From: Longjun Tang 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 --- V4 -> V5: Guard disable_cb with budget to avoid netpoll stall V3 -> V4: Update commit message and remove some comments V2 -> V3: Add fixes tag V1 -> V2: Remain agnostic to busy polling --- drivers/net/virtio_net.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 7d2eeb9b1226..0b3f1bb227d2 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3008,6 +3008,9 @@ 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); -- 2.43.0