[libvirt PATCH 02/11] qemu_snapshot: revert: always restart QEMU process for running VM

[Pavel Hrdina]

Our compatibility check code isn't complete and there are cases where it
fails to detect incompatible configuration and the revert fails. In
addition future support for external snapshot will always require
restarting the QEMU process.

To unify the behavior drop the compatibility check code and always
restart the QEMU process.

Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
---
 src/qemu/qemu_snapshot.c | 66 ++++++----------------------------------
 1 file changed, 10 insertions(+), 56 deletions(-)

diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index 3d6ec490ab..661f74146c 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
@@ -1989,62 +1989,16 @@ qemuSnapshotRevert(virDomainObj *vm,
          * to have finer control.  */
         if (virDomainObjIsActive(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 */
-            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;
-
-                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 (!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;
-            }
+            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) {
                 /* Transitions 5, 6 */
-- 
2.31.1