diff options
Diffstat (limited to 'hw/block/dataplane')
| -rw-r--r-- | hw/block/dataplane/xen-block.c | 1019 |
1 files changed, 1019 insertions, 0 deletions
diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c new file mode 100644 index 0000000000..9fae50534e --- /dev/null +++ b/hw/block/dataplane/xen-block.c @@ -0,0 +1,1019 @@ +/* + * xen paravirt block device backend + * + * (c) Gerd Hoffmann <kraxel@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; under version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, see <http://www.gnu.org/licenses/>. + * + * 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/osdep.h" +#include "qemu/units.h" +#include <sys/ioctl.h> +#include <sys/uio.h> + +#include "hw/hw.h" +#include "hw/xen/xen_backend.h" +#include "xen_blkif.h" +#include "sysemu/blockdev.h" +#include "sysemu/iothread.h" +#include "sysemu/block-backend.h" +#include "qapi/error.h" +#include "qapi/qmp/qdict.h" +#include "qapi/qmp/qstring.h" +#include "trace.h" + +/* ------------------------------------------------------------- */ + +#define BLOCK_SIZE 512 +#define IOCB_COUNT (BLKIF_MAX_SEGMENTS_PER_REQUEST + 2) + +struct ioreq { + blkif_request_t req; + int16_t status; + + /* parsed request */ + off_t start; + QEMUIOVector v; + void *buf; + size_t size; + int presync; + + /* aio status */ + int aio_inflight; + int aio_errors; + + struct XenBlkDev *blkdev; + QLIST_ENTRY(ioreq) list; + BlockAcctCookie acct; +}; + +#define MAX_RING_PAGE_ORDER 4 + +struct XenBlkDev { + struct XenLegacyDevice xendev; /* must be first */ + char *params; + char *mode; + char *type; + char *dev; + char *devtype; + bool directiosafe; + const char *fileproto; + const char *filename; + unsigned int ring_ref[1 << MAX_RING_PAGE_ORDER]; + unsigned int nr_ring_ref; + void *sring; + int64_t file_blk; + int64_t file_size; + int protocol; + blkif_back_rings_t rings; + int more_work; + + /* request lists */ + QLIST_HEAD(inflight_head, ioreq) inflight; + QLIST_HEAD(finished_head, ioreq) finished; + QLIST_HEAD(freelist_head, ioreq) freelist; + int requests_total; + int requests_inflight; + int requests_finished; + unsigned int max_requests; + + gboolean feature_discard; + + /* qemu block driver */ + DriveInfo *dinfo; + BlockBackend *blk; + QEMUBH *bh; + + IOThread *iothread; + AioContext *ctx; +}; + +/* ------------------------------------------------------------- */ + +static void ioreq_reset(struct ioreq *ioreq) +{ + memset(&ioreq->req, 0, sizeof(ioreq->req)); + ioreq->status = 0; + ioreq->start = 0; + ioreq->buf = NULL; + ioreq->size = 0; + ioreq->presync = 0; + + ioreq->aio_inflight = 0; + ioreq->aio_errors = 0; + + ioreq->blkdev = NULL; + memset(&ioreq->list, 0, sizeof(ioreq->list)); + memset(&ioreq->acct, 0, sizeof(ioreq->acct)); + + qemu_iovec_reset(&ioreq->v); +} + +static struct ioreq *ioreq_start(struct XenBlkDev *blkdev) +{ + struct ioreq *ioreq = NULL; + + if (QLIST_EMPTY(&blkdev->freelist)) { + if (blkdev->requests_total >= blkdev->max_requests) { + goto out; + } + /* allocate new struct */ + ioreq = g_malloc0(sizeof(*ioreq)); + ioreq->blkdev = blkdev; + blkdev->requests_total++; + qemu_iovec_init(&ioreq->v, 1); + } else { + /* get one from