KVM: introduce gfn_to_hva()

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

Signed-off-by: Izik Eidus <izike@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Izik Eidus 2007-11-11 22:05:04 +02:00 committed by Avi Kivity
parent f9d46eb0e4
commit 539cb6608c

View file

@ -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;