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 E8DA0381E9A; Tue, 6 Oct 2026 21:22:33 +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=1791321755; cv=none; b=cVyvIk1IbVQ77+SxMLkqkFrbTHuTU6gFt+y15/inRj7P2ucAAGM8sr0HZgF/zgGloQMhBq9KTZ9bHfGmOZe3VIUCskwEE8XvByo3zFxIKX8ne26uarunk4Px+RMbN+2+60YNr2UcdpgOboMaKWNky7DZjqYHNvh0BumglFWApjo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791321755; c=relaxed/simple; bh=UeWBVlgJFWojhkJi+cd+n88622HpQCq8j9HuKrvES4M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DaPPXRKRhcagY44wN6ZCC9eFeBVTPN32d1uGnr+rSusY5Eo6vNFNUaaFUsiPF59weuCPdAH1ctqzifXFqVAqCJVZCCfGVcrqpQV2YC/drp6vFAqAb05R7mhuQuZvTshUogK3Sp0NPOnL18rSrerMHSTHKFijRGVUNw51lyJsRaU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KvV0Av2l; 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="KvV0Av2l" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A1CD81F0089B; Tue, 6 Oct 2026 21:22:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791321753; bh=BHt0ynO7I/zLJYGK8yKQoBOgVQqwbnoeMI9XKYPGhZ8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=KvV0Av2l/BYipbielqVo1Hyj4bJeeM7HGyU39j9dAPfaL+IYSRbUyJpFZqBmUFH4m Iy8n49/p8+UuyPdQS8LlMRIL11B7wCiu4qwYsz6rz6zarzCAsz16fTIvmh5kjR4ybk B20SXYNPmvS0vHuV3fAKnmiJlgHazmy77ClTfX1c4RJWTUTdgJyYOwZbiCmR3yJB6e XkDvFtp9+a5Q2RIZPKWFJQWRBW7E7SNKl0OMsmOkQpY7I3/5NfHiBam8pkvRFbgIAt p1WHLcet3/VbzM8Wj/vBG/VHG6ISunfiQkAnGa5ygzm2vTOeDUgRYEkMlnfgkBOD1N +51VW8dry+vZA== Date: Wed, 7 Oct 2026 00:22:27 +0300 From: Leon Romanovsky To: Bjorn Helgaas Cc: Bjorn Helgaas , Logan Gunthorpe , Jason Gunthorpe , "Joerg Roedel (AMD)" , Will Deacon , Robin Murphy , Christian =?iso-8859-1?Q?K=F6nig?= , Thomas =?iso-8859-1?Q?Hellstr=F6m?= , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, iommu@lists.linux.dev, Tushar Dave , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-rdma@vger.kernel.org, kvm@vger.kernel.org, Chaitanya Kulkarni , Greg Kroah-Hartman , Jens Axboe , Alex Williamson , Ankit Agrawal , Jonathan Corbet , Shuah Khan , Randy Dunlap , Sumit Semwal Subject: Re: [PATCH v9 00/18] PCI/P2PDMA: Route peer-to-peer DMA by TLP class Message-ID: <20261006212227.GB7822@unreal> References: <20261001-fix-p2p-acs-v4-0-v9-0-1a8e0f50ddd9@nvidia.com> <20261006192955.GA703309@bhelgaas> 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-Disposition: inline In-Reply-To: <20261006192955.GA703309@bhelgaas> On Tue, Oct 06, 2026 at 02:29:55PM -0500, Bjorn Helgaas wrote: > On Thu, Oct 01, 2026 at 02:55:08PM +0300, Leon Romanovsky wrote: > > PCI P2PDMA applies Request and Completion Redirect throughout both paths. > > This misclassifies asymmetric and nested switches, and reports one answer > > for every kind of TLP. > > > > Three ACS controls act on TLP attributes the client chooses rather than > > on the topology: Translation Blocking and Direct Translated P2P act on > > a Request's Address Type, and Completion Redirect skips Completions carrying > > Relaxed Ordering. > > > > Evaluate each direction at the path divergence, decide every class from the > > one walk, and treat a client with ATS enabled as translating unless its > > driver declares per-mapping ATS. > > > > This completes the P2PDMA side; dma-buf and mlx5 follow separately. > > ... > > > Leon Romanovsky (18): > > PCI/P2PDMA: Document the TLP attribute assumptions > > PCI/P2PDMA: Derive routing from directional ACS controls > > PCI: Reject unreadable ACS controls in isolation checks > > PCI/P2PDMA: Evaluate ACS controls at the path divergence > > PCI/P2PDMA: Document directional ACS routing > > PCI/P2PDMA: Collect the path's ACS controls before deciding > > PCI/P2PDMA: Answer routing per TLP class > > PCI/P2PDMA: Route Relaxed Ordering Completions directly > > PCI/P2PDMA: Reject Translated Requests blocked by Translation Blocking > > PCI/P2PDMA: Route Translated Requests under Direct Translated P2P > > PCI/P2PDMA: Log detailed ACS routing diagnostics > > PCI/P2PDMA: Add KUnit tests for the ACS routing decisions > > PCI/P2PDMA: Test the ACS P2P routing walk > > PCI: Add KUnit coverage for ACS isolation checks > > PCI/P2PDMA: Document TLP-class routing > > PCI/P2PDMA: Let a client declare that it selects ATS per mapping > > PCI/P2PDMA: Evaluate the ATS path for clients with ATS enabled > > PCI/P2PDMA: Test the routing of clients with ATS enabled > > > > Documentation/admin-guide/kernel-parameters.txt | 15 +- > > Documentation/driver-api/pci/p2pdma.rst | 80 +++ > > drivers/pci/Kconfig | 15 + > > drivers/pci/Makefile | 1 + > > drivers/pci/p2pdma.c | 719 ++++++++++++++++++-- > > drivers/pci/pci.c | 7 +- > > drivers/pci/pci.h | 58 ++ > > drivers/pci/pci_acs_test.c | 860 ++++++++++++++++++++++++ > > drivers/pci/quirks.c | 6 +- > > include/linux/pci-p2pdma.h | 12 +- > > 10 files changed, 1687 insertions(+), 86 deletions(-) > > --- > > base-commit: 08dbfad3f5040f5bdb6c529da20d6d4e81fefd72 > > change-id: 20260821-fix-p2p-acs-v4-0-e72455e3a261 > > prerequisite-message-id: <20260830-batch-p2p-fixes-v1-0-5044e8dfbe2e@nvidia.com> > > prerequisite-patch-id: 6b25c7fcf164cdfc14e9fac5b908d97fcf6509d7 > > prerequisite-patch-id: 0d083c281001365aae4b35544cf28891a6ab9a96 > > prerequisite-patch-id: bfd9dabf271f3cc9a3a61f46387d20c20311363d > > prerequisite-patch-id: fad0275efc722830fc591509506c0a5e4f581073 > > prerequisite-patch-id: 0c83bee688fec1f6d1564654df7c630fa6a4a978 > > This seems like material for the PCI tree, but I'm not sure how to > apply it. It doesn't apply cleanly on the current pci/p2pdma > (https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/log/?h=p2pdma), > which does contain your series from > 20260830-batch-p2p-fixes-v1-0-5044e8dfbe2e@nvidia.com. > > I could probably fix the conflicts but I don't know why there should > be conflicts, since the only commits on pci/p2pdma other than yours > are a few trivial allow-list updates. So maybe this is related to these trivial updates, my series was based on the clean p2pdma branch: https://git.kernel.org/pub/scm/linux/kernel/git/leon/linux-rdma.git/log/?h=fix-p2p-acs-v9 Thanks > > Bjorn