From 777b3f49d297e387866604093b635e5bc9b9d2a6 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Tue, 16 Sep 2008 20:54:46 -0300 Subject: [PATCH] KVM: opencode gfn_to_page in kvm_vm_fault kvm_vm_fault is invoked with mmap_sem held in read mode. Since gfn_to_page will be converted to get_user_pages_fast, which requires this lock NOT to be held, switch to opencoded get_user_pages. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f42d5c2a396d..2907d05cfcc3 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1394,17 +1394,22 @@ out: static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { + struct page *page[1]; + unsigned long addr; + int npages; + gfn_t gfn = vmf->pgoff; struct kvm *kvm = vma->vm_file->private_data; - struct page *page; - if (!kvm_is_visible_gfn(kvm, vmf->pgoff)) + addr = gfn_to_hva(kvm, gfn); + if (kvm_is_error_hva(addr)) return VM_FAULT_SIGBUS; - page = gfn_to_page(kvm, vmf->pgoff); - if (is_error_page(page)) { - kvm_release_page_clean(page); + + npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page, + NULL); + if (unlikely(npages != 1)) return VM_FAULT_SIGBUS; - } - vmf->page = page; + + vmf->page = page[0]; return 0; } -- 2.20.1