KVM: Simply gfn_to_page()
Mapping a guest page to a host page is a common operation. Currently,
one has first to find the memory slot where the page belongs (gfn_to_memslot),
then locate the page itself (gfn_to_page()).
This is clumsy, and also won't work well with memory aliases. So simplify
gfn_to_page() not to require memory slot translation first, and instead do it
internally.
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 376800a..8bdb9ca 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -390,13 +390,11 @@
{
struct kvm *kvm = vcpu->kvm;
struct page *page;
- struct kvm_memory_slot *slot;
struct kvm_rmap_desc *desc;
u64 *spte;
- slot = gfn_to_memslot(kvm, gfn);
- BUG_ON(!slot);
- page = gfn_to_page(slot, gfn);
+ page = gfn_to_page(kvm, gfn);
+ BUG_ON(!page);
while (page_private(page)) {
if (!(page_private(page) & 1))
@@ -711,14 +709,12 @@
hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
{
- struct kvm_memory_slot *slot;
struct page *page;
ASSERT((gpa & HPA_ERR_MASK) == 0);
- slot = gfn_to_memslot(vcpu->kvm, gpa >> PAGE_SHIFT);
- if (!slot)
+ page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
+ if (!page)
return gpa | HPA_ERR_MASK;
- page = gfn_to_page(slot, gpa >> PAGE_SHIFT);
return ((hpa_t)page_to_pfn(page) << PAGE_SHIFT)
| (gpa & (PAGE_SIZE-1));
}