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 B43CC456DF7; Tue, 22 Sep 2026 09:27:59 +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=1790069280; cv=none; b=RU6mh1GuIEarH8VWsNG+9+hN+T2O8RuoHKcWrrszvS3aU5soH7IJz8hUTFlkD8h3cUY3EmdSC9rmvwo3M7sFnsX8QLiUbU+TBEO0l2KgjaKdbm133zZU6fH4fmQM2y+EbCqRUQEZF5VM7s7E3NeFISih4m4mGb0NyHxLgTjTjXA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790069280; c=relaxed/simple; bh=gS3AFki51Z44v57VCMt1yUS9ZPFvANxOrRZ4wXkAYmI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uhB7zD8x69ckrqfGITzcQqx5hDONamZXrUaWh0OuzXnHLEYmQlajYyI+F7yXJY8NPwWSkRXMMKg8b2kQHc2e4hyPzmcoX3RiA7zACba9CAGvGc6FOervze9fxJvkkJAFCmQfKYFxNGyFYSiw7Jz+0ROvLN+7dB3zfpbO/7gRs9Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=P93Y2JwM; 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="P93Y2JwM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 460301F000FF; Tue, 22 Sep 2026 09:27:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790069279; bh=koizuzCvTqcQymkCuZR6nRMdDkAOhPlxoac5NyN6ips=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=P93Y2JwMRUD+FjDX9JvlrJ4sdffhqSpMhQ3xyG2fMIU7w46V1TqTlurEZHFvSSmnp 2eCbfQf/foqQ/lkHF+f7ldipUiwNNQN7Y6VjMqHQ9MMC12Ja10TNRz+PBB7dYo63HN 1p45XqVVe6G71spiFanf/g1AOhtAq6jjqqf2EPcBv4PQIobYrP49/5M4kREllclt/X L5hwGCaBqXR9wDzE2cl68BHXQw4yQaN9tbvaZwd7fHT0B6gO8IZMywYJuK8wPdg+xf 2ZFKuqemyBIUzzqWh1b1M3W+Dt4g4n1tpq/O+4GBRiuEtrGT7YOxV1miHkxHvRpX74 sSTSkzvA+KpeQ== Date: Tue, 22 Sep 2026 12:27:54 +0300 From: Leon Romanovsky To: Logan Gunthorpe Cc: Bjorn Helgaas , Chaitanya Kulkarni , Greg Kroah-Hartman , Jens Axboe , Alex Williamson , Ankit Agrawal , Jason Gunthorpe , Jonathan Corbet , Shuah Khan , "Joerg Roedel (AMD)" , Will Deacon , Robin Murphy , Randy Dunlap , Sumit Semwal , Christian =?iso-8859-1?Q?K=F6nig?= , 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 Subject: Re: [PATCH v7 15/19] PCI/P2PDMA: Document TLP-class routing Message-ID: <20260922092754.GC563127@unreal> References: <20260920-fix-p2p-acs-v4-0-v7-0-ca0828ab697c@nvidia.com> <20260920-fix-p2p-acs-v4-0-v7-15-ca0828ab697c@nvidia.com> <85bb90f0-5a02-4e35-9ed6-ad7e67c1c0d8@deltatee.com> 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: <85bb90f0-5a02-4e35-9ed6-ad7e67c1c0d8@deltatee.com> On Mon, Sep 21, 2026 at 04:16:56PM -0600, Logan Gunthorpe wrote: > > > On 2026-09-20 05:41, Leon Romanovsky wrote: > > +A path is bus addressable only where both directions route directly, so with > > +nothing enabled every class is. > > I don't understand the sentence. I tried to say that we need both Requests and Completions route directly. Claude suggested something like that: --------------------------------------------------------------------------- Combining the two tables gives the mapping type: a class is bus addressable when its Request and its Completions both route directly, a blocked Request is not supported because Translation Blocking rejects the Address Type wherever the Request is addressed, and anything else goes through the host bridge. With no ACS control set anywhere, every class routes directly. --------------------------------------------------------------------------- Thanks > > > Logan