Xuan Zhuo
2022-Jul-27 07:36 UTC
[PATCH v13 16/42] virtio_ring: split: introduce virtqueue_resize_split()
On Wed, 27 Jul 2022 11:12:19 +0800, Jason Wang <jasowang at redhat.com> wrote:> > ? 2022/7/26 15:21, Xuan Zhuo ??: > > virtio ring split supports resize. > > > > Only after the new vring is successfully allocated based on the new num, > > we will release the old vring. In any case, an error is returned, > > indicating that the vring still points to the old vring. > > > > In the case of an error, re-initialize(virtqueue_reinit_split()) the > > virtqueue to ensure that the vring can be used. > > > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > > Acked-by: Jason Wang <jasowang at redhat.com> > > --- > > drivers/virtio/virtio_ring.c | 34 ++++++++++++++++++++++++++++++++++ > > 1 file changed, 34 insertions(+) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index b6fda91c8059..58355e1ac7d7 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -220,6 +220,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index, > > void (*callback)(struct virtqueue *), > > const char *name); > > static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num); > > +static void vring_free(struct virtqueue *_vq); > > > > /* > > * Helpers. > > @@ -1117,6 +1118,39 @@ static struct virtqueue *vring_create_virtqueue_split( > > return vq; > > } > > > > +static int virtqueue_resize_split(struct virtqueue *_vq, u32 num) > > +{ > > + struct vring_virtqueue_split vring_split = {}; > > + struct vring_virtqueue *vq = to_vvq(_vq); > > + struct virtio_device *vdev = _vq->vdev; > > + int err; > > + > > + err = vring_alloc_queue_split(&vring_split, vdev, num, > > + vq->split.vring_align, > > + vq->split.may_reduce_num); > > + if (err) > > + goto err; > > > I think we don't need to do anything here?Am I missing something?> > > > + > > + err = vring_alloc_state_extra_split(&vring_split); > > + if (err) { > > + vring_free_split(&vring_split, vdev); > > + goto err; > > > I suggest to move vring_free_split() into a dedicated error label.Will change. Thanks.> > Thanks > > > > + } > > + > > + vring_free(&vq->vq); > > + > > + virtqueue_vring_init_split(&vring_split, vq); > > + > > + virtqueue_init(vq, vring_split.vring.num); > > + virtqueue_vring_attach_split(vq, &vring_split); > > + > > + return 0; > > + > > +err: > > + virtqueue_reinit_split(vq); > > + return -ENOMEM; > > +} > > + > > > > /* > > * Packed ring specific functions - *_packed(). >
Jason Wang
2022-Jul-28 02:38 UTC
[PATCH v13 16/42] virtio_ring: split: introduce virtqueue_resize_split()
On Wed, Jul 27, 2022 at 3:44 PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote:> > On Wed, 27 Jul 2022 11:12:19 +0800, Jason Wang <jasowang at redhat.com> wrote: > > > > ? 2022/7/26 15:21, Xuan Zhuo ??: > > > virtio ring split supports resize. > > > > > > Only after the new vring is successfully allocated based on the new num, > > > we will release the old vring. In any case, an error is returned, > > > indicating that the vring still points to the old vring. > > > > > > In the case of an error, re-initialize(virtqueue_reinit_split()) the > > > virtqueue to ensure that the vring can be used. > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > > > Acked-by: Jason Wang <jasowang at redhat.com> > > > --- > > > drivers/virtio/virtio_ring.c | 34 ++++++++++++++++++++++++++++++++++ > > > 1 file changed, 34 insertions(+) > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > index b6fda91c8059..58355e1ac7d7 100644 > > > --- a/drivers/virtio/virtio_ring.c > > > +++ b/drivers/virtio/virtio_ring.c > > > @@ -220,6 +220,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index, > > > void (*callback)(struct virtqueue *), > > > const char *name); > > > static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num); > > > +static void vring_free(struct virtqueue *_vq); > > > > > > /* > > > * Helpers. > > > @@ -1117,6 +1118,39 @@ static struct virtqueue *vring_create_virtqueue_split( > > > return vq; > > > } > > > > > > +static int virtqueue_resize_split(struct virtqueue *_vq, u32 num) > > > +{ > > > + struct vring_virtqueue_split vring_split = {}; > > > + struct vring_virtqueue *vq = to_vvq(_vq); > > > + struct virtio_device *vdev = _vq->vdev; > > > + int err; > > > + > > > + err = vring_alloc_queue_split(&vring_split, vdev, num, > > > + vq->split.vring_align, > > > + vq->split.may_reduce_num); > > > + if (err) > > > + goto err; > > > > > > I think we don't need to do anything here? > > Am I missing something?I meant it looks to me most of the virtqueue_reinit() is unnecessary. We probably only need to reinit avail/used idx there. Thanks> > > > > > > > + > > > + err = vring_alloc_state_extra_split(&vring_split); > > > + if (err) { > > > + vring_free_split(&vring_split, vdev); > > > + goto err; > > > > > > I suggest to move vring_free_split() into a dedicated error label. > > Will change. > > Thanks. > > > > > > Thanks > > > > > > > + } > > > + > > > + vring_free(&vq->vq); > > > + > > > + virtqueue_vring_init_split(&vring_split, vq); > > > + > > > + virtqueue_init(vq, vring_split.vring.num); > > > + virtqueue_vring_attach_split(vq, &vring_split); > > > + > > > + return 0; > > > + > > > +err: > > > + virtqueue_reinit_split(vq); > > > + return -ENOMEM; > > > +} > > > + > > > > > > /* > > > * Packed ring specific functions - *_packed(). > > >