[Qemu-devel] [PATCH v8 05/11] migration: introduce postcopy-blocktime capability

[Alexey Perevalov]

Right now it could be used on destination side to
enable vCPU blocktime calculation for postcopy live migration.
vCPU blocktime - it's time since vCPU thread was put into
interruptible sleep, till memory page was copied and thread awake.

Reviewed-by: Dr. David Alan Gilbert <address@hidden>
Signed-off-by: Alexey Perevalov <address@hidden>
---
 include/migration/migration.h | 1 +
 migration/migration.c         | 9 +++++++++
 qapi-schema.json              | 5 ++++-
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index 79b5484..2e61df5 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -189,6 +189,7 @@ int migrate_compress_level(void);
 int migrate_compress_threads(void);
 int migrate_decompress_threads(void);
 bool migrate_use_events(void);
+bool migrate_postcopy_blocktime(void);
 
 /* Sending on the return path - generic and then for each message type */
 void migrate_send_rp_message(MigrationIncomingState *mis,
diff --git a/migration/migration.c b/migration/migration.c
index 2a77636..d1cc34f 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1371,6 +1371,15 @@ bool migrate_zero_blocks(void)
     return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
 }
 
+bool migrate_postcopy_blocktime(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME];
+}
+
 bool migrate_use_compression(void)
 {
     MigrationState *s;
diff --git a/qapi-schema.json b/qapi-schema.json
index 4b50b65..e906953 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -900,12 +900,15 @@
 #          offers more flexibility.
 #          (Since 2.10)
 #
+# @postcopy-blocktime: Calculate downtime for postcopy live migration
+#                     (since 2.10)
+#
 # Since: 1.2
 ##
 { 'enum': 'MigrationCapability',
   'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
            'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram',
-           'block' ] }
+           'block', 'postcopy-blocktime'] }
 
 ##
 # @MigrationCapabilityStatus:
-- 
1.9.1