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[142.68.80.239]) by smtp.gmail.com with ESMTPSA id af79cd13be357-79f1902ac2esm394037485a.59.2024.07.12.05.42.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 12 Jul 2024 05:42:38 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.95) (envelope-from ) id 1sSFbh-000FUg-Ne; Fri, 12 Jul 2024 09:42:37 -0300 Date: Fri, 12 Jul 2024 09:42:37 -0300 From: Jason Gunthorpe To: Christoph Hellwig Cc: Leon Romanovsky , Jens Axboe , Robin Murphy , Joerg Roedel , Will Deacon , Keith Busch , "Zeng, Oak" , Chaitanya Kulkarni , Sagi Grimberg , Bjorn Helgaas , Logan Gunthorpe , Yishai Hadas , Shameer Kolothum , Kevin Tian , Alex Williamson , Marek Szyprowski , =?utf-8?B?SsOpcsO0bWU=?= Glisse , Andrew Morton , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, iommu@lists.linux.dev, linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH v1 00/18] Provide a new two step DMA API mapping API Message-ID: <20240712124237.GX14050@ziepe.ca> References: <20240705063910.GA12337@lst.de> <20240708235721.GF14050@ziepe.ca> <20240709062015.GB16180@lst.de> <20240709190320.GN14050@ziepe.ca> <20240710062212.GA25895@lst.de> <20240711232917.GR14050@ziepe.ca> <20240712045422.GA4774@lst.de> 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: <20240712045422.GA4774@lst.de> On Fri, Jul 12, 2024 at 06:54:22AM +0200, Christoph Hellwig wrote: > This is all purely hypothetical, and I'm happy to just check for it > and reject it for it now. I do know a patch set is cooking to allow mixing ZONE_DEVICE P2P and anon memory in the same VMA ala HMM with transparent migration of ZONE_DEVICE to anon. In this situation userspace will be generating IO with no idea about any P2P/!P2P boundaries. Jason