[v4] vDPA shadow virtqueue

[RFC PATCH v4 09/20] vdpa: Save call_fd in vhost-vdpa

Posted by Eugenio Pérez 4 years, 4 months ago

We need to know it to switch to Shadow VirtQueue.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 include/hw/virtio/vhost-vdpa.h | 2 ++
 hw/virtio/vhost-vdpa.c         | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index 48aae59d8e..fddac248b3 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -30,6 +30,8 @@ typedef struct vhost_vdpa {
     GPtrArray *shadow_vqs;
     struct vhost_dev *dev;
     QLIST_ENTRY(vhost_vdpa) entry;
+    /* File descriptor the device uses to call VM/SVQ */
+    int call_fd[VIRTIO_QUEUE_MAX];
     VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
 } VhostVDPA;
 
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 36c954a779..57a857444a 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -652,7 +652,12 @@ static int vhost_vdpa_set_vring_kick(struct vhost_dev *dev,
 static int vhost_vdpa_set_vring_call(struct vhost_dev *dev,
                                        struct vhost_vring_file *file)
 {
+    struct vhost_vdpa *v = dev->opaque;
+    int vdpa_idx = vhost_vdpa_get_vq_index(dev, file->index);
+
     trace_vhost_vdpa_set_vring_call(dev, file->index, file->fd);
+
+    v->call_fd[vdpa_idx] = file->fd;
     return vhost_vdpa_call(dev, VHOST_SET_VRING_CALL, file);
 }
 
-- 
2.27.0

Re: [RFC PATCH v4 09/20] vdpa: Save call_fd in vhost-vdpa

Posted by Jason Wang 4 years, 3 months ago

在 2021/10/1 下午3:05, Eugenio Pérez 写道:
> We need to know it to switch to Shadow VirtQueue.
>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
>   include/hw/virtio/vhost-vdpa.h | 2 ++
>   hw/virtio/vhost-vdpa.c         | 5 +++++
>   2 files changed, 7 insertions(+)
>
> diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
> index 48aae59d8e..fddac248b3 100644
> --- a/include/hw/virtio/vhost-vdpa.h
> +++ b/include/hw/virtio/vhost-vdpa.h
> @@ -30,6 +30,8 @@ typedef struct vhost_vdpa {
>       GPtrArray *shadow_vqs;
>       struct vhost_dev *dev;
>       QLIST_ENTRY(vhost_vdpa) entry;
> +    /* File descriptor the device uses to call VM/SVQ */
> +    int call_fd[VIRTIO_QUEUE_MAX];


Any reason we don't do this for kick_fd or why 
virtio_queue_get_guest_notifier() can't work here? Need a comment or 
commit log.

I think we need to have a consistent way to handle both kick and call fd.

Thanks


>       VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
>   } VhostVDPA;
>   
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 36c954a779..57a857444a 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -652,7 +652,12 @@ static int vhost_vdpa_set_vring_kick(struct vhost_dev *dev,
>   static int vhost_vdpa_set_vring_call(struct vhost_dev *dev,
>                                          struct vhost_vring_file *file)
>   {
> +    struct vhost_vdpa *v = dev->opaque;
> +    int vdpa_idx = vhost_vdpa_get_vq_index(dev, file->index);
> +
>       trace_vhost_vdpa_set_vring_call(dev, file->index, file->fd);
> +
> +    v->call_fd[vdpa_idx] = file->fd;
>       return vhost_vdpa_call(dev, VHOST_SET_VRING_CALL, file);
>   }
>

Re: [RFC PATCH v4 09/20] vdpa: Save call_fd in vhost-vdpa

Posted by Eugenio Perez Martin 4 years, 3 months ago

On Wed, Oct 13, 2021 at 5:43 AM Jason Wang <jasowang@redhat.com> wrote:
>
>
> 在 2021/10/1 下午3:05, Eugenio Pérez 写道:
> > We need to know it to switch to Shadow VirtQueue.
> >
> > Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> > ---
> >   include/hw/virtio/vhost-vdpa.h | 2 ++
> >   hw/virtio/vhost-vdpa.c         | 5 +++++
> >   2 files changed, 7 insertions(+)
> >
> > diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
> > index 48aae59d8e..fddac248b3 100644
> > --- a/include/hw/virtio/vhost-vdpa.h
> > +++ b/include/hw/virtio/vhost-vdpa.h
> > @@ -30,6 +30,8 @@ typedef struct vhost_vdpa {
> >       GPtrArray *shadow_vqs;
> >       struct vhost_dev *dev;
> >       QLIST_ENTRY(vhost_vdpa) entry;
> > +    /* File descriptor the device uses to call VM/SVQ */
> > +    int call_fd[VIRTIO_QUEUE_MAX];
>
>
> Any reason we don't do this for kick_fd or why
> virtio_queue_get_guest_notifier() can't work here? Need a comment or
> commit log.
>
> I think we need to have a consistent way to handle both kick and call fd.
>
> Thanks
>

The reasons for it have been given in answers to patch 08/20, since
both have converged to it somehow. Please let me know if you think
otherwise and this needs to be continued here.

Thanks!

>
> >       VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
> >   } VhostVDPA;
> >
> > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> > index 36c954a779..57a857444a 100644
> > --- a/hw/virtio/vhost-vdpa.c
> > +++ b/hw/virtio/vhost-vdpa.c
> > @@ -652,7 +652,12 @@ static int vhost_vdpa_set_vring_kick(struct vhost_dev *dev,
> >   static int vhost_vdpa_set_vring_call(struct vhost_dev *dev,
> >                                          struct vhost_vring_file *file)
> >   {
> > +    struct vhost_vdpa *v = dev->opaque;
> > +    int vdpa_idx = vhost_vdpa_get_vq_index(dev, file->index);
> > +
> >       trace_vhost_vdpa_set_vring_call(dev, file->index, file->fd);
> > +
> > +    v->call_fd[vdpa_idx] = file->fd;
> >       return vhost_vdpa_call(dev, VHOST_SET_VRING_CALL, file);
> >   }
> >
>