From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 54CD63876B7; Tue, 6 Oct 2026 23:33:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791329632; cv=none; b=CgSKMGGDIyQfKjd5brRmw74cMV7+LAjGyNkGz3ziaDqVf4EiZDkDdw9BCV9YsCj5jr6plnMNRG6Z78OzrOOknRTh4uu7MxeRuGy6WU2wAGl0muaw1b14JNkXWuy2YKz+wbtCCs0+cyZn7Ik7RzkLMaLQhH8OkIcLcRRmqBvbWdM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791329632; c=relaxed/simple; bh=rmDrskrJsi/kwBicdDywelOvJ9Rek/lzsmAzTKPSyCM=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=E0OcHj/YsXeBr15621u0dHzCzTgqz9gWNNEBn3dHuoQr5dKUI2kxMzDcDCOh+JERmz35JYp6RDvbBD4jIBS7do3DfZMtU7DdLavxE3c6+hk52mXaJ3srU6F3kimx1QnXf4AwzP7MQBU85LigqBMt8jSIsR8cRjcZhxQ7CYI7GR8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LvUyGXER; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LvUyGXER" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 458C11F0089B; Tue, 6 Oct 2026 23:33:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791329631; bh=zm8j7s6dPbe68KVfUZh47NlPhrjF01bigXUXsBDCEJA=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=LvUyGXERuHldy1RvQ0Y8rrzYpA/YI/r+2a1j9oknazUvbUrCHMLeoLeDQX8ZwhRVG z8q0k5GuuU9KxJq0q+H4n74pDWMa+qW2CybIrZQulQShrjCwMnjTlOdrkum3ss7xXM 76GJ3otPNaz/ZiZ1XgePKUxFuQSMN82dtM05mL6EDJb5F0Hd4eQJhRV2Kbdk3x8TTo JjLMXVi7/OTtP4whUpRLP+aW5WPdrrCpkQ41nZSOq+CAhPa1+Jku1xySfaMhyFdEmA 0n5LPO/nyFTmEdxoYBcKCmfjYD2IGasey0tkRIjYFcLNpahx6ht/xIN+Zk5axDeKEM scg7F4PsAEaWg== Date: Tue, 6 Oct 2026 16:33:49 -0700 From: Jakub Kicinski To: Maxime Chevallier Cc: netdev-bot+sashiko@kernel.org, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, horms@kernel.org, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, linux@armlinux.org.uk, lorenzo.bianconi@oss.qualcomm.com, nb@tipi-net.de, jitendra.vegiraju@broadcom.com, thomas.petazzoni@bootlin.com, alexis.lothore@bootlin.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com, pbrobinson@gmail.com, joe@dama.to Subject: Re: [PATCH net-next v3 1/3] net: rss: Require indir table size or hash key size to support RSS Message-ID: <20261006163349.61c738e8@kernel.org> In-Reply-To: References: <20261002142806.1299041-2-maxime.chevallier@bootlin.com> <179121059086.434549.5364767976780818051@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@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 Tue, 6 Oct 2026 09:59:29 +0200 Maxime Chevallier wrote: > > [Severity: Medium] > > rss_get_data_alloc() is shared by RSS_GET, RSS_SET and RSS_CREATE. Does > > this drop flow-hash reporting for devices that have ->get_rxfh but report > > 0/0 sizes? > > Yes it does, that's the intended behaviour here. RSS bits are all optional, > but does it make sense to report hashing params when the indirection table > is size 0 and key len is 0 ? Not sure if there's an implementation in the tree but it's possible to implement poor man's RSS on strict power-of-2 queue set with some hashing built into the Rx engine, without a key. We'd still want to control which fields are hashed in this case. In the Netlink API we combine the two so we'd break this?