[libvirt PATCH 01/11] qemu_snapshot: revert: always error out if VM XML is missing
Pavel Hrdina
phrdina at redhat.com
Mon Nov 15 16:22:44 UTC 2021
The support to revert snapshots was introduced in libvirt 0.8.0 but
saving the whole VM XML was implemented later in libvirt 0.9.5.
That is more then 10 years ago so we can safely assume that nobody will
try reverting to snapshot created by that old libvirt. In the unlikely
scenario where someone would actually did it we would simply error out.
Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
---
src/qemu/qemu_snapshot.c | 138 +++++++++++++++++++--------------------
1 file changed, 66 insertions(+), 72 deletions(-)
diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index d105eead27..3d6ec490ab 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
@@ -1908,13 +1908,14 @@ qemuSnapshotRevert(virDomainObj *vm,
goto endjob;
}
+ if (!snap->def->dom) {
+ virReportError(VIR_ERR_SNAPSHOT_REVERT_RISKY,
+ _("snapshot '%s' lacks domain '%s' rollback info"),
+ snap->def->name, vm->def->name);
+ goto endjob;
+ }
+
if (!(flags & VIR_DOMAIN_SNAPSHOT_REVERT_FORCE)) {
- if (!snap->def->dom) {
- virReportError(VIR_ERR_SNAPSHOT_REVERT_RISKY,
- _("snapshot '%s' lacks domain '%s' rollback info"),
- snap->def->name, vm->def->name);
- goto endjob;
- }
if (virDomainObjIsActive(vm) &&
!(snapdef->state == VIR_DOMAIN_SNAPSHOT_RUNNING ||
snapdef->state == VIR_DOMAIN_SNAPSHOT_PAUSED) &&
@@ -1935,16 +1936,14 @@ qemuSnapshotRevert(virDomainObj *vm,
}
}
- if (snap->def->dom) {
- config = virDomainDefCopy(snap->def->dom,
- driver->xmlopt, priv->qemuCaps, true);
- if (!config)
- goto endjob;
+ config = virDomainDefCopy(snap->def->dom,
+ driver->xmlopt, priv->qemuCaps, true);
+ if (!config)
+ goto endjob;
- if (STRNEQ(config->name, vm->def->name)) {
- VIR_FREE(config->name);
- config->name = g_strdup(vm->def->name);
- }
+ if (STRNEQ(config->name, vm->def->name)) {
+ VIR_FREE(config->name);
+ config->name = g_strdup(vm->def->name);
}
if (snap->def->inactiveDom) {
@@ -1992,61 +1991,59 @@ qemuSnapshotRevert(virDomainObj *vm,
/* Transitions 5, 6, 8, 9 */
/* Check for ABI compatibility. We need to do this check against
* the migratable XML or it will always fail otherwise */
- if (config) {
- bool compatible;
+ bool compatible;
- /* Replace the CPU in config and put the original one in priv
- * once we're done. When we have the updated CPU def in the
- * cookie, we don't want to replace the CPU in migratable def
- * when doing ABI checks to make sure the current CPU exactly
- * matches the one used at the time the snapshot was taken.
- */
- if (cookie && cookie->cpu && config->cpu) {
- origCPU = config->cpu;
- if (!(config->cpu = virCPUDefCopy(cookie->cpu)))
- goto endjob;
+ /* Replace the CPU in config and put the original one in priv
+ * once we're done. When we have the updated CPU def in the
+ * cookie, we don't want to replace the CPU in migratable def
+ * when doing ABI checks to make sure the current CPU exactly
+ * matches the one used at the time the snapshot was taken.
