[PATCH 18/19] qemu: migration: Migrate block dirty bitmaps corresponding to checkpoints

Preserve block dirty bitmaps after migration with QEMU_MONITOR_MIGRATE_NON_SHARED_(DISK|INC). This patch implements functions which offer the bitmaps to the destination, check for eligibility on destination and then configure source for the migration. Signed-off-by: Peter Krempa <pkrempa(a)redhat.com&gt; --- src/qemu/qemu_migration.c | 333 +++++++++++++++++++++++++++++++++++++- 1 file changed, 331 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 36424f8493..16bfad0390 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -2203,6 +2203,91 @@ qemuMigrationSrcCleanup(virDomainObjPtr vm, } +/** + * qemuMigrationSrcBeginPhaseBlockDirtyBitmaps: + * @mig: migration cookie struct + * @vm: domain object + * @migrate_disks: disks which are being migrated + * @nmigrage_disks: number of @migrate_disks + * + * Enumerates block dirty bitmaps on disks which will undergo storage migration + * and fills them into @mig to be offered to the destination. + */ +static int +qemuMigrationSrcBeginPhaseBlockDirtyBitmaps(qemuMigrationCookiePtr mig, + virDomainObjPtr vm, + const char **migrate_disks, + size_t nmigrate_disks) + +{ + GSList *disks = NULL; + qemuDomainObjPrivatePtr priv = vm->privateData; + size_t i; + + g_autoptr(GHashTable) blockNamedNodeData = NULL; + + if (!(blockNamedNodeData = qemuBlockGetNamedNodeData(vm, priv->job.asyncJob))) + return -1; + + for (i = 0; i < vm->def->ndisks; i++) { + qemuMigrationBlockDirtyBitmapsDiskPtr disk; + GSList *bitmaps = NULL; + virDomainDiskDefPtr diskdef = vm->def->disks[i]; + qemuBlockNamedNodeDataPtr nodedata = virHashLookup(blockNamedNodeData, diskdef->src->nodeformat); + size_t j; + + if (!nodedata) + continue; + + if (migrate_disks) { + bool migrating = false; + + for (j = 0; j < nmigrate_disks; j++) { + if (STREQ(migrate_disks[j], diskdef->dst)) { + migrating = true; + break; + } + } + + if (!migrating) + continue; + } + + for (j = 0; j < nodedata->nbitmaps; j++) { + qemuMigrationBlockDirtyBitmapsDiskBitmapPtr bitmap; + + if (!qemuBlockBitmapChainIsValid(diskdef->src, + nodedata->bitmaps[j]->name, + blockNamedNodeData)) + continue; + + bitmap = g_new0(qemuMigrationBlockDirtyBitmapsDiskBitmap, 1); + bitmap->bitmapname = g_strdup(nodedata->bitmaps[j]->name); + bitmap->alias = g_strdup_printf("libvirt-%s-%s", + diskdef->dst, + nodedata->bitmaps[j]->name); + bitmaps = g_slist_prepend(bitmaps, bitmap); + } + + if (!bitmaps) + continue; + + disk = g_new0(qemuMigrationBlockDirtyBitmapsDisk, 1); + disk->target = g_strdup(diskdef->dst); + disk->bitmaps = bitmaps; + disks = g_slist_prepend(disks, disk); + } + + if (!disks) + return 0; + + mig->blockDirtyBitmaps = disks; + mig->flags |= QEMU_MIGRATION_COOKIE_BLOCK_DIRTY_BITMAPS; + + return 0; +} + + /* The caller is supposed to lock the vm and start a migration job. */ static char * qemuMigrationSrcBeginPhase(virQEMUDriverPtr driver, @@ -2315,6 +2400,12 @@ qemuMigrationSrcBeginPhase(virQEMUDriverPtr driver, if (!(mig = qemuMigrationCookieNew(vm->def, priv->origname))) return NULL; + if (cookieFlags & QEMU_MIGRATION_COOKIE_NBD && + virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_INCREMENTAL_BACKUP) && + qemuMigrationSrcBeginPhaseBlockDirtyBitmaps(mig, vm, migrate_disks, + nmigrate_disks) < 0) + return NULL; + if (qemuMigrationCookieFormat(mig, driver, vm, QEMU_MIGRATION_SOURCE, cookieout, cookieoutlen, @@ -2528,6 +2619,92 @@ qemuMigrationDstPrepare(virDomainObjPtr vm, migrateFrom, fd, NULL); } + +/** + * qemuMigrationDstPrepareAnyBlockDirtyBitmaps: + * @vm: domain object + * @mig: migration cookie + * @migParams: migration parameters + * @flags: migration flags + * + * Checks whether block dirty bitmaps offered by the migration source are + * to be migrated (e.g. they don't exist, the destination is compatible etc) + * and sets up destination qemu for migrating the bitmaps as well as updates the + * list of eligible bitmaps in the migration cookie to be sent back to the + * source. + */ +static int +qemuMigrationDstPrepareAnyBlockDirtyBitmaps(virDomainObjPtr vm, + qemuMigrationCookiePtr mig, + qemuMigrationParamsPtr migParams, + unsigned int flags) +{ + qemuDomainObjPrivatePtr priv = vm->privateData; + g_autoptr(virJSONValue) mapping = NULL; + g_autoptr(GHashTable) blockNamedNodeData = NULL; + GSList *nextdisk; + + if (!mig->nbd || + !mig->blockDirtyBitmaps || + !(flags & (VIR_MIGRATE_NON_SHARED_DISK | VIR_MIGRATE_NON_SHARED_INC)) || + !virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MIGRATION_PARAM_BLOCK_BITMAP_MAPPING)) + return 0; + + if (qemuMigrationCookieBlockDirtyBitmapsMatchDisks(vm->def, mig->blockDirtyBitmaps) < 0) + return -1; + + if (!(blockNamedNodeData = qemuBlockGetNamedNodeData(vm, QEMU_ASYNC_JOB_MIGRATION_IN))) + return -1; + + for (nextdisk = mig->blockDirtyBitmaps; nextdisk; nextdisk = nextdisk->next) { + qemuMigrationBlockDirtyBitmapsDiskPtr disk = nextdisk->data; + qemuBlockNamedNodeDataPtr nodedata; + GSList *nextbitmap; + + if (!(nodedata = virHashLookup(blockNamedNodeData, disk->nodename))) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("failed to find data for block node '%s'"), + disk->nodename); + return -1; + } + + /* don't migrate bitmaps into non-qcow2v3+ images */ + if (disk->disk->src->format != VIR_STORAGE_FILE_QCOW2 || + nodedata->qcow2v2) { + disk->skip = true; + continue; + } + + for (nextbitmap = disk->bitmaps; nextbitmap; nextbitmap = nextbitmap->next) { + qemuMigrationBlockDirtyBitmapsDiskBitmapPtr bitmap = nextbitmap->data; + size_t k; + + /* don't migrate into existing bitmaps */ + for (k = 0; k < nodedata->nbitmaps; k++) { + if (STREQ(bitmap->bitmapname, nodedata->bitmaps[k]->name)) { + bitmap->skip = true; + break; + } + } + + if (bitmap->skip) + continue; + } + } + + if (qemuMigrationCookieBlockDirtyBitmapsToParams(mig->blockDirtyBitmaps, + &mapping) < 0) + return -1; + + if (!mapping) + return 0; + + qemuMigrationParamsSetBlockDirtyBitmapMapping(migParams, &mapping); + mig->flags |= QEMU_MIGRATION_COOKIE_BLOCK_DIRTY_BITMAPS; + return 0; +} + + static int qemuMigrationDstPrepareAny(virQEMUDriverPtr driver, virConnectPtr dconn, @@ -2677,7 +2854,8 @@ qemuMigrationDstPrepareAny(virQEMUDriverPtr driver, QEMU_MIGRATION_COOKIE_CPU_HOTPLUG | QEMU_MIGRATION_COOKIE_CPU | QEMU_MIGRATION_COOKIE_ALLOW_REBOOT | - QEMU_MIGRATION_COOKIE_CAPS))) + QEMU_MIGRATION_COOKIE_CAPS | + QEMU_MIGRATION_COOKIE_BLOCK_DIRTY_BITMAPS))) goto cleanup; if (!