KVM: VMX: Use EPT Access bit in response to memory notifiers
Signed-off-by: Haitao Shan <haitao.shan@intel.com>
Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index be3cea4..d07e436 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1242,7 +1242,8 @@
int young = 0;
/*
- * Emulate the accessed bit for EPT, by checking if this page has
+ * In case of absence of EPT Access and Dirty Bits supports,
+ * emulate the accessed bit for EPT, by checking if this page has
* an EPT mapping, and clearing it if it does. On the next access,
* a new EPT mapping will be established.
* This has some overhead, but not as much as the cost of swapping
@@ -1253,11 +1254,12 @@
for (sptep = rmap_get_first(*rmapp, &iter); sptep;
sptep = rmap_get_next(&iter)) {
- BUG_ON(!(*sptep & PT_PRESENT_MASK));
+ BUG_ON(!is_shadow_present_pte(*sptep));
- if (*sptep & PT_ACCESSED_MASK) {
+ if (*sptep & shadow_accessed_mask) {
young = 1;
- clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)sptep);
+ clear_bit((ffs(shadow_accessed_mask) - 1),
+ (unsigned long *)sptep);
}
}
@@ -1281,9 +1283,9 @@
for (sptep = rmap_get_first(*rmapp, &iter); sptep;
sptep = rmap_get_next(&iter)) {
- BUG_ON(!(*sptep & PT_PRESENT_MASK));
+ BUG_ON(!is_shadow_present_pte(*sptep));
- if (*sptep & PT_ACCESSED_MASK) {
+ if (*sptep & shadow_accessed_mask) {
young = 1;
break;
}