virtqueue_add_packed() only supports virtual addresses, dma is completed in virtqueue_add_packed().
In some scenarios (such as the AF_XDP scenario), the memory is allocated and DMA is completed in advance, so it is necessary for us to support passing the DMA address to virtqueue_add_packed(). Record this information in desc_state, we can skip unmap based on this when executing dma unmap. Signed-off-by: Xuan Zhuo <[email protected]> --- drivers/virtio/virtio_ring.c | 71 +++++++++++++++++++++++++----------- 1 file changed, 50 insertions(+), 21 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index ec622403cbd5..25027a35fcf8 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -78,6 +78,7 @@ struct vring_desc_state_packed { struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ u16 num; /* Descriptor list length. */ u16 last; /* The last desc state in a list. */ + bool premapped; }; struct vring_desc_extra { @@ -1200,7 +1201,8 @@ static inline u16 packed_last_used(u16 last_used_idx) } static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, - struct vring_desc_extra *extra) + struct vring_desc_extra *extra, + bool premapped) { u16 flags; @@ -1215,6 +1217,9 @@ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, (flags & VRING_DESC_F_WRITE) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } else { + if (premapped) + return; + dma_unmap_page(vring_dma_dev(vq), extra->addr, extra->len, (flags & VRING_DESC_F_WRITE) ? @@ -1262,7 +1267,8 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, unsigned int out_sgs, unsigned int in_sgs, void *data, - gfp_t gfp) + gfp_t gfp, + bool premapped) { struct vring_packed_desc *desc; struct scatterlist *sg; @@ -1288,10 +1294,15 @@ 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)) { - addr = vring_map_one_sg(vq, sg, n < out_sgs ? - DMA_TO_DEVICE : DMA_FROM_DEVICE); - if (vring_mapping_error(vq, addr)) - goto unmap_release; + if (premapped) { + addr = sg_dma_address(sg); + + } else { + addr = vring_map_one_sg(vq, sg, n < out_sgs ? + DMA_TO_DEVICE : DMA_FROM_DEVICE); + if (vring_mapping_error(vq, addr)) + goto unmap_release; + } desc[i].flags = cpu_to_le16(n < out_sgs ? 0 : VRING_DESC_F_WRITE); @@ -1350,6 +1361,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, vq->packed.desc_state[id].data = data; vq->packed.desc_state[id].indir_desc = desc; vq->packed.desc_state[id].last = id; + vq->packed.desc_state[id].premapped = premapped; vq->num_added += 1; @@ -1359,10 +1371,11 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, return 0; unmap_release: - err_idx = i; - - for (i = 0; i < err_idx; i++) - vring_unmap_desc_packed(vq, &desc[i]); + if (!premapped) { + err_idx = i; + for (i = 0; i < err_idx; i++) + vring_unmap_desc_packed(vq, &desc[i]); + } kfree(desc); @@ -1377,6 +1390,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, unsigned int in_sgs, void *data, void *ctx, + bool premapped, gfp_t gfp) { struct vring_virtqueue *vq = to_vvq(_vq); @@ -1403,7 +1417,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, if (virtqueue_use_indirect(vq, total_sg)) { err = virtqueue_add_indirect_packed(vq, sgs, total_sg, out_sgs, - in_sgs, data, gfp); + in_sgs, data, gfp, premapped); if (err != -ENOMEM) { END_USE(vq); return err; @@ -1435,10 +1449,17 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, c = 0; for (n = 0; n < out_sgs + in_sgs; n++) { for (sg = sgs[n]; sg; sg = sg_next(sg)) { - dma_addr_t addr = vring_map_one_sg(vq, sg, n < out_sgs ? - DMA_TO_DEVICE : DMA_FROM_DEVICE); - if (vring_mapping_error(vq, addr)) - goto unmap_release; + dma_addr_t addr; + + if (premapped) { + addr = sg_dma_address(sg); + + } else { + addr = vring_map_one_sg(vq, sg, n < out_sgs ? + DMA_TO_DEVICE : DMA_FROM_DEVICE); + if (vring_mapping_error(vq, addr)) + goto unmap_release; + } flags = cpu_to_le16(vq->packed.avail_used_flags | (++c == total_sg ? 0 : VRING_DESC_F_NEXT) | @@ -1485,6 +1506,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, vq->packed.desc_state[id].data = data; vq->packed.desc_state[id].indir_desc = ctx; vq->packed.desc_state[id].last = prev; + vq->packed.desc_state[id].premapped = premapped; /* * A driver MUST NOT make the first descriptor in the list @@ -1501,22 +1523,26 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, return 0; unmap_release: + vq->packed.avail_used_flags = avail_used_flags; + + if (premapped) + goto unmap_free; + 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) break; - vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]); + vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr], false); curr = vq->packed.desc_extra[curr].next; i++; if (i >= vq->packed.vring.num) i = 0; } +unmap_free: END_USE(vq); return -EIO; } @@ -1576,8 +1602,10 @@ static void detach_buf_packed(struct vring_virtqueue *vq, struct vring_desc_state_packed *state = NULL; struct vring_packed_desc *desc; unsigned int i, curr; + bool premapped; state = &vq->packed.desc_state[id]; + premapped = state->premapped; /* Clear data ptr. */ state->data = NULL; @@ -1590,7 +1618,8 @@ static void detach_buf_packed(struct vring_virtqueue *vq, curr = id; for (i = 0; i < state->num; i++) { vring_unmap_extra_packed(vq, - &vq->packed.desc_extra[curr]); + &vq->packed.desc_extra[curr], + premapped); curr = vq->packed.desc_extra[curr].next; } } @@ -1603,7 +1632,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq, if (!desc) return; - if (vq->use_dma_api) { + if (vq->use_dma_api && !premapped) { len = vq->packed.desc_extra[id].len; for (i = 0; i < len / sizeof(struct vring_packed_desc); i++) @@ -2122,7 +2151,7 @@ static inline int virtqueue_add(struct virtqueue *_vq, struct vring_virtqueue *vq = to_vvq(_vq); return vq->packed_ring ? virtqueue_add_packed(_vq, sgs, total_sg, - out_sgs, in_sgs, data, ctx, gfp) : + out_sgs, in_sgs, data, ctx, premapped, gfp) : virtqueue_add_split(_vq, sgs, total_sg, out_sgs, in_sgs, data, ctx, premapped, gfp); } -- 2.32.0.3.g01195cf9f _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
