[Qemu-devel] [PATCH 7/7 V11] migration/ram: ensure write persistence on loading all data to PMEM.

[junyan . he]

From: Junyan He <address@hidden>

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 <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>
---
 include/qemu/pmem.h | 6 ++++++
 migration/ram.c     | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/include/qemu/pmem.h b/include/qemu/pmem.h
index ebdb070..dfb6d0d 100644
--- 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 309b567..67b620b 100644
--- 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"
@@ -3540,6 +3541,13 @@ 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();
 
-- 
2.7.4