virtio core only supports virtual addresses, dma is completed in virtio core.
In some scenarios (such as the AF_XDP), the memory is allocated and DMA mapping is completed in advance, so it is necessary for us to support passing the DMA address to virtio core. Drives can use sg->dma_address to pass the mapped dma address to virtio core. If one sg->dma_address is used then all sgs must use sg->dma_address, otherwise all must be null when passing it to the APIs of virtio. Signed-off-by: Xuan Zhuo <xuanz...@linux.alibaba.com> --- drivers/virtio/virtio_ring.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index a2a77a0dafe6..cafb720cbdc1 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 dma_map_internal; /* Do dma map internally. */ }; struct vring_desc_extra { @@ -1259,7 +1260,8 @@ 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 dma_map_internal) { u16 flags; @@ -1274,6 +1276,9 @@ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, (flags & VRING_DESC_F_WRITE) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } else { + if (!dma_map_internal) + return; + dma_unmap_page(vring_dma_dev(vq), extra->addr, extra->len, (flags & VRING_DESC_F_WRITE) ? @@ -1439,6 +1444,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, unsigned int i, n, c, descs_used; __le16 head_flags, flags; u16 head, id, prev, curr; + bool dma_map_internal; int err; START_USE(vq); @@ -1484,7 +1490,8 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, id = vq->free_head; BUG_ON(id == vq->packed.vring.num); - if (virtqueue_map_sgs(vq, sgs, total_sg, out_sgs, in_sgs)) + dma_map_internal = !sgs[0]->dma_address; + if (dma_map_internal && virtqueue_map_sgs(vq, sgs, total_sg, out_sgs, in_sgs)) return -ENOMEM; curr = id; @@ -1536,6 +1543,7 @@ 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].dma_map_internal = dma_map_internal; /* * A driver MUST NOT make the first descriptor in the list @@ -1621,7 +1629,8 @@ 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], + state->dma_map_internal); curr = vq->packed.desc_extra[curr].next; } } -- 2.32.0.3.g01195cf9f _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization