savevm: Implement block_writev_buffer()

Instead of breaking up RAM state into many small chunks, pass the iovec
to the block layer for better performance.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Kevin Wolf 2013-04-05 21:27:54 +02:00 committed by Stefan Hajnoczi
parent cf8074b382
commit 05fcc84888
2 changed files with 22 additions and 5 deletions

View File

@ -55,7 +55,7 @@ typedef int (QEMUFileGetFD)(void *opaque);
* This function writes an iovec to file.
*/
typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov,
int iovcnt);
int iovcnt, int64_t pos);
typedef struct QEMUFileOps {
QEMUFilePutBufferFunc *put_buffer;

View File

@ -176,7 +176,8 @@ static void coroutine_fn yield_until_fd_readable(int fd)
qemu_coroutine_yield();
}
static ssize_t socket_writev_buffer(void *opaque, struct iovec *iov, int iovcnt)
static ssize_t socket_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
int64_t pos)
{
QEMUFileSocket *s = opaque;
ssize_t len;
@ -458,6 +459,21 @@ fail:
return NULL;
}
static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
int64_t pos)
{
int ret;
QEMUIOVector qiov;
qemu_iovec_init_external(&qiov, iov, iovcnt);
ret = bdrv_writev_vmstate(opaque, &qiov, pos);
if (ret < 0) {
return ret;
}
return qiov.size;
}
static int block_put_buffer(void *opaque, const uint8_t *buf,
int64_t pos, int size)
{
@ -481,8 +497,9 @@ static const QEMUFileOps bdrv_read_ops = {
};
static const QEMUFileOps bdrv_write_ops = {
.put_buffer = block_put_buffer,
.close = bdrv_fclose
.put_buffer = block_put_buffer,
.writev_buffer = block_writev_buffer,
.close = bdrv_fclose
};
static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
@ -533,7 +550,7 @@ static void qemu_fflush(QEMUFile *f)
if (f->is_write && f->iovcnt > 0) {
if (f->ops->writev_buffer) {
ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt);
ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, f->pos);
if (ret >= 0) {
f->pos += ret;
}