From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) (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 B46B13C1419; Tue, 4 Aug 2026 21:56:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=204.191.154.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785880594; cv=none; b=JvveYu9hK6tyieAoqHOVQ5DiCJ+yEHgcT5cRtu5mhp1r/BGj2VFu+gNGGpAuaKhpxMLkxJXYJCebudnez0rmYf7QH5liJvHySAcU12FU9MBJDiM2aD1Yn12SYvRdnarl1XJY78TsDx9zzNChwsclDkMfFKyuDrnZZ5Wgf4e+qtY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785880594; c=relaxed/simple; bh=tBey52MboA+QfPgPpyx86JHVOQeKwAmSVSv2V7yNRH8=; h=Message-ID:Date:MIME-Version:To:Cc:References:From:In-Reply-To: Content-Type:Subject; b=P2UKBNzhfYWlopuM5kuC6AW0qjrrqsGMpk26d3Lipz9BA7BIzXCVmei152D87GCl8oLpnq7GROghZJBx/TNlOhR/9Z0HeRzp3WdfjAI3H5Ma6UPI22SvCOKgLjEIkVRZUNLuiSUQZG8LaL5TPbsNHQC93OmaPeouge2BoW9HkKM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=deltatee.com; spf=pass smtp.mailfrom=deltatee.com; dkim=pass (2048-bit key) header.d=deltatee.com header.i=@deltatee.com header.b=UbkxYsiH; arc=none smtp.client-ip=204.191.154.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=deltatee.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=deltatee.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=deltatee.com header.i=@deltatee.com header.b="UbkxYsiH" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:In-Reply-To:From:References:Cc:To: MIME-Version:Date:Message-ID:content-disposition; bh=2ZjaPusGm7oCCyaWHdROo0ArJZ50KdqtcdXZx/MR+bc=; b=UbkxYsiHglvDWQJbRDi3GYDmU5 ihFi9HCuCCSbJ/T9BUrYJENtWPuZEvtq25T6AS0KWQbjlc77SEZoBon8xUi1a3jsJFeTJZp8nQZLZ 70Xnik13lHMf5QNF+Uog4hIGDAxw5JTGV+CDajCgJfnangsbj3ZrDc80Wb7d3CaCTTGKbXUucytZe 3q5xfG8fxqTmkLwjng7GVf14MvCknK8KEtP0OCJV1BC5NBqf/lQ+Sh4kZ9LRzmj+FDslLnPcE8YmN D8kBYPQcJwdR7kFwWyJe63lYZyQpVoIxOd7UQnabX6P2n9uy/W9Cb+bCRH1tBR1D8Wdk1yZIG5M8i qLd2fDCA==; Received: from guinness.priv.deltatee.com ([172.16.1.162]) by ale.deltatee.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.98.2) (envelope-from ) id 1wrN7f-000000002TF-28JA; Tue, 04 Aug 2026 15:56:32 -0600 Message-ID: <7d91cae7-1c57-4244-b019-51f374603124@deltatee.com> Date: Tue, 4 Aug 2026 15:56:30 -0600 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Leon Romanovsky , Bjorn Helgaas , Jonathan Corbet , Shuah Khan , Alex Williamson Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org References: <20260802-fix-p2p-acs-v1-0-a7c5eb64fff6@nvidia.com> <20260802-fix-p2p-acs-v1-8-a7c5eb64fff6@nvidia.com> Content-Language: en-CA From: Logan Gunthorpe In-Reply-To: <20260802-fix-p2p-acs-v1-8-a7c5eb64fff6@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: leon@kernel.org, bhelgaas@google.com, corbet@lwn.net, skhan@linuxfoundation.org, alex@shazbot.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org X-SA-Exim-Mail-From: logang@deltatee.com X-Spam-Level: Subject: Re: [PATCH 08/13] PCI/P2PDMA: Honor ACS egress control vectors X-SA-Exim-Version: 4.2.1 (built Sun, 23 Feb 2025 07:57:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) On 2026-08-02 09:09, Leon Romanovsky wrote: > From: Leon Romanovsky > > An enabled Egress Control bit does not itself send a peer request > upstream. PCIe r7.0, sec 6.12.3, table 6-11 makes the outcome depend on > the Egress Control Vector bit for the target port: a clear bit routes the > request directly regardless of P2P Request Redirect. > > Read the vector where the paths diverge below their common upstream port. > Keep a clear vector bit on the direct path, subject to P2P Completion > Redirect. > > A set bit with Request Redirect clear is an ACS Violation. ACS acts only > on peer-to-peer Requests, so route it, and an indeterminate vector, > through the host bridge. > > Fixes: 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory") > Signed-off-by: Leon Romanovsky Reviewed-by: Logan Gunthorpe