diff options
| -rw-r--r-- | mm/gup.c | 1 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 45 |
2 files changed, 43 insertions, 3 deletions
@@ -720,6 +720,7 @@ retry: } return 0; } +EXPORT_SYMBOL_GPL(fixup_user_fault); static __always_inline long __get_user_pages_locked(struct task_struct *tsk, struct mm_struct *mm, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5aae59e00bef..154b9ab459b0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1446,9 +1446,45 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma, unsigned long addr, bool *async, bool write_fault, kvm_pfn_t *p_pfn) { - *p_pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + - vma->vm_pgoff; - BUG_ON(!kvm_is_reserved_pfn(*p_pfn)); + unsigned long pfn; + int r; + + r = follow_pfn(vma, addr, &pfn); + if (r) { + /* + * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does + * not call the fault handler, so do it here. + */ + bool unlocked = false; + r = fixup_user_fault(current, current->mm, addr, + (write_fault ? FAULT_FLAG_WRITE : 0), + &unlocked); + if (unlocked) + return -EAGAIN; + if (r) + return r; + + r = follow_pfn(vma, addr, &pfn); + if (r) + return r; + + } + + + /* + * Get a reference here because callers of *hva_to_pfn* and + * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the + * returned pfn. This is only needed if the VMA has VM_MIXEDMAP + * set, but the kvm_get_pfn/kvm_release_pfn_clean pair will + * simply do nothing for reserved pfns. + * + * Whoever called remap_pfn_range is also going to call e.g. + * unmap_mapping_range before the underlying pages are freed, + * causing a call to our MMU notifier. + */ + kvm_get_pfn(pfn); + + *p_pfn = pfn; return 0; } @@ -1493,12 +1529,15 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, goto exit; } +retry: vma = find_vma_intersection(current->mm, addr, addr + 1); if (vma == NULL) pfn = KVM_PFN_ERR_FAULT; else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) { r = hva_to_pfn_remapped(vma, addr, async, write_fault, &pfn); + if (r == -EAGAIN) + goto retry; if (r < 0) pfn = KVM_PFN_ERR_FAULT; } else { |