Re: [Qemu-devel] [PATCH v2] net:Enable vhost with vhostforce, vhost options for guests without MSI-X support

[Jason Wang <jasowang@redhat.com>]

On 06/11/2015 07:49 PM, Pankaj Gupta wrote:
>> On 06/05/2015 10:32 PM, Pankaj Gupta wrote:
>>>     We use vhostforce to enable vhost even if Guests don't have MSI-X
>>>     support
>>> and we fall back to QEMU virtio-net. This patch will enable vhost
>>> unconditionally
>>> whenever we have vhostforce='ON' or vhost='ON'.
>>>
>>> Initially, I wanted to remove vhostforce completely as an additional
>>> argument.
>>> But after discussing this in mailing list found that some programs are
>>> using vhostforce
>>> and some vhost. So, we want to keep semantics of both the options.
>>>
>>> Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
>>> ---
>>>  net/tap.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/net/tap.c b/net/tap.c
>>> index d1ca314..4618359 100644
>>> --- a/net/tap.c
>>> +++ b/net/tap.c
>>> @@ -649,13 +649,13 @@ static void net_init_tap_one(const NetdevTapOptions
>>> *tap, NetClientState *peer,
>>>          }
>>>      }
>>>  
>>> -    if (tap->has_vhost ? tap->vhost :
>>> -        vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
>>> +    if ((tap->has_vhost ? tap->vhost :
>>> +        vhostfdname) || tap->vhostforce) {

The change here seems useless.

>>>          VhostNetOptions options;
>>>  
>>>          options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
>>>          options.net_backend = &s->nc;
>>> -        options.force = tap->has_vhostforce && tap->vhostforce;
>>> +        options.force = true;
>>>  
>>>          if (tap->has_vhostfd || tap->has_vhostfds) {
>>>              vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
>> In this case, I believe there's no need to have vhost_net_query() and
>> query_guest_notifiers() callbacks (and maybe more others).
> I also thought on this. If same functions can be used by some other module in future?
> If not, I was thinking to remove those in another patch.

I could not think a usage of this in the future.
>
> Does the main functionality looks OK? 

See comment above and I prefer to remove all unnecessary functions.

Thanks