From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 C6C4E3254A5 for ; Sat, 7 Feb 2026 09:56:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770458184; cv=none; b=APOjG6Ovq5GH8hEFxX6P+Ptcaf0uv+DE8dF/oxiVrV3DAw6IGdenZIfbo9sZLZrnyqmmUIq0UkB4rA28U/MMzIRDUuQUIs1qlFDY1xWPv7yuVuO2TibBTX9V8PeUOaFXnb9rkfDGSiDPDyl3LMawgSVAKkIZigpkRKi3L69zaoU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770458184; c=relaxed/simple; bh=Emfr+9M3FTLUOX6E+ELk+kwQTMeILIbImZa7UA1b9mQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YMGgJuU1MYhD5EoKqsQTj1aiIg41Z+x88M1m8S6TtM43fPlOTOJ4js6wL6BVdsPPnlOYhATwGAYya8eymnAVh9ImBSpWVkuW3J77+CjaR9bJMRyCqPbR9yDZPVQXgEDT63Ni8iU8ExgBXVmKP24S7aEkvjbie3NKpkp5efZwVjg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=P5sg9NrS; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=fF1bc/dh; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="P5sg9NrS"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="fF1bc/dh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1770458180; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=mgkhHo4dkLMI6TIjRYX8zZ+2vJLI82aDL+YBdRqg+7o=; b=P5sg9NrSw4V+Ioj9uLWBh/ahc2O/3T5Vn5/GLKBPoIXDV2qtqHqEGFKNcuzCbJC8kLey/m zPkVVaDjPwF50GVZsTFdtuqyU4hDXK2Ku9aULMh6njhVV32Q9+Miv7T/Rj+ZQImY4xL83W fp2WOrGfODEJbozQPRft9zjgxm9NHf0= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-262-SY9O_d_nNUifx5QnRfE8Cw-1; Sat, 07 Feb 2026 04:56:19 -0500 X-MC-Unique: SY9O_d_nNUifx5QnRfE8Cw-1 X-Mimecast-MFC-AGG-ID: SY9O_d_nNUifx5QnRfE8Cw_1770458178 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-4801bceb317so39261565e9.1 for ; Sat, 07 Feb 2026 01:56:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1770458178; x=1771062978; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=mgkhHo4dkLMI6TIjRYX8zZ+2vJLI82aDL+YBdRqg+7o=; b=fF1bc/dh4DHwD/KRaAiKSQ92jFUNbQcP1wYV0YjxaJFT8M39m3ILXxC9oBeOEl6U+1 JogtLFg8H6iH4U4TbIILm7FfPYY33yLC3OuJf5C1w59RDxw6MYX5ubAgVSzMAS5woL0Y nWxxyg4eejXLn52Q4EQdZ1tLQs4YL2FCCG5fLv2UHK5xRBIiuk0cO4pBt/xP5XweYf4s LRvxuUHWPh9znzpTORc22+M858uIOp5Jnxp7Y0fZg5o7SqEtY9cKv3yrXVij5UgquFNZ k6Ap6mzhB5g39AQ3G39Kgjca3AaZkx+TrcfgY1iX8FKVZS6wXQfyxRxIfkNEODhPOzqh N1XA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770458178; x=1771062978; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=mgkhHo4dkLMI6TIjRYX8zZ+2vJLI82aDL+YBdRqg+7o=; b=Ik/+h/D5UjRRTUokd9YQK13KLJtd8U6fHzgawCu5UtN6LkR9NviJOb3GSdf3LfxwG1 38iBpLWQJ1BIPJAKKlhB0+BxxYdgZYWXoaUbHyEkFaBPHxKbgD/vAqoOK40W+hgC8HrG nBgGTv2KnbQ5+MtqQ2vcWFxKZFCreKsJHjwj9qfPQWP0fA+ge1jQXUOOwChrKVOQc6pv 8g4S46CDvgd4qGPjp0M347Opuip3DJ9KLtGl0PlCumoLn631rrmyjxSvhiebYdDUptzo Az0aYX7a6mdr8UMXFioEGniu58+jqRp7F00DFbtmX3srvOUga2gC1JU3yeYU7NUuNJFo rhVg== X-Forwarded-Encrypted: i=1; AJvYcCXwR1d2Ooz6Rp55QmdSHsQ4rY5AQM6REoUSSAsdaOIn6HHs8l4KUteC672bk39GWOWNlTjLvw0=@vger.kernel.org X-Gm-Message-State: AOJu0YyaXcxvOJVUdjWR0sRJ2BbgIu1bDWHvvTBf4wFCTQ2nIxuLPV8i g8IUPfebzxQlbBorV9l1vSSnkuO2UGmfFpQgpabkpg6f5INIHSk5eBViepLus+0qgWGXeEOwY5J