[PATCH v1 2/4] qemu: Support active disk internal snapshots
Or Ozeri
oro at il.ibm.com
Thu Jan 12 08:44:37 UTC 2023
libvirt supports taking external disk snapshots on a running VM,
using qemu's "blockdev-snapshot" command.
qemu also supports "blockdev-snapshot-internal-sync" to do the
same for internal snapshots.
This commit wraps this (old) qemu capability to allow libvirt users
to take internal disk snapshots on a running VM.
This will only work for disk types which support internal snapshots,
and thus we require the disk type to be part of a white list of known
types (only RBD disks for start).
Signed-off-by: Or Ozeri <oro at il.ibm.com>
---
src/qemu/qemu_monitor.c | 9 ++
src/qemu/qemu_monitor.h | 5 ++
src/qemu/qemu_monitor_json.c | 14 ++++
src/qemu/qemu_monitor_json.h | 5 ++
src/qemu/qemu_snapshot.c | 83 +++++++++++--------
.../disk_snapshot.xml | 2 +-
.../disk_snapshot.xml | 2 +-
.../disk_snapshot_redefine.xml | 2 +-
tests/qemumonitorjsontest.c | 1 +
9 files changed, 84 insertions(+), 39 deletions(-)
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 38f89167e0..f6dab34243 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -4225,6 +4225,15 @@ qemuMonitorTransactionSnapshotBlockdev(virJSONValue *actions,
}
+int
+qemuMonitorTransactionInternalSnapshotBlockdev(virJSONValue *actions,
+ const char *device,
+ const char *name)
+{
+ return qemuMonitorJSONTransactionInternalSnapshotBlockdev(actions, device, name);
+}
+
+
int
qemuMonitorTransactionBackup(virJSONValue *actions,
const char *device,
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 2d16214ba2..1bfd1ccbc2 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -1411,6 +1411,11 @@ qemuMonitorTransactionSnapshotBlockdev(virJSONValue *actions,
const char *node,
const char *overlay);
+int
+qemuMonitorTransactionInternalSnapshotBlockdev(virJSONValue *actions,
+ const char *device,
+ const char *name);
+
typedef enum {
QEMU_MONITOR_TRANSACTION_BACKUP_SYNC_MODE_NONE = 0,
QEMU_MONITOR_TRANSACTION_BACKUP_SYNC_MODE_INCREMENTAL,
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index db99017555..002a6caa52 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -8307,6 +8307,20 @@ qemuMonitorJSONTransactionSnapshotBlockdev(virJSONValue *actions,
NULL);
}
+
+int
+qemuMonitorJSONTransactionInternalSnapshotBlockdev(virJSONValue *actions,
+ const char *device,
+ const char *name)
+{
+ return qemuMonitorJSONTransactionAdd(actions,
+ "blockdev-snapshot-internal-sync",
+ "s:device", device,
+ "s:name", name,
+ NULL);
+}
+
+
VIR_ENUM_DECL(qemuMonitorTransactionBackupSyncMode);
VIR_ENUM_IMPL(qemuMonitorTransactionBackupSyncMode,
QEMU_MONITOR_TRANSACTION_BACKUP_SYNC_MODE_LAST,
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index 6f376cf9b7..313004f327 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -779,6 +779,11 @@ qemuMonitorJSONTransactionSnapshotBlockdev(virJSONValue *actions,
const char *node,
const char *overlay);
+int
+qemuMonitorJSONTransactionInternalSnapshotBlockdev(virJSONValue *actions,
+ const char *device,
+ const char *name);
+
int
qemuMonitorJSONTransactionBackup(virJSONValue *actions,
const char *device,
diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index b8416808b3..9146ecae2f 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
@@ -639,20 +639,13 @@ qemuSnapshotPrepare(virDomainObj *vm,
case VIR_DOMAIN_SNAPSHOT_LOCATION_INTERNAL:
found_internal = true;
- if (def->state == VIR_DOMAIN_SNAPSHOT_DISK_SNAPSHOT && active) {
- virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
- _("active qemu domains require external disk "
- "snapshots; disk %s requested internal"),
- disk->name);
- return -1;
- }
-
if (qemuSnapshotPrepareDiskInternal(dom_disk,
active) < 0)
return -1;
if (dom_disk->src->format > 0 &&
- dom_disk->src->format != VIR_STORAGE_FILE_QCOW2) {
+ dom_disk->src->format != VIR_STORAGE_FILE_QCOW2 &&
+ dom_disk->src->protocol != VIR_STORAGE_NET_PROTOCOL_RBD) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("internal snapshot for disk %s unsupported "
"for storage type %s"),
@@ -727,7 +720,7 @@ qemuSnapshotPrepare(virDomainObj *vm,
}
/* disk snapshot requires at least one disk */
- if (def->state == VIR_DOMAIN_SNAPSHOT_DISK_SNAPSHOT && !external) {
+ if (def->state == VIR_DOMAIN_SNAPSHOT_DISK_SNAPSHOT && !external && !found_internal) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("disk-only snapshots require at least "
"one disk to be selected for snapshot"));
@@ -843,6 +836,7 @@ qemuSnapshotDiskCleanup(qemuSnapshotDiskData *data,
struct _qemuSnapshotDiskContext {
qemuSnapshotDiskData *dd;
size_t ndd;
+ bool has_internal;
virJSONValue *actions;
@@ -1061,17 +1055,17 @@ qemuSnapshotDiskPrepareOne(qemuSnapshotDiskContext *snapctxt,
/**
- * qemuSnapshotDiskPrepareActiveExternal:
+ * qemuSnapshotDiskPrepareActive:
*
* Collects and prepares a list of structures that hold information about disks
* that are selected for the snapshot.
