[libvirt PATCH v2 13/81] qemu: Abort failed post-copy when we haven't called Finish yet

[Jiri Denemark <jdenemar@xxxxxxxxxx>]

When migration fails after it already switched to post-copy phase on the
source, but early enough that we haven't called Finish on the
destination yet, we know the vCPUs were not started on the destination
and the source host still has a complete state of the domain. Thus we
can just ignore the fact post-copy phase started and normally abort the
migration and resume vCPUs on the source.

Signed-off-by: Jiri Denemark <jdenemar@xxxxxxxxxx>
Reviewed-by: Peter Krempa <pkrempa@xxxxxxxxxx>
Reviewed-by: Pavel Hrdina <phrdina@xxxxxxxxxx>
---

Notes:
    Version 2:
    - put debug message on a single line

 src/qemu/qemu_migration.c |  8 ++++++++
 src/qemu/qemu_process.c   | 20 ++++++++------------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 0daf50d836..06af16c0e7 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -4412,6 +4412,14 @@ qemuMigrationSrcRun(virQEMUDriver *driver,
     virErrorPreserveLast(&orig_err);
 
     if (virDomainObjIsActive(vm)) {
+        int reason;
+        virDomainState state = virDomainObjGetState(vm, &reason);
+
+        if (state == VIR_DOMAIN_PAUSED && reason == VIR_DOMAIN_PAUSED_POSTCOPY) {
+            VIR_DEBUG("Aborting failed post-copy migration as the destination is not running yet");
+            virDomainObjSetState(vm, state, VIR_DOMAIN_PAUSED_MIGRATION);
+        }
+
         if (cancel &&
             priv->job.current->status != VIR_DOMAIN_JOB_STATUS_HYPERVISOR_COMPLETED &&
             qemuDomainObjEnterMonitorAsync(driver, vm,
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index b1725ce4cf..f5a45c898d 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -3483,20 +3483,16 @@ qemuProcessRecoverMigrationOut(virQEMUDriver *driver,
     case QEMU_MIGRATION_PHASE_PERFORM2:
     case QEMU_MIGRATION_PHASE_PERFORM3:
         /* migration is still in progress, let's cancel it and resume the
-         * domain; however we can only do that before migration enters
-         * post-copy mode
+         * domain; we can do so even in post-copy phase as the domain was not
+         * resumed on the destination host yet
          */
-        if (postcopy) {
-            qemuMigrationSrcPostcopyFailed(vm);
-        } else {
-            VIR_DEBUG("Cancelling unfinished migration of domain %s",
-                      vm->def->name);
-            if (qemuMigrationSrcCancel(driver, vm) < 0) {
-                VIR_WARN("Could not cancel ongoing migration of domain %s",
-                         vm->def->name);
-            }
-            resume = true;
+        VIR_DEBUG("Cancelling unfinished migration of domain %s",
+                  vm->def->name);
+        if (qemuMigrationSrcCancel(driver, vm) < 0) {
+            VIR_WARN("Could not cancel ongoing migration of domain %s",
+                     vm->def->name);
         }
+        resume = true;
         break;
 
     case QEMU_MIGRATION_PHASE_PERFORM3_DONE:
-- 
2.35.1