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| author | Wenbo Li <liwenbo.martin@bytedance.com> | 2024-09-19 10:13:51 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2024-09-26 10:35:27 +0200 |
| commit | c11a49d58ad229a1be1ebe08a2b68fedf83db6c8 (patch) | |
| tree | 91639008bf8f9368617bd7ba3423eb8a2e528064 | |
| parent | bonding: Fix unnecessary warnings and logs from bond_xdp_get_xmit_slave() (diff) | |
| download | linux-c11a49d58ad229a1be1ebe08a2b68fedf83db6c8.tar.xz linux-c11a49d58ad229a1be1ebe08a2b68fedf83db6c8.zip | |
virtio_net: Fix mismatched buf address when unmapping for small packets
Currently, the virtio-net driver will perform a pre-dma-mapping for
small or mergeable RX buffer. But for small packets, a mismatched address
without VIRTNET_RX_PAD and xdp_headroom is used for unmapping.
That will result in unsynchronized buffers when SWIOTLB is enabled, for
example, when running as a TDX guest.
This patch unifies the address passed to the virtio core as the address of
the virtnet header and fixes the mismatched buffer address.
Changes from v2: unify the buf that passed to the virtio core in small
and merge mode.
Changes from v1: Use ctx to get xdp_headroom.
Fixes: 295525e29a5b ("virtio_net: merge dma operations when filling mergeable buffers")
Signed-off-by: Wenbo Li <liwenbo.martin@bytedance.com>
Signed-off-by: Jiahui Cen <cenjiahui@bytedance.com>
Signed-off-by: Ying Fang <fangying.tommy@bytedance.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Link: https://patch.msgid.link/20240919081351.51772-1-liwenbo.martin@bytedance.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | drivers/net/virtio_net.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 6f4781ec2b36..f8131f92a392 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1807,6 +1807,11 @@ static struct sk_buff *receive_small(struct net_device *dev, struct page *page = virt_to_head_page(buf); struct sk_buff *skb; + /* We passed the address of virtnet header to virtio-core, + * so truncate the padding. + */ + buf -= VIRTNET_RX_PAD + xdp_headroom; + len -= vi->hdr_len; u64_stats_add(&stats->bytes, len); @@ -2422,8 +2427,9 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, if (unlikely(!buf)) return -ENOMEM; - virtnet_rq_init_one_sg(rq, buf + VIRTNET_RX_PAD + xdp_headroom, - vi->hdr_len + GOOD_PACKET_LEN); + buf += VIRTNET_RX_PAD + xdp_headroom; + + virtnet_rq_init_one_sg(rq, buf, vi->hdr_len + GOOD_PACKET_LEN); err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp); if (err < 0) { |