Re: [PATCH V2] vdpa/mlx5: preserve CVQ vringh index

[Jason Wang]

On Thu, Nov 2, 2023 at 3:10 PM Eugenio Perez Martin <eperezma@xxxxxxxxxx> wrote:
>
> On Wed, Nov 1, 2023 at 4:55 PM Steve Sistare <steven.sistare@xxxxxxxxxx> wrote:
> >
> > mlx5_vdpa does not preserve userland's view of vring base for the control
> > queue in the following sequence:
> >
> > ioctl VHOST_SET_VRING_BASE
> > ioctl VHOST_VDPA_SET_STATUS VIRTIO_CONFIG_S_DRIVER_OK
> >   mlx5_vdpa_set_status()
> >     setup_cvq_vring()
> >       vringh_init_iotlb()
> >         vringh_init_kern()
> >           vrh->last_avail_idx = 0;
> > ioctl VHOST_GET_VRING_BASE
> >
> > To fix, restore the value of cvq->vring.last_avail_idx after calling
> > vringh_init_iotlb.
> >
>
> Fixes tag missing?

+1

>
> Apart from that,
>
> Acked-by: Eugenio Pérez <eperezma@xxxxxxxxxx>

With the fix tag added.

Acked-by: Jason Wang <jasowang@xxxxxxxxxx>

Thanks

>
> > Signed-off-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
> > ---
> >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > index 946488b8989f..ca972af3c89a 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -2795,13 +2795,18 @@ static int setup_cvq_vring(struct mlx5_vdpa_dev *mvdev)
> >         struct mlx5_control_vq *cvq = &mvdev->cvq;
> >         int err = 0;
> >
> > -       if (mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ))
> > +       if (mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ)) {
> > +               u16 idx = cvq->vring.last_avail_idx;
> > +
> >                 err = vringh_init_iotlb(&cvq->vring, mvdev->actual_features,
> >                                         MLX5_CVQ_MAX_ENT, false,
> >                                         (struct vring_desc *)(uintptr_t)cvq->desc_addr,
> >                                         (struct vring_avail *)(uintptr_t)cvq->driver_addr,
> >                                         (struct vring_used *)(uintptr_t)cvq->device_addr);
> >
> > +               if (!err)
> > +                       cvq->vring.last_avail_idx = cvq->vring.last_used_idx = idx;
> > +       }
> >         return err;
> >  }
> >
> > --
> > 2.39.3
> >
>