diff options
| author | Sean Christopherson <seanjc@google.com> | 2023-02-11 03:35:33 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-03-14 17:28:57 +0300 |
| commit | 19f10315fd53599d8186aa46a0363b233292eb3d (patch) | |
| tree | bb3ad465263d06bed265805dce9dcf782ed32cc5 /arch/x86/kvm/vmx/vmx.c | |
| parent | 68ac4221497b9a54f32c452a774ae747da908a81 (diff) | |
| download | linux-19f10315fd53599d8186aa46a0363b233292eb3d.tar.xz | |
KVM: VMX: Stub out enable_evmcs static key for CONFIG_HYPERV=n
Wrap enable_evmcs in a helper and stub it out when CONFIG_HYPERV=n in
order to eliminate the static branch nop placeholders. clang-14 is clever
enough to elide the nop, but gcc-12 is not. Stubbing out the key reduces
the size of kvm-intel.ko by ~7.5% (200KiB) when compiled with gcc-12
(there are a _lot_ of VMCS accesses throughout KVM).
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230211003534.564198-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index d2d6e1b6c788..09e07fb83c37 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -595,7 +595,7 @@ static void hv_reset_evmcs(void) { struct hv_vp_assist_page *vp_ap; - if (!static_branch_unlikely(&enable_evmcs)) + if (!kvm_is_using_evmcs()) return; /* @@ -2816,8 +2816,7 @@ static int vmx_hardware_enable(void) * This can happen if we hot-added a CPU but failed to allocate * VP assist page for it. */ - if (static_branch_unlikely(&enable_evmcs) && - !hv_get_vp_assist_page(cpu)) + if (kvm_is_using_evmcs() && !hv_get_vp_assist_page(cpu)) return -EFAULT; intel_pt_handle_vmx(1); @@ -2869,7 +2868,7 @@ struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags) memset(vmcs, 0, vmcs_config.size); /* KVM supports Enlightened VMCS v1 only */ - if (static_branch_unlikely(&enable_evmcs)) + if (kvm_is_using_evmcs()) vmcs->hdr.revision_id = KVM_EVMCS_VERSION; else vmcs->hdr.revision_id = vmcs_config.revision_id; @@ -2964,7 +2963,7 @@ static __init int alloc_kvm_area(void) * still be marked with revision_id reported by * physical CPU. */ - if (static_branch_unlikely(&enable_evmcs)) + if (kvm_is_using_evmcs()) vmcs->hdr.revision_id = vmcs_config.revision_id; per_cpu(vmxarea, cpu) = vmcs; @@ -3931,7 +3930,7 @@ static void vmx_msr_bitmap_l01_changed(struct vcpu_vmx *vmx) * 'Enlightened MSR Bitmap' feature L0 needs to know that MSR * bitmap has changed. */ - if (IS_ENABLED(CONFIG_HYPERV) && static_branch_unlikely(&enable_evmcs)) { + if (kvm_is_using_evmcs()) { struct hv_enlightened_vmcs *evmcs = (void *)vmx->vmcs01.vmcs; if (evmcs->hv_enlightenments_control.msr_bitmap) @@ -7310,7 +7309,7 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu) vmx_vcpu_enter_exit(vcpu, __vmx_vcpu_run_flags(vmx)); /* All fields are clean at this point */ - if (static_branch_unlikely(&enable_evmcs)) { + if (kvm_is_using_evmcs()) { current_evmcs->hv_clean_fields |= HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL; @@ -7440,7 +7439,7 @@ static int vmx_vcpu_create(struct kvm_vcpu *vcpu) * feature only for vmcs01, KVM currently isn't equipped to realize any * performance benefits from enabling it for vmcs02. */ - if (IS_ENABLED(CONFIG_HYPERV) && static_branch_unlikely(&enable_evmcs) && + if (kvm_is_using_evmcs() && (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)) { struct hv_enlightened_vmcs *evmcs = (void *)vmx->vmcs01.vmcs; |