Add XBZRLE to ram_save_block and ram_save_live

In the outgoing migration check to see if the page is cached and
changed, then send compressed page by using save_xbrle_page function.
In the incoming migration check to see if RAM_SAVE_FLAG_XBZRLE is set
and decompress the page (by using load_xbrle function).

Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>

Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/migration.c b/migration.c
index ba81df7b66..5a5333c44b 100644
--- a/migration.c
+++ b/migration.c
@@ -43,6 +43,9 @@ enum {
 
 #define MAX_THROTTLE  (32 << 20)      /* Migration speed throttling */
 
+/* Migration XBZRLE default cache size */
+#define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
+
 static NotifierList migration_state_notifiers =
     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
 
@@ -55,6 +58,7 @@ static MigrationState *migrate_get_current(void)
     static MigrationState current_migration = {
         .state = MIG_STATE_SETUP,
         .bandwidth_limit = MAX_THROTTLE,
+        .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
     };
 
     return &current_migration;
@@ -416,6 +420,7 @@ static MigrationState *migrate_init(const MigrationParams *params)
     MigrationState *s = migrate_get_current();
     int64_t bandwidth_limit = s->bandwidth_limit;
     bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
+    int64_t xbzrle_cache_size = s->xbzrle_cache_size;
 
     memcpy(enabled_capabilities, s->enabled_capabilities,
            sizeof(enabled_capabilities));
@@ -425,6 +430,7 @@ static MigrationState *migrate_init(const MigrationParams *params)
     s->params = *params;
     memcpy(s->enabled_capabilities, enabled_capabilities,
            sizeof(enabled_capabilities));
+    s->xbzrle_cache_size = xbzrle_cache_size;
 
     s->bandwidth_limit = bandwidth_limit;
     s->state = MIG_STATE_SETUP;
@@ -524,3 +530,21 @@ void qmp_migrate_set_downtime(double value, Error **errp)
     value = MAX(0, MIN(UINT64_MAX, value));
     max_downtime = (uint64_t)value;
 }
+
+int migrate_use_xbzrle(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
+}
+
+int64_t migrate_xbzrle_cache_size(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->xbzrle_cache_size;
+}