From: Longjun Tang Date: Mon, 29 Jun 2026 02:42:30 +0000 (+0800) Subject: virtio_net: disable cb when NAPI is busy-polled X-Git-Tag: v7.2-rc2~22^2~8 X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;h=1eb8fc67ca41db71c90866ff76c990d85247daef;p=thirdparty%2Flinux.git virtio_net: disable cb when NAPI is busy-polled When busy-poll is active, napi_schedule_prep() returns false in virtqueue_napi_schedule(), so virtqueue_disable_cb() is skipped. The device may keep firing irqs until reaches virtqueue_napi_complete(). Under load (received == budget), it will lead to a large number of spurious interrupts. Fix it by disabling the callback at the virtnet_poll() entry. This keeps the callback off while we poll and it is re-enabled by virtqueue_napi_complete() when going idle. Fixes: ceef438d613f ("virtio_net: remove custom busy_poll") Acked-by: Michael S. Tsirkin Signed-off-by: Longjun Tang Link: https://patch.msgid.link/20260629024230.37325-1-lange_tang@163.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 26afa6341d16..3e2a5876c6c8 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3011,6 +3011,9 @@ static int virtnet_poll(struct napi_struct *napi, int budget) unsigned int xdp_xmit = 0; bool napi_complete; + if (budget) + virtqueue_disable_cb(rq->vq); + virtnet_poll_cleantx(rq, budget); received = virtnet_receive(rq, budget, &xdp_xmit);