On 03/24/2011 09:40 AM, Joerg Roedel wrote:
This patch enhances the kvm_amd module with functions to
support the TSC_RATE_MSR which can be used to set a given
tsc frequency for the guest vcpu.
@@ -1141,6 +1175,9 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
for (i = 0; i< NR_HOST_SAVE_USER_MSRS; i++)
rdmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
+
+ if (static_cpu_has(X86_FEATURE_TSCRATEMSR)&& svm->tsc_scale.enabled)
+ wrmsrl(MSR_AMD64_TSC_RATIO, svm->tsc_scale.ratio);
}
static void svm_vcpu_put(struct kvm_vcpu *vcpu)
@@ -1161,6 +1198,9 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu)
#endif
for (i = 0; i< NR_HOST_SAVE_USER_MSRS; i++)
wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
+
+ if (static_cpu_has(X86_FEATURE_TSCRATEMSR)&& svm->tsc_scale.enabled)
+ wrmsr(MSR_AMD64_TSC_RATIO, 0, 1);
}
This is a bit suboptimal. We could do something like
static DEFINE_PER_CPU(u64, current_tsc_scale);
static void svm_vcpu_load(...)
{
...
if (svm->tsc_scale != __get_cpu_var(current_tsc_scale)) {
__get_cpu_var(current_tsc_scale) = svm->tsc_scale;
wrmsrl(MSR_AMD64_TSC_RATIO, svm->tsc_scale);
}
}
with no changes to svm_vcpu_put() (note no tsc_scale.enabled either,
just put the unity value for disabled).
--
error compiling committee.c: too many arguments to function
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