KVM: VMX: Ignore segment G and D bits when considering whether we can virtualize

We will enter the guest with G and D cleared; as real hardware ignores D in
real mode, and G is taken care of by the limit test, we allow more code to
run in vm86 mode.

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

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 62b2d0c..248c2b4 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3320,7 +3320,7 @@ static bool rmode_segment_valid(struct kvm_vcpu *vcpu, int seg)
                return false;
        if (var.limit < 0xffff)
                return false;
-       if ((ar | (3 << AR_DPL_SHIFT)) != 0xf3)
+       if (((ar | (3 << AR_DPL_SHIFT)) & ~(AR_G_MASK | AR_DB_MASK)) != 0xf3)
                return false;
 
        return true;