Re: [libvirt] [PATCH 7/7] qemu: snapshot: Correctly revert snapshots in PMSUSPENDED state

PMSUSPENDED state implies the qemu process running, so we should treat it that way. This increases the possible state space of transitions that may happen during the snapshot revert so this patch documents them as well. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1079162 --- src/qemu/qemu_driver.c | 67 ++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 48 insertions(+), 19 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 1f98f4a..f93e0fd 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -14052,22 +14052,29 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot, virDomainDefPtr config = NULL; virQEMUDriverConfigPtr cfg = NULL; virCapsPtr caps = NULL; - int oldState = vm->state.state; + int oldState; virCheckFlags(VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING | VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED | VIR_DOMAIN_SNAPSHOT_REVERT_FORCE, -1); /* We have the following transitions, which create the following events: - * 1. inactive -> inactive: none - * 2. inactive -> running: EVENT_STARTED - * 3. inactive -> paused: EVENT_STARTED, EVENT_PAUSED - * 4. running -> inactive: EVENT_STOPPED - * 5. running -> running: none - * 6. running -> paused: EVENT_PAUSED - * 7. paused -> inactive: EVENT_STOPPED - * 8. paused -> running: EVENT_RESUMED - * 9. paused -> paused: none + * 1. inactive -> inactive: none + * 2. inactive -> running: EVENT_STARTED + * 3. inactive -> paused: EVENT_STARTED, EVENT_PAUSED + * 4. running -> inactive: EVENT_STOPPED + * 5. running -> running: none + * 6. running -> paused: EVENT_PAUSED + * 7. paused -> inactive: EVENT_STOPPED + * 8. paused -> running: EVENT_RESUMED + * 9. paused -> paused: none + * 10. pmsuspended -> pmsuspended: none

+ * 11. pmsuspended -> inactive: EVENT_STOPPED + * 12. pmsuspended -> running: EVENT_RESUMED + * 13. pmsuspended -> paused: EVENT_PAUSED + * 14. inactive -> pmsuspended: EVENT_STARTED, EVENT_PMSUSPENDED + * 15. paused -> pmsuspended: EVENT_PMSUSPENDED + * 16. running -> pmsuspended: EVENT_PMSUSPENDED

* Also, several transitions occur even if we fail partway through, * and use of FORCE can cause multiple transitions. */ @@ -14075,6 +14082,8 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot, if (!(vm = qemuDomObjFromSnapshot(snapshot))) return -1; + oldState = vm->state.state; + cfg = virQEMUDriverGetConfig(driver); if (virDomainRevertToSnapshotEnsureACL(snapshot->domain->conn, vm->def) < 0) @@ -14127,6 +14136,14 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot, } } + if (snap->def->state == VIR_DOMAIN_PMSUSPENDED && + (flags & VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING || + flags & VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED)) { + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s", + _("snapshot of a VM in PMSUSPENDED state cannot be " + "reverted to a running or paused state"));