[PATCH 1/4] KVM: VMX: cache secondary exec controls
From: Paolo Bonzini
Date: Thu Aug 24 2017 - 09:38:15 EST
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@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 100 +++++++++++++++++++++++++++++------------------------
1 file 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 |
--
1.8.3.1