On Mon, Mar 27, 2023 at 12:05 PM Xuan Zhuo <[email protected]> wrote: > > 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 dma_address must be null when passing it to the APIs of > virtio. > > Signed-off-by: Xuan Zhuo <[email protected]>
Acked-by: Jason Wang <[email protected]> Thanks > --- > drivers/virtio/virtio_ring.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 2afff1dc6c74..d5dffbe50070 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -1338,6 +1338,7 @@ static int virtqueue_add_indirect_packed(struct > vring_virtqueue *vq, > unsigned int i, n; > u16 head, id; > dma_addr_t addr; > + bool dma_map_internal; > > head = vq->packed.next_avail_idx; > desc = alloc_indirect_packed(total_sg, gfp); > @@ -1355,7 +1356,8 @@ static int virtqueue_add_indirect_packed(struct > vring_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)) > goto err_map; > > for (n = 0; n < out_sgs + in_sgs; n++) { > @@ -1417,6 +1419,8 @@ 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].flags = dma_map_internal ? > VRING_STATE_F_MAP_INTERNAL : 0; > + > > vq->num_added += 1; > > @@ -1426,7 +1430,8 @@ static int virtqueue_add_indirect_packed(struct > vring_virtqueue *vq, > return 0; > > unmap_release: > - virtqueue_unmap_sgs(vq, sgs, total_sg, out_sgs, in_sgs); > + if (dma_map_internal) > + virtqueue_unmap_sgs(vq, sgs, total_sg, out_sgs, in_sgs); > > err_map: > kfree(desc); > @@ -1653,7 +1658,7 @@ static void detach_buf_packed(struct vring_virtqueue > *vq, > if (!desc) > return; > > - if (vq->use_dma_api) { > + if (vq->use_dma_api && dma_map_internal) { > len = vq->packed.desc_extra[id].len; > for (i = 0; i < len / sizeof(struct > vring_packed_desc); > i++) > -- > 2.32.0.3.g01195cf9f > _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
