KVM: VMX: cache secondary exec controls

Currently, secondary execution controls are divided in three groups:

- static, depending mostly on the module arguments or the processor
  (vmx_secondary_exec_control)

- static, depending on CPUID (vmx_cpuid_update)

- dynamic, depending on nested VMX or local APIC state

Because walking CPUID is expensive, prepare_vmcs02 is using only
the first group.  This however is unnecessarily complicated.  Just
cache the static secondary execution controls, and then prepare_vmcs02
does not need to compute them every time.  Computation of all static
secondary execution controls is now kept in a single function,
vmx_compute_secondary_exec_control.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

@@ -576,6 +576,8 @@ struct vcpu_vmx {
 #endif
 	u32 vm_entry_controls_shadow;
 	u32 vm_exit_controls_shadow;
+	u32 secondary_exec_control;
+
 	/*
 	 * loaded_vmcs points to the VMCS currently used in this vcpu. For a
 	 * non-nested (L1) guest, it always points to vmcs01. For a nested
@@ -2807,7 +2809,10 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
 	vmx->nested.nested_vmx_procbased_ctls_low &=
 		~(CPU_BASED_CR3_LOAD_EXITING | CPU_BASED_CR3_STORE_EXITING);
 
-	/* secondary cpu-based controls */
+	/*
+	 * secondary cpu-based controls.  Do not include those that
+	 * depend on CPUID bits, they are added later by vmx_cpuid_update.
+	 */
 	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
 		vmx->nested.nested_vmx_secondary_ctls_low,
 		vmx->nested.nested_vmx_secondary_ctls_high);
@@ -2815,7 +2820,6 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
 	vmx->nested.nested_vmx_secondary_ctls_high &=
 		SECONDARY_EXEC_RDRAND | SECONDARY_EXEC_RDSEED |
 		SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
-		SECONDARY_EXEC_RDTSCP |
 		SECONDARY_EXEC_DESC |
 		SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
 		SECONDARY_EXEC_APIC_REGISTER_VIRT |
@@ -5269,10 +5273,12 @@ static u32 vmx_exec_control(struct vcpu_vmx *vmx)
 	return exec_control;
 }
 
-static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx)
+static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx)
 {
+	struct kvm_vcpu *vcpu = &vmx->vcpu;
+
 	u32 exec_control = vmcs_config.cpu_based_2nd_exec_ctrl;
-	if (!cpu_need_virtualize_apic_accesses(&vmx->vcpu))
+	if (!cpu_need_virtualize_apic_accesses(vcpu))
 		exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
 	if (vmx->vpid == 0)
 		exec_control &= ~SECONDARY_EXEC_ENABLE_VPID;
@@ -5286,7 +5292,7 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx)
 		exec_control &= ~SECONDARY_EXEC_UNRESTRICTED_GUEST;
 	if (!ple_gap)
 		exec_control &= ~SECONDARY_EXEC_PAUSE_LOOP_EXITING;
-	if (!kvm_vcpu_apicv_active(&vmx->vcpu))
+	if (!kvm_vcpu_apicv_active(vcpu))
 		exec_control &= ~(SECONDARY_EXEC_APIC_REGISTER_VIRT |
 				  SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);
 	exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
@@ -5300,7 +5306,43 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx)
 	if (!enable_pml)
 		exec_control &= ~SECONDARY_EXEC_ENABLE_PML;
 
