diff options
| -rw-r--r-- | include/exec/memory.h | 10 | ||||
| -rw-r--r-- | migration/migration.c | 9 | ||||
| -rw-r--r-- | migration/migration.h | 1 | ||||
| -rw-r--r-- | migration/ram.c | 30 | ||||
| -rw-r--r-- | softmmu/physmem.c | 5 |
5 files changed, 47 insertions, 8 deletions
diff --git a/include/exec/memory.h b/include/exec/memory.h index 5728a681b2..c8b9088924 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -131,7 +131,7 @@ typedef struct IOMMUTLBEvent { #define RAM_SHARED (1 << 1) /* Only a portion of RAM (used_length) is actually used, and migrated. - * This used_length size can change across reboots. + * Resizing RAM while migrating can result in the migration being canceled. */ #define RAM_RESIZEABLE (1 << 2) @@ -955,7 +955,9 @@ void memory_region_init_ram_shared_nomigrate(MemoryRegion *mr, * RAM. Accesses into the region will * modify memory directly. Only an initial * portion of this RAM is actually used. - * The used size can change across reboots. + * Changing the size while migrating + * can result in the migration being + * canceled. * * @mr: the #MemoryRegion to be initialized. * @owner: the object that tracks the region's reference count @@ -1586,8 +1588,8 @@ void *memory_region_get_ram_ptr(MemoryRegion *mr); /* memory_region_ram_resize: Resize a RAM region. * - * Only legal before guest might have detected the memory size: e.g. on - * incoming migration, or right after reset. + * Resizing RAM while migrating can result in the migration being canceled. + * Care has to be taken if the guest might have already detected the memory. * * @mr: a memory region created with @memory_region_init_resizeable_ram. * @newsize: the new size the region diff --git a/migration/migration.c b/migration/migration.c index fdadee290e..4698b47442 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -223,13 +223,18 @@ void migration_object_init(void) dirty_bitmap_mig_init(); } +void migration_cancel(void) +{ + migrate_fd_cancel(current_migration); +} + void migration_shutdown(void) { /* * Cancel the current migration - that will (eventually) * stop the migration using this structure */ - migrate_fd_cancel(current_migration); + migration_cancel(); object_unref(OBJECT(current_migration)); /* @@ -2307,7 +2312,7 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk, void qmp_migrate_cancel(Error **errp) { - migrate_fd_cancel(migrate_get_current()); + migration_cancel(); } void qmp_migrate_continue(MigrationStatus state, Error **errp) diff --git a/migration/migration.h b/migration/migration.h index db6708326b..f7b388d718 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -375,5 +375,6 @@ int foreach_not_ignored_block(RAMBlockIterFunc func, void *opaque); void migration_make_urgent_request(void); void migration_consume_urgent_request(void); bool migration_rate_limit(void); +void migration_cancel(void); #endif diff --git a/migration/ram.c b/migration/ram.c index bb52bd97db..77922c445e 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -4096,8 +4096,38 @@ static SaveVMHandlers savevm_ram_handlers = { .resume_prepare = ram_resume_prepare, }; +static void ram_mig_ram_block_resized(RAMBlockNotifier *n, void *host, + size_t old_size, size_t new_size) +{ + ram_addr_t offset; + RAMBlock *rb = qemu_ram_block_from_host(host, false, &offset); + Error *err = NULL; + + if (ramblock_is_ignored(rb)) { + return; + } + + if (!migration_is_idle()) { + /* + * Precopy code on the source cannot deal with the size of RAM blocks + * changing at random points in time - especially after sending the + * RAM block sizes in the migration stream, they must no longer change. + * Abort and indicate a proper reason. + */ + error_setg(&err, "RAM block '%s' resized during precopy.", rb->idstr); + migrate_set_error(migrate_get_current(), err); + error_free(err); + migration_cancel(); + } +} + +static RAMBlockNotifier ram_mig_ram_notifier = { + .ram_block_resized = ram_mig_ram_block_resized, +}; + void ram_mig_init(void) { qemu_mutex_init(&XBZRLE.lock); register_savevm_live("ram", 0, 4, &savevm_ram_handlers, &ram_state); + ram_block_notifier_add(&ram_mig_ram_notifier); } diff --git a/softmmu/physmem.c b/softmmu/physmem.c index 81ec3b85b9..813a3efe8e 100644 --- a/softmmu/physmem.c +++ b/softmmu/physmem.c @@ -1798,8 +1798,9 @@ static int memory_try_enable_merging(void *addr, size_t len) return qemu_madvise(addr, len, QEMU_MADV_MERGEABLE); } -/* Only legal before guest might have detected the memory size: e.g. on - * incoming migration, or right after reset. +/* + * Resizing RAM while migrating can result in the migration being canceled. + * Care has to be taken if the guest might have already detected the memory. * * As memory core doesn't know how is memory accessed, it is up to * resize callback to update device state and/or add assertions to detect |