*/
static qemuSnapshotDiskContext *
-qemuSnapshotDiskPrepareActiveExternal(virDomainObj *vm,
- virDomainMomentObj *snap,
- bool reuse,
- GHashTable *blockNamedNodeData,
- virDomainAsyncJob asyncJob)
+qemuSnapshotDiskPrepareActive(virDomainObj *vm,
+ virDomainMomentObj *snap,
+ bool reuse,
+ GHashTable *blockNamedNodeData,
+ virDomainAsyncJob asyncJob)
{
g_autoptr(qemuSnapshotDiskContext) snapctxt = NULL;
size_t i;
@@ -1080,16 +1074,33 @@ qemuSnapshotDiskPrepareActiveExternal(virDomainObj *vm,
snapctxt = qemuSnapshotDiskContextNew(snapdef->ndisks, vm, asyncJob);
for (i = 0; i < snapdef->ndisks; i++) {
- if (snapdef->disks[i].snapshot != VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL)
- continue;
+ switch (snapdef->disks[i].snapshot) {
+ case VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL: {
+ if (qemuSnapshotDiskPrepareOne(snapctxt,
+ vm->def->disks[i],
+ snapdef->disks + i,
+ blockNamedNodeData,
+ reuse,
+ true) < 0)
+ return NULL;
+ break;
+ }
- if (qemuSnapshotDiskPrepareOne(snapctxt,
- vm->def->disks[i],
- snapdef->disks + i,
- blockNamedNodeData,
- reuse,
- true) < 0)
- return NULL;
+ case VIR_DOMAIN_SNAPSHOT_LOCATION_INTERNAL: {
+ snapctxt->has_internal = true;
+ if (qemuMonitorTransactionInternalSnapshotBlockdev(snapctxt->actions,
+ vm->def->disks[i]->src->nodeformat,
+ snapdef->disks[i].snapshot_name) < 0)
+ return NULL;
+ break;
+ }
+
+ case VIR_DOMAIN_SNAPSHOT_LOCATION_DEFAULT:
+ case VIR_DOMAIN_SNAPSHOT_LOCATION_NO:
+ case VIR_DOMAIN_SNAPSHOT_LOCATION_MANUAL:
+ case VIR_DOMAIN_SNAPSHOT_LOCATION_LAST:
+ continue;
+ }
}
return g_steal_pointer(&snapctxt);
@@ -1173,7 +1184,7 @@ qemuSnapshotDiskCreate(qemuSnapshotDiskContext *snapctxt)
int rc;
/* check whether there's anything to do */
- if (snapctxt->ndd == 0)
+ if (snapctxt->ndd == 0 && !snapctxt->has_internal)
return 0;
if (qemuDomainObjEnterMonitorAsync(snapctxt->vm, snapctxt->asyncJob) < 0)
@@ -1206,11 +1217,11 @@ qemuSnapshotDiskCreate(qemuSnapshotDiskContext *snapctxt)
/* The domain is expected to be locked and active. */
static int
-qemuSnapshotCreateActiveExternalDisks(virDomainObj *vm,
- virDomainMomentObj *snap,
- GHashTable *blockNamedNodeData,
- unsigned int flags,
- virDomainAsyncJob asyncJob)
+qemuSnapshotCreateActiveDisks(virDomainObj *vm,
+ virDomainMomentObj *snap,
+ GHashTable *blockNamedNodeData,
+ unsigned int flags,
+ virDomainAsyncJob asyncJob)
{
bool reuse = (flags & VIR_DOMAIN_SNAPSHOT_CREATE_REUSE_EXT) != 0;
g_autoptr(qemuSnapshotDiskContext) snapctxt = NULL;
@@ -1220,8 +1231,8 @@ qemuSnapshotCreateActiveExternalDisks(virDomainObj *vm,
/* prepare a list of objects to use in the vm definition so that we don't
* have to roll back later */
- if (!(snapctxt = qemuSnapshotDiskPrepareActiveExternal(vm, snap, reuse,
- blockNamedNodeData, asyncJob)))
+ if (!(snapctxt = qemuSnapshotDiskPrepareActive(vm, snap, reuse,
+ blockNamedNodeData, asyncJob)))
return -1;
if (qemuSnapshotDiskCreate(snapctxt) < 0)
