Merge tag 'imx-fixes-3.11' of git://git.linaro.org/people/shawnguo/linux-2.6 into...

[~andy/linux] / arch / x86 / kvm / vmx.c

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a7e18551c9689b5192d528ccae10ee9dbb20e84a..064d0be67ecc23734aa465541138d9b5be295277 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3404,15 +3404,22 @@ static void vmx_get_segment(struct kvm_vcpu *vcpu,
        var->limit = vmx_read_guest_seg_limit(vmx, seg);
        var->selector = vmx_read_guest_seg_selector(vmx, seg);
        ar = vmx_read_guest_seg_ar(vmx, seg);
+       var->unusable = (ar >> 16) & 1;
        var->type = ar & 15;
        var->s = (ar >> 4) & 1;
        var->dpl = (ar >> 5) & 3;
-       var->present = (ar >> 7) & 1;
+       /*
+        * Some userspaces do not preserve unusable property. Since usable
+        * segment has to be present according to VMX spec we can use present
+        * property to amend userspace bug by making unusable segment always
+        * nonpresent. vmx_segment_access_rights() already marks nonpresent
+        * segment as unusable.
+        */
+       var->present = !var->unusable;
        var->avl = (ar >> 12) & 1;
        var->l = (ar >> 13) & 1;
        var->db = (ar >> 14) & 1;
        var->g = (ar >> 15) & 1;
-       var->unusable = (ar >> 16) & 1;
 }
 
 static u64 vmx_get_segment_base(struct kvm_vcpu *vcpu, int seg)