From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from qs51p00im-qukt01072301.me.com (qs51p00im-qukt01072301.me.com [17.57.155.12]) (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 DBED81598EC for ; Wed, 24 Apr 2024 10:57:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=17.57.155.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713956231; cv=none; b=I8V75t6uoIH7664dnnu8FCOqA149hbvOoSqgbsonbFKm7QWjah9YkFR6bdZm5Ym2tox4DbemGnshg4iFApBzmIIz7BVNUv9VcMcYxQE0tqgTFkHi0Dzn7xqHXh7siAwGnaWFFByPtlG03vHxg9Isxb4EchTm1AeNtMigT2fG01A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713956231; c=relaxed/simple; bh=OaGZMm9pKWH+8fGEG1ssaTnVEf6IsxdarNXbBFZpZKM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=arbAo+Fm7zjhf2ehMyLexOKoRVFIIQXrr+UU5i4Gio59OQYx+a8MpSOYtuBeYoFON9a8dKq/ta1cGKts0BHQsKJL/OTrJpbOqpdrNFB7Lqk54t+xfTqjHXkizBzT7uWgwD6rPEQH+vHB/TUnX0w1gmD4izeyha+N53WZ1X21aqE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ovs.to; spf=pass smtp.mailfrom=ovs.to; dkim=pass (2048-bit key) header.d=ovs.to header.i=@ovs.to header.b=pTEio9xT; arc=none smtp.client-ip=17.57.155.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ovs.to Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ovs.to Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ovs.to header.i=@ovs.to header.b="pTEio9xT" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ovs.to; s=sig1; t=1713956228; bh=UWC2JDeqhopdUAA3a6ItrwHEC6ucS1ZQ3oowEpM9ofw=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=pTEio9xTqdxG+fKfoJ+bNcsdFdWTvUhtppF6GvS8AGo1EM1MgCa7K5INjgLTA+51H KyzYV99HGptkVeUji5/4gcwcbrpMFR3VSHIDXNKLpzYagv0qN59Va3pPJCJOlq62Uy 9vHaTolna1zAiQS1zFHb0aUh4wDsFV3tAJkfIdRwrVcGoNN7trbUjDMMNsdJaI81ch AkQcMZXxKRsuSxaWNre/bnwYMuOVvKO9YYDYTkGy9G/RjM9As5kN2tqgegf1g0Qi0V 7Ome8NX3paXfDxJWwfDj+Av/zUPvUhRaAWfcnMpEpjcENaxjrsj8GAQsxqjkOtPB3/ fp6ZBpd9FGKVQ== Received: from localhost (qs51p00im-dlb-asmtp-mailmevip.me.com [17.57.155.28]) by qs51p00im-qukt01072301.me.com (Postfix) with ESMTPSA id EF9F425400F3; Wed, 24 Apr 2024 10:57:06 +0000 (UTC) From: Konstantin Ovsepian To: stable@vger.kernel.org, gregkh@linuxfoundation.org Cc: davem@davemloft.net, hengqi@linux.alibaba.com, leitao@debian.org, xuanzhuo@linux.alibaba.com, ovs@meta.com, qemu-devel@nongnu.org Subject: [PATCH 6.1.y] virtio_net: Do not send RSS key if it is not supported Date: Wed, 24 Apr 2024 03:57:04 -0700 Message-ID: <20240424105704.182708-1-ovs@ovs.to> X-Mailer: git-send-email 2.43.0 In-Reply-To: <2024041414-humming-alarm-eb41@gregkh> References: <2024041414-humming-alarm-eb41@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-GUID: sdjGZWmWw7_ebjwMuRx20I3WAV38thMO X-Proofpoint-ORIG-GUID: sdjGZWmWw7_ebjwMuRx20I3WAV38thMO X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.1011,Hydra:6.0.650,FMLib:17.11.176.26 definitions=2024-04-24_08,2024-04-23_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 spamscore=0 mlxlogscore=957 bulkscore=0 malwarescore=0 clxscore=1030 adultscore=0 phishscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2308100000 definitions=main-2404240045 From: Breno Leitao commit 059a49aa2e25c58f90b50151f109dd3c4cdb3a47 upstream There is a bug when setting the RSS options in virtio_net that can break the whole machine, getting the kernel into an infinite loop. Running the following command in any QEMU virtual machine with virtionet will