When loading a normal page to persistent memory, load its data by
libpmem function pmem_memcpy_nodrain() instead of memcpy(). Combined
with a call to pmem_drain() at the end of memory loading, we can
guarantee all those normal pages are persistenly loaded to PMEM.
Signed-off-by: Haozhong Zhang <haozhong.zh...@intel.com>
---
include/migration/qemu-file-types.h | 1 +
include/qemu/pmem.h | 6 ++++++
migration/qemu-file.c | 41 ++++++++++++++++++++++++++++---------
migration/ram.c | 6 +++++-
4 files changed, 43 insertions(+), 11 deletions(-)
diff --git a/include/migration/qemu-file-types.h
b/include/migration/qemu-file-types.h
index bd6d7dd7f9..bb5c547498 100644
--- a/include/migration/qemu-file-types.h
+++ b/include/migration/qemu-file-types.h
@@ -34,6 +34,7 @@ void qemu_put_be16(QEMUFile *f, unsigned int v);
void qemu_put_be32(QEMUFile *f, unsigned int v);
void qemu_put_be64(QEMUFile *f, uint64_t v);
size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size);
+size_t qemu_get_buffer_to_pmem(QEMUFile *f, uint8_t *buf, size_t size);
int qemu_get_byte(QEMUFile *f);
diff --git a/include/qemu/pmem.h b/include/qemu/pmem.h
index 861d8ecc21..77ee1fc4eb 100644
--- a/include/qemu/pmem.h
+++ b/include/qemu/pmem.h
@@ -26,6 +26,12 @@ pmem_memcpy_persist(void *pmemdest, const void *src, size_t
len)
return memcpy(pmemdest, src, len);
}
+static inline void *
+pmem_memcpy_nodrain(void *pmemdest, const void *src, size_t len)
+{
+ return memcpy(pmemdest, src, len);
+}
+
static inline void *pmem_memset_nodrain(void *pmemdest, int c, size_t len)
{
return memset(pmemdest, c, len);
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 2ab2bf362d..7e573010d9 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -26,6 +26,7 @@
#include "qemu-common.h"
#include "qemu/error-report.h"
#include "qemu/iov.h"
+#include "qemu/pmem.h"
#include "migration.h"
#include "qemu-file.h"
#include "trace.h"
@@ -471,15 +472,8 @@ size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t
size, size_t offset)
return size;
}
-/*
- * Read 'size' bytes of data from the file into buf.
- * 'size' can be larger than the internal buffer.
- *
- * It will return size bytes unless there was an error, in which case it will
- * return as many as it managed to read (assuming blocking fd's which
- * all current QEMUFile are)
- */
-size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size)
+static size_t
+qemu_get_buffer_common(QEMUFile *f, uint8_t *buf, size_t size, bool is_pmem)
{
size_t pending = size;
size_t done = 0;
@@ -492,7 +486,11 @@ size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t
size)
if (res == 0) {
return done;
}
- memcpy(buf, src, res);
+ if (!is_pmem) {
+ memcpy(buf, src, res);
+ } else {
+ pmem_memcpy_nodrain(buf, src, res);
+ }
qemu_file_skip(f, res);
buf += res;
pending -= res;
@@ -501,6 +499,29 @@ size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t
size)
return done;
}
+/*
+ * Read 'size' bytes of data from the file into buf.
+ * 'size' can be larger than the internal buffer.
+ *
+ * It will return size bytes unless there was an error, in which case it will
+ * return as many as it managed to read (assuming blocking fd's which
+ * all current QEMUFile are)
+ */
+size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size)
+{
+ return qemu_get_buffer_common(f, buf, size, false);
+}
+
+/*
+ * Mostly the same as qemu_get_buffer(), except that
+ * 1) it's for the case that 'buf' is in the persistent memory, and
+ * 2) it takes necessary operations to ensure the data persistence in 'buf'.
+ */
+size_t qemu_get_buffer_to_pmem(QEMUFile *f, uint8_t *buf, size_t size)
+{
+ return qemu_get_buffer_common(f, buf, size, true);
+}
+
/*
* Read 'size' bytes of data from the file.
* 'size' can be larger than the internal buffer.
diff --git a/migration/ram.c b/migration/ram.c
index 5a0e503818..5a79bbff64 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2950,7 +2950,11 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
break;
case RAM_SAVE_FLAG_PAGE:
- qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
+ if (!is_pmem) {
+ qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
+ } else {
+ qemu_get_buffer_to_pmem(f, host, TARGET_PAGE_SIZE);
+ }
break;
case RAM_SAVE_FLAG_COMPRESS_PAGE:
--
2.14.1
