KVM: MMU: unalias gfn before sp->gfns[] comparison in sync_page
sp->gfns[] contain unaliased gfns, but gpte might contain pointer
to aliased region.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 15e379e..22f1379 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -586,7 +586,7 @@
unsigned pte_access;
pt_element_t gpte;
gpa_t pte_gpa;
- gfn_t gfn = sp->gfns[i];
+ gfn_t gfn;
if (!is_shadow_present_pte(sp->spt[i]))
continue;
@@ -597,8 +597,9 @@
sizeof(pt_element_t)))
return -EINVAL;
- if (gpte_to_gfn(gpte) != gfn || !is_present_gpte(gpte) ||
- !(gpte & PT_ACCESSED_MASK)) {
+ gfn = gpte_to_gfn(gpte);
+ if (unalias_gfn(vcpu->kvm, gfn) != sp->gfns[i] ||
+ !is_present_gpte(gpte) || !(gpte & PT_ACCESSED_MASK)) {
u64 nonpresent;
rmap_remove(vcpu->kvm, &sp->spt[i]);