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[34.142.255.199]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2c164fa00b3sm237800395ad.32.2026.06.10.08.28.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Jun 2026 08:28:05 -0700 (PDT) Date: Wed, 10 Jun 2026 15:27:57 +0000 From: Pranjal Shrivastava To: Jason Gunthorpe Cc: Alex Williamson , Matt Evans , Leon Romanovsky , Alex Mastro , Christian =?iso-8859-1?Q?K=F6nig?= , Bjorn Helgaas , Logan Gunthorpe , Mahmoud Adam , David Matlack , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Sumit Semwal , Kevin Tian , Ankit Agrawal , Alistair Popple , Vivek Kasireddy , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, kvm@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH v2 1/9] PCI/P2PDMA: Add CONFIG_PCI_P2PDMA_CORE Message-ID: References: <20260527102319.100128-1-mattev@meta.com> <20260527102319.100128-2-mattev@meta.com> <20260527150946.312b3042@nvidia.com> <20260529230553.GE3195266@nvidia.com> Precedence: bulk X-Mailing-List: linux-pci@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: <20260529230553.GE3195266@nvidia.com> On Fri, May 29, 2026 at 08:05:53PM -0300, Jason Gunthorpe wrote: > On Wed, May 27, 2026 at 03:09:46PM -0600, Alex Williamson wrote: > > This deserves a /* CONFIG_PCI_P2PDMA */ reference like the previous > > long span, though potentially a better solution would be to split the > > core code out to a separate file with shared header. I asked opus to > > see what this would look like and it generated the patch below > > (unverified, compile tested only). Bigger diff, harder to follow > > blame, but the shape of the core is much more apparent. You're welcome > > to take or leave it. > > I think it is a good idea, it will make it easier to add more stuff to > these different aspects. > > Really they are now two different things with one layered on top of > the other. > A little late to this party. I agree with this split per status quo. Although, one observation from me, I've posted a concurrent RFC [1] that implements ZONE_DEVICE P2P registration for VFIO. That work relies on pci_p2pdma_add_resource(), which requires ZONE_DEVICE and the full CONFIG_PCI_P2PDMA stack rather than just the CORE part. I guess I can be careful to guard the ZONE_DEVICE P2P registration feature in VFIO with the full PCI_P2PDMA config. Apart from that, this split provides a clean foundation for both series to coexist. Thanks, Praan [1] https://lore.kernel.org/all/20260610151853.3608948-1-praan@google.com/