migration/ram: ensure write persistence on loading all data to PMEM.

Because we need to make sure the pmem kind memory data is synced
after migration, we choose to call pmem_persist() when the migration
finish. This will make sure the data of pmem is safe and will not
lose if power is off.

Signed-off-by: Junyan He <junyan.he@intel.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/include/qemu/pmem.h b/include/qemu/pmem.h
index ebdb0702106d67264290f525ebeecdd0989be53e..dfb6d0da62cbc2470ac2577b9861ccf3aaf4bd23 100644 (file)
--- a/include/qemu/pmem.h
+++ b/include/qemu/pmem.h
@@ -25,6 +25,12 @@ pmem_memcpy_persist(void *pmemdest, const void *src, size_t len)
     return NULL;
 }
 
+static inline void
+pmem_persist(const void *addr, size_t len)
+{
+    g_assert_not_reached();
+}
+
 #endif /* CONFIG_LIBPMEM */
 
 #endif /* !QEMU_PMEM_H */

diff --git a/migration/ram.c b/migration/ram.c
index 5beefae7f55456a017b6293e81767dc11022e269..fa79d0a5b91e2dc8c15dd7ac28e887b072887a5d 100644 (file)
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -33,6 +33,7 @@
 #include "qemu/bitops.h"
 #include "qemu/bitmap.h"
 #include "qemu/main-loop.h"
+#include "qemu/pmem.h"
 #include "xbzrle.h"
 #include "ram.h"
 #include "migration.h"
@@ -3547,6 +3548,13 @@ static int ram_load_setup(QEMUFile *f, void *opaque)
 static int ram_load_cleanup(void *opaque)
 {
     RAMBlock *rb;
+
+    RAMBLOCK_FOREACH_MIGRATABLE(rb) {
+        if (ramblock_is_pmem(rb)) {
+            pmem_persist(rb->host, rb->used_length);
+        }
+    }
+
     xbzrle_load_cleanup();
     compress_threads_load_cleanup();