Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 777b3f49 authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Avi Kivity
Browse files

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: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent bfadaded

virt/kvm/kvm_main.c

+12 −7
Original line number Diff line number Diff line
@@ -1394,17 +1394,22 @@ static long kvm_vm_ioctl(struct file *filp, 


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;

}