(vm = virDomainObjListAdd(driver->domains, *def, @@ -2770,6 +2948,9 @@ qemuMigrationDstPrepareAny(virQEMUDriverPtr driver, goto stopjob; } + if (qemuMigrationDstPrepareAnyBlockDirtyBitmaps(vm, mig, migParams, flags) < 0) + goto stopjob; + if (qemuMigrationParamsCheck(driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN, migParams, mig->caps->automatic) < 0) goto stopjob; @@ -3653,6 +3834,145 @@ qemuMigrationSetDBusVMState(virQEMUDriverPtr driver, } +/** + * qemuMigrationSrcRunPrepareBlockDirtyBitmapsMerge: + * @vm: domain object + * @mig: migration cookie + * + * When migrating full disks, which means that the backing chain of the disk + * will be squashed into a single image we need to calculate bitmaps + * corresponding to the checkpoints which express the same set of changes + * for migration. + * + * This function prepares temporary bitmaps and corresponding merges, updates + * the data so that the temporary bitmaps are used and registers the temporary + * bitmaps for deletion on failed migration. + */ +static int +qemuMigrationSrcRunPrepareBlockDirtyBitmapsMerge(virDomainObjPtr vm, + qemuMigrationCookiePtr mig) +{ + g_autoslist(qemuDomainJobPrivateMigrateTempBitmap) tmpbitmaps = NULL; + qemuDomainObjPrivatePtr priv = vm->privateData; + qemuDomainJobPrivatePtr jobPriv = priv->job.privateData; + virQEMUDriverPtr driver = priv->driver; + g_autoptr(virJSONValue) actions = virJSONValueNewArray(); + g_autoptr(GHashTable) blockNamedNodeData = NULL; + GSList *nextdisk; + int rc; + + if (!(blockNamedNodeData = qemuBlockGetNamedNodeData(vm, QEMU_ASYNC_JOB_MIGRATION_OUT))) + return -1; + + for (nextdisk = mig->blockDirtyBitmaps; nextdisk; nextdisk = nextdisk->next) { + qemuMigrationBlockDirtyBitmapsDiskPtr disk = nextdisk->data; + GSList *nextbitmap; + + /* if a disk doesn't have a backing chain we don't need the code below */ + if (!virStorageSourceHasBacking(disk->disk->src)) + continue; + + for (nextbitmap = disk->bitmaps; nextbitmap; nextbitmap = nextbitmap->next) { + qemuMigrationBlockDirtyBitmapsDiskBitmapPtr bitmap = nextbitmap->data; + qemuDomainJobPrivateMigrateTempBitmapPtr tmpbmp; + virStorageSourcePtr n; + unsigned long long granularity = 0; + g_autoptr(virJSONValue) merge = virJSONValueNewArray(); + + for (n = disk->disk->src; virStorageSourceIsBacking(n); n = n->backingStore) { + qemuBlockNamedNodeDataBitmapPtr b; + + if (!