sched_clock() should time the vcpu run time. Subtract stolen time from
realtime pvclock.
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Index: kvm/arch/x86/kernel/kvmclock.c
===================================================================
--- kvm.orig/arch/x86/kernel/kvmclock.c
+++ kvm/arch/x86/kernel/kvmclock.c
@@ -38,7 +38,16 @@ static int parse_no_kvmclock(char *arg)
early_param("no-kvmclock", parse_no_kvmclock);
/* The hypervisor will put information about time periodically here */
-static DEFINE_PER_CPU_SHARED_ALIGNED(struct pvclock_vcpu_time_info, hv_clock);
+struct time_info {
+ struct pvclock_vcpu_time_info hv_clock;
+ struct kvm_vcpu_runtime_info run_info;
+};
+
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct time_info, time_info);
+
+#define hv_clock time_info.hv_clock
+#define run_info time_info.run_info
+
static struct pvclock_wall_clock wall_clock;
/*
@@ -84,6 +93,40 @@ static cycle_t kvm_clock_get_cycles(stru
return kvm_clock_read();
}
+cycle_t kvm_runtime_read(struct pvclock_vcpu_time_info *src,
+ struct kvm_vcpu_runtime_info *rinfo)
+{
+ struct pvclock_shadow_time shadow;
+ unsigned version;
+ cycle_t ret, offset;
+ unsigned long long stolen;
+
+ do {
+ version = pvclock_get_time_values(&shadow, src);
+ barrier();
+ offset = pvclock_get_nsec_offset(&shadow);
+ stolen = rinfo->stolen_time;
+ ret = shadow.system_timestamp + offset - stolen;
+ barrier();
+ } while (version != src->version);
+
+ return ret;
+}
+
+static cycle_t kvm_clock_read_unstolen(void)
+{
+ struct pvclock_vcpu_time_info *src;
+ struct kvm_vcpu_runtime_info *rinfo;
+ cycle_t ret;
+
+ src = &get_cpu_var(hv_clock);
+ rinfo = &get_cpu_var(run_info);
+ ret = kvm_runtime_read(src, rinfo);
+ put_cpu_var(run_info);
+ put_cpu_var(hv_clock);
+ return ret;
+}
+
/*
* If we don't do that, there is the possibility that the guest
* will calibrate under heavy load - thus, getting a lower lpj -
@@ -133,14 +176,30 @@ static int kvm_register_clock(char *txt)
return native_write_msr_safe(MSR_KVM_SYSTEM_TIME, low, high);
}
+static int kvm_register_run_info(char *txt)
+{
+ int cpu = smp_processor_id();
+ int low, high;
+
+ low = (int) __pa(&per_cpu(run_info, cpu)) | 1;
+ high = ((u64)__pa(&per_cpu(run_info, cpu)) >> 32);
+ printk(KERN_INFO "kvm-runtime-info: cpu %d, msr %x:%x, %s\n",
+ cpu, high, low, txt);
+ return native_write_msr_safe(MSR_KVM_RUN_TIME, low, high);
+}
+
#ifdef CONFIG_X86_LOCAL_APIC
static void __cpuinit kvm_setup_secondary_clock(void)
{
+ char *txt = "secondary cpu clock";
+
/*
* Now that the first cpu already had this clocksource initialized,
* we shouldn't fail.
*/
- WARN_ON(kvm_register_clock("secondary cpu clock"));
+ WARN_ON(kvm_register_clock(txt));
+ if (kvm_para_has_feature(KVM_FEATURE_RUNTIME_INFO))
+ kvm_register_run_info(txt);
/* ok, done with our trickery, call native */
setup_secondary_APIC_clock();
}
@@ -149,7 +208,11 @@ static void __cpuinit kvm_setup_secondar
#ifdef CONFIG_SMP
static void __init kvm_smp_prepare_boot_cpu(void)
{
- WARN_ON(kvm_register_clock("primary cpu clock"));
+ char *txt = "primary cpu clock";
+
+ WARN_ON(kvm_register_clock(txt));
+ if (kvm_para_has_feature(KVM_FEATURE_RUNTIME_INFO))
+ kvm_register_run_info(txt);
native_smp_prepare_boot_cpu();
}
#endif
@@ -204,4 +267,6 @@ void __init kvmclock_init(void)
pv_info.paravirt_enabled = 1;
pv_info.name = "KVM";
}
+ if (kvm_para_has_feature(KVM_FEATURE_RUNTIME_INFO))
+ pv_time_ops.sched_clock = kvm_clock_read_unstolen;
}
--
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