From e23f6d490eb0dc85617bc193c0bfce24abb5ba15 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 23 Apr 2021 15:19:12 -0700 Subject: [PATCH] KVM: VMX: Invert the inlining of MSR interception helpers Invert the inline declarations of the MSR interception helpers between the wrapper, vmx_set_intercept_for_msr(), and the core implementations, vmx_{dis,en}able_intercept_for_msr(). Letting the compiler _not_ inline the implementation reduces KVM's code footprint by ~3k bytes. Back when the helpers were added in commit 904e14fb7cb9 ("KVM: VMX: make MSR bitmaps per-VCPU"), both the wrapper and the implementations were __always_inline because the end code distilled down to a few conditionals and a bit operation. Today, the implementations involve a variety of checks and bit ops in order to support userspace MSR filtering. Furthermore, the vast majority of calls to manipulate MSR interception are not performance sensitive, e.g. vCPU creation and x2APIC toggling. On the other hand, the one path that is performance sensitive, dynamic LBR passthrough, uses the wrappers, i.e. is largely untouched by inverting the inlining. In short, forcing the low level MSR interception code to be inlined no longer makes sense. No functional change intended. Signed-off-by: Sean Christopherson Message-Id: <20210423221912.3857243-1-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/vmx.c | 17 ++--------------- arch/x86/kvm/vmx/vmx.h | 15 +++++++++++++-- 2 files changed, 15 insertions(+), 17 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 2791c2b4c917..026fe770a5cd 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -362,8 +362,6 @@ static const struct kernel_param_ops vmentry_l1d_flush_ops = { module_param_cb(vmentry_l1d_flush, &vmentry_l1d_flush_ops, NULL, 0644); static u32 vmx_segment_access_rights(struct kvm_segment *var); -static __always_inline void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu, - u32 msr, int type); void vmx_vmexit(void); @@ -3818,8 +3816,7 @@ static void vmx_set_msr_bitmap_write(ulong *msr_bitmap, u32 msr) __set_bit(msr & 0x1fff, msr_bitmap + 0xc00 / f); } -static __always_inline void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu, - u32 msr, int type) +void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr, int type) { struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned long *msr_bitmap = vmx->vmcs01.msr_bitmap; @@ -3864,8 +3861,7 @@ static __always_inline void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu, vmx_clear_msr_bitmap_write(msr_bitmap, msr); } -static __always_inline void vmx_enable_intercept_for_msr(struct kvm_vcpu *vcpu, - u32 msr, int type) +void vmx_enable_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr, int type) { struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned long *msr_bitmap = vmx->vmcs01.msr_bitmap; @@ -3898,15 +3894,6 @@ static __always_inline void vmx_enable_intercept_for_msr(struct kvm_vcpu *vcpu, vmx_set_msr_bitmap_write(msr_bitmap, msr); } -void vmx_set_intercept_for_msr(struct kvm_vcpu *vcpu, - u32 msr, int type, bool value) -{ - if (value) - vmx_enable_intercept_for_msr(vcpu, msr, type); - else - vmx_disable_intercept_for_msr(vcpu, msr, type); -} - static u8 vmx_msr_bitmap_mode(struct kvm_vcpu *vcpu) { u8 mode = 0; diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 19fe09fad2fe..008cb87ff088 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -392,8 +392,19 @@ void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp); bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, bool launched); int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr); void vmx_ept_load_pdptrs(struct kvm_vcpu *vcpu); -void vmx_set_intercept_for_msr(struct kvm_vcpu *vcpu, - u32 msr, int type, bool value); + +void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr, int type); +void vmx_enable_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr, int type); + +static inline void vmx_set_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr, + int type, bool value) +{ + if (value) + vmx_enable_intercept_for_msr(vcpu, msr, type); + else + vmx_disable_intercept_for_msr(vcpu, msr, type); +} + void vmx_update_cpu_dirty_logging(struct kvm_vcpu *vcpu); static inline u8 vmx_get_rvi(void)