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