KVM: nVMX: Fix EPT switching advertising

I can use vmxcap tool to observe "EPTP Switching   yes" even if EPT is not
exposed to L1.

EPT switching is advertised unconditionally since it is emulated, however,
it can be treated as an extended feature for EPT and it should not be
advertised if EPT itself is not exposed. This patch fixes it.

Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 69d45734091fa20332d16da86140d352d1aeb2a2..dba0f6ad4e575a15af578ae6e500b71bed44fa0e 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2842,8 +2842,9 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
                 * Advertise EPTP switching unconditionally
                 * since we emulate it
                 */
-               vmx->nested.nested_vmx_vmfunc_controls =
-                       VMX_VMFUNC_EPTP_SWITCHING;
+               if (enable_ept)
+                       vmx->nested.nested_vmx_vmfunc_controls =
+                               VMX_VMFUNC_EPTP_SWITCHING;
        }
 
        /*