Re: [PATCH V5 1/6] vhost: introduce vhost_vring_call

[Jason Wang <jasowang@xxxxxxxxxx>]

On 2020/8/10 下午9:37, Michael S. Tsirkin wrote:
> On Wed, Aug 05, 2020 at 10:16:16AM +0800, Jason Wang wrote:
> > On 2020/8/4 下午5:21, Michael S. Tsirkin wrote:
> > > > > > >     +struct vhost_vring_call {
> > > > > > > +    struct eventfd_ctx *ctx;
> > > > > > > +    struct irq_bypass_producer producer;
> > > > > > > +    spinlock_t ctx_lock;
> > > > > > It's not clear to me why we need ctx_lock here.
> > > > > >
> > > > > > Thanks
> > > > > Hi Jason,
> > > > >
> > > > > we use this lock to protect the eventfd_ctx and irq from race conditions,
> > > > We don't support irq notification from vDPA device driver in this version,
> > > > do we still have race condition?
> > > >
> > > > Thanks
> > > Jason I'm not sure what you are trying to say here.
> >
> > I meant we change the API from V4 so driver won't notify us if irq is
> > changed.
> >
> > Then it looks to me there's no need for the ctx_lock, everyhing could be
> > synchronized with vq mutex.
> >
> > Thanks
> Jason do you want to post a cleanup patch simplifying code along these
> lines?


Ling Shan promised to post a patch to fix this.

Thanks


> Thanks,
>
>
> > >