KVM: MMU: fix broken page accessed tracking with ept enabled

In current code, if ept is enabled(shadow_accessed_mask = 0), the page
accessed tracking is lost.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index d2ea9cabc06..9b3b916ebea 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -687,7 +687,7 @@ static void drop_spte(struct kvm *kvm, u64 *sptep, u64 new_spte)
         if (!is_rmap_spte(old_spte))
                 return;
         pfn = spte_to_pfn(old_spte);
-        if (old_spte & shadow_accessed_mask)
+        if (!shadow_accessed_mask || old_spte & shadow_accessed_mask)
                 kvm_set_pfn_accessed(pfn);
         if (is_writable_pte(old_spte))
                 kvm_set_pfn_dirty(pfn);
@@ -815,7 +815,8 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
                                 kvm_set_pfn_dirty(spte_to_pfn(*spte));
                         old_spte = __xchg_spte(spte, new_spte);
                         if (is_shadow_present_pte(old_spte)
-                            && (old_spte & shadow_accessed_mask))
+                            && (!shadow_accessed_mask ||
+                            old_spte & shadow_accessed_mask))
                                 mark_page_accessed(pfn_to_page(spte_to_pfn(old_spte)));
                         spte = rmap_next(kvm, rmapp, spte);
                 }