virtio_net: fix the missing of the dma cpu sync

Commit 295525e29a ("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: 295525e29a ("virtio_net: merge dma operations when filling mergeable buffers")
Reported-by: Michael Roth <michael.roth@amd.com>
Closes: http://lore.kernel.org/all/20230926130451.axgodaa6tvwqs3ut@amd.com
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Xuan Zhuo 2023-09-27 13:52:46 +08:00 committed by Linus Torvalds
parent 11d3f72613
commit 5720c43d52

View File

@ -607,17 +607,17 @@ 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);
}
return;
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);
put_page(page);