From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793336036; b=vOB8IaRvVrYhMs7HcixQYHQrkLB/l+kzs7RsUsGJkSAZ7sZBUig4KMMYXxWNldgvT3qp +s8K5TLAvdDd0EpiQ9SW30fXhy5orEaHhtV333NC2MX1dxbn8+uPuXTJ03YopC6LikDDV l/LgJz3fe14O8dkJslM/e5wmw5kFN09L7j4FGfGAERMx8WhZ1KQtoU4N8av3Y8LiAg15e Ml1ACSXkFI54mPS8MFbGWyqjcX4GYQJFx69ps4b7q0ycbzJ9wq6FdfHtVTyEkgJE2PM7h Rp5RtoNQmq2J1ITdMh/TAXq9YvwoPCofELf0tlyo+ZRhRbvDMaHDbafU/Pc4N1kd4tg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793336036; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=uXaYhg7n0DU5KMcbLH+cFn+AJqbTCEQyZ6F4B+pyQog=; b=hTCmtjfja/BPfjHDlvgJe8bN4pHVwDxpJMOTLDjUFIq1oVkCHkpCh49jAhGcqWvd7Are /X84DNaDArsfsHXihQd3mTlMGYuOL7NbaBdkgBS2MNeOkkTu8L/DZGLpOyqmEXeVwOkvs pWb84wnZtmIlzNuwqTAGZr4jbCLwxdr4RLUd7AnkOGPWlo6Wo68M5ragpOHCrMaXYpEK4 bSCmkR1fq+alOuVEdoSfAB1PCmRbku+FzXr/Txx12/6pXO8wA3BZMxLnv5O12Zr5Of7Dc QSqF4Dxkvdr0kTL2xXIb2FCnET8TW8FWS2p3Orsn9kFf1zzw1CjLYST6uCnHf0VR2bw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Uq4BVWzV; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 57444606A320 for ; Fri, 30 Oct 2026 04:53:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Uq4BVWzV Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15FF21F00A21; Fri, 30 Oct 2026 04:53:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793336036; bh=uXaYhg7n0DU5KMcbLH+cFn+AJqbTCEQyZ6F4B+pyQog=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Uq4BVWzVAXCBjUfqo8shT5dc9fLUJ3c3wZPRLs1GE53ZIWtGwf0/n7qfZCRqt7/jo 7ZeR17Rf+605LaSIb9JkO4rd8HMukHObPVCd903RPXTKzvU4q//tLm1VLiBY1L7TXU eavF97ceZN7BxNseb6hZ3Wm1HmZlrxumpqHL253ovRMpy9NEuWP+3SmBBywT8SlTwJ WFgqIOwTKuZ2l6vf00+ghIHnSikydE5ShirBQ1aCYxD1RgWISpQTuwTlc6SZ4ZryN+ o6Y2W3/kGwZHEwDteCn/YDazHRbAEIa5q27ycrJiUhFnl0LeVyTRHKWmReDsAFNziN MSfCkusbVKNjg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH net-next v3 2/8] net: netkit: declare NETMEM_TX_NO_DMA mode Reply-To: sashiko-reviews@lists.linux.dev To: "Bobby Eshleman" Cc: linux-rdma@vger.kernel.org In-Reply-To: <20260507-tcp-dm-netkit-v3-2-52821445867c@meta.com> References: <20260507-tcp-dm-netkit-v3-2-52821445867c@meta.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 30 Oct 2026 04:53:55 +0000 X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Bobby Eshleman >=20 > Some virtual devices like netkit (or ifb) never DMA and never touch frag > contents, they just forward the skb to another device. They are unable > to forward unreadable skbs, however, because they fail to pass TX > validation checks on dev->netmem_tx. The existing two-state > NETMEM_TX_NONE / NETMEM_TX_DMA doesn't give the TX validator enough > information to differentiate devices that will attempt DMA on the > unreadable skb from those that will simply route it untouched. >=20 > Add a third mode to the enum so drivers can indicate 1) if they have > netmem TX support, and 2) if they do, whether they are DMA-capable: >=20 > NETMEM_TX_NO_DMA - pass-through, device never DMAs >=20 > Widen dev->netmem_tx from a 1-bit field to 2 bits to fit the new value, > and declare netkit as NETMEM_TX_NO_DMA. Devmem TX support over these > devices comes in a follow-up patch. >=20 > Signed-off-by: Bobby Eshleman Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260507-tcp-dm-net= kit-v3-0-52821445867c@meta.com?part=3D2