diff mbox series

[vhost,v11,04/10] virtio_ring: support add premapped buf

Message ID 20230710034237.12391-5-xuanzhuo@linux.alibaba.com (mailing list archive)
State Superseded
Headers show
Series virtio core prepares for AF_XDP | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Xuan Zhuo July 10, 2023, 3:42 a.m. UTC 
If the vq is the premapped mode, use the sg_dma_address() directly.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

Comments

Jason Wang July 12, 2023, 8:31 a.m. UTC | #1 
On Mon, Jul 10, 2023 at 11:42 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
>
> If the vq is the premapped mode, use the sg_dma_address() directly.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>  drivers/virtio/virtio_ring.c | 19 +++++++++++++++++--
>  1 file changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 5ace4539344c..d471dee3f4f7 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -361,6 +361,11 @@ static struct device *vring_dma_dev(const struct vring_virtqueue *vq)
>  static int vring_map_one_sg(const struct vring_virtqueue *vq, struct scatterlist *sg,
>                             enum dma_data_direction direction, dma_addr_t *addr)
>  {
> +       if (vq->premapped) {
> +               *addr = sg_dma_address(sg);
> +               return 0;
> +       }
> +
>         if (!vq->use_dma_api) {
>                 /*
>                  * If DMA is not used, KMSAN doesn't know that the scatterlist
> @@ -639,8 +644,12 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>                 dma_addr_t addr = vring_map_single(
>                         vq, desc, total_sg * sizeof(struct vring_desc),
>                         DMA_TO_DEVICE);
> -               if (vring_mapping_error(vq, addr))
> +               if (vring_mapping_error(vq, addr)) {
> +                       if (vq->premapped)
> +                               goto free_indirect;

Under which case could we hit this? A bug of the driver?

Thanks

> +
>                         goto unmap_release;
> +               }
>
>                 virtqueue_add_desc_split(_vq, vq->split.vring.desc,
>                                          head, addr,
> @@ -706,6 +715,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>                         i = vring_unmap_one_split(vq, i);
>         }
>
> +free_indirect:
>         if (indirect)
>                 kfree(desc);
>
> @@ -1307,8 +1317,12 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
>         addr = vring_map_single(vq, desc,
>                         total_sg * sizeof(struct vring_packed_desc),
>                         DMA_TO_DEVICE);
> -       if (vring_mapping_error(vq, addr))
> +       if (vring_mapping_error(vq, addr)) {
> +               if (vq->premapped)
> +                       goto free_desc;
> +
>                 goto unmap_release;
> +       }
>
>         vq->packed.vring.desc[head].addr = cpu_to_le64(addr);
>         vq->packed.vring.desc[head].len = cpu_to_le32(total_sg *
> @@ -1366,6 +1380,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
>         for (i = 0; i < err_idx; i++)
>                 vring_unmap_desc_packed(vq, &desc[i]);
>
> +free_desc:
>         kfree(desc);
>
>         END_USE(vq);
> --
> 2.32.0.3.g01195cf9f
>
Xuan Zhuo July 12, 2023, 8:33 a.m. UTC | #2 
On Wed, 12 Jul 2023 16:31:35 +0800, Jason Wang <jasowang@redhat.com> wrote:
> On Mon, Jul 10, 2023 at 11:42 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
> >
> > If the vq is the premapped mode, use the sg_dma_address() directly.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > ---
> >  drivers/virtio/virtio_ring.c | 19 +++++++++++++++++--
> >  1 file changed, 17 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index 5ace4539344c..d471dee3f4f7 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -361,6 +361,11 @@ static struct device *vring_dma_dev(const struct vring_virtqueue *vq)
> >  static int vring_map_one_sg(const struct vring_virtqueue *vq, struct scatterlist *sg,
> >                             enum dma_data_direction direction, dma_addr_t *addr)
> >  {
> > +       if (vq->premapped) {
> > +               *addr = sg_dma_address(sg);
> > +               return 0;
> > +       }
> > +
> >         if (!vq->use_dma_api) {
> >                 /*
> >                  * If DMA is not used, KMSAN doesn't know that the scatterlist
> > @@ -639,8 +644,12 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
> >                 dma_addr_t addr = vring_map_single(
> >                         vq, desc, total_sg * sizeof(struct vring_desc),
> >                         DMA_TO_DEVICE);
> > -               if (vring_mapping_error(vq, addr))
> > +               if (vring_mapping_error(vq, addr)) {
> > +                       if (vq->premapped)
> > +                               goto free_indirect;
>
> Under which case could we hit this? A bug of the driver?

