From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6B93B46444; Tue, 10 Sep 2024 09:36:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725960983; cv=none; b=nYJtYDWKC71L/0x38Kj1JbvlRcnRcdbj7d1+oEjNl4S8m3uO9OvMvKcU3hApg31yCrmguOR8Xy0b6xncCd1CWQCz9RzaixDsszLlXXoIhO6tKKQ7rfaItduXyEO3oeml+u/aXwNHuQqBRpP9P3jgLRr4i6UK902gi8HQaeJEFys= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725960983; c=relaxed/simple; bh=vR86I937CbA2+ZZLY0J4MJbSb0qKNBrNEg5Y9TyY3Gg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iG6yuik4cJF6zjSxIo6nIl0pjJI70kdky2NwgXVOibzeEC3P+9+uiDg/JCCWWyUURIyRN6LB/E40UlzIFIzC/NEkxfPW1brnxdSAoSF+J5O4tv6cGwpiYt5HWo2APxAcZ5VspxX4D5IaEOKKQCpq94doxxcWwy2s/ywjBLsvcSc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CrRL9Elk; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="CrRL9Elk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B8BEC4CEC3; Tue, 10 Sep 2024 09:36:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1725960983; bh=vR86I937CbA2+ZZLY0J4MJbSb0qKNBrNEg5Y9TyY3Gg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CrRL9ElkOfgx1Vrd+bi7tuwY+P6GoHOWLqNy0FQh9OrNeSrsnNfwcJXaPdk82ZljG Y6V244Q0f5Trb4ci+qnrql9TRYUkrOSoSqkoXBv3jh6zWKb52dfzL+cCb+DMS1BCLV 3koV6c6FghpRRuolswj/Pmt+riy4ni18e/g1BOIg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jakub Kicinski , Breno Leitao , "Michael S. Tsirkin" , Jason Wang , Heng Qi , Shivani Agarwal Subject: [PATCH 4.19 14/96] virtio_net: Fix napi_skb_cache_put warning Date: Tue, 10 Sep 2024 11:31:16 +0200 Message-ID: <20240910092542.050513879@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240910092541.383432924@linuxfoundation.org> References: <20240910092541.383432924@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Breno Leitao 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 Signed-off-by: Breno Leitao Reviewed-by: Jakub Kicinski Acked-by: Michael S. Tsirkin Acked-by: Jason Wang Reviewed-by: Heng Qi Link: https://patch.msgid.link/20240712115325.54175-1-leitao@debian.org Signed-off-by: Jakub Kicinski [Shivani: Modified to apply on v4.19.y-v5.10.y] Signed-off-by: Shivani Agarwal Signed-off-by: Greg Kroah-Hartman --- drivers/net/virtio_net.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1428,7 +1428,7 @@ static bool is_xdp_raw_buffer_queue(stru 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); @@ -1439,7 +1439,7 @@ static void virtnet_poll_cleantx(struct return; if (__netif_tx_trylock(txq)) { - free_old_xmit_skbs(sq, true); + free_old_xmit_skbs(sq, !!budget); __netif_tx_unlock(txq); } @@ -1456,7 +1456,7 @@ static int virtnet_poll(struct napi_stru unsigned int received; unsigned int xdp_xmit = 0; - virtnet_poll_cleantx(rq); + virtnet_poll_cleantx(rq, budget); received = virtnet_receive(rq, budget, &xdp_xmit); @@ -1526,7 +1526,7 @@ static int virtnet_poll_tx(struct napi_s 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);