Commit 295525e29a5b ("virtio_net: merge dma operations when filling mergeable buffers") unmaps the buffer with DMA_ATTR_SKIP_CPU_SYNC when the dma->ref is zero. We do that with DMA_ATTR_SKIP_CPU_SYNC, because we do not want to do the sync for the entire page_frag. But that misses the sync for the current area.
This patch does cpu sync regardless of whether the ref is zero or not. Fixes: 295525e29a5b ("virtio_net: merge dma operations when filling mergeable buffers") Reported-by: Michael Roth <michael.r...@amd.com> Closes: http://lore.kernel.org/all/20230926130451.axgodaa6tvwqs...@amd.com Signed-off-by: Xuan Zhuo <xuanz...@linux.alibaba.com> --- drivers/net/virtio_net.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 98dc9b49d56b..9ece27dc5144 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -589,16 +589,16 @@ static void virtnet_rq_unmap(struct receive_queue *rq, void *buf, u32 len) --dma->ref; - if (dma->ref) { - if (dma->need_sync && len) { - offset = buf - (head + sizeof(*dma)); + if (dma->need_sync && len) { + offset = buf - (head + sizeof(*dma)); - virtqueue_dma_sync_single_range_for_cpu(rq->vq, dma->addr, offset, - len, DMA_FROM_DEVICE); - } + virtqueue_dma_sync_single_range_for_cpu(rq->vq, dma->addr, + offset, len, + DMA_FROM_DEVICE); + } + if (dma->ref) return; - } virtqueue_dma_unmap_single_attrs(rq->vq, dma->addr, dma->len, DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC); -- 2.32.0.3.g01195cf9f _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization