KVM: VMX: Allow real mode emulation using vm86 with dpl=0
Real mode is always entered from protected mode with dpl=0. Since
the dpl doesn't affect execution, and we already override it to 3
in the vmcs (as vmx requires), we can allow execution in that state.
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 88eeb40..4811d91 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3317,7 +3317,7 @@
return false;
if (var.limit != 0xffff)
return false;
- if (ar != 0xf3)
+ if ((ar | (3 << AR_DPL_SHIFT)) != 0xf3)
return false;
return true;