From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-111.freemail.mail.aliyun.com (out30-111.freemail.mail.aliyun.com [115.124.30.111]) (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 E52025677D; Mon, 25 Mar 2024 06:00:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.111 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711346417; cv=none; b=fuuHpxgL9CKNNBG/wvyVGMabTJ5SMNYLtYPqDmXayv+5+fUk8QLM62x/haDGzevpPG5MZlxp+uxeVoy/xIzsLdXV+3xADIt1hUTURCj1ulQSLTQewPxyblIZLfd8sk8c3E29YEPblZiH/cgKld6p5fWMjG2Br/++VobRUbhDTSU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711346417; c=relaxed/simple; bh=pkhfJ+Q1nAAONeQTS6q9Z+AlngVVouzqkHVOLqRn46s=; h=Message-ID:Subject:Date:From:To:Cc:References:In-Reply-To; b=BYGgJHR914tqOlVbJx5CtWVmBwhwGduQU3Ldqm0RiipfuixVfDwHEOwppSUstgcoQo18FwMdfO4EyKJIWbPRcYm+zytjM/92URTTvnHrIw3jXPdQKRVoSJCe1IADuzJjPH4x9bkilKJVXtFXdqQh1aCI18JKzI/2LDEZtRcvWSA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=hoKZ9qlo; arc=none smtp.client-ip=115.124.30.111 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="hoKZ9qlo" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1711346413; h=Message-ID:Subject:Date:From:To; bh=JNL9A38afeP0aEJfOCNG1LEpvhSBCwkDLxX/IRTOtms=; b=hoKZ9qloGzGZjW1UBci6ghhqAiZ7vJiUqa14wLENKkRafNZ2JPuv6rSD2nGsfG5wggAzlNZyb/w05dbs7TMfmeWOKEHBlZQalGC5+EVqjWo1DuxSHZB2ksP/Gps3DVbQv59Mx43/yRO8enSvZF/sg6UKV4N6eB+tMMe3JRmxDIg= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R151e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046051;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0W39kIMB_1711346410; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0W39kIMB_1711346410) by smtp.aliyun-inc.com; Mon, 25 Mar 2024 14:00:11 +0800 Message-ID: <1711346273.5079622-1-xuanzhuo@linux.alibaba.com> Subject: Re: [PATCH] virtio_net: Do not send RSS key if it is not supported Date: Mon, 25 Mar 2024 13:57:53 +0800 From: Xuan Zhuo To: Breno Leitao Cc: rbc@meta.com, riel@surriel.com, stable@vger.kernel.org, qemu-devel@nongnu.org, "open list:VIRTIO CORE AND NET DRIVERS" , "open list:NETWORKING DRIVERS" , open list , "Michael S. Tsirkin" , Jason Wang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Andrew Melnychenko References: <20240321165431.3517868-1-leitao@debian.org> <1711072822.882584-1-xuanzhuo@linux.alibaba.com> In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: On Fri, 22 Mar 2024 03:21:21 -0700, Breno Leitao wrote: > Hello Xuan, > > On Fri, Mar 22, 2024 at 10:00:22AM +0800, Xuan Zhuo wrote: > > On Thu, 21 Mar 2024 09:54:30 -0700, Breno Leitao wrote: > > > > 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; > > > > > > > > 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)); > > vi->rss_key_size = > > virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size)); > > > > vi->rss_hash_types_supported = > > virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types)); > > vi->rss_hash_types_supported &= > > ~(VIRTIO_NET_RSS_HASH_TYPE_IP_EX | > > VIRTIO_NET_RSS_HASH_TYPE_TCP_EX | > > VIRTIO_NET_RSS_HASH_TYPE_UDP_EX); > > > > dev->hw_features |= NETIF_F_RXHASH; > > } > > > > > > vi->rss_key_size is initiated here, I wonder if there is something wrong? > > Not really, the code above is never executed (in my machines). This is > because `vi->has_rss` and `vi->has_rss_hash_report` are both unset. > > Looking further, vdev does not have the VIRTIO_NET_F_RSS and > VIRTIO_NET_F_HASH_REPORT features. > > Also, when I run `ethtool -x`, I got: > > # ethtool -x eth0 > RX flow hash indirection table for eth0 with 1 RX ring(s): > Operation not supported > RSS hash key: > Operation not supported > RSS hash function: > toeplitz: on > xor: off > crc32: off The spec saies: Note that if the device offers VIRTIO_NET_F_HASH_REPORT, even if it supports only one pair of virtqueues, it MUST support at least one of commands of VIRTIO_NET_CTRL_MQ class to configure reported hash parameters: If the device offers VIRTIO_NET_F_RSS, it MUST support VIRTIO_NET_CTRL_MQ_RSS_CONFIG command per 5.1.6.5.7.1. Otherwise the device MUST support VIRTIO_NET_CTRL_MQ_HASH_CONFIG command per 5.1.6.5.6.4. So if we have not anyone of `vi->has_rss` and `vi->has_rss_hash_report`, we should return from virtnet_set_rxfh directly. Thanks.