[Qemu-devel] [PATCH 23/46] MIG_STATE_POSTCOPY_ACTIVE: Add new migration state

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

'MIG_STATE_POSTCOPY_ACTIVE' is entered after the precopy timelimit
has expired and migration switches to postcopy.

'migration_postcopy_phase' is provided for other sections to know if
they're in postcopy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 include/migration/migration.h |  2 ++
 migration.c                   | 76 +++++++++++++++++++++++++++++++++++++++----
 2 files changed, 71 insertions(+), 7 deletions(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index d2754f7..71442d8 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -146,6 +146,8 @@ MigrationState *migrate_init(const MigrationParams *params);
 bool migration_in_setup(MigrationState *);
 bool migration_has_finished(MigrationState *);
 bool migration_has_failed(MigrationState *);
+/* True if outgoing migration has entered postcopy phase */
+bool migration_postcopy_phase(MigrationState *);
 MigrationState *migrate_get_current(void);
 
 uint64_t ram_bytes_remaining(void);
diff --git a/migration.c b/migration.c
index 20ed6fa..d9a9e5b 100644
--- a/migration.c
+++ b/migration.c
@@ -38,13 +38,14 @@
     do { } while (0)
 #endif
 
-enum {
+enum MigrationPhase {
     MIG_STATE_ERROR = -1,
     MIG_STATE_NONE,
     MIG_STATE_SETUP,
     MIG_STATE_CANCELLING,
     MIG_STATE_CANCELLED,
     MIG_STATE_ACTIVE,
+    MIG_STATE_POSTCOPY_ACTIVE,
     MIG_STATE_COMPLETED,
 };
 
@@ -226,13 +227,30 @@ MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
     return head;
 }
 
+/* Return true if we're already in the middle of a migration
+ * (i.e. any of the active or setup states)
+ */
+static bool migration_already_active(MigrationState *ms)
+{
+    switch (ms->state) {
+    case MIG_STATE_ACTIVE:
+    case MIG_STATE_POSTCOPY_ACTIVE:
+    case MIG_STATE_SETUP:
+        return true;
+
+    default:
+        return false;
+
+    }
+}
+
 void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
                                   Error **errp)
 {
     MigrationState *s = migrate_get_current();
     MigrationCapabilityStatusList *cap;
 
-    if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP) {
+    if (migration_already_active(s)) {
         error_set(errp, QERR_MIGRATION_ACTIVE);
         return;
     }
@@ -248,7 +266,7 @@ void qmp_migrate_set_parameters(MigrationParameterList *params,
     MigrationState *s = migrate_get_current();
     MigrationParameterList *parm;
 
-    if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP) {
+    if (migration_already_active(s)) {
         error_set(errp, QERR_MIGRATION_ACTIVE);
         return;
     }
@@ -347,6 +365,40 @@ MigrationInfo *qmp_query_migrate(Error **errp)
 
         get_xbzrle_cache_stats(info);
         break;
+    case MIG_STATE_POSTCOPY_ACTIVE:
+        /* Mostly the same as active; TODO add some postcopy stats */
+        info->has_status = true;
+        info->status = g_strdup("postcopy-active");
+        info->has_total_time = true;
+        info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
+            - s->total_time;
+        info->has_expected_downtime = true;
+        info->expected_downtime = s->expected_downtime;
+        info->has_setup_time = true;
+        info->setup_time = s->setup_time;
+
+        info->has_ram = true;
+        info->ram = g_malloc0(sizeof(*info->ram));
+        info->ram->transferred = ram_bytes_transferred();
+        info->ram->remaining = ram_bytes_remaining();
+        info->ram->total = ram_bytes_total();
+        info->ram->duplicate = dup_mig_pages_transferred();
+        info->ram->skipped = skipped_mig_pages_transferred();
+        info->ram->normal = norm_mig_pages_transferred();
+        info->ram->normal_bytes = norm_mig_bytes_transferred();
+        info->ram->dirty_pages_rate = s->dirty_pages_rate;
+        info->ram->mbps = s->mbps;
+
+        if (blk_mig_active()) {
+            info->has_disk = true;
+            info->disk = g_malloc0(sizeof(*info->disk));
+            info->disk->transferred = blk_mig_bytes_transferred();
+            info->disk->remaining = blk_mig_bytes_remaining();
+            info->disk->total = blk_mig_bytes_total();
+        }
+
+        get_xbzrle_cache_stats(info);
+        break;
     case MIG_STATE_COMPLETED:
         get_xbzrle_cache_stats(info);
 
@@ -423,7 +475,8 @@ static void migrate_fd_cleanup(void *opaque)
         s->file = NULL;
     }
 
-    assert(s->state != MIG_STATE_ACTIVE);
+    assert((s->state != MIG_STATE_ACTIVE) &&
+           (s->state != MIG_STATE_POSTCOPY_ACTIVE));
 
     if (s->state != MIG_STATE_COMPLETED) {
         qemu_savevm_state_cancel();
@@ -451,7 +504,8 @@ static void migrate_fd_cancel(MigrationState *s)
 
     do {
         old_state = s->state;
-        if (old_state != MIG_STATE_SETUP && old_state != MIG_STATE_ACTIVE) {
+        if (old_state != MIG_STATE_SETUP && old_state != MIG_STATE_ACTIVE &&
+            old_state != MIG_STATE_POSTCOPY_ACTIVE) {
             break;
         }
         migrate_set_state(s, old_state, MIG_STATE_CANCELLING);
@@ -484,6 +538,11 @@ bool migration_has_failed(MigrationState *s)
             s->state == MIG_STATE_ERROR);
 }
 
+bool migration_postcopy_phase(MigrationState *s)
+{
+    return (s->state == MIG_STATE_POSTCOPY_ACTIVE);
+}
+
 MigrationState *migrate_init(const MigrationParams *params)
 {
     MigrationState *s = migrate_get_current();
@@ -536,7 +595,7 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     params.blk = has_blk && blk;
     params.shared = has_inc && inc;
 
-    if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP ||
+    if (migration_already_active(s) ||
         s->state == MIG_STATE_CANCELLING) {
         error_set(errp, QERR_MIGRATION_ACTIVE);
         return;
@@ -847,7 +906,10 @@ static void *migration_thread(void *opaque)
     s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
     migrate_set_state(s, MIG_STATE_SETUP, MIG_STATE_ACTIVE);
 
-    while (s->state == MIG_STATE_ACTIVE) {
+    DPRINTF("setup complete\n");
+
+    while (s->state == MIG_STATE_ACTIVE ||
+           s->state == MIG_STATE_POSTCOPY_ACTIVE) {
         int64_t current_time;
         uint64_t pending_size;
 
-- 
1.9.3