t4XovzzGik0L6Mt4HmLCjyRBnulvdaZXA4ru3cN+tO2QO97Xly9TGw2SlRg== X-Gm-Gg: AZuq6aLXIILVHysR22t89R8U0CvG2xxJ9tVVOJEY0o9f2+5apF6v610Wd7rQIjZuaur Xtoy41Qo/oFQOKysPGNrNOGM1PlL1pc+vHqPSyXuJmkakMS9VxzqQ6BAdmz+9HqmK5pttoooskC 56C4Zi5BW/c3is2nQJQAhOTkOuJqwSdqzkC7n08qFSuGVCIHcV7pA5DceyELzfETgEFF+F5hYG7 Ppyw8AWGq7PMxBO8DPmsaAiRKAJk4oUo15fVRBPGPqD/cKDZMzaaWmqmDDcep7r2AbobYne6EOX DwE83NXN+onovnKTf0FgY9PzbaHObOTxhJBzwAN4J/Kyr1d8sSsU9DP4fga53pTcfPebV9XLcgy wKixLVmC4Nvj7AezMlJzk0RX6m5HJ82/CuQ== X-Received: by 2002:a05:600c:64c6:b0:477:a36f:1a57 with SMTP id 5b1f17b1804b1-483201fffeamr73947465e9.3.1770458178040; Sat, 07 Feb 2026 01:56:18 -0800 (PST) X-Received: by 2002:a05:600c:64c6:b0:477:a36f:1a57 with SMTP id 5b1f17b1804b1-483201fffeamr73947285e9.3.1770458177554; Sat, 07 Feb 2026 01:56:17 -0800 (PST) Received: from redhat.com (IGLD-80-230-34-155.inter.net.il. [80.230.34.155]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4832040a3cesm68665225e9.3.2026.02.07.01.56.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 07 Feb 2026 01:56:16 -0800 (PST) Date: Sat, 7 Feb 2026 04:56:13 -0500 From: "Michael S. Tsirkin" To: Jakub Kicinski Cc: Srujana Challa , netdev@vger.kernel.org, virtualization@lists.linux.dev, pabeni@redhat.com, jasowang@redhat.com, xuanzhuo@linux.alibaba.com, eperezma@redhat.com, davem@davemloft.net, edumazet@google.com, ndabilpuram@marvell.com, kshankar@marvell.com Subject: Re: [PATCH v2 net-next] virtio_net: Improve RSS key size validation and use NETDEV_RSS_KEY_LEN Message-ID: <20260207045416-mutt-send-email-mst@kernel.org> References: <20260206120154.2548079-1-schalla@marvell.com> <20260206191308.7fdbfef4@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260206191308.7fdbfef4@kernel.org> On Fri, Feb 06, 2026 at 07:13:08PM -0800, Jakub Kicinski wrote: > On Fri, 6 Feb 2026 17:31:54 +0530 Srujana Challa wrote: > > Replace hardcoded RSS max key size limit with NETDEV_RSS_KEY_LEN to > > align with kernel's standard RSS key length. Add validation for RSS > > key size against spec minimum (40 bytes) and driver maximum. When > > validation fails, gracefully disable RSS features and continue > > initialization rather than failing completely. > > Hm, FWIW clang says: > > drivers/net/virtio_net.c:6841:31: warning: result of comparison of constant 256 with expression of type 'u8' (aka 'unsigned char') is always false [-Wtautological-constant-out-of-range-compare] > 6841 | } else if (vi->rss_key_size > VIRTIO_NET_RSS_MAX_KEY_SIZE) { > | ~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Which is kinda annoying because the value was increased in net-next. > If Machael wants this backported then we need to keep the check > and follow up in net-next? We could try to cast the u32 away but > that feels dirty.. I'd say yes. the warning is harmless. so patch 1 - this code patch 2 - replace with BUILD_BUG_ON but i ask then whether this code was actually tested against net-next. -- MST