virtio_net: fix the missing of the dma cpu sync
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.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>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index fe7f314..d67f742 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -607,17 +607,17 @@
--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);
