qemu: Add pause-before-switchover migration capability

This new capability enables a pause before device state serialization so
that we can finish all block jobs without racing with the end of the
migration. The pause is indicated by "pre-switchover" state. Once we're
done QEMU enters "device" migration state.

This patch just defines the new capability and QEMU migration states and
their mapping to our job states.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

src/qemu/qemu_domain.c

@@ -423,6 +423,7 @@ qemuDomainJobStatusToType(qemuDomainJobStatus status)
     case QEMU_DOMAIN_JOB_STATUS_MIGRATING:
     case QEMU_DOMAIN_JOB_STATUS_QEMU_COMPLETED:
     case QEMU_DOMAIN_JOB_STATUS_POSTCOPY:
+    case QEMU_DOMAIN_JOB_STATUS_PAUSED:
         return VIR_DOMAIN_JOB_UNBOUNDED;
 
     case QEMU_DOMAIN_JOB_STATUS_COMPLETED:

src/qemu/qemu_domain.h

@@ -103,6 +103,7 @@ typedef enum {
     QEMU_DOMAIN_JOB_STATUS_ACTIVE,
     QEMU_DOMAIN_JOB_STATUS_MIGRATING,
     QEMU_DOMAIN_JOB_STATUS_QEMU_COMPLETED,
+    QEMU_DOMAIN_JOB_STATUS_PAUSED,
     QEMU_DOMAIN_JOB_STATUS_POSTCOPY,
     QEMU_DOMAIN_JOB_STATUS_COMPLETED,
     QEMU_DOMAIN_JOB_STATUS_FAILED,

src/qemu/qemu_migration.c

@@ -1366,6 +1366,14 @@ qemuMigrationUpdateJobType(qemuDomainJobInfoPtr jobInfo)
         jobInfo->status = QEMU_DOMAIN_JOB_STATUS_CANCELED;
         break;
 
+    case QEMU_MONITOR_MIGRATION_STATUS_PRE_SWITCHOVER:
+        jobInfo->status = QEMU_DOMAIN_JOB_STATUS_PAUSED;
+        break;
+
+    case QEMU_MONITOR_MIGRATION_STATUS_DEVICE:
+        jobInfo->status = QEMU_DOMAIN_JOB_STATUS_MIGRATING;
+        break;
+
     case QEMU_MONITOR_MIGRATION_STATUS_SETUP:
     case QEMU_MONITOR_MIGRATION_STATUS_ACTIVE:
     case QEMU_MONITOR_MIGRATION_STATUS_CANCELLING:
@@ -1459,6 +1467,7 @@ qemuMigrationCheckJobStatus(virQEMUDriverPtr driver,
     case QEMU_DOMAIN_JOB_STATUS_MIGRATING:
     case QEMU_DOMAIN_JOB_STATUS_QEMU_COMPLETED:
     case QEMU_DOMAIN_JOB_STATUS_POSTCOPY:
+    case QEMU_DOMAIN_JOB_STATUS_PAUSED:
         break;
     }
 
@@ -1474,6 +1483,7 @@ enum qemuMigrationCompletedFlags {
     QEMU_MIGRATION_COMPLETED_ABORT_ON_ERROR = (1 << 0),
     QEMU_MIGRATION_COMPLETED_CHECK_STORAGE  = (1 << 1),
     QEMU_MIGRATION_COMPLETED_POSTCOPY       = (1 << 2),
+    QEMU_MIGRATION_COMPLETED_PRE_SWITCHOVER = (1 << 3),
 };
 
 
@@ -1534,6 +1544,7 @@ qemuMigrationCompleted(virQEMUDriverPtr driver,
     switch (jobInfo->status) {
     case QEMU_DOMAIN_JOB_STATUS_MIGRATING:
     case QEMU_DOMAIN_JOB_STATUS_POSTCOPY:
+    case QEMU_DOMAIN_JOB_STATUS_PAUSED:
         /* The migration was aborted by us rather than QEMU itself. */
         jobInfo->status = QEMU_DOMAIN_JOB_STATUS_FAILED;
         return -2;

src/qemu/qemu_monitor.c

@@ -172,14 +172,15 @@ VIR_ONCE_GLOBAL_INIT(qemuMonitor)
 VIR_ENUM_IMPL(qemuMonitorMigrationStatus,
               QEMU_MONITOR_MIGRATION_STATUS_LAST,
               "inactive", "setup",
-              "active", "postcopy-active",
+              "active", "pre-switchover",
+              "device", "postcopy-active",
               "completed", "failed",
               "cancelling", "cancelled")
 
 VIR_ENUM_IMPL(qemuMonitorMigrationCaps,
               QEMU_MONITOR_MIGRATION_CAPS_LAST,
               "xbzrle", "auto-converge", "rdma-pin-all", "events",
-              "postcopy-ram", "compress")
+              "postcopy-ram", "compress", "pause-before-switchover")
 
 VIR_ENUM_IMPL(qemuMonitorVMStatus,
               QEMU_MONITOR_VM_STATUS_LAST,

src/qemu/qemu_monitor.h

@@ -641,6 +641,8 @@ typedef enum {
     QEMU_MONITOR_MIGRATION_STATUS_INACTIVE,
     QEMU_MONITOR_MIGRATION_STATUS_SETUP,
     QEMU_MONITOR_MIGRATION_STATUS_ACTIVE,
+    QEMU_MONITOR_MIGRATION_STATUS_PRE_SWITCHOVER,
+    QEMU_MONITOR_MIGRATION_STATUS_DEVICE,
     QEMU_MONITOR_MIGRATION_STATUS_POSTCOPY,
     QEMU_MONITOR_MIGRATION_STATUS_COMPLETED,
     QEMU_MONITOR_MIGRATION_STATUS_ERROR,
@@ -706,6 +708,7 @@ typedef enum {
     QEMU_MONITOR_MIGRATION_CAPS_EVENTS,
     QEMU_MONITOR_MIGRATION_CAPS_POSTCOPY,
     QEMU_MONITOR_MIGRATION_CAPS_COMPRESS,
+    QEMU_MONITOR_MIGRATION_CAPS_PAUSE_BEFORE_SWITCHOVER,
 
     QEMU_MONITOR_MIGRATION_CAPS_LAST
 } qemuMonitorMigrationCaps;

src/qemu/qemu_monitor_json.c

@@ -2846,6 +2846,8 @@ qemuMonitorJSONGetMigrationStatsReply(virJSONValuePtr reply,
     case QEMU_MONITOR_MIGRATION_STATUS_POSTCOPY:
     case QEMU_MONITOR_MIGRATION_STATUS_COMPLETED:
     case QEMU_MONITOR_MIGRATION_STATUS_CANCELLING:
+    case QEMU_MONITOR_MIGRATION_STATUS_PRE_SWITCHOVER:
+    case QEMU_MONITOR_MIGRATION_STATUS_DEVICE:
         ram = virJSONValueObjectGetObject(ret, "ram");
         if (!ram) {
             virReportError(VIR_ERR_INTERNAL_ERROR, "%s",