freelist */ + ioreq = QLIST_FIRST(&blkdev->freelist); + QLIST_REMOVE(ioreq, list); + } + QLIST_INSERT_HEAD(&blkdev->inflight, ioreq, list); + blkdev->requests_inflight++; + +out: + return ioreq; +} + +static void ioreq_finish(struct ioreq *ioreq) +{ + struct XenBlkDev *blkdev = ioreq->blkdev; + + QLIST_REMOVE(ioreq, list); + QLIST_INSERT_HEAD(&blkdev->finished, ioreq, list); + blkdev->requests_inflight--; + blkdev->requests_finished++; +} + +static void ioreq_release(struct ioreq *ioreq, bool finish) +{ + struct XenBlkDev *blkdev = ioreq->blkdev; + + QLIST_REMOVE(ioreq, list); + ioreq_reset(ioreq); + ioreq->blkdev = blkdev; + QLIST_INSERT_HEAD(&blkdev->freelist, ioreq, list); + if (finish) { + blkdev->requests_finished--; + } else { + blkdev->requests_inflight--; + } +} + +/* + * translate request into iovec + start offset + * do sanity checks along the way + */ +static int ioreq_parse(struct ioreq *ioreq) +{ + struct XenBlkDev *blkdev = ioreq->blkdev; + struct XenLegacyDevice *xendev = &blkdev->xendev; + size_t len; + int i; + + xen_pv_printf( + xendev, 3, + "op %d, nr %d, handle %d, id %" PRId64 ", sector %" PRId64 "\n", + ioreq->req.operation, ioreq->req.nr_segments, + ioreq->req.handle, ioreq->req.id, ioreq->req.sector_number); + switch (ioreq->req.operation) { + case BLKIF_OP_READ: + break; + case BLKIF_OP_FLUSH_DISKCACHE: + ioreq->presync = 1; + if (!ioreq->req.nr_segments) { + return 0; + } + /* fall through */ + case BLKIF_OP_WRITE: + break; + case BLKIF_OP_DISCARD: + return 0; + default: + xen_pv_printf(xendev, 0, "error: unknown operation (%d)\n", + ioreq->req.operation); + goto err; + }; + + if (ioreq->req.operation != BLKIF_OP_READ && blkdev->mode[0] != 'w') { + xen_pv_printf(xendev, 0, "error: write req for ro device\n"); + goto err; + } + + ioreq->start = ioreq->req.sector_number * blkdev->file_blk; + for (i = 0; i < ioreq->req.nr_segments; i++) { + if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) { + xen_pv_printf(xendev, 0, "error: nr_segments too big\n"); + goto err; + } + if (ioreq->req.seg[i].first_sect > ioreq->req.seg[i].last_sect) { + xen_pv_printf(xendev, 0, "error: first > last sector\n"); + goto err; + } + if (ioreq->req.seg[i].last_sect * BLOCK_SIZE >= XC_PAGE_SIZE) { + xen_pv_printf(xendev, 0, "error: page crossing\n"); + goto err; + } + + len = (ioreq->req.seg[i].last_sect - + ioreq->req.seg[i].first_sect + 1) * blkdev->file_blk; + ioreq->size += len; + } + if (ioreq->start + ioreq->size > blkdev->file_size) { + xen_pv_printf(xendev, 0, "error: access beyond end of file\n"); + goto err; + } + return 0; + +err: + ioreq->status = BLKIF_RSP_ERROR; + return -1; +} + +static int ioreq_grant_copy(struct ioreq *ioreq) +{ + struct XenBlkDev *blkdev = ioreq->blkdev; + struct XenLegacyDevice *xendev = &blkdev->xendev; + XenGrantCopySegment segs[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + int i, count, rc; + int64_t file_blk = blkdev->file_blk; + bool to_domain = (ioreq->req.operation == BLKIF_OP_READ); + void *virt = ioreq->buf; + + if (ioreq->req.nr_segments == 0) { + return 0; + } + + count = ioreq->req.nr_segments; + + for (i = 0; i < count; i++) { + if (to_domain) { + segs[i].dest.foreign.ref = ioreq->req.seg[i].gref; + segs[i].dest.foreign.offset = ioreq->req.seg[i].first_sect * + file_blk; + segs[i].source.virt = virt; + } else { + segs[i].source.foreign.ref = ioreq->req.seg[i].gref; + segs[i].source.foreign.offset = ioreq->req.seg[i].first_sect * + file_blk; + segs[i].dest.virt = virt; + } + segs[i].len = (ioreq->req.seg[i].last_sect + - ioreq->req.seg[i].first_sect + 1) * file_blk; + virt += segs[i].len; + } + + rc = xen_be_copy_grant_refs(xendev, to_domain, segs, count); + + if (rc) { + xen_pv_printf(xendev, 0, + "failed to copy data %d\n", rc); + ioreq->aio_errors++; + return -1; + } + + return rc; +} + +static int ioreq_runio_qemu_aio(struct ioreq *ioreq); + +static void qemu_aio_complete(void *opaque, int ret) +{ + struct ioreq *ioreq = opaque; + struct XenBlkDev *blkdev = ioreq->blkdev; + struct XenLegacyDevice *xendev = &blkdev->xendev; + + aio_context_acquire(blkdev->ctx); + + if (ret != 0) { + xen_pv_printf(xendev, 0, "%s I/O error\n", + ioreq->req.operation == BLKIF_OP_READ ? "read" : "write"); + ioreq->aio_errors++; + } + + ioreq->aio_inflight--; + if (ioreq->presync) { + ioreq->presync = 0; + ioreq_runio_qemu_aio(ioreq); + goto done; + } + if (ioreq->aio_inflight > 0) { + goto done; + } + + switch (ioreq->req.operation) { + case BLKIF_OP_READ: + /* in case of failure ioreq->aio_errors is increased */ + if (ret == 0) { + ioreq_grant_copy(ioreq); + } + qemu_vfree(ioreq->buf); + break; + case BLKIF_OP_WRITE: + case BLKIF_OP_FLUSH_DISKCACHE: + if (!ioreq->req.nr_segments) { + break; + } + qemu_vfree(ioreq->buf); + break; + default: + break; + } + + ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY; + ioreq_finish(ioreq); + + switch (ioreq->req.operation) { + case BLKIF_OP_WRITE: + case BLKIF_OP_FLUSH_DISKCACHE: + if (!ioreq->req.nr_segments) { + break; + } + case BLKIF_OP_READ: + if (ioreq->status == BLKIF_RSP_OKAY) { + block_acct_done(blk_get_stats(blkdev->blk), &ioreq->acct); + } else { + block_acct_failed(blk_get_stats(blkdev->blk), &ioreq->acct); + } + break; + case BLKIF_OP_DISCARD: + default: + break; + } + qemu_bh_schedule(blkdev->bh); + +done: + aio_context_release(blkdev->ctx); +} + +static bool blk_split_discard(struct ioreq *ioreq, blkif_sector_t sector_number, + uint64_t nr_sectors) +{ + struct XenBlkDev *blkdev = ioreq->blkdev; + int64_t byte_offset; + int byte_chunk; + uint64_t byte_remaining, limit; + uint64_t sec_start = sector_number; + uint64_t sec_count = nr_sectors; + + /* Wrap around, or overflowing byte limit? */ + if (sec_start + sec_count < sec_count || + sec_start + sec_count > INT64_MAX >> BDRV_SECTOR_BITS) { + return false; + } + + limit = BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS; + byte_offset = sec_start << BDRV_SECTOR_BITS; + byte_remaining = sec_count << BDRV_SECTOR_BITS; + + do { + byte_chunk = byte_remaining > limit ? limit : byte_remaining; + ioreq->aio_inflight++; + blk_aio_pdiscard(blkdev->blk, byte_offset, byte_chunk, + qemu_aio_complete, ioreq); + byte_remaining -= byte_chunk; + byte_offset += byte_chunk; + } while (byte_remaining > 0); + + return true; +} + +static int ioreq_runio_qemu_aio(struct ioreq *ioreq) +{ + struct XenBlkDev *blkdev = ioreq->blkdev; + + ioreq->buf = qemu_memalign(XC_PAGE_SIZE, ioreq->size); + if (ioreq->req.nr_segments && + (ioreq->req.operation == BLKIF_OP_WRITE || + ioreq->req.operation == BLKIF_OP_FLUSH_DISKCACHE) && + ioreq_grant_copy(ioreq)) { + qemu_vfree(ioreq->buf); + goto err; + } + + ioreq->aio_inflight++; + if (ioreq->presync) { + blk_aio_flush(ioreq->blkdev->blk, qemu_aio_complete, ioreq); + return 0; + } + + switch (ioreq->req.operation) { + case BLKIF_OP_READ: + qemu_iovec_add(&ioreq->v, ioreq->buf, ioreq->size); + block_acct_start(blk_get_stats(blkdev->blk), &ioreq->acct, + ioreq->v.size, BLOCK_ACCT_READ); + ioreq->aio_inflight++; + blk_aio_preadv(blkdev->blk, ioreq->start, &ioreq->v, 0, + qemu_aio_complete, ioreq); + break; + case BLKIF_OP_WRITE: + case BLKIF_OP_FLUSH_DISKCACHE: + if (!ioreq->req.nr_segments) { + break; + } + + qemu_iovec_add(&ioreq->v, ioreq->buf, ioreq->size); + block_acct_start(blk_get_stats(blkdev->blk), &ioreq->acct, + ioreq->v.size, + ioreq->req.operation == BLKIF_OP_WRITE ? + BLOCK_ACCT_WRITE : BLOCK_ACCT_FLUSH); + ioreq->aio_inflight++; + blk_aio_pwritev(blkdev->blk, ioreq->start, &ioreq->v, 0, + qemu_aio_complete, ioreq); + break; + case BLKIF_OP_DISCARD: + { + struct blkif_request_discard *req = (void *)&ioreq->req; + if (!blk_split_discard(ioreq, req->sector_number, req->nr_sectors)) { + goto err; + } + break; + } + default: + /* unknown operation (shouldn't happen -- parse catches this) */ + goto err; + } + + qemu_aio_complete(ioreq, 0); + + return 0; + +err: + ioreq_finish(ioreq); + ioreq->status = BLKIF_RSP_ERROR; + return -1; +} + +static int blk_send_response_one(struct ioreq *ioreq) +{ + struct XenBlkDev *blkdev = ioreq->blkdev; + int send_notify = 0; + int have_requests = 0; + blkif_response_t *resp; + + /* Place on the response ring for the relevant domain. */ + switch (blkdev->protocol) { + case BLKIF_PROTOCOL_NATIVE: + resp = (blkif_response_t *)RING_GET_RESPONSE( + &blkdev->rings.native, + blkdev->rings.native.rsp_prod_pvt); + break; + case BLKIF_PROTOCOL_X86_32: + resp = (blkif_response_t *)RING_GET_RESPONSE( + &blkdev->rings.x86_32_part, + blkdev->rings.x86_32_part.rsp_prod_pvt); + break; + case BLKIF_PROTOCOL_X86_64: + resp = (blkif_response_t *)RING_GET_RESPONSE( + &blkdev->rings.x86_64_part, + blkdev->rings.x86_64_part.rsp_prod_pvt); + break; + default: + return 0; + } + + resp->id = ioreq->req.id; + resp->operation = ioreq->req.operation; + resp->status = ioreq->status; + + blkdev->rings.common.rsp_prod_pvt++; + + RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blkdev->rings.common, send_notify); + if (blkdev->rings.common.rsp_prod_pvt == blkdev->rings.common.req_cons) { + /* + * Tail check for pending requests. Allows frontend to avoid + * notifications if requests are already in flight (lower + * overheads and promotes batching). + */ + RING_FINAL_CHECK_FOR_REQUESTS(&blkdev->rings.common, have_requests); + } else if (RING_HAS_UNCONSUMED_REQUESTS(&blkdev->rings.common)) { + have_requests = 1; + } + + if (have_requests) { + blkdev->more_work++; + } + return send_notify; +} + +/* walk finished list, send outstanding responses, free requests */ +static void blk_send_response_all(struct