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 AE18A33BBAF; Tue, 19 May 2026 14:37:10 +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=1779201430; cv=none; b=uouh/Qlf1H0EhK/4yNYWUfyY/k0x5c28wiXTPXDvnERFpvS52hJWsciGthuVE7UqZAem94mh/8bp1w4HGm6e6qoxwHmyXy52i27WVmUCuAHgzrgBBv2VKH7H65ot4VMYDA3GWLI1Evz/5QgXUTnjuqUf2OV5UMtzI9hJOOsn7/U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779201430; c=relaxed/simple; bh=+a2mLdBcsDsGU+5BGxIWppLWszl9Od7wqmJ0aNKiRJw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=D/gLHA81Jmq9z6MZnKD26jih7kH+8oKZY/q9P/Htk+KcCWtWZmD/Mwzh32kXdLA6zTsQ9+h1EqUmyN8EeGw2zZUOhwCp+UpHXXnCBwdlD0sfR82YpGSc/ufkIpIe3uV9TE2DemM8BIU1u/iVtj0uGtx4x2eGjq0UwAGq9fDMgtQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Cg/WX+0q; 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="Cg/WX+0q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C493DC2BCB3; Tue, 19 May 2026 14:37:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779201430; bh=+a2mLdBcsDsGU+5BGxIWppLWszl9Od7wqmJ0aNKiRJw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Cg/WX+0qLWt63pPbkt2cfcw3AIzRrO06o8o9d85fML38Pdxdw0/9KFC/l+/o4TpCn C4Msv/nAseZVQNiI36nDHzcjWUXFGroxS6uE1OopMmZh6xfYHlNizSfHYxmI96gL6/ UxxCu4i8s7Z6Xd8wiYd9l0mT9yzKMaLAgpxxwdhyPU1CN+8XMY9E1prY9C6i1SvagB quWE9mzHgyWNG/LNlRC0jPLCIIaqRvO8RUA7dGtFd1sUZoc1nb8h53zWCia1AYYSlG W2W6S3mnlWN9SoOIVCeuXAXBdY5ggqq5GDBUkc1si0fj0VeDVmQVAfbO6YumkkhGAZ pR/mnD6hCdn+A== Date: Tue, 19 May 2026 17:37:04 +0300 From: Leon Romanovsky To: Max Makarov Cc: netdev@vger.kernel.org, linux-rdma@vger.kernel.org, saeedm@nvidia.com, tariqt@nvidia.com, mbloch@nvidia.com Subject: Re: [QUESTION] mlx5: format_select_dw_8_6_ext capability on ConnectX-7 Message-ID: <20260519143704.GY33515@unreal> References: <177912266235.29998.14244693862353385829@volta.cloud> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <177912266235.29998.14244693862353385829@volta.cloud> On Tue, May 19, 2026 at 01:44:22AM +0900, Max Makarov wrote: > Hi, > > Question about the cmd_hca_cap_2.format_select_dw_8_6_ext bit (introduced > into mlx5_ifc.h in v6.12-rc1). > > On all three of our standalone ConnectX-7 SKUs (PSIDs MT_0000000838, > MT_0000000840, MT_0000000892, firmware 28.48.1000) this bit reads as 0 in > both GET_CUR and GET_MAX modes. The DPDK code at > drivers/net/mlx5/hws/mlx5dr_cmd.c reads it without any device-ID > conditional, so it appears to be exclusively firmware-controlled — yet > firmware reports 0 across all our CX-7 cards, including the latest > public release. > > This blocks DOCA Flow CT pipe for IPv6 (which requires the 11-DW jumbo > STE format gated by this bit). > > Two questions: > > 1. Is the kernel's filter that rejects SET_HCA_CAP for cap_class != > MLX5_CAP_GENERAL intentional? If so, what's the rationale? > > 2. From the NVIDIA side: is this capability hardware-fused on standalone > CX-7 (BlueField-3 advertises it as 1), or could a future firmware > release enable it on CX-7? Please contact your NVIDIA support representative. Thanks > > Thanks, > Max Makarov > Volta Cloud >