Commit 539cb660 authored by Izik Eidus's avatar Izik Eidus Committed by Avi Kivity
Browse files

KVM: introduce gfn_to_hva() 



Convert a guest frame number to the corresponding host virtual address.

Signed-off-by: default avatarIzik Eidus <izike@qumranet.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent f9d46eb0

drivers/kvm/kvm_main.c

+17 −8
Original line number Diff line number Diff line
@@ -559,28 +559,37 @@ int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) 
}

EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);



static unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)

{

	struct kvm_memory_slot *slot;



	gfn = unalias_gfn(kvm, gfn);

	slot = __gfn_to_memslot(kvm, gfn);

	if (!slot)

		return bad_hva();

	return (slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE);

}



/*

 * Requires current->mm->mmap_sem to be held

 */

static struct page *__gfn_to_page(struct kvm *kvm, gfn_t gfn)

{

	struct kvm_memory_slot *slot;

	struct page *page[1];

	unsigned long addr;

	int npages;



	might_sleep();



	gfn = unalias_gfn(kvm, gfn);

	slot = __gfn_to_memslot(kvm, gfn);

	if (!slot) {

	addr = gfn_to_hva(kvm, gfn);

	if (kvm_is_error_hva(addr)) {

		get_page(bad_page);

		return bad_page;

	}



	npages = get_user_pages(current, current->mm,

				slot->userspace_addr

				+ (gfn - slot->base_gfn) * PAGE_SIZE, 1,

				1, 1, page, NULL);

	npages = get_user_pages(current, current->mm, addr, 1, 1, 1, page,

				NULL);



	if (npages != 1) {

		get_page(bad_page);

		return bad_page;