Re: [Qemu-devel] [[RFC v3 12/12] virtio: feature vhost-net support for packed ring

[Wei Xu <wexu@redhat.com>]

On Mon, Oct 15, 2018 at 03:50:21PM +0800, Jason Wang wrote:
> 
> 
> On 2018年10月11日 22:08, wexu@redhat.com wrote:
> >From: Wei Xu <wexu@redhat.com>
> >
> >(cherry picked from commit 305a2c4640c15c5717245067ab937fd10f478ee6)
> >Signed-off-by: Wei Xu <wexu@redhat.com>
> >(cherry picked from commit 46476dae6f44c6fef8802a4a0ac7d0d79fe399e3)
> >Signed-off-by: Wei Xu <wexu@redhat.com>
> 
> The cherry-pick tag looks odd.

My bad.

> 
> >---
> >  hw/virtio/vhost.c          | 3 +++
> >  hw/virtio/virtio.c         | 4 ++++
> >  include/hw/virtio/virtio.h | 1 +
> >  3 files changed, 8 insertions(+)
> >
> >diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> >index 9df2da3..de06d55 100644
> >--- a/hw/virtio/vhost.c
> >+++ b/hw/virtio/vhost.c
> >@@ -974,6 +974,9 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
> >      }
> >      state.num = virtio_queue_get_last_avail_idx(vdev, idx);
> >+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
> >+        state.num |= ((int)virtio_queue_packed_get_wc(vdev, idx)) << 31;
> >+    }
> 
> We decide to use bit 15 instead.
> 
> And please refer the recent discussion for the agreement.

OK.

> 
> Thanks
> 
> >      r = dev->vhost_ops->vhost_set_vring_base(dev, &state);
> >      if (r) {
> >          VHOST_OPS_DEBUG("vhost_set_vring_base failed");
> >diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> >index 1d25776..2a90163 100644
> >--- a/hw/virtio/virtio.c
> >+++ b/hw/virtio/virtio.c
> >@@ -2894,6 +2894,10 @@ void virtio_init(VirtIODevice *vdev, const char *name,
> >      vdev->use_guest_notifier_mask = true;
> >  }
> >+bool virtio_queue_packed_get_wc(VirtIODevice *vdev, int n)
> >+{
> >+    return vdev->vq[n].avail_wrap_counter;
> >+}
> >  hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n)
> >  {
> >      return vdev->vq[n].vring.desc;
> >diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> >index 9af8839..0bb3be5 100644
> >--- a/include/hw/virtio/virtio.h
> >+++ b/include/hw/virtio/virtio.h
> >@@ -295,6 +295,7 @@ void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
> >                                                  VirtIOHandleAIOOutput handle_output);
> >  VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
> >  VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
> >+bool virtio_queue_packed_get_wc(VirtIODevice *vdev, int n);
> >  static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
> >  {
> 
>