KVM: nEPT: Advertise WB type EPTP

At least WB must be possible.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

@@ -2251,8 +2251,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	if (enable_ept) {
 		/* nested EPT: emulate EPT also to L1 */
 		nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT;
-		nested_vmx_ept_caps = VMX_EPT_PAGE_WALK_4_BIT;
-		nested_vmx_ept_caps |= VMX_EPT_INVEPT_BIT;
+		nested_vmx_ept_caps = VMX_EPT_PAGE_WALK_4_BIT |
+			 VMX_EPTP_WB_BIT | VMX_EPT_INVEPT_BIT;
 		nested_vmx_ept_caps &= vmx_capability.ept;
 		/*
 		 * Since invept is completely emulated we support both global