[PATCH 07/11] block-backend: add _co_ versions of blk_save_vmstate / blk_load_vmstate

[Vladimir Sementsov-Ogievskiy]

To be used in further commit. Don't worry about some duplication with
existing blk_save_vmstate() and blk_load_vmstate(): they will be
removed soon.

Note the difference: new functions returns 0 on success.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
 include/sysemu/block-backend.h |  3 +++
 block/block-backend.c          | 37 ++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 880e903293..8676bbde5a 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -245,6 +245,9 @@ int blk_pdiscard(BlockBackend *blk, int64_t offset, int 
bytes);
 int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
                      int64_t pos, int size);
 int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size);
+int blk_co_save_vmstate(BlockBackend *blk, const uint8_t *buf,
+                        int64_t pos, int size);
+int blk_co_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int 
size);
 int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz);
 int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo);
 BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
diff --git a/block/block-backend.c b/block/block-backend.c
index 413af51f3b..d7f91ce7ad 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -14,6 +14,7 @@
 #include "sysemu/block-backend.h"
 #include "block/block_int.h"
 #include "block/blockjob.h"
+#include "block/coroutines.h"
 #include "block/throttle-groups.h"
 #include "hw/qdev-core.h"
 #include "sysemu/blockdev.h"
@@ -2227,6 +2228,42 @@ int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, 
int64_t pos, int size)
     return bdrv_load_vmstate(blk_bs(blk), buf, pos, size);
 }
 
+int blk_co_save_vmstate(BlockBackend *blk, const uint8_t *buf,
+                        int64_t pos, int size)
+{
+    int ret;
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, size);
+
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
+    ret = bdrv_co_writev_vmstate(blk_bs(blk), &qiov, pos);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (!blk->enable_write_cache) {
+        ret = bdrv_flush(blk_bs(blk));
+    }
+
+    return ret < 0 ? ret : 0;
+}
+
+int blk_co_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size)
+{
+    int ret;
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, size);
+
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
+    ret = bdrv_co_readv_vmstate(blk_bs(blk), &qiov, pos);
+
+    return ret < 0 ? ret : 0;
+}
+
 int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz)
 {
     if (!blk_is_available(blk)) {
-- 
2.29.2