[PATCH 3/4] KVM: VMX: Drop caching of KVM's desired sec exec controls for vmcs01

From: Sean Christopherson
Date: Tue Aug 10 2021 - 13:20:19 EST


Remove the secondary execution controls cache now that it's effectively
dead code; it is only read immediately after it is written.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 20 ++++++++------------
arch/x86/kvm/vmx/vmx.h | 3 +--
2 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ae8e62df16dd..6c93122363b2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4212,7 +4212,7 @@ vmx_adjust_secondary_exec_control(struct vcpu_vmx *vmx, u32 *exec_control,
#define vmx_adjust_sec_exec_exiting(vmx, exec_control, lname, uname) \
vmx_adjust_sec_exec_control(vmx, exec_control, lname, uname, uname##_EXITING, true)

-static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx)
+u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx)
{
struct kvm_vcpu *vcpu = &vmx->vcpu;

@@ -4298,7 +4298,7 @@ static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx)
if (!vcpu->kvm->arch.bus_lock_detection_enabled)
exec_control &= ~SECONDARY_EXEC_BUS_LOCK_DETECTION;

- vmx->secondary_exec_control = exec_control;
+ return exec_control;
}

#define VMX_XSS_EXIT_BITMAP 0
@@ -4322,10 +4322,8 @@ static void init_vmcs(struct vcpu_vmx *vmx)

exec_controls_set(vmx, vmx_exec_control(vmx));

- if (cpu_has_secondary_exec_ctrls()) {
- vmx_compute_secondary_exec_control(vmx);
- secondary_exec_controls_set(vmx, vmx->secondary_exec_control);
- }
+ if (cpu_has_secondary_exec_ctrls())
+ secondary_exec_controls_set(vmx, vmx_secondary_exec_control(vmx));

if (kvm_vcpu_apicv_active(&vmx->vcpu)) {
vmcs_write64(EOI_EXIT_BITMAP0, 0);
@@ -6982,7 +6980,7 @@ static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
return (cache << VMX_EPT_MT_EPTE_SHIFT) | ipat;
}

-static void vmcs_set_secondary_exec_control(struct vcpu_vmx *vmx)
+static void vmcs_set_secondary_exec_control(struct vcpu_vmx *vmx, u32 new_ctl)
{
/*
* These bits in the secondary execution controls field
@@ -6996,7 +6994,6 @@ static void vmcs_set_secondary_exec_control(struct vcpu_vmx *vmx)
SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
SECONDARY_EXEC_DESC;

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

secondary_exec_controls_set(vmx, (new_ctl & ~mask) | (cur_ctl & mask));
@@ -7141,10 +7138,9 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)

vmx_setup_uret_msrs(vmx);

- if (cpu_has_secondary_exec_ctrls()) {
- vmx_compute_secondary_exec_control(vmx);
- vmcs_set_secondary_exec_control(vmx);
- }
+ if (cpu_has_secondary_exec_ctrls())
+ vmcs_set_secondary_exec_control(vmx,
+ vmx_secondary_exec_control(vmx));

if (nested_vmx_allowed(vcpu))
to_vmx(vcpu)->msr_ia32_feature_control_valid_bits |=
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 414b440de9ac..2bd07867e9da 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -263,8 +263,6 @@ struct vcpu_vmx {
u64 spec_ctrl;
u32 msr_ia32_umwait_control;

- 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
@@ -477,6 +475,7 @@ static inline u32 vmx_vmexit_ctrl(void)
}

u32 vmx_exec_control(struct vcpu_vmx *vmx);
+u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx);
u32 vmx_pin_based_exec_ctrl(struct vcpu_vmx *vmx);

static inline struct kvm_vmx *to_kvm_vmx(struct kvm *kvm)
--
2.32.0.605.g8dce9f2422-goog