The patch below does not apply to the 6.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.10.y git checkout FETCH_HEAD git cherry-pick -x dc4547fbba874718af76e5c28c815fcef5c13c6c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024091301-suitcase-hazard-0817@gregkh' --subject-prefix 'PATCH 6.10.y' HEAD^..

Possible dependencies:

dc4547fbba87 ("Revert "virtio_net: rx remove premapped failover code"") e9f3962441c0 ("virtio_net: xsk: rx: support fill with xsk buffer") 19a5a7710ee1 ("virtio_net: xsk: support wakeup") 09d2b3182c8e ("virtio_net: xsk: bind/unbind xsk for rx")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From dc4547fbba874718af76e5c28c815fcef5c13c6c Mon Sep 17 00:00:00 2001 From: Xuan Zhuo xuanzhuo@linux.alibaba.com Date: Fri, 6 Sep 2024 20:31:35 +0800 Subject: [PATCH] Revert "virtio_net: rx remove premapped failover code"

This reverts commit defd28aa5acb0fd7c15adc6bc40a8ac277d04dea.

Recover the code to disable premapped mode.

Signed-off-by: Xuan Zhuo xuanzhuo@linux.alibaba.com Acked-by: Michael S. Tsirkin mst@redhat.com Tested-by: Takero Funaki flintglass@gmail.com Link: https://patch.msgid.link/20240906123137.108741-2-xuanzhuo@linux.alibaba.com Signed-off-by: Jakub Kicinski kuba@kernel.org

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); }