block: Make bdrv_load/save_vmstate coroutine_fns

This allows drivers to share code between normal I/O and vmstate
accesses.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Kevin Wolf 2016-06-09 16:24:44 +02:00
parent b433d9424d
commit 1a8ae82217
2 changed files with 64 additions and 26 deletions

View File

@ -1840,6 +1840,62 @@ int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
}
typedef struct BdrvVmstateCo {
BlockDriverState *bs;
QEMUIOVector *qiov;
int64_t pos;
bool is_read;
int ret;
} BdrvVmstateCo;
static int coroutine_fn
bdrv_co_rw_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos,
bool is_read)
{
BlockDriver *drv = bs->drv;
if (!drv) {
return -ENOMEDIUM;
} else if (drv->bdrv_load_vmstate) {
return is_read ? drv->bdrv_load_vmstate(bs, qiov, pos)
: drv->bdrv_save_vmstate(bs, qiov, pos);
} else if (bs->file) {
return bdrv_co_rw_vmstate(bs->file->bs, qiov, pos, is_read);
}
return -ENOTSUP;
}
static void coroutine_fn bdrv_co_rw_vmstate_entry(void *opaque)
{
BdrvVmstateCo *co = opaque;
co->ret = bdrv_co_rw_vmstate(co->bs, co->qiov, co->pos, co->is_read);
}
static inline int
bdrv_rw_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos,
bool is_read)
{
if (qemu_in_coroutine()) {
return bdrv_co_rw_vmstate(bs, qiov, pos, is_read);
} else {
BdrvVmstateCo data = {
.bs = bs,
.qiov = qiov,
.pos = pos,
.is_read = is_read,
.ret = -EINPROGRESS,
};
Coroutine *co = qemu_coroutine_create(bdrv_co_rw_vmstate_entry);
qemu_coroutine_enter(co, &data);
while (data.ret == -EINPROGRESS) {
aio_poll(bdrv_get_aio_context(bs), true);
}
return data.ret;
}
}
int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
int64_t pos, int size)
{
@ -1862,17 +1918,7 @@ int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
{
BlockDriver *drv = bs->drv;
if (!drv) {
return -ENOMEDIUM;
} else if (drv->bdrv_save_vmstate) {
return drv->bdrv_save_vmstate(bs, qiov, pos);
} else if (bs->file) {
return bdrv_writev_vmstate(bs->file->bs, qiov, pos);
}
return -ENOTSUP;
return bdrv_rw_vmstate(bs, qiov, pos, false);
}
int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
@ -1896,17 +1942,7 @@ int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
{
BlockDriver *drv = bs->drv;
if (!drv) {
return -ENOMEDIUM;
} else if (drv->bdrv_load_vmstate) {
return drv->bdrv_load_vmstate(bs, qiov, pos);
} else if (bs->file) {
return bdrv_readv_vmstate(bs->file->bs, qiov, pos);
}
return -ENOTSUP;
return bdrv_rw_vmstate(bs, qiov, pos, true);
}
/**************************************************************/

View File

@ -224,10 +224,12 @@ struct BlockDriver {
int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
int64_t pos);
int (*bdrv_load_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
int64_t pos);
int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
QEMUIOVector *qiov,
int64_t pos);
int coroutine_fn (*bdrv_load_vmstate)(BlockDriverState *bs,
QEMUIOVector *qiov,
int64_t pos);
int (*bdrv_change_backing_file)(BlockDriverState *bs,
const char *backing_file, const char *backing_fmt);