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>
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index dfb65e2..04544ae 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -559,28 +559,37 @@
}
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;