Re: [Qemu-devel] Headsup: windows virtio networking does not work on current git

[Anthony Liguori <aliguori@us.ibm.com>]

Vadim Rozenfeld <vrozenfe@redhat.com> writes:

> On Sat, 2013-02-02 at 20:42 +0800, Jason Wang wrote:
>> 
>> Have a look at this issue. It was caused by multiqueue patch who adds a
>> new field to virtio_net_cfg. Not sure multiqueue is the root cause since
>> I also find even w/o multiqueue, adding any new field to virtio_net_cfg
>> will break windows guest. Haven't had a clue on this, will continue
>> investigate.
>
> cc'ing Yan, our NDIS guy.

If it helps, mq changes the config size from 8 to 16 bytes.  If the
driver was making an assumption about an 8-byte config size, that's
likely what the problem is.

Regards,

Anthony Liguori

> Thank you,
> Vadim.
>> >
>> >>> Regards,
>> >>>
>> >>> Anthony Liguori
>> >>>
>> >>>> commit fed699f9ca6ae8a0fb62803334cf46fa64d1eb91
>> >>>> Author: Jason Wang <jasowang@redhat.com>
>> >>>> Date:   Wed Jan 30 19:12:39 2013 +0800
>> >>>>
>> >>>>       virtio-net: multiqueue support
>> >>>>
>> >>>>       This patch implements both userspace and vhost support for multiple queue
>> >>>>       virtio-net (VIRTIO_NET_F_MQ). This is done by introducing an array of
>> >>>>       VirtIONetQueue to VirtIONet.
>> >>>>
>> >>>>       Signed-off-by: Jason Wang <jasowang@redhat.com>
>> >>>>       Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
>> >>>>
>> >>>> After this commit, win guest (winXP and win7) shows yellow
>> >>>> exclamation sign and is unable to start the device with
>> >>>> code 10.
>> >>>>
>> >>>> FWIW.  I'm not sure it is a good idea to make a release with
>> >>>> such a breakage, even rc0.
>> >>>>
>> >>>> Thanks,
>> >>>>
>> >>>> /mjt
>> >
>>