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-rw-r--r--arch/x86/kvm/svm/nested.c4
-rw-r--r--arch/x86/kvm/svm/svm.c32
-rw-r--r--arch/x86/kvm/svm/svm.h2
3 files changed, 23 insertions, 15 deletions
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index bed5e1692cef..3361258640a2 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -982,7 +982,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
if (svm->tsc_ratio_msr != kvm_default_tsc_scaling_ratio) {
WARN_ON(!svm->tsc_scaling_enabled);
vcpu->arch.tsc_scaling_ratio = vcpu->arch.l1_tsc_scaling_ratio;
- svm_write_tsc_multiplier(vcpu, vcpu->arch.tsc_scaling_ratio);
+ __svm_write_tsc_multiplier(vcpu->arch.tsc_scaling_ratio);
}
svm->nested.ctl.nested_cr3 = 0;
@@ -1387,7 +1387,7 @@ 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, vcpu->arch.tsc_scaling_ratio);
+ __svm_write_tsc_multiplier(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 63880b33ce37..478e6ee81d88 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -465,11 +465,24 @@ static int has_svm(void)
return 1;
}
+void __svm_write_tsc_multiplier(u64 multiplier)
+{
+ preempt_disable();
+
+ if (multiplier == __this_cpu_read(current_tsc_ratio))
+ goto out;
+
+ wrmsrl(MSR_AMD64_TSC_RATIO, multiplier);
+ __this_cpu_write(current_tsc_ratio, multiplier);
+out:
+ preempt_enable();
+}
+
static void svm_hardware_disable(void)
{
/* Make sure we clean up behind us */
if (tsc_scaling)
- wrmsrl(MSR_AMD64_TSC_RATIO, SVM_TSC_RATIO_DEFAULT);
+ __svm_write_tsc_multiplier(SVM_TSC_RATIO_DEFAULT);
cpu_svm_disable();
@@ -515,8 +528,7 @@ static int svm_hardware_enable(void)
* Set the default value, even if we don't use TSC scaling
* to avoid having stale value in the msr
*/
- wrmsrl(MSR_AMD64_TSC_RATIO, SVM_TSC_RATIO_DEFAULT);
- __this_cpu_write(current_tsc_ratio, SVM_TSC_RATIO_DEFAULT);
+ __svm_write_tsc_multiplier(SVM_TSC_RATIO_DEFAULT);
}
@@ -999,11 +1011,12 @@ static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
}
-void svm_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 multiplier)
+static void svm_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 multiplier)
{
- wrmsrl(MSR_AMD64_TSC_RATIO, 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)
@@ -1363,13 +1376,8 @@ static void svm_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
sev_es_prepare_switch_to_guest(hostsa);
}
- if (tsc_scaling) {
- u64 tsc_ratio = vcpu->arch.tsc_scaling_ratio;
- if (tsc_ratio != __this_cpu_read(current_tsc_ratio)) {
- __this_cpu_write(current_tsc_ratio, tsc_ratio);
- wrmsrl(MSR_AMD64_TSC_RATIO, tsc_ratio);
- }
- }
+ if (tsc_scaling)
+ __svm_write_tsc_multiplier(vcpu->arch.tsc_scaling_ratio);
if (likely(tsc_aux_uret_slot >= 0))
kvm_set_user_return_msr(tsc_aux_uret_slot, svm->tsc_aux, -1ull);
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 45a87b2a8b3c..29d6fd205a49 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -590,7 +590,7 @@ 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(struct kvm_vcpu *vcpu, u64 multiplier);
+void __svm_write_tsc_multiplier(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,