On Fri, Jul 21, 2023 at 11:57 PM Si-Wei Liu <si-wei....@oracle.com> wrote:
>
>
>
> On 7/20/2023 11:14 AM, Eugenio Pérez wrote:
> > Split out vq reset operation in its own function, as it may be called
> > with ring reset.
> >
> > Signed-off-by: Eugenio Pérez <epere...@redhat.com>
> > ---
> > hw/virtio/vhost-vdpa.c | 16 ++++++++++++++++
> > 1 file changed, 16 insertions(+)
> >
> > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> > index 6ae276ccde..df2515a247 100644
> > --- a/hw/virtio/vhost-vdpa.c
> > +++ b/hw/virtio/vhost-vdpa.c
> > @@ -547,6 +547,21 @@ int vhost_vdpa_set_vring_ready(struct vhost_vdpa *v,
> > unsigned idx)
> > return vhost_vdpa_set_vring_ready_internal(v, idx, true);
> > }
> >
> > +/* TODO: Properly reorder static functions */
> > +static void vhost_vdpa_svq_stop(struct vhost_dev *dev, unsigned idx);
> > +static void vhost_vdpa_reset_queue(struct vhost_dev *dev, int idx)
> > +{
> > + struct vhost_vdpa *v = dev->opaque;
> > +
> > + if (dev->features & VIRTIO_F_RING_RESET) {
> > + vhost_vdpa_set_vring_ready_internal(v, idx, false);
> I'm not sure I understand this patch - this is NOT the spec defined way
> to initiate RING_RESET? Quoting the spec diff from the original
> RING_RESET tex doc:
>
> +The device MUST reset the queue when 1 is written to \field{queue_reset}, and
> +present a 1 in \field{queue_reset} after the queue has been reset, until the
> +driver re-enables the queue via \field{queue_enable} or the device is reset.
> +The device MUST present consistent default values after queue reset.
> +(see \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue
> Reset}).
>
> Or you intend to rewrite it to be spec conforming later on?
>
Sorry for the late notice, but yes, the plan would be either to
rewrite this piece of code or to make vDPA uAPI work that way
(unlikely). I didn't create a new ioctl for that.
Please see
https://lists.nongnu.org/archive/html/qemu-devel/2023-07/msg04144.html
Thanks!
> -Siwei
> > + }
> > +
> > + if (v->shadow_vqs_enabled) {
> > + vhost_vdpa_svq_stop(dev, idx - dev->vq_index);
> > + }
> > +}
> > +
> > /*
> > * The use of this function is for requests that only need to be
> > * applied once. Typically such request occurs at the beginning
> > @@ -1543,4 +1558,5 @@ const VhostOps vdpa_ops = {
> > .vhost_force_iommu = vhost_vdpa_force_iommu,
> > .vhost_set_config_call = vhost_vdpa_set_config_call,
> > .vhost_reset_status = vhost_vdpa_reset_status,
> > + .vhost_reset_queue = vhost_vdpa_reset_queue,
> > };
>
