diff options
| -rw-r--r-- | exec.c | 54 | ||||
| -rw-r--r-- | include/exec/cpu-common.h | 1 | ||||
| -rw-r--r-- | include/migration/postcopy-ram.h | 7 | ||||
| -rw-r--r-- | migration/postcopy-ram.c | 30 | ||||
| -rw-r--r-- | migration/ram.c | 24 | ||||
| -rw-r--r-- | migration/trace-events | 2 |
6 files changed, 60 insertions, 58 deletions
@@ -45,6 +45,7 @@ #include "exec/address-spaces.h" #include "sysemu/xen-mapcache.h" #include "trace-root.h" + #endif #include "exec/cpu-all.h" #include "qemu/rcu_queue.h" @@ -3294,4 +3295,57 @@ int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque) rcu_read_unlock(); return ret; } + +/* + * Unmap pages of memory from start to start+length such that + * they a) read as 0, b) Trigger whatever fault mechanism + * the OS provides for postcopy. + * The pages must be unmapped by the end of the function. + * Returns: 0 on success, none-0 on failure + * + */ +int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length) +{ + int ret = -1; + + uint8_t *host_startaddr = rb->host + start; + + if ((uintptr_t)host_startaddr & (rb->page_size - 1)) { + error_report("ram_block_discard_range: Unaligned start address: %p", + host_startaddr); + goto err; + } + + if ((start + length) <= rb->used_length) { + uint8_t *host_endaddr = host_startaddr + length; + if ((uintptr_t)host_endaddr & (rb->page_size - 1)) { + error_report("ram_block_discard_range: Unaligned end address: %p", + host_endaddr); + goto err; + } + + errno = ENOTSUP; /* If we are missing MADVISE etc */ + +#if defined(CONFIG_MADVISE) + /* Note: We need the madvise MADV_DONTNEED behaviour of definitely + * freeing the page. + */ + ret = madvise(host_startaddr, length, MADV_DONTNEED); +#endif + if (ret) { + ret = -errno; + error_report("ram_block_discard_range: Failed to discard range " + "%s:%" PRIx64 " +%zx (%d)", + rb->idstr, start, length, ret); + } + } else { + error_report("ram_block_discard_range: Overrun block '%s' (%" PRIu64 + "/%zx/" RAM_ADDR_FMT")", + rb->idstr, start, length, rb->used_length); + } + +err: + return ret; +} + #endif diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h index bd15853e51..1350c2e441 100644 --- a/include/exec/cpu-common.h +++ b/include/exec/cpu-common.h @@ -105,6 +105,7 @@ typedef int (RAMBlockIterFunc)(const char *block_name, void *host_addr, ram_addr_t offset, ram_addr_t length, void *opaque); int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque); +int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length); #endif diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h index b6a7491f2d..43bbbcadc5 100644 --- a/include/migration/postcopy-ram.h +++ b/include/migration/postcopy-ram.h @@ -35,13 +35,6 @@ int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages); int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis); /* - * Discard the contents of 'length' bytes from 'start' - * We can assume that if we've been called postcopy_ram_hosttest returned true - */ -int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start, - size_t length); - -/* * Userfault requires us to mark RAM as NOHUGEPAGE prior to discard * however leaving it until after precopy means that most of the precopy * data is still THPd diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index a40dddbaf6..1e3d22fddc 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -200,27 +200,6 @@ out: return ret; } -/** - * postcopy_ram_discard_range: Discard a range of memory. - * We can assume that if we've been called postcopy_ram_hosttest returned true. - * - * @mis: Current incoming migration state. - * @start, @length: range of memory to discard. - * - * returns: 0 on success. - */ -int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start, - size_t length) -{ - trace_postcopy_ram_discard_range(start, length); - if (madvise(start, length, MADV_DONTNEED)) { - error_report("%s MADV_DONTNEED: %s", __func__, strerror(errno)); - return -1; - } - - return 0; -} - /* * Setup an area of RAM so that it *can* be used for postcopy later; this * must be done right at the start prior to pre-copy. @@ -239,7 +218,7 @@ static int init_range(const char *block_name, void *host_addr, * - we're going to get the copy from the source anyway. * (Precopy will just overwrite this data, so doesn't need the discard) */ - if (postcopy_ram_discard_range(mis, host_addr, length)) { + if (ram_discard_range(mis, block_name, 0, length)) { return -1; } @@ -658,13 +637,6 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) return -1; } -int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start, - size_t length) -{ - assert(0); - return -1; -} - int postcopy_ram_prepare_discard(MigrationIncomingState *mis) { assert(0); diff --git a/migration/ram.c b/migration/ram.c index 7c5cdf98c9..44fe960eb5 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1890,6 +1890,8 @@ int ram_discard_range(MigrationIncomingState *mis, { int ret = -1; + trace_ram_discard_range(block_name, start, length); + rcu_read_lock(); RAMBlock *rb = qemu_ram_block_by_name(block_name); @@ -1899,27 +1901,7 @@ int ram_discard_range(MigrationIncomingState *mis, goto err; } - uint8_t *host_startaddr = rb->host + start; - - if ((uintptr_t)host_startaddr & (qemu_host_page_size - 1)) { - error_report("ram_discard_range: Unaligned start address: %p", - host_startaddr); - goto err; - } - - if ((start + length) <= rb->used_length) { - uint8_t *host_endaddr = host_startaddr + length; - if ((uintptr_t)host_endaddr & (qemu_host_page_size - 1)) { - error_report("ram_discard_range: Unaligned end address: %p", - host_endaddr); - goto err; - } - ret = postcopy_ram_discard_range(mis, host_startaddr, length); - } else { - error_report("ram_discard_range: Overrun block '%s' (%" PRIu64 - "/%zx/" RAM_ADDR_FMT")", - block_name, start, length, rb->used_length); - } + ret = ram_block_discard_range(rb, start, length); err: rcu_read_unlock(); diff --git a/migration/trace-events b/migration/trace-events index fa660e35b1..7372ce2a51 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -68,6 +68,7 @@ get_queued_page_not_dirty(const char *block_name, uint64_t tmp_offset, uint64_t migration_bitmap_sync_start(void) "" migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64 migration_throttle(void) "" +ram_discard_range(const char *rbname, uint64_t start, size_t len) "%s: start: %" PRIx64 " %zx" ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x" ram_postcopy_send_discard_bitmap(void) "" ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: start: %zx len: %zx" @@ -176,7 +177,6 @@ rdma_start_outgoing_migration_after_rdma_source_init(void) "" # migration/postcopy-ram.c postcopy_discard_send_finish(const char *ramblock, int nwords, int ncmds) "%s mask words sent=%d in %d commands" postcopy_discard_send_range(const char *ramblock, unsigned long start, unsigned long length) "%s:%lx/%lx" -postcopy_ram_discard_range(void *start, size_t length) "%p,+%zx" postcopy_cleanup_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx" postcopy_init_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx" postcopy_nhp_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx" |