Re: [Qemu-devel] [RFC 1/2] spec/vhost-user: Introduce secondary channel for slave initiated requests

[Marc-André Lureau]

Hi

On Tue, Apr 11, 2017 at 5:53 PM Maxime Coquelin <address@hidden>
wrote:

> Hi Marc-André,
>
> On 04/11/2017 03:06 PM, Marc-André Lureau wrote:
> > Hi
> >
> > On Tue, Apr 11, 2017 at 12:10 PM Maxime Coquelin
> > <address@hidden <mailto:address@hidden>> wrote:
> >
> >     This vhost-user specification update aims at enabling the
> >     slave to send requests to the master using a dedicated socket
> >     created by the master.
> >
> >     It can be used for example when the slave implements a device
> >     IOTLB to send cache miss requests to the master.
> >
> >     The message types list is updated with an "Initiator" field to
> >     indicate for each type whether the master and/or slave can
> >     initiate the request.
> >
> >     Signed-off-by: Maxime Coquelin <address@hidden
> >     <mailto:address@hidden>>
> >
> >
> > This is very similar to a patch I proposed for shutdown slave initiated
> > requests:
> > https://lists.gnu.org/archive/html/qemu-devel/2016-04/msg00095.html
>
> Indeed, thanks for pointing this out, I wasn't aware of your series.
>
> I find your proposal of having dedicated messages types
> (VHOST_USER_SLAVE_*) cleaner.
>
> ok


> Are you ok if I handover your patch, and replace
> VHOST_USER_SET_SLAVE_FD to VHOST_USER_SET_SLAVE_REQ_FD?
>

They are very similar, I suggest you update your patch with the best of
both.

I suppose you came to the same conclusion with me that trying to make the
communication both ways on the same fd would be quite difficult, although
it's a bit strange that the qemu implementation forces the design of the
protocol in some direction.
-- 
Marc-André Lureau