Re: [Qemu-devel] [PATCH] net: Remove vhostforce option in addition to vhost parameter

[Jason Wang <jasowang@redhat.com>]

On 05/27/2015 07:57 PM, Michael S. Tsirkin wrote:
> On Wed, May 27, 2015 at 04:45:34PM +0800, Jason Wang wrote:
>> > 
>> > 
>> > On 05/27/2015 02:26 PM, Pankaj Gupta wrote:
>>> > > Ping.
>>> > >
>>> > > Can I get any suggestions on this patch.
>>> > >
>>> > > Best regards,
>>> > > Pankaj
>>> > >
>>>> > >> vhostforce was added to enable vhost when
>>>> > >>  guest don't have MSI-X support.
>>>> > >>  Now, we have scenarios like DPDK in Guest which dont use
>>>> > >>  interrupts and still use vhost. Also, performance of guests
>>>> > >>  without MSI-X support is getting less popular.
>>>> > >>
>>>> > >>  Its OK to remove this extra option and enable vhost
>>>> > >>  on the basis of vhost=ON/OFF.
>>>> > >>  Done basic testing with vhost on/off for latest guests
>>>> > >>  and old guests(non-msix).
>>>> > >>
>>>> > >> Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
>> > 
>> > Looks good. Two questions:
>> > 
>> > - Did libvirt use this? if not, we may want to drop vhostfore option
>> > completely.
> Yes, it did.
>

For vhost-user, vhostforce is mandatory. But how about tap? Looks like
it was not used, and I could not even find any option in
http://libvirt.org/formatdomain.html.