[PATCH 35/43] KVM: VMX: Shadow VMCS secondary execution controls

From: Paolo Bonzini
Date: Thu Jun 13 2019 - 13:10:24 EST


From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

Prepare to shadow all major control fields on a per-VMCS basis, which
allows KVM to avoid costly VMWRITEs when switching between vmcs01 and
vmcs02.

Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 12 ++++++------
arch/x86/kvm/vmx/vmx.c | 40 ++++++++++++++++++++--------------------
arch/x86/kvm/vmx/vmx.h | 2 ++
3 files changed, 28 insertions(+), 26 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index a754a2ed6295..9703fcf19837 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -192,7 +192,7 @@ static void nested_vmx_abort(struct kvm_vcpu *vcpu, u32 indicator)

static void vmx_disable_shadow_vmcs(struct vcpu_vmx *vmx)
{
- vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL, SECONDARY_EXEC_SHADOW_VMCS);
+ secondary_exec_controls_clearbit(vmx, SECONDARY_EXEC_SHADOW_VMCS);
vmcs_write64(VMCS_LINK_POINTER, -1ull);
}

@@ -287,6 +287,7 @@ static void vmx_switch_vmcs(struct kvm_vcpu *vcpu, struct loaded_vmcs *vmcs)
vm_exit_controls_reset_shadow(vmx);
pin_controls_reset_shadow(vmx);
exec_controls_reset_shadow(vmx);
+ secondary_exec_controls_reset_shadow(vmx);
vmx_segment_cache_clear(vmx);
}

@@ -2083,7 +2084,7 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
vmcs_write16(GUEST_INTR_STATUS,
vmcs12->guest_intr_status);

- vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
+ secondary_exec_controls_init(vmx, exec_control);
}

/*
@@ -2853,8 +2854,8 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu)
hpa = page_to_phys(vmx->nested.apic_access_page);
vmcs_write64(APIC_ACCESS_ADDR, hpa);
} else {
- vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL,
- SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
+ secondary_exec_controls_clearbit(vmx,
+ SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
}
}

@@ -4667,8 +4668,7 @@ static void set_current_vmptr(struct vcpu_vmx *vmx, gpa_t vmptr)
{
vmx->nested.current_vmptr = vmptr;
if (enable_shadow_vmcs) {
- vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL,
- SECONDARY_EXEC_SHADOW_VMCS);
+ secondary_exec_controls_setbit(vmx, SECONDARY_EXEC_SHADOW_VMCS);
vmcs_write64(VMCS_LINK_POINTER,
__pa(vmx->vmcs01.shadow_vmcs));
vmx->nested.need_vmcs12_to_shadow_sync = true;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index fcb1a80270bc..1104f52d281c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2909,6 +2909,7 @@ void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)

int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
/*
* Pass through host's Machine Check Enable value to hw_cr4, which
* is in force while we are in guest mode. Do not let guests control
@@ -2919,20 +2920,19 @@ int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
hw_cr4 = (cr4_read_shadow() & X86_CR4_MCE) | (cr4 & ~X86_CR4_MCE);
if (enable_unrestricted_guest)
hw_cr4 |= KVM_VM_CR4_ALWAYS_ON_UNRESTRICTED_GUEST;
- else if (to_vmx(vcpu)->rmode.vm86_active)
+ else if (vmx->rmode.vm86_active)
hw_cr4 |= KVM_RMODE_VM_CR4_ALWAYS_ON;
else
hw_cr4 |= KVM_PMODE_VM_CR4_ALWAYS_ON;

if (!boot_cpu_has(X86_FEATURE_UMIP) && vmx_umip_emulated()) {
if (cr4 & X86_CR4_UMIP) {
- vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL,
- SECONDARY_EXEC_DESC);
+ secondary_exec_controls_setbit(vmx, SECONDARY_EXEC_DESC);
hw_cr4 &= ~X86_CR4_UMIP;
} else if (!is_guest_mode(vcpu) ||
- !nested_cpu_has2(get_vmcs12(vcpu), SECONDARY_EXEC_DESC))
- vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL,
- SECONDARY_EXEC_DESC);
+ !nested_cpu_has2(get_vmcs12(vcpu), SECONDARY_EXEC_DESC)) {
+ secondary_exec_controls_clearbit(vmx, SECONDARY_EXEC_DESC);
+ }
}

if (cr4 & X86_CR4_VMXE) {
@@ -2947,7 +2947,7 @@ int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
return 1;
}

