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bh=/LTFAI/rqmR3hwJglOVbPiSwlXYuTcEYmfn8Oa+rUSI=; b=r2ka4H0eslO+1egp1WCctWQBKXJWSAN+/t2lXQiCZawt0oOi/YtT4FTsHCBL4QsQeGlJXi 5lHmZ5vCG7R2hkpbRGaYUppZkmv305zChEuvkQ1oTOyAXS4FSM1pxbr8qSM/CthV736a30 nNGSe5p6YqDqLayIiA0loug9Lvx0My0= Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=eW0LSj5O; dmarc=pass (policy=none) header.from=linuxfoundation.org; spf=pass (imf07.hostedemail.com: domain of gregkh@linuxfoundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: BA5254000D X-Rspam-User: X-Stat-Signature: zaqhyif9ebjqdqcfymny76fu8jmybiib X-HE-Tag: 1657041723-734867 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jul 05, 2022 at 06:50:39PM +0200, Christoph Hellwig wrote: > [note for the newcomers, this is about allowing mmap()ing the PCIe > P2P memory from the generic PCI P2P code through sysfs, and more > importantly how to revoke it on device removal] We allow mmap on PCIe config space today, right? Why is this different from what pci_create_legacy_files() does today? > On Tue, Jul 05, 2022 at 10:44:49AM -0600, Logan Gunthorpe wrote: > > We might be able to. I'm not sure. I'll have to figure out how to find > > that inode from the p2pdma code. I haven't found an obvious interface to > > do that. > > I think the right way to approach this would be a new sysfs API > that internally calls unmap_mapping_range internally instead of > exposing the inode. I suspect that might actually be the right thing > to do for iomem_inode as well. Why do we need something new and how is this any different from the PCI binary files I mention above? We have supported PCI hotplug for a very long time, do the current PCI binary sysfs files not work properly with mmap and removing a device? thanks, greg k-h