* Alexander Graf (ag...@suse.de) wrote:
> One of the really nice things about the VM description format is that it goes
> over the wire when live migration is happening. Unfortunately QEMU today
> closes
> any socket once it sees VM_EOF coming, so we never give the VMDESC the chance
> to
> actually land on the wire.
>
> This patch makes QEMU read the description as well. This way we ensure that
> anything wire tapping us in between will get the chance to also interpret the
> stream.
>
> Along the way we also fix virt tests that assume that number_bytes_sent on the
> sender side is equal to number_bytes_read which was true before the VMDESC
> patches and is true again with this patch.
>
> Signed-off-by: Alexander Graf <ag...@suse.de>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
and I've tested the set of 3 and it works, so:
Tested-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
Dave
>
> ---
>
> v1 -> v2:
>
> - read in small chunks
> ---
> savevm.c | 22 +++++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/savevm.c b/savevm.c
> index 8040766..1b78654 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -929,6 +929,7 @@ int qemu_loadvm_state(QEMUFile *f)
> uint8_t section_type;
> unsigned int v;
> int ret;
> + int file_error_after_eof = -1;
>
> if (qemu_savevm_state_blocked(&local_err)) {
> error_report("%s", error_get_pretty(local_err));
> @@ -1034,6 +1035,24 @@ int qemu_loadvm_state(QEMUFile *f)
> }
> }
>
> + file_error_after_eof = qemu_file_get_error(f);
> +
> + /*
> + * Try to read in the VMDESC section as well, so that dumping tools that
> + * intercept our migration stream have the chance to see it.
> + */
> + if (qemu_get_byte(f) == QEMU_VM_VMDESCRIPTION) {
> + uint32_t size = qemu_get_be32(f);
> + uint8_t *buf = g_malloc(0x1000);
> +
> + while (size > 0) {
> + uint32_t read_chunk = MIN(size, 0x1000);
> + qemu_get_buffer(f, buf, read_chunk);
> + size -= read_chunk;
> + }
> + g_free(buf);
> + }
> +
> cpu_synchronize_all_post_init();
>
> ret = 0;
> @@ -1045,7 +1064,8 @@ out:
> }
>
> if (ret == 0) {
> - ret = qemu_file_get_error(f);
> + /* We may not have a VMDESC section, so ignore relative errors */
> + ret = file_error_after_eof;
> }
>
> return ret;
> --
> 1.7.12.4
>
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
