Xuan Zhuo
2023-Jun-02 09:21 UTC
[PATCH vhost v10 03/10] virtio_ring: split: support add premapped buf
If the vq is the premapped mode, use the sg_dma_address() directly.
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 46 ++++++++++++++++++++++--------------
1 file changed, 28 insertions(+), 18 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 2afdfb9e3e30..18212c3e056b 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -598,8 +598,12 @@ static inline int virtqueue_add_split(struct virtqueue
*_vq,
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
dma_addr_t addr;
- if (vring_map_one_sg(vq, sg, DMA_TO_DEVICE, &addr))
- goto unmap_release;
+ if (vq->premapped) {
+ addr = sg_dma_address(sg);
+ } else {
+ if (vring_map_one_sg(vq, sg, DMA_TO_DEVICE, &addr))
+ goto unmap_release;
+ }
prev = i;
/* Note that we trust indirect descriptor
@@ -614,8 +618,12 @@ static inline int virtqueue_add_split(struct virtqueue
*_vq,
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
dma_addr_t addr;
- if (vring_map_one_sg(vq, sg, DMA_FROM_DEVICE, &addr))
- goto unmap_release;
+ if (vq->premapped) {
+ addr = sg_dma_address(sg);
+ } else {
+ if (vring_map_one_sg(vq, sg, DMA_FROM_DEVICE, &addr))
+ goto unmap_release;
+ }
prev = i;
/* Note that we trust indirect descriptor
@@ -689,21 +697,23 @@ static inline int virtqueue_add_split(struct virtqueue
*_vq,
return 0;
unmap_release:
- err_idx = i;
+ if (!vq->premapped) {
+ err_idx = i;
- if (indirect)
- i = 0;
- else
- i = head;
-
- for (n = 0; n < total_sg; n++) {
- if (i == err_idx)
- break;
- if (indirect) {
- vring_unmap_one_split_indirect(vq, &desc[i]);
- i = virtio16_to_cpu(_vq->vdev, desc[i].next);
- } else
- i = vring_unmap_one_split(vq, i);
+ if (indirect)
+ i = 0;
+ else
+ i = head;
+
+ for (n = 0; n < total_sg; n++) {
+ if (i == err_idx)
+ break;
+ if (indirect) {
+ vring_unmap_one_split_indirect(vq, &desc[i]);
+ i = virtio16_to_cpu(_vq->vdev, desc[i].next);
+ } else
+ i = vring_unmap_one_split(vq, i);
+ }
}
if (indirect)
--
2.32.0.3.g01195cf9f
Jason Wang
2023-Jun-27 08:03 UTC
[PATCH vhost v10 03/10] virtio_ring: split: support add premapped buf
On Fri, Jun 2, 2023 at 5:22?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote:> > If the vq is the premapped mode, use the sg_dma_address() directly. > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > --- > drivers/virtio/virtio_ring.c | 46 ++++++++++++++++++++++-------------- > 1 file changed, 28 insertions(+), 18 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 2afdfb9e3e30..18212c3e056b 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -598,8 +598,12 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, > for (sg = sgs[n]; sg; sg = sg_next(sg)) { > dma_addr_t addr; > > - if (vring_map_one_sg(vq, sg, DMA_TO_DEVICE, &addr)) > - goto unmap_release; > + if (vq->premapped) { > + addr = sg_dma_address(sg); > + } else { > + if (vring_map_one_sg(vq, sg, DMA_TO_DEVICE, &addr)) > + goto unmap_release; > + }Btw, I wonder whether or not it would be simple to implement the vq->premapped check inside vring_map_one_sg() assuming the !use_dma_api is done there as well.> > prev = i; > /* Note that we trust indirect descriptor > @@ -614,8 +618,12 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, > for (sg = sgs[n]; sg; sg = sg_next(sg)) { > dma_addr_t addr; > > - if (vring_map_one_sg(vq, sg, DMA_FROM_DEVICE, &addr)) > - goto unmap_release; > + if (vq->premapped) { > + addr = sg_dma_address(sg); > + } else { > + if (vring_map_one_sg(vq, sg, DMA_FROM_DEVICE, &addr)) > + goto unmap_release; > + } > > prev = i; > /* Note that we trust indirect descriptor > @@ -689,21 +697,23 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, > return 0; > > unmap_release: > - err_idx = i; > + if (!vq->premapped) {Can vq->premapped be true here? The label is named as "unmap_relase" which implies "map" beforehand which seems not the case for premapping. Thanks> + err_idx = i; > > - if (indirect) > - i = 0; > - else > - i = head; > - > - for (n = 0; n < total_sg; n++) { > - if (i == err_idx) > - break; > - if (indirect) { > - vring_unmap_one_split_indirect(vq, &desc[i]); > - i = virtio16_to_cpu(_vq->vdev, desc[i].next); > - } else > - i = vring_unmap_one_split(vq, i); > + if (indirect) > + i = 0; > + else > + i = head; > + > + for (n = 0; n < total_sg; n++) { > + if (i == err_idx) > + break; > + if (indirect) { > + vring_unmap_one_split_indirect(vq, &desc[i]); > + i = virtio16_to_cpu(_vq->vdev, desc[i].next); > + } else > + i = vring_unmap_one_split(vq, i); > + } > } > > if (indirect) > -- > 2.32.0.3.g01195cf9f >