(b = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData, n, + bitmap->bitmapname))) + break; + + if (granularity == 0) + granularity = b->granularity; + + if (qemuMonitorTransactionBitmapMergeSourceAddBitmap(merge, + n->nodeformat, + b->name) < 0) + return -1; + } + + bitmap->sourcebitmap = g_strdup_printf("libvirt-migration-%s", bitmap->alias); + bitmap->persistent = VIR_TRISTATE_BOOL_YES; + + if (qemuMonitorTransactionBitmapAdd(actions, + disk->disk->src->nodeformat, + bitmap->sourcebitmap, + false, false, granularity) < 0) + return -1; + + if (qemuMonitorTransactionBitmapMerge(actions, + disk->disk->src->nodeformat, + bitmap->sourcebitmap, + &merge) < 0) + return -1; + + tmpbmp = g_new0(qemuDomainJobPrivateMigrateTempBitmap, 1); + tmpbmp->nodename = g_strdup(disk->disk->src->nodeformat); + tmpbmp->bitmapname = g_strdup(bitmap->sourcebitmap); + tmpbitmaps = g_slist_prepend(tmpbitmaps, tmpbmp); + } + } + + if (qemuDomainObjEnterMonitorAsync(driver, vm, QEMU_ASYNC_JOB_MIGRATION_OUT) < 0) + return -1; + + rc = qemuMonitorTransaction(priv->mon, &actions); + + if (qemuDomainObjExitMonitor(driver, vm) < 0 || rc < 0) + return -1; + + jobPriv->migTempBitmaps = g_steal_pointer(&tmpbitmaps); + + return 0; +} + + +/** + * qemuMigrationSrcRunPrepareBlockDirtyBitmaps: + * @vm: domain object + * @mig: migration cookie + * @migParams: migration parameters + * @flags: migration flags + * + * Configures the source for bitmap migration when the destination asks + * for bitmaps. + */ +static int +qemuMigrationSrcRunPrepareBlockDirtyBitmaps(virDomainObjPtr vm, + qemuMigrationCookiePtr mig, + qemuMigrationParamsPtr migParams, + unsigned int flags) + +{ + g_autoptr(virJSONValue) mapping = NULL; + + if (!mig->blockDirtyBitmaps) + return 0; + + if (qemuMigrationCookieBlockDirtyBitmapsMatchDisks(vm->def, mig->blockDirtyBitmaps) < 0) + return -1; + + /* For QEMU_MONITOR_MIGRATE_NON_SHARED_INC we can migrate the bitmaps + * directly, otherwise we must create merged bitmaps from the whole + * chain */ + + if (!(flags & QEMU_MONITOR_MIGRATE_NON_SHARED_INC) && + qemuMigrationSrcRunPrepareBlockDirtyBitmapsMerge(vm, mig)) + return -1; + + if (qemuMigrationCookieBlockDirtyBitmapsToParams(mig->blockDirtyBitmaps, + &mapping) < 0) + return -1; + + qemuMigrationParamsSetBlockDirtyBitmapMapping(migParams, &mapping); + return 0; +} + + static int qemuMigrationSrcRun(virQEMUDriverPtr driver, virDomainObjPtr vm, @@ -3709,6 +4029,10 @@ qemuMigrationSrcRun(virQEMUDriverPtr driver, cookieFlags |= QEMU_MIGRATION_COOKIE_NBD; } + if (cookieFlags & QEMU_MIGRATION_COOKIE_NBD && + virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MIGRATION_PARAM_BLOCK_BITMAP_MAPPING)) + cookieFlags |= QEMU_MIGRATION_COOKIE_BLOCK_DIRTY_BITMAPS; + if (virLockManagerPluginUsesState(driver->lockManager) && !cookieout) { virReportError(VIR_ERR_INTERNAL_ERROR, @@ -3741,13 +4065,18 @@ qemuMigrationSrcRun(virQEMUDriverPtr driver, cookiein, cookieinlen, cookieFlags | QEMU_MIGRATION_COOKIE_GRAPHICS | - QEMU_MIGRATION_COOKIE_CAPS); + QEMU_MIGRATION_COOKIE_CAPS | + QEMU_MIGRATION_COOKIE_BLOCK_DIRTY_BITMAPS); if (!mig) goto error; if (qemuMigrationSrcGraphicsRelocate(driver, vm, mig, graphicsuri) < 0) VIR_WARN("unable to provide data for graphics client relocation"); + if (mig->blockDirtyBitmaps && + qemuMigrationSrcRunPrepareBlockDirtyBitmaps(vm, mig, migParams, flags) < 0) + goto error; + if (qemuMigrationParamsCheck(driver, vm, QEMU_ASYNC_JOB_MIGRATION_OUT, migParams, mig->caps->automatic) < 0) goto error; -- 2.29.2