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virtio_net: Fix napi_skb_cache_put warning

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commit f8321fa75102246d7415a6af441872f6637c93ab upstream.

After the commit bdacf3e34945 ("net: Use nested-BH locking for
napi_alloc_cache.") was merged, the following warning began to appear:

	 WARNING: CPU: 5 PID: 1 at net/core/skbuff.c:1451 napi_skb_cache_put+0x82/0x4b0

	  __warn+0x12f/0x340
	  napi_skb_cache_put+0x82/0x4b0
	  napi_skb_cache_put+0x82/0x4b0
	  report_bug+0x165/0x370
	  handle_bug+0x3d/0x80
	  exc_invalid_op+0x1a/0x50
	  asm_exc_invalid_op+0x1a/0x20
	  __free_old_xmit+0x1c8/0x510
	  napi_skb_cache_put+0x82/0x4b0
	  __free_old_xmit+0x1c8/0x510
	  __free_old_xmit+0x1c8/0x510
	  __pfx___free_old_xmit+0x10/0x10

The issue arises because virtio is assuming it's running in NAPI context
even when it's not, such as in the netpoll case.

To resolve this, modify virtnet_poll_tx() to only set NAPI when budget
is available. Same for virtnet_poll_cleantx(), which always assumed that
it was in a NAPI context.

Fixes: df133f3f9625 ("virtio_net: bulk free tx skbs")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Heng Qi <hengqi@linux.alibaba.com>
Link: https://patch.msgid.link/20240712115325.54175-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[Shivani: Modified to apply on v4.19.y-v5.10.y]
Signed-off-by: Shivani Agarwal <shivani.agarwal@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Breno Leitao 2024-07-12 04:53:25 -07:00 committed by Ksawlii
parent 55d08f4214
commit a5315ef480
1 changed files with 4 additions and 4 deletions
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8
drivers/net/virtio_net.c
View file

@ -1497,7 +1497,7 @@ static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
return false;
}
static void virtnet_poll_cleantx(struct receive_queue *rq)
static void virtnet_poll_cleantx(struct receive_queue *rq, int budget)
{
struct virtnet_info *vi = rq->vq->vdev->priv;
unsigned int index = vq2rxq(rq->vq);
@ -1508,7 +1508,7 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
return;
if (__netif_tx_trylock(txq)) {
free_old_xmit_skbs(sq, true);
free_old_xmit_skbs(sq, !!budget);
__netif_tx_unlock(txq);
}
@ -1525,7 +1525,7 @@ static int virtnet_poll(struct napi_struct *napi, int budget)
unsigned int received;
unsigned int xdp_xmit = 0;
virtnet_poll_cleantx(rq);
virtnet_poll_cleantx(rq, budget);
received = virtnet_receive(rq, budget, &xdp_xmit);
@ -1598,7 +1598,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget)
txq = netdev_get_tx_queue(vi->dev, index);
__netif_tx_lock(txq, raw_smp_processor_id());
virtqueue_disable_cb(sq->vq);
free_old_xmit_skbs(sq, true);
free_old_xmit_skbs(sq, !!budget);
opaque = virtqueue_enable_cb_prepare(sq->vq);