From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CE0CACCF9F8 for ; Fri, 7 Nov 2025 20:27:26 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 218E010EB79; Fri, 7 Nov 2025 20:27:26 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="GnHfPvK9"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id BC01910EB79 for ; Fri, 7 Nov 2025 20:27:24 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 77AA241B35; Fri, 7 Nov 2025 20:27:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 836D6C4CEF5; Fri, 7 Nov 2025 20:27:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762547244; bh=VAySUlKP+gpY13ehfWvqZiKxHmLFx9bZKqh1eqOc7BU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GnHfPvK9RlbGueuO2dIzOFloCGUIJO+4STJ9acaeZ4mwoNgCLVysGF3G1CD2dslTO J8xEeZg2TWQROLBRgu9cIRspJbvL0T9YEBkcbbcqYSRUqcnzE6UpSuE7s17MqR38od k1auiNEzsLsrcn/e5bmLAUXdt14ph1onYr5+m4OBZiUnSghRHlS5cz0wreim7qkvti AitNvNVxIXHxoXVVQZB1fuCmNeB+VUFl+qA0fr1ukYsVMffsErSLFPHEZkD3QhPl33 mZVBp/M5pmVMtLNk4jfzBFQR0vtiXMXgOHw2XwWQXqRS2kcJr3JwuXFYWK3abcXYgE W34/n88w3YbCg== Date: Fri, 7 Nov 2025 22:27:18 +0200 From: Leon Romanovsky To: Randy Dunlap Cc: Bjorn Helgaas , Logan Gunthorpe , Jens Axboe , Robin Murphy , Joerg Roedel , Will Deacon , Marek Szyprowski , Jason Gunthorpe , Andrew Morton , Jonathan Corbet , Sumit Semwal , Christian =?iso-8859-1?Q?K=F6nig?= , Kees Cook , "Gustavo A. R. Silva" , Ankit Agrawal , Yishai Hadas , Shameer Kolothum , Kevin Tian , Alex Williamson , Krishnakant Jaju , Matt Ochs , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, iommu@lists.linux.dev, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, kvm@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH v7 05/11] PCI/P2PDMA: Document DMABUF model Message-ID: <20251107202718.GE15456@unreal> References: <20251106-dmabuf-vfio-v7-0-2503bf390699@nvidia.com> <20251106-dmabuf-vfio-v7-5-2503bf390699@nvidia.com> <135df7eb-9291-428b-9c86-d58c2e19e052@infradead.org> <20251107160120.GD15456@unreal> <0c265a9b-fdc5-40d7-845f-30910f1ac6ea@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0c265a9b-fdc5-40d7-845f-30910f1ac6ea@infradead.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, Nov 07, 2025 at 10:58:27AM -0800, Randy Dunlap wrote: > > > On 11/7/25 8:01 AM, Leon Romanovsky wrote: > > On Thu, Nov 06, 2025 at 10:15:07PM -0800, Randy Dunlap wrote: > >> > >> > >> On 11/6/25 6:16 AM, Leon Romanovsky wrote: > >>> From: Jason Gunthorpe > >>> > >>> Reflect latest changes in p2p implementation to support DMABUF lifecycle. > >>> > >>> Signed-off-by: Leon Romanovsky > >>> Signed-off-by: Jason Gunthorpe > >>> --- > >>> Documentation/driver-api/pci/p2pdma.rst | 95 +++++++++++++++++++++++++-------- > >>> 1 file changed, 72 insertions(+), 23 deletions(-) <...> > >>> -The second issue is that to make use of existing interfaces in Linux, > >>> -memory that is used for P2P transactions needs to be backed by struct > >>> -pages. However, PCI BARs are not typically cache coherent so there are > >>> -a few corner case gotchas with these pages so developers need to > >>> -be careful about what they do with them. > >>> +For PCIe the routing of TLPs is well defined up until they reach a host bridge > >> > >> Define what TLP means? > > > > In PCIe "world", TLP is very well-known and well-defined acronym, which > > means Transaction Layer Packet. > > It's your choice (or Bjorn's). I'm just reviewing... Thanks a lot.