2010-08-20 08:09:05

by Zachary Amsden

[permalink] [raw]
Subject: [KVM timekeeping 21/35] Track max tsc_khz

Signed-off-by: Zachary Amsden <[email protected]>
---
arch/x86/kvm/x86.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 718bed9..517daf3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -898,6 +898,7 @@ static void kvm_get_time_scale(uint32_t scaled_khz, uint32_t base_khz,
}

static DEFINE_PER_CPU(unsigned long, cpu_tsc_khz);
+unsigned long max_tsc_khz;

static inline int kvm_tsc_changes_freq(void)
{
@@ -4351,11 +4352,20 @@ static void kvm_timer_init(void)
{
int cpu;

+ max_tsc_khz = tsc_khz;
register_hotcpu_notifier(&kvmclock_cpu_notifier_block);
if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
+#ifdef CONFIG_CPU_FREQ
+ struct cpufreq_policy policy;
+ memset(&policy, 0, sizeof(policy));
+ cpufreq_get_policy(&policy, get_cpu());
+ if (policy.cpuinfo.max_freq)
+ max_tsc_khz = policy.cpuinfo.max_freq;
+#endif
cpufreq_register_notifier(&kvmclock_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
}
+ pr_debug("kvm: max_tsc_khz = %ld\n", max_tsc_khz);
for_each_online_cpu(cpu)
smp_call_function_single(cpu, tsc_khz_changed, NULL, 1);
}
--
1.7.1