vmstate: Avoid seeking

Seeking on vmstate save/load does not work if the underlying file is a
stream. We could try to make all QEMUFile* forward-seek-aware, but first
attempts in this direction indicated that it's saner to convert the few
qemu_fseek-on-vmstates users to plain reads/writes.

This fixes various subtle vmstate corruptions where unused fields were
involved.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Jan Kiszka 2009-12-02 12:36:35 +01:00 committed by Anthony Liguori
parent e560125e26
commit 21174c34b6

View file

@ -959,13 +959,27 @@ const VMStateInfo vmstate_info_buffer = {
static int get_unused_buffer(QEMUFile *f, void *pv, size_t size)
{
qemu_fseek(f, size, SEEK_CUR);
return 0;
uint8_t buf[1024];
int block_len;
while (size > 0) {
block_len = MIN(sizeof(buf), size);
size -= block_len;
qemu_get_buffer(f, buf, block_len);
}
return 0;
}
static void put_unused_buffer(QEMUFile *f, void *pv, size_t size)
{
qemu_fseek(f, size, SEEK_CUR);
static const uint8_t buf[1024];
int block_len;
while (size > 0) {
block_len = MIN(sizeof(buf), size);
size -= block_len;
qemu_put_buffer(f, buf, block_len);
}
}
const VMStateInfo vmstate_info_unused_buffer = {