On Tue, 27 Jun 2023 16:03:29 +0800, Jason Wang <jasowang@xxxxxxxxxx> wrote:
> On Fri, Jun 2, 2023 at 5:22 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote:
> >
> > If the vq is the premapped mode, use the sg_dma_address() directly.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> > ---
> > drivers/virtio/virtio_ring.c | 36 ++++++++++++++++++++++++++----------
> > 1 file changed, 26 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index 18212c3e056b..dc109fbc05a5 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -1299,9 +1299,13 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
> >
> > for (n = 0; n < out_sgs + in_sgs; n++) {
> > for (sg = sgs[n]; sg; sg = sg_next(sg)) {
> > - if (vring_map_one_sg(vq, sg, n < out_sgs ?
> > - DMA_TO_DEVICE : DMA_FROM_DEVICE, &addr))
> > - goto unmap_release;
> > + if (vq->premapped) {
> > + addr = sg_dma_address(sg);
> > + } else {
> > + if (vring_map_one_sg(vq, sg, n < out_sgs ?
> > + DMA_TO_DEVICE : DMA_FROM_DEVICE, &addr))
> > + goto unmap_release;
> > + }
> >
> > desc[i].flags = cpu_to_le16(n < out_sgs ?
> > 0 : VRING_DESC_F_WRITE);
> > @@ -1369,10 +1373,12 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
> > return 0;
> >
> > unmap_release:
> > - err_idx = i;
> > + if (!vq->premapped) {
> > + err_idx = i;
> >
> > - for (i = 0; i < err_idx; i++)
> > - vring_unmap_desc_packed(vq, &desc[i]);
> > + for (i = 0; i < err_idx; i++)
> > + vring_unmap_desc_packed(vq, &desc[i]);
> > + }
> >
> > kfree(desc);
> >
> > @@ -1447,9 +1453,13 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
> > for (sg = sgs[n]; sg; sg = sg_next(sg)) {
> > dma_addr_t addr;
> >
> > - if (vring_map_one_sg(vq, sg, n < out_sgs ?
> > - DMA_TO_DEVICE : DMA_FROM_DEVICE, &addr))
> > - goto unmap_release;
> > + if (vq->premapped) {
> > + addr = sg_dma_address(sg);
> > + } else {
> > + if (vring_map_one_sg(vq, sg, n < out_sgs ?
> > + DMA_TO_DEVICE : DMA_FROM_DEVICE, &addr))
> > + goto unmap_release;
> > + }
> >
> > flags = cpu_to_le16(vq->packed.avail_used_flags |
> > (++c == total_sg ? 0 : VRING_DESC_F_NEXT) |
> > @@ -1512,11 +1522,17 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
> > return 0;
> >
> > unmap_release:
> > + vq->packed.avail_used_flags = avail_used_flags;
> > +
> > + if (vq->premapped) {
>
> Similar to the split path, I think we can't hit vq->premapped here.
YES, similar to the above reply, we can have a better way.
But, we can hit vq->premapped, when we fail doing dma for the indirect desc
array.
Thanks.
>
> Thanks
>
>
> > + END_USE(vq);
> > + return -EIO;
> > + }
> > +
> > err_idx = i;
> > i = head;
> > curr = vq->free_head;
> >
> > - vq->packed.avail_used_flags = avail_used_flags;
> >
> > for (n = 0; n < total_sg; n++) {
> > if (i == err_idx)
> > --
> > 2.32.0.3.g01195cf9f
> >
>
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