+ */
+ if (cookie && cookie->cpu && config->cpu) {
+ origCPU = config->cpu;
+ if (!(config->cpu = virCPUDefCopy(cookie->cpu)))
+ goto endjob;
- compatible = qemuDomainDefCheckABIStability(driver,
- priv->qemuCaps,
- vm->def,
- config);
- } else {
- compatible = qemuDomainCheckABIStability(driver, vm, config);
- }
+ compatible = qemuDomainDefCheckABIStability(driver,
+ priv->qemuCaps,
+ vm->def,
+ config);
+ } else {
+ compatible = qemuDomainCheckABIStability(driver, vm, config);
+ }
- /* If using VM GenID, there is no way currently to change
- * the genid for the running guest, so set an error,
- * mark as incompatible, and don't allow change of genid
- * if the revert force flag would start the guest again. */
- if (compatible && config->genidRequested) {
- virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
- _("domain genid update requires restart"));
- compatible = false;
- start_flags &= ~VIR_QEMU_PROCESS_START_GEN_VMID;
- }
+ /* If using VM GenID, there is no way currently to change
+ * the genid for the running guest, so set an error,
+ * mark as incompatible, and don't allow change of genid
+ * if the revert force flag would start the guest again. */
+ if (compatible && config->genidRequested) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("domain genid update requires restart"));
+ compatible = false;
+ start_flags &= ~VIR_QEMU_PROCESS_START_GEN_VMID;
+ }
- if (!compatible) {
- virErrorPtr err = virGetLastError();
+ if (!compatible) {
+ virErrorPtr err = virGetLastError();
- if (!(flags & VIR_DOMAIN_SNAPSHOT_REVERT_FORCE)) {
- /* Re-spawn error using correct category. */
- if (err->code == VIR_ERR_CONFIG_UNSUPPORTED)
- virReportError(VIR_ERR_SNAPSHOT_REVERT_RISKY, "%s",
- err->str2);
- goto endjob;
- }
- virResetError(err);
- qemuProcessStop(driver, vm,
- VIR_DOMAIN_SHUTOFF_FROM_SNAPSHOT,
- QEMU_ASYNC_JOB_START, 0);
- virDomainAuditStop(vm, "from-snapshot");
- detail = VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT;
- event = virDomainEventLifecycleNewFromObj(vm,
- VIR_DOMAIN_EVENT_STOPPED,
- detail);
- virObjectEventStateQueue(driver->domainEventState, event);
- goto load;
+ if (!(flags & VIR_DOMAIN_SNAPSHOT_REVERT_FORCE)) {
+ /* Re-spawn error using correct category. */
+ if (err->code == VIR_ERR_CONFIG_UNSUPPORTED)
+ virReportError(VIR_ERR_SNAPSHOT_REVERT_RISKY, "%s",
+ err->str2);
+ goto endjob;
}
+ virResetError(err);
+ qemuProcessStop(driver, vm,
+ VIR_DOMAIN_SHUTOFF_FROM_SNAPSHOT,
+ QEMU_ASYNC_JOB_START, 0);
+ virDomainAuditStop(vm, "from-snapshot");
+ detail = VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT;
+ event = virDomainEventLifecycleNewFromObj(vm,
+ VIR_DOMAIN_EVENT_STOPPED,
+ detail);
+ virObjectEventStateQueue(driver->domainEventState, event);
+ goto load;
}
if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_RUNNING) {
@@ -2073,10 +2070,9 @@ qemuSnapshotRevert(virDomainObj *vm,
* failed loadvm attempt? */
goto endjob;
}
- if (config) {
- virCPUDefFree(priv->origCPU);
- priv->origCPU = g_steal_pointer(&origCPU);
- }
+
+ virCPUDefFree(priv->origCPU);
+ priv->origCPU = g_steal_pointer(&origCPU);
if (cookie && !cookie->slirpHelper)
priv->disableSlirp = true;
@@ -2097,10 +2093,8 @@ qemuSnapshotRevert(virDomainObj *vm,
defined = true;
}
- if (config) {
- virDomainObjAssignDef(vm, config, true, NULL);
- config = NULL;
- }
+ virDomainObjAssignDef(vm, config, true, NULL);
+ config = NULL;
/* No cookie means libvirt which saved the domain was too old to
* mess up the CPU definitions.
--
2.31.1
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