@@ -1361,9 +1372,9 @@ qemuSnapshotCreateActiveExternal(virQEMUDriver *driver,
/* the domain is now paused if a memory snapshot was requested */
- if ((ret = qemuSnapshotCreateActiveExternalDisks(vm, snap,
- blockNamedNodeData, flags,
- VIR_ASYNC_JOB_SNAPSHOT)) < 0)
+ if ((ret = qemuSnapshotCreateActiveDisks(vm, snap,
+ blockNamedNodeData, flags,
+ VIR_ASYNC_JOB_SNAPSHOT)) < 0)
goto cleanup;
/* the snapshot is complete now */
diff --git a/tests/qemudomainsnapshotxml2xmlin/disk_snapshot.xml b/tests/qemudomainsnapshotxml2xmlin/disk_snapshot.xml
index cf5ea0814e..87b6251a7f 100644
--- a/tests/qemudomainsnapshotxml2xmlin/disk_snapshot.xml
+++ b/tests/qemudomainsnapshotxml2xmlin/disk_snapshot.xml
@@ -4,7 +4,7 @@
<disks>
<disk name='/dev/HostVG/QEMUGuest1'/>
<disk name='hdb' snapshot='no'/>
- <disk name='hdc' snapshot='internal'/>
+ <disk name='hdc' snapshot='internal' snapshotName='snap1'/>
<disk name='hdd' snapshot='external'>
<source/>
<driver type='qed'/>
diff --git a/tests/qemudomainsnapshotxml2xmlout/disk_snapshot.xml b/tests/qemudomainsnapshotxml2xmlout/disk_snapshot.xml
index 76c543d25c..6cf93183d5 100644
--- a/tests/qemudomainsnapshotxml2xmlout/disk_snapshot.xml
+++ b/tests/qemudomainsnapshotxml2xmlout/disk_snapshot.xml
@@ -5,7 +5,7 @@
<disks>
<disk name='/dev/HostVG/QEMUGuest1'/>
<disk name='hdb' snapshot='no'/>
- <disk name='hdc' snapshot='internal'/>
+ <disk name='hdc' snapshot='internal' snapshotName='snap1'/>
<disk name='hdd' snapshot='external' type='file'>
<driver type='qed'/>
</disk>
diff --git a/tests/qemudomainsnapshotxml2xmlout/disk_snapshot_redefine.xml b/tests/qemudomainsnapshotxml2xmlout/disk_snapshot_redefine.xml
index 24b41ba7c5..f574793edf 100644
--- a/tests/qemudomainsnapshotxml2xmlout/disk_snapshot_redefine.xml
+++ b/tests/qemudomainsnapshotxml2xmlout/disk_snapshot_redefine.xml
@@ -10,7 +10,7 @@
<disks>
<disk name='hda' snapshot='no'/>
<disk name='hdb' snapshot='no'/>
- <disk name='hdc' snapshot='internal'/>
+ <disk name='hdc' snapshot='internal' snapshotName='snap1'/>
<disk name='hdd' snapshot='external' type='file'>
<driver type='qed'/>
<source file='/path/to/generated4'/>
diff --git a/tests/qemumonitorjsontest.c b/tests/qemumonitorjsontest.c
index 1db1f2b949..1269c74e43 100644
--- a/tests/qemumonitorjsontest.c
+++ b/tests/qemumonitorjsontest.c
@@ -2587,6 +2587,7 @@ testQemuMonitorJSONTransaction(const void *opaque)
qemuMonitorTransactionBitmapDisable(actions, "node4", "bitmap4") < 0 ||
qemuMonitorTransactionBitmapMerge(actions, "node5", "bitmap5", &mergebitmaps) < 0 ||
qemuMonitorTransactionSnapshotBlockdev(actions, "node7", "overlay7") < 0 ||
+ qemuMonitorTransactionInternalSnapshotBlockdev(actions, "device1", "snapshot1") < 0 ||
qemuMonitorTransactionBackup(actions, "dev8", "job8", "target8", "bitmap8",
QEMU_MONITOR_TRANSACTION_BACKUP_SYNC_MODE_NONE) < 0 ||
qemuMonitorTransactionBackup(actions, "dev9", "job9", "target9", "bitmap9",
--
2.25.1
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