XenBlkDev *blkdev) +{ + struct ioreq *ioreq; + int send_notify = 0; + + while (!QLIST_EMPTY(&blkdev->finished)) { + ioreq = QLIST_FIRST(&blkdev->finished); + send_notify += blk_send_response_one(ioreq); + ioreq_release(ioreq, true); + } + if (send_notify) { + xen_pv_send_notify(&blkdev->xendev); + } +} + +static int blk_get_request(struct XenBlkDev *blkdev, struct ioreq *ioreq, + RING_IDX rc) +{ + switch (blkdev->protocol) { + case BLKIF_PROTOCOL_NATIVE: + memcpy(&ioreq->req, RING_GET_REQUEST(&blkdev->rings.native, rc), + sizeof(ioreq->req)); + break; + case BLKIF_PROTOCOL_X86_32: + blkif_get_x86_32_req(&ioreq->req, + RING_GET_REQUEST(&blkdev->rings.x86_32_part, rc)); + break; + case BLKIF_PROTOCOL_X86_64: + blkif_get_x86_64_req(&ioreq->req, + RING_GET_REQUEST(&blkdev->rings.x86_64_part, rc)); + break; + } + /* Prevent the compiler from accessing the on-ring fields instead. */ + barrier(); + return 0; +} + +static void blk_handle_requests(struct XenBlkDev *blkdev) +{ + RING_IDX rc, rp; + struct ioreq *ioreq; + + blkdev->more_work = 0; + + rc = blkdev->rings.common.req_cons; + rp = blkdev->rings.common.sring->req_prod; + xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ + + blk_send_response_all(blkdev); + while (rc != rp) { + /* pull request from ring */ + if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc)) { + break; + } + ioreq = ioreq_start(blkdev); + if (ioreq == NULL) { + blkdev->more_work++; + break; + } + blk_get_request(blkdev, ioreq, rc); + blkdev->rings.common.req_cons = ++rc; + + /* parse them */ + if (ioreq_parse(ioreq) != 0) { + + switch (ioreq->req.operation) { + case BLKIF_OP_READ: + block_acct_invalid(blk_get_stats(blkdev->blk), + BLOCK_ACCT_READ); + break; + case BLKIF_OP_WRITE: + block_acct_invalid(blk_get_stats(blkdev->blk), + BLOCK_ACCT_WRITE); + break; + case BLKIF_OP_FLUSH_DISKCACHE: + block_acct_invalid(blk_get_stats(blkdev->blk), + BLOCK_ACCT_FLUSH); + default: + break; + }; + + if (blk_send_response_one(ioreq)) { + xen_pv_send_notify(&blkdev->xendev); + } + ioreq_release(ioreq, false); + continue; + } + + ioreq_runio_qemu_aio(ioreq); + } + + if (blkdev->more_work && blkdev->requests_inflight < blkdev->max_requests) { + qemu_bh_schedule(blkdev->bh); + } +} + +/* ------------------------------------------------------------- */ + +static void blk_bh(void *opaque) +{ + struct XenBlkDev *blkdev = opaque; + + aio_context_acquire(blkdev->ctx); + blk_handle_requests(blkdev); + aio_context_release(blkdev->ctx); +} + +static void blk_alloc(struct XenLegacyDevice *xendev) +{ + struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); + Error *err = NULL; + + trace_xen_disk_alloc(xendev->name); + + QLIST_INIT(&blkdev->inflight); + QLIST_INIT(&blkdev->finished); + QLIST_INIT(&blkdev->freelist); + + blkdev->iothread = iothread_create(xendev->name, &err); + assert(!err); + + blkdev->ctx = iothread_get_aio_context(blkdev->iothread); + blkdev->bh = aio_bh_new(blkdev->ctx, blk_bh, blkdev); +} + +static void blk_parse_discard(struct XenBlkDev *blkdev) +{ + struct XenLegacyDevice *xendev = &blkdev->xendev; + int enable; + + blkdev->feature_discard = true; + + if (xenstore_read_be_int(xendev, "discard-enable", &enable) == 