From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: shahafs@mellanox.com, wanpengli@tencent.com, parav@mellanox.com,
kvm@vger.kernel.org, netdev@vger.kernel.org,
sean.j.christopherson@intel.com,
virtualization@lists.linux-foundation.org, eli@mellanox.com,
pbonzini@redhat.com, "Zhu, Lingshan" <lingshan.zhu@intel.com>
Subject: Re: [PATCH V5 1/6] vhost: introduce vhost_vring_call
Date: Mon, 10 Aug 2020 09:37:00 -0400 [thread overview]
Message-ID: <20200810093630-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <14fd2bf1-e9c1-a192-bd6c-f1ee5fd227f6@redhat.com>
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?
Thanks,
> >
> >
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next prev parent reply other threads:[~2020-08-10 13:37 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200731065533.4144-1-lingshan.zhu@intel.com>
[not found] ` <20200731065533.4144-2-lingshan.zhu@intel.com>
2020-08-04 8:38 ` [PATCH V5 1/6] vhost: introduce vhost_vring_call Jason Wang
[not found] ` <d51dd4e3-7513-c771-104c-b61f9ee70f30@intel.com>
2020-08-04 8:53 ` Jason Wang
2020-08-04 9:21 ` Michael S. Tsirkin
2020-08-05 2:16 ` Jason Wang
[not found] ` <bf10cde9-db86-a1ac-e2a8-363735e49afb@intel.com>
2020-08-05 5:53 ` Jason Wang
2020-08-10 13:37 ` Michael S. Tsirkin [this message]
2020-08-11 2:53 ` Jason Wang
[not found] ` <4605de34-c426-33d4-714b-e03716d0374c@intel.com>
2020-08-05 2:20 ` Jason Wang
[not found] ` <20200731065533.4144-5-lingshan.zhu@intel.com>
2020-08-04 8:51 ` [PATCH V5 4/6] vhost_vdpa: implement IRQ offloading in vhost_vdpa Jason Wang
[not found] ` <ae5385dc-6637-c5a3-b00a-02f66bb9a85f@intel.com>
2020-08-04 9:36 ` Michael S. Tsirkin
2020-08-05 2:36 ` Jason Wang
[not found] ` <cb01a490-e9e6-42f5-b6c3-caefa2d91b9f@intel.com>
2020-08-05 5:51 ` Jason Wang
2020-08-05 8:06 ` Jason Wang
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