Re: [PATCH v3 2/2] virtio: decrement avail idx with buffer detach for packed ring
> > On 2019/8/9 下午2:48, Pankaj Gupta wrote: > > This patch decrements 'next_avail_idx' count when detaching a buffer > > from vq for packed ring code. Split ring code already does this in > > virtqueue_detach_unused_buf_split function. This updates the > > 'next_avail_idx' to the previous correct index after an unused buffer > > is detatched from the vq. > > > > Signed-off-by: Pankaj Gupta > > --- > > drivers/virtio/virtio_ring.c | 6 ++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index c8be1c4f5b55..7c69181113e2 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -1537,6 +1537,12 @@ static void > > *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq) > > /* detach_buf clears data, so grab it now. */ > > buf = vq->packed.desc_state[i].data; > > detach_buf_packed(vq, i, NULL); > > + vq->packed.next_avail_idx--; > > + if (vq->packed.next_avail_idx < 0) { > > + vq->packed.next_avail_idx = vq->packed.vring.num - 1; > > + vq->packed.avail_wrap_counter ^= 1; > > + } > > + > > END_USE(vq); > > return buf; > > } > > > Acked-by: Jason Wang Thank you, Jason. Best regards, Pankaj > > > ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH v3 2/2] virtio: decrement avail idx with buffer detach for packed ring
> On Fri, Aug 09, 2019 at 12:18:47PM +0530, Pankaj Gupta wrote: > > This patch decrements 'next_avail_idx' count when detaching a buffer > > from vq for packed ring code. Split ring code already does this in > > virtqueue_detach_unused_buf_split function. This updates the > > 'next_avail_idx' to the previous correct index after an unused buffer > > is detatched from the vq. > > > > Signed-off-by: Pankaj Gupta > > I would make this patch 1, not patch 2, otherwise > patch 1 corrupts the ring. Sure. Will post this patch as patch 1 in next version. Thanks, Pankaj > > > > --- > > drivers/virtio/virtio_ring.c | 6 ++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index c8be1c4f5b55..7c69181113e2 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -1537,6 +1537,12 @@ static void > > *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq) > > /* detach_buf clears data, so grab it now. */ > > buf = vq->packed.desc_state[i].data; > > detach_buf_packed(vq, i, NULL); > > + vq->packed.next_avail_idx--; > > + if (vq->packed.next_avail_idx < 0) { > > + vq->packed.next_avail_idx = vq->packed.vring.num - 1; > > + vq->packed.avail_wrap_counter ^= 1; > > + } > > + > > END_USE(vq); > > return buf; > > } > > -- > > 2.20.1 > ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH v3 2/2] virtio: decrement avail idx with buffer detach for packed ring
On 2019/8/9 下午2:48, Pankaj Gupta wrote: This patch decrements 'next_avail_idx' count when detaching a buffer from vq for packed ring code. Split ring code already does this in virtqueue_detach_unused_buf_split function. This updates the 'next_avail_idx' to the previous correct index after an unused buffer is detatched from the vq. Signed-off-by: Pankaj Gupta --- drivers/virtio/virtio_ring.c | 6 ++ 1 file changed, 6 insertions(+) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index c8be1c4f5b55..7c69181113e2 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1537,6 +1537,12 @@ static void *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq) /* detach_buf clears data, so grab it now. */ buf = vq->packed.desc_state[i].data; detach_buf_packed(vq, i, NULL); + vq->packed.next_avail_idx--; + if (vq->packed.next_avail_idx < 0) { + vq->packed.next_avail_idx = vq->packed.vring.num - 1; + vq->packed.avail_wrap_counter ^= 1; + } + END_USE(vq); return buf; } Acked-by: Jason Wang ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH v3 2/2] virtio: decrement avail idx with buffer detach for packed ring
On Fri, Aug 09, 2019 at 12:18:47PM +0530, Pankaj Gupta wrote: > This patch decrements 'next_avail_idx' count when detaching a buffer > from vq for packed ring code. Split ring code already does this in > virtqueue_detach_unused_buf_split function. This updates the > 'next_avail_idx' to the previous correct index after an unused buffer > is detatched from the vq. > > Signed-off-by: Pankaj Gupta I would make this patch 1, not patch 2, otherwise patch 1 corrupts the ring. > --- > drivers/virtio/virtio_ring.c | 6 ++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index c8be1c4f5b55..7c69181113e2 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -1537,6 +1537,12 @@ static void *virtqueue_detach_unused_buf_packed(struct > virtqueue *_vq) > /* detach_buf clears data, so grab it now. */ > buf = vq->packed.desc_state[i].data; > detach_buf_packed(vq, i, NULL); > + vq->packed.next_avail_idx--; > + if (vq->packed.next_avail_idx < 0) { > + vq->packed.next_avail_idx = vq->packed.vring.num - 1; > + vq->packed.avail_wrap_counter ^= 1; > + } > + > END_USE(vq); > return buf; > } > -- > 2.20.1 ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization