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Tue, 28 Sep 2021 12:55:20 -0700 (PDT) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1mVJCA-007Gjs-VN; Tue, 28 Sep 2021 16:55:18 -0300 Date: Tue, 28 Sep 2021 16:55:18 -0300 From: Jason Gunthorpe To: Logan Gunthorpe Cc: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Stephen Bates , Christoph Hellwig , Dan Williams , Christian =?utf-8?B?S8O2bmln?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Jakowski Andrzej , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Martin Oliveira , Chaitanya Kulkarni Subject: Re: [PATCH v3 19/20] PCI/P2PDMA: introduce pci_mmap_p2pmem() Message-ID: <20210928195518.GV3544071@ziepe.ca> References: <20210916234100.122368-1-logang@deltatee.com> <20210916234100.122368-20-logang@deltatee.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210916234100.122368-20-logang@deltatee.com> Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=ziepe.ca header.s=google header.b=ZeD06VES; spf=pass (imf10.hostedemail.com: domain of jgg@ziepe.ca designates 209.85.166.45 as permitted sender) smtp.mailfrom=jgg@ziepe.ca; dmarc=none X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 5B72B600198A X-Stat-Signature: ycc8n1rgcrcs51n6mq6jmnqghonbbeoc X-HE-Tag: 1632858921-941657 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 Thu, Sep 16, 2021 at 05:40:59PM -0600, Logan Gunthorpe wrote: > +int pci_mmap_p2pmem(struct pci_dev *pdev, struct vm_area_struct *vma) > +{ > + struct pci_p2pdma_map *pmap; > + struct pci_p2pdma *p2pdma; > + int ret; > + > + /* prevent private mappings from being established */ > + if ((vma->vm_flags & VM_MAYSHARE) != VM_MAYSHARE) { > + pci_info_ratelimited(pdev, > + "%s: fail, attempted private mapping\n", > + current->comm); > + return -EINVAL; > + } > + > + pmap = pci_p2pdma_map_alloc(pdev, vma->vm_end - vma->vm_start); > + if (!pmap) > + return -ENOMEM; > + > + rcu_read_lock(); > + p2pdma = rcu_dereference(pdev->p2pdma); > + if (!p2pdma) { > + ret = -ENODEV; > + goto out; > + } > + > + ret = simple_pin_fs(&pci_p2pdma_fs_type, &pci_p2pdma_fs_mnt, > + &pci_p2pdma_fs_cnt); > + if (ret) > + goto out; > + > + ihold(p2pdma->inode); > + pmap->inode = p2pdma->inode; > + rcu_read_unlock(); > + > + vma->vm_flags |= VM_MIXEDMAP; Why is this a VM_MIXEDMAP? Everything fault sticks in here has a struct page, right? Jason