[PATCH 1/3] qemu: don't pause vm when creating internal snapshot
From: Maxim Nestratov <mnestratov(a)virtuozzo.com>
The pause was introduced in [1] in ancient times when probably distro's
QEMU does not have RESUME event. Yet the event was in the upstream QEMU at
the time version according to [2].
So the event is supported since QEMU version 0.13 which is much older
then oldest currently supported 2.11.0 version and we can remove manual
pause/resume. Except for the halt case.
[1] commit 346236fea97602e9e6529c5d41a32ed26b126082
Author: Jiri Denemark <jdenemar(a)redhat.com>
Date: Thu Feb 24 16:46:44 2011 +0100
qemu: Stop guest CPUs before creating a snapshot
commit 6ed2c484f261fd8bd217f855b9e5e5f981e63f0a
Author: Luiz Capitulino <lcapitulino(a)redhat.com>
Date: Tue Apr 27 20:35:59 2010 -0300
QMP: Introduce RESUME event
Signed-off-by: Nikolay Shirokovskiy <nikolay.shirokovskiy(a)openvz.org>
---
src/qemu/qemu_snapshot.c | 29 ++++-------------------------
1 file changed, 4 insertions(+), 25 deletions(-)
diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index a7901779fc..a41c782c7f 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
@@ -291,23 +291,18 @@ qemuSnapshotCreateActiveInternal(virQEMUDriver *driver,
{
qemuDomainObjPrivate *priv = vm->privateData;
virObjectEvent *event = NULL;
- bool resume = false;
virDomainSnapshotDef *snapdef = virDomainSnapshotObjGetDef(snap);
+ bool halt = !!(flags & VIR_DOMAIN_SNAPSHOT_CREATE_HALT);
int ret = -1;
if (!qemuMigrationSrcIsAllowed(driver, vm, false, 0))
goto cleanup;
- if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_RUNNING) {
- /* savevm monitor command pauses the domain emitting an event which
- * confuses libvirt since it's not notified when qemu resumes the
- * domain. Thus we stop and start CPUs ourselves.
- */
+ if (halt) {
if (qemuProcessStopCPUs(driver, vm, VIR_DOMAIN_PAUSED_SAVE,
QEMU_ASYNC_JOB_SNAPSHOT) < 0)
goto cleanup;
- resume = true;
if (!virDomainObjIsActive(vm)) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("guest unexpectedly quit"));
@@ -316,10 +311,8 @@ qemuSnapshotCreateActiveInternal(virQEMUDriver *driver,
}
if (qemuDomainObjEnterMonitorAsync(driver, vm,
- QEMU_ASYNC_JOB_SNAPSHOT) < 0) {
- resume = false;
+ QEMU_ASYNC_JOB_SNAPSHOT) < 0)
goto cleanup;
- }
ret = qemuMonitorCreateSnapshot(priv->mon, snap->def->name);
qemuDomainObjExitMonitor(driver, vm);
@@ -329,29 +322,15 @@ qemuSnapshotCreateActiveInternal(virQEMUDriver *driver,
if (!(snapdef->cookie = (virObject *) qemuDomainSaveCookieNew(vm)))
goto cleanup;
- if (flags & VIR_DOMAIN_SNAPSHOT_CREATE_HALT) {
+ if (halt) {
event = virDomainEventLifecycleNewFromObj(vm, VIR_DOMAIN_EVENT_STOPPED,
VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT);
qemuProcessStop(driver, vm, VIR_DOMAIN_SHUTOFF_FROM_SNAPSHOT,
QEMU_ASYNC_JOB_SNAPSHOT, 0);
virDomainAuditStop(vm, "from-snapshot");
- resume = false;
}
cleanup:
- if (resume && virDomainObjIsActive(vm) &&
- qemuProcessStartCPUs(driver, vm,
- VIR_DOMAIN_RUNNING_UNPAUSED,
- QEMU_ASYNC_JOB_SNAPSHOT) < 0) {
- event = virDomainEventLifecycleNewFromObj(vm,
- VIR_DOMAIN_EVENT_SUSPENDED,
- VIR_DOMAIN_EVENT_SUSPENDED_API_ERROR);
- if (virGetLastErrorCode() == VIR_ERR_OK) {
- virReportError(VIR_ERR_OPERATION_FAILED, "%s",
- _("resuming after snapshot failed"));
- }
- }
-
virObjectEventStateQueue(driver->domainEventState, event);
return ret;
--
2.35.1