Here the map operate is for the indirect descs array.

So this is done inside the virtio core.

Thanks.




>
> Thanks
>
> > +
> >                         goto unmap_release;
> > +               }
> >
> >                 virtqueue_add_desc_split(_vq, vq->split.vring.desc,
> >                                          head, addr,
> > @@ -706,6 +715,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
> >                         i = vring_unmap_one_split(vq, i);
> >         }
> >
> > +free_indirect:
> >         if (indirect)
> >                 kfree(desc);
> >
> > @@ -1307,8 +1317,12 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
> >         addr = vring_map_single(vq, desc,
> >                         total_sg * sizeof(struct vring_packed_desc),
> >                         DMA_TO_DEVICE);
> > -       if (vring_mapping_error(vq, addr))
> > +       if (vring_mapping_error(vq, addr)) {
> > +               if (vq->premapped)
> > +                       goto free_desc;
> > +
> >                 goto unmap_release;
> > +       }
> >
> >         vq->packed.vring.desc[head].addr = cpu_to_le64(addr);
> >         vq->packed.vring.desc[head].len = cpu_to_le32(total_sg *
> > @@ -1366,6 +1380,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
> >         for (i = 0; i < err_idx; i++)
> >                 vring_unmap_desc_packed(vq, &desc[i]);
> >
> > +free_desc:
> >         kfree(desc);
> >
> >         END_USE(vq);
> > --
> > 2.32.0.3.g01195cf9f
> >
>
diff mbox series

Patch

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 5ace4539344c..d471dee3f4f7 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -361,6 +361,11 @@  static struct device *vring_dma_dev(const struct vring_virtqueue *vq)
 static int vring_map_one_sg(const struct vring_virtqueue *vq, struct scatterlist *sg,
 			    enum dma_data_direction direction, dma_addr_t *addr)
 {
+	if (vq->premapped) {
+		*addr = sg_dma_address(sg);
+		return 0;
+	}
+
 	if (!vq->use_dma_api) {
 		/*
 		 * If DMA is not used, KMSAN doesn't know that the scatterlist
@@ -639,8 +644,12 @@  static inline int virtqueue_add_split(struct virtqueue *_vq,
 		dma_addr_t addr = vring_map_single(
 			vq, desc, total_sg * sizeof(struct vring_desc),
 			DMA_TO_DEVICE);
-		if (vring_mapping_error(vq, addr))
+		if (vring_mapping_error(vq, addr)) {
+			if (vq->premapped)
+				goto free_indirect;
+
 			goto unmap_release;
+		}
 
 		virtqueue_add_desc_split(_vq, vq->split.vring.desc,
 					 head, addr,
@@ -706,6 +715,7 @@  static inline int virtqueue_add_split(struct virtqueue *_vq,
 			i = vring_unmap_one_split(vq, i);
 	}
 
+free_indirect:
 	if (indirect)
 		kfree(desc);
 
@@ -1307,8 +1317,12 @@  static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
 	addr = vring_map_single(vq, desc,
 			total_sg * sizeof(struct vring_packed_desc),
 			DMA_TO_DEVICE);
-	if (vring_mapping_error(vq, addr))
+	if (vring_mapping_error(vq, addr)) {
+		if (vq->premapped)
+			goto free_desc;
+
 		goto unmap_release;
+	}
 
 	vq->packed.vring.desc[head].addr = cpu_to_le64(addr);
 	vq->packed.vring.desc[head].len = cpu_to_le32(total_sg *
@@ -1366,6 +1380,7 @@  static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
 	for (i = 0; i < err_idx; i++)
 		vring_unmap_desc_packed(vq, &desc[i]);
 
+free_desc:
 	kfree(desc);
 
 	END_USE(vq);