsigned int v) +{ + qemu_put_byte(f, v >> 8); + qemu_put_byte(f, v); +} + +void qemu_put_be32(QEMUFile *f, unsigned int v) +{ + qemu_put_byte(f, v >> 24); + qemu_put_byte(f, v >> 16); + qemu_put_byte(f, v >> 8); + qemu_put_byte(f, v); +} + +void qemu_put_be64(QEMUFile *f, uint64_t v) +{ + qemu_put_be32(f, v >> 32); + qemu_put_be32(f, v); +} + +unsigned int qemu_get_be16(QEMUFile *f) +{ + unsigned int v; + v = qemu_get_byte(f) << 8; + v |= qemu_get_byte(f); + return v; +} + +unsigned int qemu_get_be32(QEMUFile *f) +{ + unsigned int v; + v = qemu_get_byte(f) << 24; + v |= qemu_get_byte(f) << 16; + v |= qemu_get_byte(f) << 8; + v |= qemu_get_byte(f); + return v; +} + +uint64_t qemu_get_be64(QEMUFile *f) +{ + uint64_t v; + v = (uint64_t)qemu_get_be32(f) << 32; + v |= qemu_get_be32(f); + return v; +} + +#define QSB_CHUNK_SIZE (1 << 10) +#define QSB_MAX_CHUNK_SIZE (16 * QSB_CHUNK_SIZE) + +/** + * Create a QEMUSizedBuffer + * This type of buffer uses scatter-gather lists internally and + * can grow to any size. Any data array in the scatter-gather list + * can hold different amount of bytes. + * + * @buffer: Optional buffer to copy into the QSB + * @len: size of initial buffer; if @buffer is given, buffer must + * hold at least len bytes + * + * Returns a pointer to a QEMUSizedBuffer or NULL on allocation failure + */ +QEMUSizedBuffer *qsb_create(const uint8_t *buffer, size_t len) +{ + QEMUSizedBuffer *qsb; + size_t alloc_len, num_chunks, i, to_copy; + size_t chunk_size = (len > QSB_MAX_CHUNK_SIZE) + ? QSB_MAX_CHUNK_SIZE + : QSB_CHUNK_SIZE; + + num_chunks = DIV_ROUND_UP(len ? len : QSB_CHUNK_SIZE, chunk_size); + alloc_len = num_chunks * chunk_size; + + qsb = g_try_new0(QEMUSizedBuffer, 1); + if (!qsb) { + return NULL; + } + + qsb->iov = g_try_new0(struct iovec, num_chunks); + if (!qsb->iov) { + g_free(qsb); + return NULL; + } + + qsb->n_iov = num_chunks; + + for (i = 0; i < num_chunks; i++) { + qsb->iov[i].iov_base = g_try_malloc0(chunk_size); + if (!qsb->iov[i].iov_base) { + /* qsb_free is safe since g_free can cope with NULL */ + qsb_free(qsb); + return NULL; + } + + qsb->iov[i].iov_len = chunk_size; + if (buffer) { + to_copy = (len - qsb->used) > chunk_size + ? chunk_size : (len - qsb->used); + memcpy(qsb->iov[i].iov_base, &buffer[qsb->used], to_copy); + qsb->used += to_copy; + } + } + + qsb->size = alloc_len; + + return qsb; +} + +/** + * Free the QEMUSizedBuffer + * + * @qsb: The QEMUSizedBuffer to free + */ +void qsb_free(QEMUSizedBuffer *qsb) +{ + size_t i; + + if (!qsb) { + return; + } + + for (i = 0; i < qsb->n_iov; i++) { + g_free(qsb->iov[i].iov_base); + } + g_free(qsb->iov); + g_free(qsb); +} + +/** + * Get the number of used bytes in the QEMUSizedBuffer + * + * @qsb: A QEMUSizedBuffer + * + * Returns the number of bytes currently used in this buffer + */ +size_t qsb_get_length(const QEMUSizedBuffer *qsb) +{ + return qsb->used; +} + +/** + * Set the length of the buffer; the primary usage of this + * function is to truncate the number of used bytes in the buffer. + * The size will not be extended beyond the current number of + * allocated bytes in the QEMUSizedBuffer. + * + * @qsb: A QEMUSizedBuffer + * @new_len: The new length of bytes in the buffer + * + * Returns the number of bytes the buffer was truncated or extended + * to. + */ +size_t qsb_set_length(QEMUSizedBuffer *qsb, size_t new_len) +{ + if (new_len <= qsb->size) { + qsb->used = new_len; + } else { + qsb->used = qsb->size; + } + return qsb->used; +} + +/** + * Get the iovec that holds the data for a given position @pos. + * + * @qsb: A QEMUSizedBuffer + * @pos: The index of a byte in the buffer + * @d_off: Pointer to an offset that this function will indicate + * at what position within the returned iovec the byte + * is to be found + * + * Returns the index of the iovec that holds the byte at the given + * index @pos in the byte stream; a negative number if the iovec + * for the given position @pos does not exist. + */ +static ssize_t qsb_get_iovec(const QEMUSizedBuffer *qsb, + off_t pos, off_t *d_off) +{ + ssize_t i; + off_t curr = 0; + + if (pos > qsb->used) { + return -1; + } + + for (i = 0; i < qsb->n_iov; i++) { + if (curr + qsb->iov[i].iov_len > pos) { + *d_off = pos - curr; + return i; + } + curr += qsb->iov[i].iov_len; + } + return -1; +} + +/* + * Convert the QEMUSizedBuffer into a flat buffer. + * + * Note: If at all possible, try to avoid this function since it + * may unnecessarily copy memory around. + * + * @qsb: pointer to QEMUSizedBuffer + * @start: offset to start at + * @count: number of bytes to copy + * @buf: a pointer to a buffer to write into (at least @count bytes) + * + * Returns the number of bytes copied into the output buffer + */ +ssize_t qsb_get_buffer(const QEMUSizedBuffer *qsb, off_t start, + size_t count, uint8_t *buffer) +{ + const struct iovec *iov; + size_t to_copy, all_copy; + ssize_t index; + off_t s_off; + off_t d_off = 0; + char *s; + + if (start > qsb->used) { + return 0; + } + + all_copy = qsb->used - start; + if (all_copy > count) { + all_copy = count; + } else { + count = all_copy; + } + + index = qsb_get_iovec(qsb, start, &s_off); + if (index < 0) { + return 0; + } + + while (all_copy > 0) { + iov = &qsb->iov[index]; + + s = iov->iov_base; + + to_copy = iov->iov_len - s_off; + if (to_copy > all_copy) { + to_copy = all_copy; + } + memcpy(&buffer[d_off], &s[s_off], to_copy); + + d_off += to_copy; + all_copy -= to_copy; + + s_off = 0; + index++; + } + + return count; +} + +/** + * Grow the QEMUSizedBuffer to the given size and allocate + * memory for it. + * + * @qsb: A QEMUSizedBuffer + * @new_size: The new size of the buffer + * + * Return: + * a negative error code in case of memory allocation failure + * or + * the new size of the buffer. The returned size may be greater or equal + * to @new_size. + */ +static ssize_t qsb_grow(QEMUSizedBuffer *qsb, size_t new_size) +{ + size_t needed_chunks, i; + + if (qsb->size < new_size) { + struct iovec *new_iov; + size_t size_diff = new_size - qsb->size; + size_t chunk_size = (size_diff > QSB_MAX_CHUNK_SIZE) + ? QSB_MAX_CHUNK_SIZE : QSB_CHUNK_SIZE; + + needed_chunks = DIV_ROUND_UP(size_diff, chunk_size); + + new_iov = g_try_new(struct iovec, qsb->n_iov + needed_chunks); + if (new_iov == NULL) { + return -ENOMEM; + } + + /* Allocate new chunks as needed into new_iov */ + for (i = qsb->n_iov; i < qsb->n_iov + needed_chunks; i++) { + new_iov[i].iov_base = g_try_malloc0(chunk_size); + new_iov[i].iov_len = chunk_size; + if (!new_iov[i].iov_base) { + size_t j; + + /* Free previously allocated new chunks */ + for (j = qsb->n_iov; j < i; j++) { + g_free(new_iov[j].iov_base); + } + g_free(new_iov); + + return -ENOMEM; + } + } + + /* + * Now we can't get any allocation errors, copy over to new iov + * and switch. + */ + for (i = 0; i < qsb->n_iov; i++) { + new_iov[i] = qsb->iov[i]; + } + + qsb->n_iov += needed_chunks; + g_free(qsb->iov); + qsb->iov = new_iov; + qsb->size += (needed_chunks * chunk_size); + } + + return qsb->size; +} + +/** + * Write into the QEMUSizedBuffer at a given position and a given + * number of