KVM: nVMX: Prepare to sanitize tertiary execution controls with eVMCS

In preparation to restoring vmcs_conf sanitization for KVM-on-Hyper-V,
(and for completeness) add tertiary VM-execution controls to
'evmcs_supported_ctrls'.

No functional change intended as KVM doesn't yet expose
MSR_IA32_VMX_PROCBASED_CTLS3 to its guests.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20221104144708.435865-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/hyperv.c

@@ -363,6 +363,7 @@ enum evmcs_ctrl_type {
 	EVMCS_ENTRY_CTRLS,
 	EVMCS_EXEC_CTRL,
 	EVMCS_2NDEXEC,
+	EVMCS_3RDEXEC,
 	EVMCS_PINCTRL,
 	EVMCS_VMFUNC,
 	NR_EVMCS_CTRLS,
@@ -381,6 +382,9 @@ static const u32 evmcs_supported_ctrls[NR_EVMCS_CTRLS][NR_EVMCS_REVISIONS] = {
 	[EVMCS_2NDEXEC] = {
 		[EVMCSv1_LEGACY] = EVMCS1_SUPPORTED_2NDEXEC & ~SECONDARY_EXEC_TSC_SCALING,
 	},
+	[EVMCS_3RDEXEC] = {
+		[EVMCSv1_LEGACY] = EVMCS1_SUPPORTED_3RDEXEC,
+	},
 	[EVMCS_PINCTRL] = {
 		[EVMCSv1_LEGACY] = EVMCS1_SUPPORTED_PINCTRL,
 	},

arch/x86/kvm/vmx/hyperv.h

@@ -98,6 +98,8 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs);
 	 SECONDARY_EXEC_NOTIFY_VM_EXITING |				\
 	 SECONDARY_EXEC_ENCLS_EXITING)
 
+#define EVMCS1_SUPPORTED_3RDEXEC (0ULL)
+
 #define EVMCS1_SUPPORTED_VMEXIT_CTRL					\
 	(VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR |				\
 	 VM_EXIT_SAVE_DEBUG_CONTROLS |					\