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 333284DD6FD; Thu, 22 Jan 2026 15:52:08 +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=1769097129; cv=none; b=bQXbpmlMKMqlTIstrfhCBokXV+EQ9xedFCDR3xjA30BKaJ/q3uBYVGNN7vE1cj1UpObxhLShdIUl64fGCbCIiDDgttOfxrM9D0CmhQX3sRmea7Hqv9qq4xlc34cWE+jiuJqI2wOa7orX+vfSuYsq1kj9BVMtKypGoVjX0/h/BIY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769097129; c=relaxed/simple; bh=H4l1iCP7+VOlZiUZ0OKn22FT1fDkfwOd/D4+GeFIj5I=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=J4jz1i2j/tqzyEEzMTzUuXdczC6fpG1nrTi1/H5hHfp5IYw3sGJFYyEU/EpK1AEqLajEGXz912VYO9H5OTV4BebnvFKWChmPe+TNPNIyd4foRM5rQteZD17Z3+MnOcpeeUg60nZTXns0hI+nujiEflBMbm7Y/gA3s7/t6y4GJJE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SsYIVTIr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SsYIVTIr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0BA2C116C6; Thu, 22 Jan 2026 15:52:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769097128; bh=H4l1iCP7+VOlZiUZ0OKn22FT1fDkfwOd/D4+GeFIj5I=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=SsYIVTIrs2T6yP7qetT6dLHxtGob184hnkzuxvIKZ5/GKUyNyCyjeHUorA1x8hH/A 8lDdFXjIzJtDJMllwS6ha4K+38OytVR4bMIpiZU5jA6nVUPaK0JULGPjNBqK1MRO02 ayeA2w046WtdRe+QIji36SH7Y4bn3pQHxBujUw8GzlHQtkKit9rCLOOYjO8SlG4Q0X xrgbMIyMN1o1wWk3vLxBttEGnf2Eu5ozvL38cbzkDrDdBdgOuev5zcFNLEcIxvUfjV CTP/74H6CDhUq5VUiQlJAlzAN8QJJdyVgefVDXmVfI54+qWOu/pX41BHlGCOttyeub 3KYEzb+60Zlcw== Date: Thu, 22 Jan 2026 07:52:06 -0800 From: Jakub Kicinski To: Srujana Challa , Willem de Bruijn Cc: , , , , , , , , , , , Willem de Bruijn Subject: Re: [PATCH net-next] virtio_net: Increase RSS max key size to match NETDEV_RSS_KEY_LEN Message-ID: <20260122075206.504ec591@kernel.org> In-Reply-To: <20260122091527.339180-1-schalla@marvell.com> References: <20260122091527.339180-1-schalla@marvell.com> 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-Transfer-Encoding: 7bit On Thu, 22 Jan 2026 14:45:27 +0530 Srujana Challa wrote: > Increase VIRTIO_NET_RSS_MAX_KEY_SIZE from 40 to 52 bytes to align with > the kernel's standard RSS key length defined by NETDEV_RSS_KEY_LEN. I've been meaning to bump NETDEV_RSS_KEY_LEN to 128 or some such. Most modern drivers can't use netdev_rss_key_fill() either because core generates a tiny key. And the devices support hashing over two layers of IPv6 for tunnels. Willem, WDYT? Is there a reason to keep the core key small? Or deprecate netdev_rss_key_fill()? > The virtio specification requires devices to support at least 40 bytes > for the RSS key size. However, devices may support larger key sizes > up to 52 bytes (as reported by the device's rss_max_key_size config > field). This change allows such devices to work properly. > Previously, devices reporting rss_max_key_size > 40 would fail with > an error during initialization. > > The driver already handles variable key sizes dynamically through > vi->rss_key_size, so increasing the maximum limit is safe and > maintains backward compatibility with devices that support smaller > key sizes. > -#define VIRTIO_NET_RSS_MAX_KEY_SIZE 40 > +#define VIRTIO_NET_RSS_MAX_KEY_SIZE 52