0) { + blkdev->feature_discard = !!enable; + } + + if (blkdev->feature_discard) { + xenstore_write_be_int(xendev, "feature-discard", 1); + } +} + +static int blk_init(struct XenLegacyDevice *xendev) +{ + struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); + int info = 0; + char *directiosafe = NULL; + + trace_xen_disk_init(xendev->name); + + /* read xenstore entries */ + if (blkdev->params == NULL) { + char *h = NULL; + blkdev->params = xenstore_read_be_str(xendev, "params"); + if (blkdev->params != NULL) { + h = strchr(blkdev->params, ':'); + } + if (h != NULL) { + blkdev->fileproto = blkdev->params; + blkdev->filename = h + 1; + *h = 0; + } else { + blkdev->fileproto = "<unset>"; + blkdev->filename = blkdev->params; + } + } + if (!strcmp("aio", blkdev->fileproto)) { + blkdev->fileproto = "raw"; + } + if (!strcmp("vhd", blkdev->fileproto)) { + blkdev->fileproto = "vpc"; + } + if (blkdev->mode == NULL) { + blkdev->mode = xenstore_read_be_str(xendev, "mode"); + } + if (blkdev->type == NULL) { + blkdev->type = xenstore_read_be_str(xendev, "type"); + } + if (blkdev->dev == NULL) { + blkdev->dev = xenstore_read_be_str(xendev, "dev"); + } + if (blkdev->devtype == NULL) { + blkdev->devtype = xenstore_read_be_str(xendev, "device-type"); + } + directiosafe = xenstore_read_be_str(xendev, "direct-io-safe"); + blkdev->directiosafe = (directiosafe && atoi(directiosafe)); + + /* do we have all we need? */ + if (blkdev->params == NULL || + blkdev->mode == NULL || + blkdev->type == NULL || + blkdev->dev == NULL) { + goto out_error; + } + + /* read-only ? */ + if (strcmp(blkdev->mode, "w")) { + info |= VDISK_READONLY; + } + + /* cdrom ? */ + if (blkdev->devtype && !strcmp(blkdev->devtype, "cdrom")) { + info |= VDISK_CDROM; + } + + blkdev->file_blk = BLOCK_SIZE; + + /* fill info + * blk_connect supplies sector-size and sectors + */ + xenstore_write_be_int(xendev, "feature-flush-cache", 1); + xenstore_write_be_int(xendev, "info", info); + + xenstore_write_be_int(xendev, "max-ring-page-order", + MAX_RING_PAGE_ORDER); + + blk_parse_discard(blkdev); + + g_free(directiosafe); + return 0; + +out_error: + g_free(blkdev->params); + blkdev->params = NULL; + g_free(blkdev->mode); + blkdev->mode = NULL; + g_free(blkdev->type); + blkdev->type = NULL; + g_free(blkdev->dev); + blkdev->dev = NULL; + g_free(blkdev->devtype); + blkdev->devtype = NULL; + g_free(directiosafe); + blkdev->directiosafe = false; + return -1; +} + +static int blk_connect(struct XenLegacyDevice *xendev) +{ + struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); + int index, qflags; + bool readonly = true; + bool writethrough = true; + int order, ring_ref; + unsigned int ring_size, max_grants; + unsigned int i; + + trace_xen_disk_connect(xendev->name); + + /* read-only ? */ + if (blkdev->directiosafe) { + qflags = BDRV_O_NOCACHE | BDRV_O_NATIVE_AIO; + } else { + qflags = 0; + writethrough = false; + } + if (strcmp(blkdev->mode, "w") == 0) { + qflags |= BDRV_O_RDWR; + readonly = false; + } + if (blkdev->feature_discard) { + qflags |= BDRV_O_UNMAP; + } + + /* init qemu block driver */ + index = (xendev->dev - 202 * 256) / 16; + blkdev->dinfo = drive_get(IF_XEN, 0, index); + if (!blkdev->dinfo) { + Error *local_err = NULL; + QDict *options = NULL; + + if (strcmp(blkdev->fileproto, "<unset>")) { + options = qdict_new(); + qdict_put_str(options, "driver", blkdev->fileproto); + } + + /* setup via xenbus -> create new block driver instance */ + xen_pv_printf(xendev, 2, "create new bdrv (xenbus setup)\n"); + blkdev->blk = blk_new_open(blkdev->filename, NULL, options, + qflags, &local_err); + if (!blkdev->blk) { + xen_pv_printf(xendev, 0, "error: %s\n", + error_get_pretty(local_err)); + error_free(local_err); + return -1; + } + blk_set_enable_write_cache(blkdev->blk, !writethrough); + } else { + /* setup via qemu cmdline -> already setup for us */ + xen_pv_printf(xendev, 2, + "get configured bdrv (cmdline setup)\n"); + blkdev->blk = blk_by_legacy_dinfo(blkdev->dinfo); + if (blk_is_read_only(blkdev->blk) && !readonly) { + xen_pv_printf(xendev, 0, "Unexpected read-only drive"); + blkdev->blk = NULL; + return -1; + } + /* blkdev->blk is not create by us, we get a reference + * so we can blk_unref() unconditionally */ + blk_ref(blkdev->blk); + } + blk_attach_dev_legacy(blkdev->blk, blkdev); + blkdev->file_size = blk_getlength(blkdev->blk); + if (blkdev->file_size < 0) { + BlockDriverState *bs = blk_bs(blkdev->blk); + const char *drv_name = bs ? bdrv_get_format_name(bs) : NULL; + xen_pv_printf(xendev, 1, "blk_getlength: %d (%s) | drv %s\n", + (int)blkdev->file_size, strerror(-blkdev->file_size), + drv_name ?: "-"); + blkdev->file_size = 0; + } + + xen_pv_printf(xendev, 1, "type \"%s\", fileproto \"%s\", filename \"%s\"," + " size %" PRId64 " (%" PRId64 " MB)\n", + blkdev->type, blkdev->fileproto, blkdev->filename, + blkdev->file_size, blkdev->file_size / MiB); + + /* Fill in number of sector size and number of sectors */ + xenstore_write_be_int(xendev, "sector-size", blkdev->file_blk); + xenstore_write_be_int64(xendev, "sectors", + blkdev->file_size / blkdev->file_blk); + + if (xenstore_read_fe_int(xendev, "ring-page-order", + &order) == -1) { + blkdev->nr_ring_ref = 1; + + if (xenstore_read_fe_int(xendev, "ring-ref", + &ring_ref) == -1) { + return -1; + } + blkdev->ring_ref[0] = ring_ref; + + } else if (order >= 0 && order <= MAX_RING_PAGE_ORDER) { + blkdev->nr_ring_ref = 1 << order; + + for (i = 0; i < blkdev->nr_ring_ref; i++) { + char *key; + + key = g_strdup_printf("ring-ref%u", i); + if (!key) { + return -1; + } + + if (xenstore_read_fe_int(xendev, key, + &ring_ref) == -1) { + g_free(key); + return -1; + } + blkdev->ring_ref[i] = ring_ref; + + g_free(key); + } + } else { + xen_pv_printf(xendev, 0, "invalid ring-page-order: %d\n", + order); + return -1; + } + + if (xenstore_read_fe_int(xendev, "event-channel", + &xendev->remote_port) == -1) { + return -1; + } + + if (!xendev->protocol) { + blkdev->protocol = BLKIF_PROTOCOL_NATIVE; + } else if (strcmp(xendev->protocol, XEN_IO_PROTO_ABI_NATIVE) == 0) { + blkdev->protocol = BLKIF_PROTOCOL_NATIVE; + } else if (strcmp(xendev->protocol, XEN_IO_PROTO_ABI_X86_32) == 0) { + blkdev->protocol = BLKIF_PROTOCOL_X86_32; + } else if (strcmp(xendev->protocol, XEN_IO_PROTO_ABI_X86_64) == 0) { + blkdev->protocol = BLKIF_PROTOCOL_X86_64; + } else { + blkdev->protocol = BLKIF_PROTOCOL_NATIVE; + } + + ring_size = XC_PAGE_SIZE * blkdev->nr_ring_ref; + switch (blkdev->protocol) { + case BLKIF_PROTOCOL_NATIVE: + { + blkdev->max_requests = __CONST_RING_SIZE(blkif, ring_size); + break; + } + case BLKIF_PROTOCOL_X86_32: + { + blkdev->max_requests = __CONST_RING_SIZE(blkif_x86_32, ring_size); + break; + } + case BLKIF_PROTOCOL_X86_64: + { + blkdev->max_requests = __CONST_RING_SIZE(blkif_x86_64, ring_size); + break; + } + default: + return -1; + } + + /* Add on the number needed for the ring pages */ + max_grants = blkdev->nr_ring_ref; + + xen_be_set_max_grant_refs(xendev, max_grants); + blkdev->sring = xen_be_map_grant_refs(xendev, blkdev->ring_ref, + blkdev->nr_ring_ref, + PROT_READ | PROT_WRITE); + if (!blkdev->sring) { + return -1; + } + + switch (blkdev->protocol) { + case BLKIF_PROTOCOL_NATIVE: + { + blkif_sring_t *sring_native = blkdev->sring; + BACK_RING_INIT(&blkdev->rings.native, sring_native, ring_size); + break; + } + case BLKIF_PROTOCOL_X86_32: + { + blkif_x86_32_sring_t *sring_x86_32 = blkdev->sring; + + BACK_RING_INIT(&blkdev->rings.x86_32_part, sring_x86_32, ring_size); + break; + } + case BLKIF_PROTOCOL_X86_64: + { + blkif_x86_64_sring_t *sring_x86_64 = blkdev->sring; + + BACK_RING_INIT(&blkdev->rings.x86_64_part, sring_x86_64, ring_size); + break; + } + } + + blk_set_aio_context(blkdev->blk, blkdev->ctx); + + xen_be_bind_evtchn(xendev); + + xen_pv_printf(xendev, 1, "ok: proto %s, nr-ring-ref %u, " + "remote port %d, local port %d\n", + xendev->protocol, blkdev->nr_ring_ref, + xendev->remote_port, xendev->local_port); + return 0; +} + +static void blk_disconnect(struct XenLegacyDevice *xendev) +{ + struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); + + trace_xen_disk_disconnect(xendev->name); + + aio_context_acquire(blkdev->ctx); + + if (blkdev->blk) { + blk_set_aio_context(blkdev->blk, qemu_get_aio_context()); + blk_detach_dev(blkdev->blk, blkdev); + blk_unref(blkdev->blk); + blkdev->blk = NULL; + } + xen_pv_unbind_evtchn(xendev); + + aio_context_release(blkdev->ctx); + + if (blkdev->sring) { + xen_be_unmap_grant_refs(xendev, blkdev->sring, + blkdev->nr_ring_ref); + blkdev->sring = NULL; + } +} + +static int blk_free(struct XenLegacyDevice *xendev) +{ + struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); + struct ioreq *ioreq; + + trace_xen_disk_free(xendev->name); + + blk_disconnect(xendev); + + while (!QLIST_EMPTY(&blkdev->freelist)) { + ioreq = QLIST_FIRST(&blkdev->freelist); + QLIST_REMOVE(ioreq, list); + qemu_iovec_destroy(&ioreq->v); + g_free(ioreq); + } + + g_free(blkdev->params); + g_free(blkdev->mode); + g_free(blkdev->type); + g_free(blkdev->dev); + g_free(blkdev->devtype); + qemu_bh_delete(blkdev->bh); + iothread_destroy(blkdev->iothread); + return 0; +} + +static void blk_event(struct XenLegacyDevice *xendev) +{ + struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); + + qemu_bh_schedule(blkdev->bh); +} + +struct XenDevOps xen_blkdev_ops = { + .flags = DEVOPS_FLAG_NEED_GNTDEV, + .size = sizeof(struct XenBlkDev), + .alloc = blk_alloc, + .init = blk_init, + .initialise = blk_connect, + .disconnect = blk_disconnect, + .event = blk_event, + .free = blk_free, +}; |