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>

1 files changed, 54 insertions, 46 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 19aa69af7c2d..08381a5d8879 100644
--- a/arch/x86/kvm/vmx.c
+++ b/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 |