Re: [PATCH v3 02/11] vdpa: Add set/get_vq_affinity callbacks in vdpa_config_ops

From: Yongji Xie <xieyongji@bytedance.com>
To: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Christoph Hellwig <hch@lst.de>,
	virtualization <virtualization@lists.linux-foundation.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 02/11] vdpa: Add set/get_vq_affinity callbacks in vdpa_config_ops
Date: Fri, 17 Mar 2023 15:10:08 +0800	[thread overview]
Message-ID: <CACycT3v7kzJ5f+ENzP6d_Y=wyhL4z1uaSAJH+3keTyquTAKf5A@mail.gmail.com> (raw)
In-Reply-To: <319ece63-ac4f-db05-8a55-65ecad75e437@redhat.com>

On Thu, Mar 16, 2023 at 11:27 AM Jason Wang <jasowang@redhat.com> wrote:
>
>
> 在 2023/2/28 17:41, Xie Yongji 写道:
> > This introduces set/get_vq_affinity callbacks in
> > vdpa_config_ops to support interrupt affinity
> > management for vdpa device drivers.
> >
> > Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> > Acked-by: Jason Wang <jasowang@redhat.com>
> > ---
> >   drivers/virtio/virtio_vdpa.c | 28 ++++++++++++++++++++++++++++
> >   include/linux/vdpa.h         | 13 +++++++++++++
> >   2 files changed, 41 insertions(+)
> >
> > diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
> > index d7f5af62ddaa..f72696b4c1c2 100644
> > --- a/drivers/virtio/virtio_vdpa.c
> > +++ b/drivers/virtio/virtio_vdpa.c
> > @@ -337,6 +337,32 @@ static const char *virtio_vdpa_bus_name(struct virtio_device *vdev)
> >       return dev_name(&vdpa->dev);
> >   }
> >
> > +static int virtio_vdpa_set_vq_affinity(struct virtqueue *vq,
> > +                                    const struct cpumask *cpu_mask)
> > +{
> > +     struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev);
> > +     struct vdpa_device *vdpa = vd_dev->vdpa;
> > +     const struct vdpa_config_ops *ops = vdpa->config;
> > +     unsigned int index = vq->index;
> > +
> > +     if (ops->set_vq_affinity)
> > +             return ops->set_vq_affinity(vdpa, index, cpu_mask);
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct cpumask *
> > +virtio_vdpa_get_vq_affinity(struct virtio_device *vdev, int index)
> > +{
> > +     struct vdpa_device *vdpa = vd_get_vdpa(vdev);
> > +     const struct vdpa_config_ops *ops = vdpa->config;
> > +
> > +     if (ops->get_vq_affinity)
> > +             return ops->get_vq_affinity(vdpa, index);
> > +
> > +     return NULL;
> > +}
> > +
> >   static const struct virtio_config_ops virtio_vdpa_config_ops = {
> >       .get            = virtio_vdpa_get,
> >       .set            = virtio_vdpa_set,
> > @@ -349,6 +375,8 @@ static const struct virtio_config_ops virtio_vdpa_config_ops = {
> >       .get_features   = virtio_vdpa_get_features,
> >       .finalize_features = virtio_vdpa_finalize_features,
> >       .bus_name       = virtio_vdpa_bus_name,
> > +     .set_vq_affinity = virtio_vdpa_set_vq_affinity,
> > +     .get_vq_affinity = virtio_vdpa_get_vq_affinity,
> >   };
> >
> >   static void virtio_vdpa_release_dev(struct device *_d)
> > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> > index 43f59ef10cc9..d61f369f9cd6 100644
> > --- a/include/linux/vdpa.h
> > +++ b/include/linux/vdpa.h
> > @@ -250,6 +250,15 @@ struct vdpa_map_file {
> >    *                          @vdev: vdpa device
> >    *                          Returns the iova range supported by
> >    *                          the device.
> > + * @set_vq_affinity:         Set the irq affinity of virtqueue (optional)
>
>
> Nit: it's better not mention IRQ here because the virtqueue notification
> is not necessarily backed on IRQ.
>

OK.

Thanks,
Yongji