diff options
| -rw-r--r-- | virt/kvm/kvm_main.c | 49 |
1 files changed, 37 insertions, 12 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b6a59498b5a7..f9dd20606c40 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -532,6 +532,7 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) struct page *page[1]; unsigned long addr; int npages; + pfn_t pfn; might_sleep(); @@ -544,19 +545,38 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) npages = get_user_pages(current, current->mm, addr, 1, 1, 1, page, NULL); - if (npages != 1) { - get_page(bad_page); - return page_to_pfn(bad_page); - } + if (unlikely(npages != 1)) { + struct vm_area_struct *vma; - return page_to_pfn(page[0]); + vma = find_vma(current->mm, addr); + if (vma == NULL || addr < vma->vm_start || + !(vma->vm_flags & VM_PFNMAP)) { + get_page(bad_page); + return page_to_pfn(bad_page); + } + + pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; + BUG_ON(pfn_valid(pfn)); + } else + pfn = page_to_pfn(page[0]); + + return pfn; } EXPORT_SYMBOL_GPL(gfn_to_pfn); struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) { - return pfn_to_page(gfn_to_pfn(kvm, gfn)); + pfn_t pfn; + + pfn = gfn_to_pfn(kvm, gfn); + if (pfn_valid(pfn)) + return pfn_to_page(pfn); + + WARN_ON(!pfn_valid(pfn)); + + get_page(bad_page); + return bad_page; } EXPORT_SYMBOL_GPL(gfn_to_page); @@ -569,7 +589,8 @@ EXPORT_SYMBOL_GPL(kvm_release_page_clean); void kvm_release_pfn_clean(pfn_t pfn) { - put_page(pfn_to_page(pfn)); + if (pfn_valid(pfn)) + put_page(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_release_pfn_clean); @@ -594,21 +615,25 @@ EXPORT_SYMBOL_GPL(kvm_set_page_dirty); void kvm_set_pfn_dirty(pfn_t pfn) { - struct page *page = pfn_to_page(pfn); - if (!PageReserved(page)) - SetPageDirty(page); + if (pfn_valid(pfn)) { + struct page *page = pfn_to_page(pfn); + if (!PageReserved(page)) + SetPageDirty(page); + } } EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty); void kvm_set_pfn_accessed(pfn_t pfn) { - mark_page_accessed(pfn_to_page(pfn)); + if (pfn_valid(pfn)) + mark_page_accessed(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed); void kvm_get_pfn(pfn_t pfn) { - get_page(pfn_to_page(pfn)); + if (pfn_valid(pfn)) + get_page(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_get_pfn); |