block-migration: efficiently encode zero blocks
this patch adds a efficient encoding for zero blocks by
adding a new flag indicating a block is completely zero.
additionally bdrv_write_zeros() is used at the destination
to efficiently write these zeroes. depending on the implementation
this avoids that the destination target gets fully provisioned.
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/migration.c b/migration.c
index 9f5a423..a9c0421 100644
--- a/migration.c
+++ b/migration.c
@@ -493,6 +493,15 @@
return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
}
+bool migrate_zero_blocks(void)
+{
+ MigrationState *s;
+
+ s = migrate_get_current();
+
+ return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
+}
+
int migrate_use_xbzrle(void)
{
MigrationState *s;