Re: [RFC PATCH 1/4] Add a new API to virtio-pci

Anthony Liguori
2010-09-13T15:59:37Z

On 09/13/2010 04:04 AM, Michael S. Tsirkin wrote:
> On Mon, Sep 13, 2010 at 09:50:42AM +0530, Krishna Kumar2 wrote:
>
>> "Michael S. Tsirkin"<mst@redhat.com> wrote on 09/12/2010 05:16:37 PM:
>>
>>
>>> "Michael S. Tsirkin"<mst@redhat.com>
>>> 09/12/2010 05:16 PM
>>>
>>> On Thu, Sep 09, 2010 at 07:19:33PM +0530, Krishna Kumar2 wrote:
>>>
>>>> Unfortunately I need a
>>>> constant in vhost for now.
>>>>
>>> Maybe not even that: you create multiple vhost-net
>>> devices so vhost-net in kernel does not care about these
>>> either, right? So this can be just part of vhost_net.h
>>> in qemu.
>>>
>> Sorry, I didn't understand what you meant.
>>
>> I can remove all socks[] arrays/constants by pre-allocating
>> sockets in vhost_setup_vqs. Then I can remove all "socks"
>> parameters in vhost_net_stop, vhost_net_release and
>> vhost_net_reset_owner.
>>
>> Does this make sense?
>>
>> Thanks,
>>
>> - KK
>>
> Here's what I mean: each vhost device includes 1 TX
> and 1 RX VQ. Instead of teaching vhost about multiqueue,
> we could simply open /dev/vhost-net multiple times.
> How many times would be up to qemu.
>

Trouble is, each vhost-net device is associated with 1 tun/tap device
which means that each vhost-net device is associated with a transmit and
receive queue.

I don't know if you'll always have an equal number of transmit and
receive queues but there's certainly challenge in terms of flexibility
with this model.

Regards,

Anthony Liguori