KVM: MMU: Move sync_page() first pte address calculation out of loop
Move first pte address calculation out of loop to save some cycles.
Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index d9dea28..5910557 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -572,12 +572,15 @@
{
int i, offset, nr_present;
bool reset_host_protection;
+ gpa_t first_pte_gpa;
offset = nr_present = 0;
if (PTTYPE == 32)
offset = sp->role.quadrant << PT64_LEVEL_BITS;
+ first_pte_gpa = gfn_to_gpa(sp->gfn) + offset * sizeof(pt_element_t);
+
for (i = 0; i < PT64_ENT_PER_PAGE; i++) {
unsigned pte_access;
pt_element_t gpte;
@@ -587,8 +590,7 @@
if (!is_shadow_present_pte(sp->spt[i]))
continue;
- pte_gpa = gfn_to_gpa(sp->gfn);
- pte_gpa += (i+offset) * sizeof(pt_element_t);
+ pte_gpa = first_pte_gpa + i * sizeof(pt_element_t);
if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte,
sizeof(pt_element_t)))
