On Wed, Sep 04, 2024 at 02:08:53AM -0700, Shivani Agarwal wrote:
From: Breno Leitao leitao@debian.org
[ Upstream commit f8321fa75102246d7415a6af441872f6637c93ab ]
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+0x10/0x10The 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 Signed-off-by: Sasha Levin sashal@kernel.org [Shivani: Modified to apply on v4.19.y-v5.10.y] Signed-off-by: Shivani Agarwal shivani.agarwal@broadcom.com
All now queued up, thanks.
greg k-h