* Jan Kiszka <jan.kis...@web.de> [2009-12-01 17:44]:
> 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.kis...@siemens.com>
With this patch and the VMSTATE_MACADDR patch, localhost migration with
e1000 is working again.
Acked-by: Ryan Harper <ry...@us.ibm.com>
> ---
>
> hw/virtio-net.c | 7 ++-----
> savevm.c | 18 ++++++++++++++++--
> 2 files changed, 18 insertions(+), 7 deletions(-)
>
> diff --git a/hw/virtio-net.c b/hw/virtio-net.c
> index 2f147e5..9ccd4c8 100644
> --- a/hw/virtio-net.c
> +++ b/hw/virtio-net.c
> @@ -745,12 +745,9 @@ static int virtio_net_load(QEMUFile *f, void *opaque,
> int version_id)
>
> if (version_id >= 5) {
> n->mac_table.in_use = qemu_get_be32(f);
> + qemu_get_buffer(f, n->mac_table.macs, n->mac_table.in_use *
> ETH_ALEN);
> /* MAC_TABLE_ENTRIES may be different from the saved image */
> - if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
> - qemu_get_buffer(f, n->mac_table.macs,
> - n->mac_table.in_use * ETH_ALEN);
> - } else if (n->mac_table.in_use) {
> - qemu_fseek(f, n->mac_table.in_use * ETH_ALEN, SEEK_CUR);
> + if (n->mac_table.in_use > MAC_TABLE_ENTRIES) {
> n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
> n->mac_table.in_use = 0;
> }
> diff --git a/savevm.c b/savevm.c
> index 8fe9349..1e54a42 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -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);
> + 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 = {
>
--
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
ry...@us.ibm.com