bytes. This function will automatically grow the + * QEMUSizedBuffer. + * + * @qsb: A QEMUSizedBuffer + * @source: A byte array to copy data from + * @pos: The position within the @qsb to write data to + * @size: The number of bytes to copy into the @qsb + * + * Returns @size or a negative error code in case of memory allocation failure, + * or with an invalid 'pos' + */ +ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *source, + off_t pos, size_t count) +{ + ssize_t rc = qsb_grow(qsb, pos + count); + size_t to_copy; + size_t all_copy = count; + const struct iovec *iov; + ssize_t index; + char *dest; + off_t d_off, s_off = 0; + + if (rc < 0) { + return rc; + } + + if (pos + count > qsb->used) { + qsb->used = pos + count; + } + + index = qsb_get_iovec(qsb, pos, &d_off); + if (index < 0) { + return -EINVAL; + } + + while (all_copy > 0) { + iov = &qsb->iov[index]; + + dest = iov->iov_base; + + to_copy = iov->iov_len - d_off; + if (to_copy > all_copy) { + to_copy = all_copy; + } + + memcpy(&dest[d_off], &source[s_off], to_copy); + + s_off += to_copy; + all_copy -= to_copy; + + d_off = 0; + index++; + } + + return count; +} + +/** + * Create a deep copy of the given QEMUSizedBuffer. + * + * @qsb: A QEMUSizedBuffer + * + * Returns a clone of @qsb or NULL on allocation failure + */ +QEMUSizedBuffer *qsb_clone(const QEMUSizedBuffer *qsb) +{ + QEMUSizedBuffer *out = qsb_create(NULL, qsb_get_length(qsb)); + size_t i; + ssize_t res; + off_t pos = 0; + + if (!out) { + return NULL; + } + + for (i = 0; i < qsb->n_iov; i++) { + res = qsb_write_at(out, qsb->iov[i].iov_base, + pos, qsb->iov[i].iov_len); + if (res < 0) { + qsb_free(out); + return NULL; + } + pos += res; + } + + return out; +} + +typedef struct QEMUBuffer { + QEMUSizedBuffer *qsb; + QEMUFile *file; +} QEMUBuffer; + +static int buf_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size) +{ + QEMUBuffer *s = opaque; + ssize_t len = qsb_get_length(s->qsb) - pos; + + if (len <= 0) { + return 0; + } + + if (len > size) { + len = size; + } + return qsb_get_buffer(s->qsb, pos, len, buf); +} + +static int buf_put_buffer(void *opaque, const uint8_t *buf, + int64_t pos, int size) +{ + QEMUBuffer *s = opaque; + + return qsb_write_at(s->qsb, buf, pos, size); +} + +static int buf_close(void *opaque) +{ + QEMUBuffer *s = opaque; + + qsb_free(s->qsb); + + g_free(s); + + return 0; +} + +const QEMUSizedBuffer *qemu_buf_get(QEMUFile *f) +{ + QEMUBuffer *p; + + qemu_fflush(f); + + p = f->opaque; + + return p->qsb; +} + +static const QEMUFileOps buf_read_ops = { + .get_buffer = buf_get_buffer, + .close = buf_close, +}; + +static const QEMUFileOps buf_write_ops = { + .put_buffer = buf_put_buffer, + .close = buf_close, +}; + +QEMUFile *qemu_bufopen(const char *mode, QEMUSizedBuffer *input) +{ + QEMUBuffer *s; + + if (mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || + mode[1] != '\0') { + error_report("qemu_bufopen: Argument validity check failed"); + return NULL; + } + + s = g_malloc0(sizeof(QEMUBuffer)); + if (mode[0] == 'r') { + s->qsb = input; + } + + if (s->qsb == NULL) { + s->qsb = qsb_create(NULL, 0); + } + if (!s->qsb) { + g_free(s); + error_report("qemu_bufopen: qsb_create failed"); + return NULL; + } + + + if (mode[0] == 'r') { + s->file = qemu_fopen_ops(s, &buf_read_ops); + } else { + s->file = qemu_fopen_ops(s, &buf_write_ops); + } + return s->file; +} diff --git a/migration/vmstate.c b/migration/vmstate.c new file mode 100644 index 0000000000..3dde574c0f --- /dev/null +++ b/migration/vmstate.c @@ -0,0 +1,687 @@ +#include "qemu-common.h" +#include "migration/migration.h" +#include "migration/qemu-file.h" +#include "migration/vmstate.h" +#include "qemu/bitops.h" +#include "trace.h" + +static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, + void *opaque); +static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, + void *opaque); + +static int vmstate_n_elems(void *opaque, VMStateField *field) +{ + int n_elems = 1; + + if (field->flags & VMS_ARRAY) { + n_elems = field->num; + } else if (field->flags & VMS_VARRAY_INT32) { + n_elems = *(int32_t *)(opaque+field->num_offset); + } else if (field->flags & VMS_VARRAY_UINT32) { + n_elems = *(uint32_t *)(opaque+field->num_offset); + } else if (field->flags & VMS_VARRAY_UINT16) { + n_elems = *(uint16_t *)(opaque+field->num_offset); + } else if (field->flags & VMS_VARRAY_UINT8) { + n_elems = *(uint8_t *)(opaque+field->num_offset); + } + + return n_elems; +} + +static int vmstate_size(void *opaque, VMStateField *field) +{ + int size = field->size; + + if (field->flags & VMS_VBUFFER) { + size = *(int32_t *)(opaque+field->size_offset); + if (field->flags & VMS_MULTIPLY) { + size *= field->size; + } + } + + return size; +} + +static void *vmstate_base_addr(void *opaque, VMStateField *field, bool alloc) +{ + void *base_addr = opaque + field->offset; + + if (field->flags & VMS_POINTER) { + if (alloc && (field->flags & VMS_ALLOC)) { + gsize size = 0; + if (field->flags & VMS_VBUFFER) { + size = vmstate_size(opaque, field); + } else { + int n_elems = vmstate_n_elems(opaque, field); + if (n_elems) { + size = n_elems * field->size; + } + } + if (size) { + *((void **)base_addr + field->start) = g_malloc(size); + } + } + base_addr = *(void **)base_addr + field->start; + } + + return base_addr; +} + +int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, + void *opaque, int version_id) +{ + VMStateField *field = vmsd->fields; + int ret; + + if (version_id > vmsd->version_id) { + return -EINVAL; + } + if (version_id < vmsd->minimum_version_id) { + if (vmsd->load_state_old && + version_id >= vmsd->minimum_version_id_old) { + return vmsd->load_state_old(f, opaque, version_id); + } + return -EINVAL; + } + if (vmsd->pre_load) { + int ret = vmsd->pre_load(opaque); + if (ret) { + return ret; + } + } + while (field->name) { + if ((field->field_exists && + field->field_exists(opaque, version_id)) || + (!field->field_exists && + field->version_id <= version_id)) { + void *base_addr = vmstate_base_addr(opaque, field, true); + int i, n_elems = vmstate_n_elems(opaque, field); + int size = vmstate_size(opaque, field); + + for (i = 0; i < n_elems; i++) { + void *addr = base_addr + size * i; + + if (field->flags & VMS_ARRAY_OF_POINTER) { + addr = *(void **)addr; + } + if (field->flags & VMS_STRUCT) { + ret = vmstate_load_state(f, field->vmsd, addr, + field->vmsd->version_id); + } else { + ret = field->info->get(f, addr, size); + + } + if (ret >= 0) { + ret = qemu_file_get_error(f); + } + if (ret < 0) { + qemu_file_set_error(f, ret); + trace_vmstate_load_field_error(field->name, ret); + return ret; + } + } + } else if (field->flags & VMS_MUST_EXIST) { + fprintf(stderr, "Input validation failed: %s/%s\n", + vmsd->name, field->name); + return -1; + } + field++; + } + ret = vmstate_subsection_load(f, vmsd, opaque); + if (ret != 0) { + return ret; + } + if (vmsd->post_load) { + return vmsd->post_load(opaque, version_id); + } + return 0; +} + +void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd, + void *opaque) +{ + VMStateField *field = vmsd->fields; + + if (vmsd->pre_save) { + vmsd->pre_save(opaque); + } + while (field->name) { + if (!field->field_exists || + field->field_exists(opaque, vmsd->version_id)) { + void *base_addr = vmstate_base_addr(opaque, field, false); + int i, n_elems = vmstate_n_elems(opaque, field); + int size = vmstate_size(opaque, field); + + for (i = 0; i < n_elems; i++) { + void *addr = base_addr + size * i; + + if (field->flags & VMS_ARRAY_OF_POINTER) { + addr = *(void **)addr; + } + if (field->flags & VMS_STRUCT) { + vmstate_save_state(f, field->vmsd, addr); + } else { + field->info->put(f, addr, size); + } + } + } else { + if (field->flags & VMS_MUST_EXIST) { + fprintf(stderr, "Output state validation failed: %s/%s\n", + vmsd->name, field->name); + assert(!(field->flags & VMS_MUST_EXIST)); + } + } + field++; + } + vmstate_subsection_save(f, vmsd, opaque); +} + +static const VMStateDescription * + vmstate_get_subsection(const VMStateSubsection *sub, char *idstr) +{ + while (sub && sub->needed) { + if (strcmp(idstr, sub->vmsd->name) == 0) { + return sub->vmsd; + } + sub++; + } + return NULL; +} + +static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, + void *opaque) +{ + while (qemu_peek_byte(f, 0) == QEMU_VM_SUBSECTION) { + char idstr[256]; + int ret; + uint8_t version_id, len, size; + const VMStateDescription *sub_vmsd; + + len = qemu_peek_byte(f, 1); + if (len < strlen(vmsd->name) + 1) { + /* subsection name has be be "section_name/a" */ + return 0; + } + size = qemu_peek_buffer(f, (uint8_t *)idstr, len, 2); + if (size != len) { + return 0; + } + idstr[size] = 0; + + if (strncmp(vmsd->name, idstr, strlen(vmsd->name)) != 0) { + /* it don't have a valid subsection name */ + return 0; + } + sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr); + if (sub_vmsd == NULL) { + return -ENOENT; + } + qemu_file_skip(f, 1); /* subsection */ + qemu_file_skip(f, 1); /* len */ + qemu_file_skip(f, len); /* idstr */ + version_id = qemu_get_be32(f); + + ret = vmstate_load_state(f, sub_vmsd, opaque, version_id); + if (ret) { + return ret; + } + } + return 0; +} + +static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, + void *opaque) +{ + const VMStateSubsection *sub = vmsd->subsections; + + while (sub && sub->needed) { + if (sub->needed(opaque)) { + const VMStateDescription *vmsd = sub->vmsd; + uint8_t len; + + qemu_put_byte(f, QEMU_VM_SUBSECTION); + len = strlen(vmsd->name); + qemu_put_byte(f, len); + qemu_put_buffer(f, (uint8_t *)vmsd->name, len); + qemu_put_be32(f, vmsd->version_id); + vmstate_save_state(f, vmsd, opaque); + } + sub++; + } +} + +/* bool */ + +static int get_bool(QEMUFile *f, void *pv, size_t size) +{ + bool *v = pv; + *v = qemu_get_byte(f); + return 0; +} + +static void put_bool(QEMUFile *f, void *pv, size_t size) +{ + bool *v = pv; + qemu_put_byte(f, *v); +} + +const VMStateInfo vmstate_info_bool = { + .name = "bool", + .get = get_bool, + .put = put_bool, +}; + +/* 8 bit int */ + +static int get_int8(QEMUFile *f, void *pv, size_t size) +{ + int8_t *v = pv; + qemu_get_s8s(f, v); + return 0; +} + +static void put_int8(QEMUFile *f, void *pv, size_t size) +{ + int8_t *v = pv; + qemu_put_s8s(f, v); +} + +const VMStateInfo vmstate_info_int8 = { + .name = "int8", + .get = get_int8, + .put = put_int8, +}; + +/* 16 bit int */ + +static int get_int16(QEMUFile *f, void *pv, size_t size) +{ + int16_t *v = pv; + qemu_get_sbe16s(f, v); + return 0; +} + +static void put_int16(QEMUFile *f, void *pv, size_t size) +{ + int16_t *v = pv; + qemu_put_sbe16s(f, v); +} + +const VMStateInfo vmstate_info_int16 = { + .name = "int16", + .get = get_int16, + .put = put_int16, +}; + +/* 32 bit int */ + +static int get_int32(QEMUFile *f, void *pv, size_t size) +{ + int32_t *v = pv; + qemu_get_sbe32s(f, v); + return 0; +} + +static void put_int32(QEMUFile *f, void *pv, size_t size) +{ + int32_t *v = pv; + qemu_put_sbe32s(f, v); +} + +const VMStateInfo vmstate_info_int32 = { + .name = "int32", + .get = get_int32, + .put = put_int32, +}; + +/* 32 bit int. See that the received value is the same than the one + in the field */ + +static int get_int32_equal(QEMUFile *f, void *pv, size_t size) +{ + int32_t *v = pv; + int32_t v2; + qemu_get_sbe32s(f, &v2); + + if (*v == v2) { + return 0; + } + return -EINVAL; +} + +const VMStateInfo vmstate_info_int32_equal = { + .name = "int32 equal", + .get = get_int32_equal, + .put = put_int32, +}; + +/* 32 bit int. Check that the received value is non-negative + * and less than or equal to the one in the field. + */ + +static int get_int32_le(QEMUFile *f, void *pv, size_t size) +{ + int32_t *cur = pv; + int32_t loaded; + qemu_get_sbe32s(f, &loaded); + + if (loaded >= 0 && loaded <= *cur) { + *cur = loaded; + return 0; + } + return -EINVAL; +} + +const VMStateInfo vmstate_info_int32_le = { + .name = "int32 le", + .get = get_int32_le, + .put = put_int32, +}; + +/* 64 bit int */ + +static int get_int64(QEMUFile *f, void *pv, size_t size) +{ + int64_t *v = pv; + qemu_get_sbe64s(f, v); + return 0; +} + +static void put_int64(QEMUFile *f, void *pv, size_t size) +{ + int64_t *v = pv; + qemu_put_sbe64s(f, v); +} + +const VMStateInfo vmstate_info_int64 = { + .name = "int64", + .get = get_int64, + .put = put_int64, +}; + +/* 8 bit unsigned int */ + +static int get_uint8(QEMUFile *f, void *pv, size_t size) +{ + uint8_t *v = pv; + qemu_get_8s(f, v); + return 0; +} + +static void put_uint8(QEMUFile *f, void *pv, size_t size) +{ + uint8_t *v = pv; + qemu_put_8s(f, v); +} + +const VMStateInfo vmstate_info_uint8 = { + .name = "uint8", + .get = get_uint8, + .put = put_uint8, +}; + +/* 16 bit unsigned int */ + +static int get_uint16(QEMUFile *f, void *pv, size_t size) +{ + uint16_t *v = pv; + qemu_get_be16s(f, v); + return 0; +} + +static void put_uint16(QEMUFile *f, void *pv, size_t size) +{ + uint16_t *v = pv; + qemu_put_be16s(f, v); +} + +const VMStateInfo vmstate_info_uint16 = { + .name = "uint16", + .get = get_uint16, + .put = put_uint16, +}; + +/* 32 bit unsigned int */ + +static int get_uint32(QEMUFile *f, void *pv, size_t size) +{ + uint32_t *v = pv; + qemu_get_be32s(f, v); + return 0; +} + +static void put_uint32(QEMUFile *f, void *pv, size_t size) +{ + uint32_t *v = pv; + qemu_put_be32s(f, v); +} + +const VMStateInfo vmstate_info_uint32 = { + .name = "uint32", + .get = get_uint32, + .put = put_uint32, +}; + +/* 32 bit uint. See that the received value is the same than the one + in the field */ + +static int get_uint32_equal(QEMUFile *f, void *pv, size_t size) +{ + uint32_t *v = pv; + uint32_t v2; + qemu_get_be32s(f, &v2); + + if (*v == v2) { + return 0; + } + return -EINVAL; +} + +const VMStateInfo vmstate_info_uint32_equal = { + .name = "uint32 equal", + .get = get_uint32_equal, + .put = put_uint32, +}; + +/* 64 bit unsigned int */ + +static int get_uint64(QEMUFile *f, void *pv, size_t size) +{ + uint64_t *v = pv; + qemu_get_be64s(f, v); + return 0; +} + +static void put_uint64(QEMUFile *f, void *pv, size_t size) +{ + uint64_t *v = pv; + qemu_put_be64s(f, v); +} + +const VMStateInfo vmstate_info_uint64 = { + .name = "uint64", + .get = get_uint64, + .put = put_uint64, +}; + +/* 64 bit unsigned int. See that the