KVM: MMU: Don't treat a global pte as such if cr4.pge is cleared

The pte.g bit is meaningless if global pages are disabled; deferring
mmu page synchronization on these ptes will lead to the guest using stale
shadow ptes.

Fixes Vista x86 smp bootloader failure.

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 641c07844e6e..d50ebac6a07f 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1669,6 +1669,8 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
         u64 mt_mask = shadow_mt_mask;
         struct kvm_mmu_page *sp = page_header(__pa(shadow_pte));
 
+        if (!(vcpu->arch.cr4 & X86_CR4_PGE))
+                global = 0;
         if (!global && sp->global) {
                 sp->global = 0;
                 if (sp->unsync) {