diff mbox

[v4,1/7] migration: Add 'pause-before-switchover' capability

Message ID 20171020090556.18631-2-dgilbert@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dr. David Alan Gilbert Oct. 20, 2017, 9:05 a.m. UTC
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

When 'pause-before-switchover' is enabled, the outgoing migration
will pause before invalidating the block devices and serializing
the device state.
At this point the management layer gets the chance to clean up any
device jobs or other device users before the migration completes.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
---
 migration/migration.c | 10 ++++++++++
 migration/migration.h |  1 +
 qapi/migration.json   |  5 ++++-
 3 files changed, 15 insertions(+), 1 deletion(-)

Comments

Juan Quintela Oct. 23, 2017, 10:55 a.m. UTC | #1
"Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> When 'pause-before-switchover' is enabled, the outgoing migration
> will pause before invalidating the block devices and serializing
> the device state.
> At this point the management layer gets the chance to clean up any
> device jobs or other device users before the migration completes.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Reviewed-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Juan Quintela <quintela@redhat.com>
diff mbox

Patch

diff --git a/migration/migration.c b/migration/migration.c
index 98429dc843..fba3342368 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1521,6 +1521,16 @@  bool migrate_use_multifd(void)
     return s->enabled_capabilities[MIGRATION_CAPABILITY_X_MULTIFD];
 }
 
+bool migrate_pause_before_switchover(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->enabled_capabilities[
+        MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER];
+}
+
 int migrate_multifd_channels(void)
 {
     MigrationState *s;
diff --git a/migration/migration.h b/migration/migration.h
index b83cceadc4..969866303e 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -177,6 +177,7 @@  bool migrate_zero_blocks(void);
 
 bool migrate_auto_converge(void);
 bool migrate_use_multifd(void);
+bool migrate_pause_before_switchover(void);
 int migrate_multifd_channels(void);
 int migrate_multifd_page_count(void);
 
diff --git a/qapi/migration.json b/qapi/migration.json
index f8b365e3f5..4960231ba2 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -341,6 +341,9 @@ 
 # @return-path: If enabled, migration will use the return path even
 #               for precopy. (since 2.10)
 #
+# @pause-before-switchover: Pause outgoing migration before serialising device
+#          state and before disabling block IO (since 2.11)
+#
 # @x-multifd: Use more than one fd for migration (since 2.11)
 #
 # Since: 1.2
@@ -348,7 +351,7 @@ 
 { 'enum': 'MigrationCapability',
   'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
            'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram',
-           'block', 'return-path', 'x-multifd' ] }
+           'block', 'return-path', 'pause-before-switchover', 'x-multifd' ] }
 
 ##
 # @MigrationCapabilityStatus: