[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <20240904061009.90785-1-liwenbo.martin@bytedance.com>
Date: Wed, 4 Sep 2024 14:10:09 +0800
From: Wenbo Li <liwenbo.martin@...edance.com>
To: mst@...hat.com,
jasowang@...hat.com,
xuanzhuo@...ux.alibaba.com,
eperezma@...hat.com,
davem@...emloft.net,
edumazet@...gle.com,
kuba@...nel.org,
pabeni@...hat.com
Cc: virtualization@...ts.linux.dev,
netdev@...r.kernel.org,
linux-kernel@...r.kernel.org,
Wenbo Li <liwenbo.martin@...edance.com>,
Jiahui Cen <cenjiahui@...edance.com>,
Ying Fang <fangying.tommy@...edance.com>
Subject: [PATCH v2] 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 handles small and mergeable packets separately and fixes
the mismatched buffer address.
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@...edance.com>
Signed-off-by: Jiahui Cen <cenjiahui@...edance.com>
Signed-off-by: Ying Fang <fangying.tommy@...edance.com>
---
drivers/net/virtio_net.c | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index c6af18948..cbc3c0ae4 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -891,6 +891,23 @@ static void *virtnet_rq_get_buf(struct receive_queue *rq, u32 *len, void **ctx)
return buf;
}
+static void *virtnet_rq_get_buf_small(struct receive_queue *rq,
+ u32 *len,
+ void **ctx,
+ unsigned int header_offset)
+{
+ void *buf;
+ unsigned int xdp_headroom;
+
+ buf = virtqueue_get_buf_ctx(rq->vq, len, ctx);
+ if (buf) {
+ xdp_headroom = (unsigned long)*ctx;
+ virtnet_rq_unmap(rq, buf + VIRTNET_RX_PAD + xdp_headroom, *len);
+ }
+
+ return buf;
+}
+
static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32 len)
{
struct virtnet_rq_dma *dma;
@@ -2692,13 +2709,23 @@ static int virtnet_receive_packets(struct virtnet_info *vi,
int packets = 0;
void *buf;
- if (!vi->big_packets || vi->mergeable_rx_bufs) {
+ if (vi->mergeable_rx_bufs) {
void *ctx;
while (packets < budget &&
(buf = virtnet_rq_get_buf(rq, &len, &ctx))) {
receive_buf(vi, rq, buf, len, ctx, xdp_xmit, stats);
packets++;
}
+ } else if (!vi->big_packets) {
+ void *ctx;
+ unsigned int xdp_headroom = virtnet_get_headroom(vi);
+ unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
+
+ while (packets < budget &&
+ (buf = virtnet_rq_get_buf_small(rq, &len, &ctx, header_offset))) {
+ receive_buf(vi, rq, buf, len, ctx, xdp_xmit, stats);
+ packets++;
+ }
} else {
while (packets < budget &&
(buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
--
2.20.1
Powered by blists - more mailing lists