-	return exec_control;
+	if (vmx_rdtscp_supported()) {
+		bool rdtscp_enabled = guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP);
+		if (!rdtscp_enabled)
+			exec_control &= ~SECONDARY_EXEC_RDTSCP;
+
+		if (nested) {
+			if (rdtscp_enabled)
+				vmx->nested.nested_vmx_secondary_ctls_high |=
+					SECONDARY_EXEC_RDTSCP;
+			else
+				vmx->nested.nested_vmx_secondary_ctls_high &=
+					~SECONDARY_EXEC_RDTSCP;
+		}
+	}
+
+	if (vmx_invpcid_supported()) {
+		/* Exposing INVPCID only when PCID is exposed */
+		bool invpcid_enabled =
+			guest_cpuid_has(vcpu, X86_FEATURE_INVPCID) &&
+			guest_cpuid_has(vcpu, X86_FEATURE_PCID);
+
+		if (!invpcid_enabled) {
+			exec_control &= ~SECONDARY_EXEC_ENABLE_INVPCID;
+			guest_cpuid_clear(vcpu, X86_FEATURE_INVPCID);
+		}
+
+		if (nested) {
+			if (invpcid_enabled)
+				vmx->nested.nested_vmx_secondary_ctls_high |=
+					SECONDARY_EXEC_ENABLE_INVPCID;
+			else
+				vmx->nested.nested_vmx_secondary_ctls_high &=
+					~SECONDARY_EXEC_ENABLE_INVPCID;
+		}
+	}
+
+	vmx->secondary_exec_control = exec_control;
 }
 
 static void ept_set_mmio_spte_mask(void)
@@ -5344,8 +5386,9 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
 	vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, vmx_exec_control(vmx));
 
 	if (cpu_has_secondary_exec_ctrls()) {
+		vmx_compute_secondary_exec_control(vmx);
 		vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
-				vmx_secondary_exec_control(vmx));
+			     vmx->secondary_exec_control);
 	}
 
 	if (kvm_vcpu_apicv_active(&vmx->vcpu)) {
@@ -9623,47 +9666,12 @@ static void nested_vmx_cr_fixed1_bits_update(struct kvm_vcpu *vcpu)
 static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	u32 secondary_exec_ctl = vmx_secondary_exec_control(vmx);
-
-	if (vmx_rdtscp_supported()) {
-		bool rdtscp_enabled = guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP);
-		if (!rdtscp_enabled)
-			secondary_exec_ctl &= ~SECONDARY_EXEC_RDTSCP;
-
-		if (nested) {
-			if (rdtscp_enabled)
-				vmx->nested.nested_vmx_secondary_ctls_high |=
-					SECONDARY_EXEC_RDTSCP;
-			else
-				vmx->nested.nested_vmx_secondary_ctls_high &=
-					~SECONDARY_EXEC_RDTSCP;
-		}
-	}
 
-	if (vmx_invpcid_supported()) {
-		/* Exposing INVPCID only when PCID is exposed */
-		bool invpcid_enabled =
-			guest_cpuid_has(vcpu, X86_FEATURE_INVPCID) &&
-			guest_cpuid_has(vcpu, X86_FEATURE_PCID);
-
-		if (!invpcid_enabled) {
-			secondary_exec_ctl &= ~SECONDARY_EXEC_ENABLE_INVPCID;
-			guest_cpuid_clear(vcpu, X86_FEATURE_INVPCID);
-		}
-
-		if (nested) {
-			if (invpcid_enabled)
-				vmx->nested.nested_vmx_secondary_ctls_high |=
-					SECONDARY_EXEC_ENABLE_INVPCID;
-			else
-				vmx->nested.nested_vmx_secondary_ctls_high &=
-					~SECONDARY_EXEC_ENABLE_INVPCID;
-		}
+	if (cpu_has_secondary_exec_ctrls()) {
+		vmx_compute_secondary_exec_control(vmx);
+		vmcs_set_secondary_exec_control(vmx->secondary_exec_control);
 	}
 
-	if (cpu_has_secondary_exec_ctrls())
-		vmcs_set_secondary_exec_control(secondary_exec_ctl);
-
 	if (nested_vmx_allowed(vcpu))
 		to_vmx(vcpu)->msr_ia32_feature_control_valid_bits |=
 			FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;
@@ -10356,7 +10364,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 		enable_ept ? vmcs12->page_fault_error_code_match : 0);
 
 	if (cpu_has_secondary_exec_ctrls()) {
-		exec_control = vmx_secondary_exec_control(vmx);
+		exec_control = vmx->secondary_exec_control;
 
 		/* Take the following fields only from vmcs12 */
 		exec_control &= ~(SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |