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 E1F983E7BD5; Mon, 12 Oct 2026 13:15:17 +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=1791810918; cv=none; b=bqboyU2P8rbx6Np5tYyk+yMsHr4tSmKR3jbjZoFPPVYkLXUbibOE+irwB4MUXWavPfC3XVJIaYTcRxdOMl2RlDMLHam/8s0fMREHT4FfxcKOX0JqBAos+zL1JK3SwePdl6cvJ0SaVZfJYbBKeo7MZze6Z8E96183UwbDwi3oKKc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791810918; c=relaxed/simple; bh=Secd611NVld8zSX1i8AQkJaQNh8sE93RTRF/gDHE/mY=; h=Message-ID:From:Subject:To:Cc:In-Reply-To:References:Content-Type: Date; b=JE1CPtrucBxKcdvlv8hCOiagBnzsPXFFH5fSVxYniGInsa+ag9m+YhE5p9Dv6WBVCGzcK0t3swKKihTcjGWiYn2JET+GblgnlaKH0iiE8nLGVOyeAU5XaaY02PNVJLvSuhEFuZsvjAvEFsXL2M+PuLqxz8FDJKplGiTI9OLOCKs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=algrs0+y; 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="algrs0+y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A8EF1F0089B; Mon, 12 Oct 2026 13:15:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791810917; bh=pbwolV2gpLlhco6YnOqT4f0AFWu7v8BeH4SkpDuXrms=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=algrs0+yoH1mDGhKhiinVo4Tojv/6YsugbCK8b5gMgSmwb+By68xiMTvfEUg14eas 4MrEsFDZntb28NSPVZrl21Q1tcJXZnZCP9ovv71msbBleWC/5vmgmspv00gJ0J8GKu ur5klKTANWlCw61b+3SawqWTY5DKOv9hp/Ms4MogqJd32hqLEvQ1WsQ/SlKK9yP2Wc FMSRFaRYjxWu0OkMeOdWdnVg4kbhNDMCPTjQg4A3wz+5A//xUuK5sRUpKpPT4Ny16G FnDiLDVHfftJqTVIPMToImL+HdHOUy/yc+0YIEK6CfH724feJ2beZWQLAtr7hb4OUz 7VU2OBZsRj5RQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v10 04/18] PCI/P2PDMA: Evaluate ACS controls at the path divergence Reply-To: sashiko-reviews@lists.linux.dev To: "Leon Romanovsky" Cc: linux-rdma@vger.kernel.org, media-ci@linuxtv.org, kvm@vger.kernel.org, linux-pci@vger.kernel.org, dri-devel@lists.freedesktop.org In-Reply-To: <20261012-fix-p2p-acs-v4-0-v10-4-6ffe7b7a4517@nvidia.com> References: <20261012-fix-p2p-acs-v4-0-v10-0-6ffe7b7a4517@nvidia.com> <20261012-fix-p2p-acs-v4-0-v10-4-6ffe7b7a4517@nvidia.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 12 Oct 2026 13:15:17 +0000 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > From: Leon Romanovsky >=20 > ACS redirect controls choose between peer and upstream routes only at the > path divergence. Applying them below that point rejects valid nested > topologies because traffic already has only an upstream route. >=20 > Host bridge 1 Host bridge 2 > | | > PCIe switch 1 PCIe switch 2 > | | | > A B C >=20 > A's and B's paths diverge in switch 1. A and C share no upstream bridge, > so no direct route exists for ACS to gate. >=20 > Evaluate Request controls on the Requester-side divergence port and > Completion Redirect on the Completer-side port and reject an unreadable A= CS > Control register. >=20 > Fixes: 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory") > Reviewed-by: Logan Gunthorpe > Tested-by: Tushar Dave > Signed-off-by: Leon Romanovsky Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261012-fix-p2p-ac= s-v4-0-v10-0-6ffe7b7a4517@nvidia.com?part=3D4