This reverts commit defd28aa5acb0fd7c15adc6bc40a8ac277d04dea. Recover the code to disable premapped mode. Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Tested-by: Takero Funaki <flintglass@xxxxxxxxx> Link: https://patch.msgid.link/20240906123137.108741-2-xuanzhuo@xxxxxxxxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index c6af18948092..6fa8aab18484 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -356,6 +356,9 @@ struct receive_queue { struct xdp_rxq_info xsk_rxq_info; struct xdp_buff **xsk_buffs; + + /* Do dma by self */ + bool do_dma; }; /* This structure can contain rss message with maximum settings for indirection table and keysize @@ -885,7 +888,7 @@ static void *virtnet_rq_get_buf(struct receive_queue *rq, u32 *len, void **ctx) void *buf; buf = virtqueue_get_buf_ctx(rq->vq, len, ctx); - if (buf) + if (buf && rq->do_dma) virtnet_rq_unmap(rq, buf, *len); return buf; @@ -898,6 +901,11 @@ static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32 len) u32 offset; void *head; + if (!rq->do_dma) { + sg_init_one(rq->sg, buf, len); + return; + } + head = page_address(rq->alloc_frag.page); offset = buf - head; @@ -923,42 +931,44 @@ static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp) head = page_address(alloc_frag->page); - dma = head; + if (rq->do_dma) { + dma = head; - /* new pages */ - if (!alloc_frag->offset) { - if (rq->last_dma) { - /* Now, the new page is allocated, the last dma - * will not be used. So the dma can be unmapped - * if the ref is 0. + /* new pages */ + if (!alloc_frag->offset) { + if (rq->last_dma) { + /* Now, the new page is allocated, the last dma + * will not be used. So the dma can be unmapped + * if the ref is 0. + */ + virtnet_rq_unmap(rq, rq->last_dma, 0); + rq->last_dma = NULL; + } + + dma->len = alloc_frag->size - sizeof(*dma); + + addr = virtqueue_dma_map_single_attrs(rq->vq, dma + 1, + dma->len, DMA_FROM_DEVICE, 0); + if (virtqueue_dma_mapping_error(rq->vq, addr)) + return NULL; + + dma->addr = addr; + dma->need_sync = virtqueue_dma_need_sync(rq->vq, addr); + + /* Add a reference to dma to prevent the entire dma from + * being released during error handling. This reference + * will be freed after the pages are no longer used. */ - virtnet_rq_unmap(rq, rq->last_dma, 0); - rq->last_dma = NULL; + get_page(alloc_frag->page); + dma->ref = 1; + alloc_frag->offset = sizeof(*dma); + + rq->last_dma = dma; } - dma->len = alloc_frag->size - sizeof(*dma); - - addr = virtqueue_dma_map_single_attrs(rq->vq, dma + 1, - dma->len, DMA_FROM_DEVICE, 0); - if (virtqueue_dma_mapping_error(rq->vq, addr)) - return NULL; - - dma->addr = addr; - dma->need_sync = virtqueue_dma_need_sync(rq->vq, addr); - - /* Add a reference to dma to prevent the entire dma from - * being released during error handling. This reference - * will be freed after the pages are no longer used. - */ - get_page(alloc_frag->page); - dma->ref = 1; - alloc_frag->offset = sizeof(*dma); - - rq->last_dma = dma; + ++dma->ref; } - ++dma->ref; - buf = head + alloc_frag->offset; get_page(alloc_frag->page); @@ -975,9 +985,12 @@ static void virtnet_rq_set_premapped(struct virtnet_info *vi) if (!vi->mergeable_rx_bufs && vi->big_packets) return; - for (i = 0; i < vi->max_queue_pairs; i++) - /* error should never happen */ - BUG_ON(virtqueue_set_dma_premapped(vi->rq[i].vq)); + for (i = 0; i < vi->max_queue_pairs; i++) { + if (virtqueue_set_dma_premapped(vi->rq[i].vq)) + continue; + + vi->rq[i].do_dma = true; + } } static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf) @@ -2430,7 +2443,8 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp); if (err < 0) { - virtnet_rq_unmap(rq, buf, 0); + if (rq->do_dma) + virtnet_rq_unmap(rq, buf, 0); put_page(virt_to_head_page(buf)); } @@ -2544,7 +2558,8 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, ctx = mergeable_len_to_ctx(len + room, headroom); err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp); if (err < 0) { - virtnet_rq_unmap(rq, buf, 0); + if (rq->do_dma) + virtnet_rq_unmap(rq, buf, 0); put_page(virt_to_head_page(buf)); } @@ -5892,7 +5907,7 @@ static void free_receive_page_frags(struct virtnet_info *vi) int i; for (i = 0; i < vi->max_queue_pairs; i++) if (vi->rq[i].alloc_frag.page) { - if (vi->rq[i].last_dma) + if (vi->rq[i].do_dma && vi->rq[i].last_dma) virtnet_rq_unmap(&vi->rq[i], vi->rq[i].last_dma, 0); put_page(vi->rq[i].alloc_frag.page); }
