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 <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Marcelo Tosatti 2008-09-16 20:54:46 -03:00 committed by Avi Kivity
parent bfadaded0d
commit 777b3f49d2
1 changed files with 12 additions and 7 deletions

View File

@ -1394,17 +1394,22 @@ out:
static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 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 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; return VM_FAULT_SIGBUS;
page = gfn_to_page(kvm, vmf->pgoff);
if (is_error_page(page)) { npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
kvm_release_page_clean(page); NULL);
if (unlikely(npages != 1))
return VM_FAULT_SIGBUS; return VM_FAULT_SIGBUS;
}
vmf->page = page; vmf->page = page[0];
return 0; return 0;
} }