received value is the same than the one + in the field */ + +static int get_uint64_equal(QEMUFile *f, void *pv, size_t size) +{ + uint64_t *v = pv; + uint64_t v2; + qemu_get_be64s(f, &v2); + + if (*v == v2) { + return 0; + } + return -EINVAL; +} + +const VMStateInfo vmstate_info_uint64_equal = { + .name = "int64 equal", + .get = get_uint64_equal, + .put = put_uint64, +}; + +/* 8 bit int. See that the received value is the same than the one + in the field */ + +static int get_uint8_equal(QEMUFile *f, void *pv, size_t size) +{ + uint8_t *v = pv; + uint8_t v2; + qemu_get_8s(f, &v2); + + if (*v == v2) { + return 0; + } + return -EINVAL; +} + +const VMStateInfo vmstate_info_uint8_equal = { + .name = "uint8 equal", + .get = get_uint8_equal, + .put = put_uint8, +}; + +/* 16 bit unsigned int int. See that the received value is the same than the one + in the field */ + +static int get_uint16_equal(QEMUFile *f, void *pv, size_t size) +{ + uint16_t *v = pv; + uint16_t v2; + qemu_get_be16s(f, &v2); + + if (*v == v2) { + return 0; + } + return -EINVAL; +} + +const VMStateInfo vmstate_info_uint16_equal = { + .name = "uint16 equal", + .get = get_uint16_equal, + .put = put_uint16, +}; + +/* floating point */ + +static int get_float64(QEMUFile *f, void *pv, size_t size) +{ + float64 *v = pv; + + *v = make_float64(qemu_get_be64(f)); + return 0; +} + +static void put_float64(QEMUFile *f, void *pv, size_t size) +{ + uint64_t *v = pv; + + qemu_put_be64(f, float64_val(*v)); +} + +const VMStateInfo vmstate_info_float64 = { + .name = "float64", + .get = get_float64, + .put = put_float64, +}; + +/* uint8_t buffers */ + +static int get_buffer(QEMUFile *f, void *pv, size_t size) +{ + uint8_t *v = pv; + qemu_get_buffer(f, v, size); + return 0; +} + +static void put_buffer(QEMUFile *f, void *pv, size_t size) +{ + uint8_t *v = pv; + qemu_put_buffer(f, v, size); +} + +const VMStateInfo vmstate_info_buffer = { + .name = "buffer", + .get = get_buffer, + .put = put_buffer, +}; + +/* unused buffers: space that was used for some fields that are + not useful anymore */ + +static int get_unused_buffer(QEMUFile *f, void *pv, size_t size) +{ + uint8_t buf[1024]; + int block_len; + + while (size > 0) { + block_len = MIN(sizeof(buf), size); + size -= block_len; + qemu_get_buffer(f, buf, block_len); + } + return 0; +} + +static void put_unused_buffer(QEMUFile *f, void *pv, size_t size) +{ + static const uint8_t buf[1024]; + int block_len; + + while (size > 0) { + block_len = MIN(sizeof(buf), size); + size -= block_len; + qemu_put_buffer(f, buf, block_len); + } +} + +const VMStateInfo vmstate_info_unused_buffer = { + .name = "unused_buffer", + .get = get_unused_buffer, + .put = put_unused_buffer, +}; + +/* bitmaps (as defined by bitmap.h). Note that size here is the size + * of the bitmap in bits. The on-the-wire format of a bitmap is 64 + * bit words with the bits in big endian order. The in-memory format + * is an array of 'unsigned long', which may be either 32 or 64 bits. + */ +/* This is the number of 64 bit words sent over the wire */ +#define BITS_TO_U64S(nr) DIV_ROUND_UP(nr, 64) +static int get_bitmap(QEMUFile *f, void *pv, size_t size) +{ + unsigned long *bmp = pv; + int i, idx = 0; + for (i = 0; i < BITS_TO_U64S(size); i++) { + uint64_t w = qemu_get_be64(f); + bmp[idx++] = w; + if (sizeof(unsigned long) == 4 && idx < BITS_TO_LONGS(size)) { + bmp[idx++] = w >> 32; + } + } + return 0; +} + +static void put_bitmap(QEMUFile *f, void *pv, size_t size) +{ + unsigned long *bmp = pv; + int i, idx = 0; + for (i = 0; i < BITS_TO_U64S(size); i++) { + uint64_t w = bmp[idx++]; + if (sizeof(unsigned long) == 4 && idx < BITS_TO_LONGS(size)) { + w |= ((uint64_t)bmp[idx++]) << 32; + } + qemu_put_be64(f, w); + } +} + +const VMStateInfo vmstate_info_bitmap = { + .name = "bitmap", + .get = get_bitmap, + .put = put_bitmap, +}; diff --git a/migration/xbzrle.c b/migration/xbzrle.c new file mode 100644 index 0000000000..8e220bf25b --- /dev/null +++ b/migration/xbzrle.c @@ -0,0 +1,175 @@ +/* + * Xor Based Zero Run Length Encoding + * + * Copyright 2013 Red Hat, Inc. and/or its affiliates + * + * Authors: + * Orit Wasserman <owasserm@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ +#include "qemu-common.h" +#include "include/migration/migration.h" + +/* + page = zrun nzrun + | zrun nzrun page + + zrun = length + + nzrun = length byte... + + length = uleb128 encoded integer + */ +int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen, + uint8_t *dst, int dlen) +{ + uint32_t zrun_len = 0, nzrun_len = 0; + int d = 0, i = 0; + long res; + uint8_t *nzrun_start = NULL; + + g_assert(!(((uintptr_t)old_buf | (uintptr_t)new_buf | slen) % + sizeof(long))); + + while (i < slen) { + /* overflow */ + if (d + 2 > dlen) { + return -1; + } + + /* not aligned to sizeof(long) */ + res = (slen - i) % sizeof(long); + while (res && old_buf[i] == new_buf[i]) { + zrun_len++; + i++; + res--; + } + + /* word at a time for speed */ + if (!res) { + while (i < slen && + (*(long *)(old_buf + i)) == (*(long *)(new_buf + i))) { + i += sizeof(long); + zrun_len += sizeof(long); + } + + /* go over the rest */ + while (i < slen && old_buf[i] == new_buf[i]) { + zrun_len++; + i++; + } + } + + /* buffer unchanged */ + if (zrun_len == slen) { + return 0; + } + + /* skip last zero run */ + if (i == slen) { + return d; + } + + d += uleb128_encode_small(dst + d, zrun_len); + + zrun_len = 0; + nzrun_start = new_buf + i; + + /* overflow */ + if (d + 2 > dlen) { + return -1; + } + /* not aligned to sizeof(long) */ + res = (slen - i) % sizeof(long); + while (res && old_buf[i] != new_buf[i]) { + i++; + nzrun_len++; + res--; + } + + /* word at a time for speed, use of 32-bit long okay */ + if (!res) { + /* truncation to 32-bit long okay */ + unsigned long mask = (unsigned long)0x0101010101010101ULL; + while (i < slen) { + unsigned long xor; + xor = *(unsigned long *)(old_buf + i) + ^ *(unsigned long *)(new_buf + i); + if ((xor - mask) & ~xor & (mask << 7)) { + /* found the end of an nzrun within the current long */ + while (old_buf[i] != new_buf[i]) { + nzrun_len++; + i++; + } + break; + } else { + i += sizeof(long); + nzrun_len += sizeof(long); + } + } + } + + d += uleb128_encode_small(dst + d, nzrun_len); + /* overflow */ + if (d + nzrun_len > dlen) { + return -1; + } + memcpy(dst + d, nzrun_start, nzrun_len); + d += nzrun_len; + nzrun_len = 0; + } + + return d; +} + +int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen) +{ + int i = 0, d = 0; + int ret; + uint32_t count = 0; + + while (i < slen) { + + /* zrun */ + if ((slen - i) < 2) { + return -1; + } + + ret = uleb128_decode_small(src + i, &count); + if (ret < 0 || (i && !count)) { + return -1; + } + i += ret; + d += count; + + /* overflow */ + if (d > dlen) { + return -1; + } + + /* nzrun */ + if ((slen - i) < 2) { + return -1; + } + + ret = uleb128_decode_small(src + i, &count); + if (ret < 0 || !count) { + return -1; + } + i += ret; + + /* overflow */ + if (d + count > dlen || i + count > slen) { + return -1; + } + + memcpy(dst + d, src + i, count); + d += count; + i += count; + } + + return d; +} |