- if (to_vmx(vcpu)->nested.vmxon && !nested_cr4_valid(vcpu, cr4))
+ if (vmx->nested.vmxon && !nested_cr4_valid(vcpu, cr4))
return 1;

vcpu->arch.cr4 = cr4;
@@ -3565,7 +3565,7 @@ static u8 vmx_msr_bitmap_mode(struct kvm_vcpu *vcpu)
u8 mode = 0;

if (cpu_has_secondary_exec_ctrls() &&
- (vmcs_read32(SECONDARY_VM_EXEC_CONTROL) &
+ (secondary_exec_controls_get(to_vmx(vcpu)) &
SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE)) {
mode |= MSR_BITMAP_MODE_X2APIC;
if (enable_apicv && kvm_vcpu_apicv_active(vcpu))
@@ -3845,11 +3845,11 @@ static void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
pin_controls_set(vmx, vmx_pin_based_exec_ctrl(vmx));
if (cpu_has_secondary_exec_ctrls()) {
if (kvm_vcpu_apicv_active(vcpu))
- vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL,
+ secondary_exec_controls_setbit(vmx,
SECONDARY_EXEC_APIC_REGISTER_VIRT |
SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);
else
- vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL,
+ secondary_exec_controls_clearbit(vmx,
SECONDARY_EXEC_APIC_REGISTER_VIRT |
SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);
}
@@ -4047,8 +4047,7 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx)

if (cpu_has_secondary_exec_ctrls()) {
vmx_compute_secondary_exec_control(vmx);
- vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
- vmx->secondary_exec_control);
+ secondary_exec_controls_init(vmx, vmx->secondary_exec_control);
}

if (kvm_vcpu_apicv_active(&vmx->vcpu)) {
@@ -5969,6 +5968,7 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)

void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 sec_exec_control;

if (!lapic_in_kernel(vcpu))
@@ -5980,11 +5980,11 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu)

/* Postpone execution until vmcs01 is the current VMCS. */
if (is_guest_mode(vcpu)) {
- to_vmx(vcpu)->nested.change_vmcs01_virtual_apic_mode = true;
+ vmx->nested.change_vmcs01_virtual_apic_mode = true;
return;
}

- sec_exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
+ sec_exec_control = secondary_exec_controls_get(vmx);
sec_exec_control &= ~(SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE);

@@ -6006,7 +6006,7 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
break;
}
- vmcs_write32(SECONDARY_VM_EXEC_CONTROL, sec_exec_control);
+ secondary_exec_controls_set(vmx, sec_exec_control);

vmx_update_msr_bitmap(vcpu);
}
@@ -6827,7 +6827,7 @@ static int vmx_get_lpage_level(void)
return PT_PDPE_LEVEL;
}

-static void vmcs_set_secondary_exec_control(u32 new_ctl)
+static void vmcs_set_secondary_exec_control(struct vcpu_vmx *vmx)
{
/*
* These bits in the secondary execution controls field
@@ -6841,10 +6841,10 @@ static void vmcs_set_secondary_exec_control(u32 new_ctl)
SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
SECONDARY_EXEC_DESC;

- u32 cur_ctl = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
+ u32 new_ctl = vmx->secondary_exec_control;
+ u32 cur_ctl = secondary_exec_controls_get(vmx);

- vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
- (new_ctl & ~mask) | (cur_ctl & mask));
+ secondary_exec_controls_set(vmx, (new_ctl & ~mask) | (cur_ctl & mask));
}

/*
@@ -6982,7 +6982,7 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)

if (cpu_has_secondary_exec_ctrls()) {
vmx_compute_secondary_exec_control(vmx);
- vmcs_set_secondary_exec_control(vmx->secondary_exec_control);
+ vmcs_set_secondary_exec_control(vmx);
}

if (nested_vmx_allowed(vcpu))
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 0bb0f75ebcb9..b4d5684b0be9 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -90,6 +90,7 @@ struct vmx_controls_shadow {
u32 vm_exit;
u32 pin;
u32 exec;
+ u32 secondary_exec;
};

/*
@@ -427,6 +428,7 @@ static inline u8 vmx_get_rvi(void)
BUILD_CONTROLS_SHADOW(vm_exit, VM_EXIT_CONTROLS)
BUILD_CONTROLS_SHADOW(pin, PIN_BASED_VM_EXEC_CONTROL)
BUILD_CONTROLS_SHADOW(exec, CPU_BASED_VM_EXEC_CONTROL)
+BUILD_CONTROLS_SHADOW(secondary_exec, SECONDARY_VM_EXEC_CONTROL)

static inline void vmx_segment_cache_clear(struct vcpu_vmx *vmx)
{
--
1.8.3.1