reproduce this problem: # ethtool -X eth0 hfunc toeplitz This is how the problem happens: 1) ethtool_set_rxfh() calls virtnet_set_rxfh() 2) virtnet_set_rxfh() calls virtnet_commit_rss_command() 3) virtnet_commit_rss_command() populates 4 entries for the rss scatter-gather 4) Since the command above does not have a key, then the last scatter-gatter entry will be zeroed, since rss_key_size == 0. sg_buf_size = vi->rss_key_size; 5) This buffer is passed to qemu, but qemu is not happy with a buffer with zero length, and do the following in virtqueue_map_desc() (QEMU function): if (!sz) { virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 6) virtio_error() (also QEMU function) set the device as broken vdev->broken = true; 7) Qemu bails out, and do not repond this crazy kernel. 8) The kernel is waiting for the response to come back (function virtnet_send_command()) 9) The kernel is waiting doing the following : while (!virtqueue_get_buf(vi->cvq, &tmp) && !virtqueue_is_broken(vi->cvq)) cpu_relax(); 10) None of the following functions above is true, thus, the kernel loops here forever. Keeping in mind that virtqueue_is_broken() does not look at the qemu `vdev->broken`, so, it never realizes that the vitio is broken at QEMU side. Fix it by not sending RSS commands if the feature is not available in the device. Fixes: c7114b1249fa ("drivers/net/virtio_net: Added basic RSS support.") Cc: stable@vger.kernel.org Cc: qemu-devel@nongnu.org Signed-off-by: Breno Leitao Reviewed-by: Heng Qi Reviewed-by: Xuan Zhuo Signed-off-by: David S. Miller (cherry picked from commit 059a49aa2e25c58f90b50151f109dd3c4cdb3a47) Signed-off-by: Konstantin Ovsepian --- drivers/net/virtio_net.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 45f1a871b7da..32cddb633793 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -2948,19 +2948,35 @@ static int virtnet_get_rxfh(struct net_device *dev, u32 *indir, u8 *key, u8 *hfu static int virtnet_set_rxfh(struct net_device *dev, const u32 *indir, const u8 *key, const u8 hfunc) { struct virtnet_info *vi = netdev_priv(dev); + bool update = false; int i; if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP) return -EOPNOTSUPP; if (indir) { + if (!vi->has_rss) + return -EOPNOTSUPP; + for (i = 0; i < vi->rss_indir_table_size; ++i) vi->ctrl->rss.indirection_table[i] = indir[i]; + update = true; } - if (key) + + if (key) { + /* If either _F_HASH_REPORT or _F_RSS are negotiated, the + * device provides hash calculation capabilities, that is, + * hash_key is configured. + */ + if (!vi->has_rss && !vi->has_rss_hash_report) + return -EOPNOTSUPP; + memcpy(vi->ctrl->rss.key, key, vi->rss_key_size); + update = true; + } - virtnet_commit_rss_command(vi); + if (update) + virtnet_commit_rss_command(vi); return 0; } @@ -3852,13 +3868,15 @@ static int virtnet_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT)) vi->has_rss_hash_report = true; - if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS)) + if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS)) { vi->has_rss = true; - if (vi->has_rss || vi->has_rss_hash_report) { vi->rss_indir_table_size = virtio_cread16(vdev, offsetof(struct virtio_net_config, rss_max_indirection_table_length)); + } + + if (vi->has_rss || vi->has_rss_hash_report) { vi->rss_key_size = virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size)); -- 2.43.0