From c0dc39bd2c584879748dfd1321f8541d1cbeb9b8 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 28 Jul 2023 18:15:50 -0700 Subject: [PATCH] KVM: nSVM: Use the "outer" helper for writing multiplier to MSR_AMD64_TSC_RATIO When emulating nested SVM transitions, use the outer helper for writing the TSC multiplier for L2. Using the inner helper only for one-off cases, i.e. for paths where KVM is NOT emulating or modifying vCPU state, will allow for multiple cleanups: - Explicitly disabling preemption only in the outer helper - Getting the multiplier from the vCPU field in the outer helper - Skipping the WRMSR in the outer helper if guest state isn't loaded Opportunistically delete an extra newline. No functional change intended. Link: https://lore.kernel.org/r/20230729011608.1065019-4-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/nested.c | 4 ++-- arch/x86/kvm/svm/svm.c | 5 ++--- arch/x86/kvm/svm/svm.h | 2 +- 3 files changed, 5 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index c66c823..5d5a1d7 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1103,7 +1103,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm) if (kvm_caps.has_tsc_control && vcpu->arch.tsc_scaling_ratio != vcpu->arch.l1_tsc_scaling_ratio) { vcpu->arch.tsc_scaling_ratio = vcpu->arch.l1_tsc_scaling_ratio; - __svm_write_tsc_multiplier(vcpu->arch.tsc_scaling_ratio); + svm_write_tsc_multiplier(vcpu, vcpu->arch.tsc_scaling_ratio); } svm->nested.ctl.nested_cr3 = 0; @@ -1536,7 +1536,7 @@ void nested_svm_update_tsc_ratio_msr(struct kvm_vcpu *vcpu) vcpu->arch.tsc_scaling_ratio = kvm_calc_nested_tsc_multiplier(vcpu->arch.l1_tsc_scaling_ratio, svm->tsc_ratio_msr); - __svm_write_tsc_multiplier(vcpu->arch.tsc_scaling_ratio); + svm_write_tsc_multiplier(vcpu, vcpu->arch.tsc_scaling_ratio); } /* Inverse operation of nested_copy_vmcb_control_to_cache(). asid is copied too. */ diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 4785d78..7217f75 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -567,7 +567,7 @@ static int svm_check_processor_compat(void) return 0; } -void __svm_write_tsc_multiplier(u64 multiplier) +static void __svm_write_tsc_multiplier(u64 multiplier) { preempt_disable(); @@ -1150,12 +1150,11 @@ static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS); } -static void svm_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 multiplier) +void svm_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 multiplier) { __svm_write_tsc_multiplier(multiplier); } - /* Evaluate instruction intercepts that depend on guest CPUID features. */ static void svm_recalc_instruction_intercepts(struct kvm_vcpu *vcpu, struct vcpu_svm *svm) diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 18af7e7..7132c0a 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -658,7 +658,7 @@ int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr, bool has_error_code, u32 error_code); int nested_svm_exit_special(struct vcpu_svm *svm); void nested_svm_update_tsc_ratio_msr(struct kvm_vcpu *vcpu); -void __svm_write_tsc_multiplier(u64 multiplier); +void svm_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 multiplier); void nested_copy_vmcb_control_to_cache(struct vcpu_svm *svm, struct vmcb_control_area *control); void nested_copy_vmcb_save_to_cache(struct vcpu_svm *svm, -- 2.7.4