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@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
This commit is contained in:
Peter Krempa 2021-02-08 11:37:50 +01:00
parent 1475baed36
commit 9f61d14a9e

View File

@ -2205,6 +2205,91 @@ 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,
@ -2317,6 +2402,12 @@ qemuMigrationSrcBeginPhase(virQEMUDriverPtr driver,
if (!(mig = qemuMigrationCookieNew(vm->def, priv->origname)))
return NULL;
if (cookieFlags & QEMU_MIGRATION_COOKIE_NBD &&
virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MIGRATION_PARAM_BLOCK_BITMAP_MAPPING) &&
qemuMigrationSrcBeginPhaseBlockDirtyBitmaps(mig, vm, migrate_disks,
nmigrate_disks) < 0)
return NULL;
if (qemuMigrationCookieFormat(mig, driver, vm,
QEMU_MIGRATION_SOURCE,
cookieout, cookieoutlen,
@ -2530,6 +2621,92 @@ 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;
}
/* Bitmaps can only be migrated to qcow2 v3+ */
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,
@ -2679,7 +2856,8 @@ 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,
@ -2772,6 +2950,9 @@ 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;
@ -3654,6 +3835,145 @@ 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) < 0)
return -1;
if (qemuMigrationCookieBlockDirtyBitmapsToParams(mig->blockDirtyBitmaps,
&mapping) < 0)
return -1;
qemuMigrationParamsSetBlockDirtyBitmapMapping(migParams, &mapping);
return 0;
}
static int
qemuMigrationSrcRun(virQEMUDriverPtr driver,
virDomainObjPtr vm,
@ -3710,6 +4030,10 @@ 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,
@ -3742,13 +4066,18 @@ 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;