svn commit: r276454 - in projects/paravirt/sys/x86: include x86

[Bryan Venteicher]

Author: bryanv
Date: Wed Dec 31 06:59:22 2014
New Revision: 276454
URL: https://svnweb.freebsd.org/changeset/base/276454

Log:
  Add code to calculate the TSC frequency from the KVM/PV clock
  
  Not currently used. Could later be used similarly to the VMware code
  to avoid attempting to calibrate the TSC.

Modified:
  projects/paravirt/sys/x86/include/kvm.h
  projects/paravirt/sys/x86/include/pvclock.h
  projects/paravirt/sys/x86/x86/kvm_clock.c
  projects/paravirt/sys/x86/x86/pvclock.c

Modified: projects/paravirt/sys/x86/include/kvm.h
==============================================================================
--- projects/paravirt/sys/x86/include/kvm.h	Wed Dec 31 06:54:28 2014	(r276453)
+++ projects/paravirt/sys/x86/include/kvm.h	Wed Dec 31 06:59:22 2014	(r276454)
@@ -43,5 +43,6 @@
 
 int		kvm_paravirt_supported(void);
 uint32_t	kvm_get_features(void);
+uint64_t	kvm_clock_tsc_freq(void);
 
 #endif /* !_X86_KVM_H_ */

Modified: projects/paravirt/sys/x86/include/pvclock.h
==============================================================================
--- projects/paravirt/sys/x86/include/pvclock.h	Wed Dec 31 06:54:28 2014	(r276453)
+++ projects/paravirt/sys/x86/include/pvclock.h	Wed Dec 31 06:59:22 2014	(r276454)
@@ -50,6 +50,7 @@ struct pvclock_wall_clock {
 } __packed;
 
 void		pvclock_resume(void);
+uint64_t	pvclock_tsc_freq(struct pvclock_vcpu_time_info *ti);
 uint64_t	pvclock_get_timecount(struct pvclock_vcpu_time_info *ti);
 void		pvclock_get_wallclock(struct pvclock_wall_clock *wc,
 		    struct timespec *ts);

Modified: projects/paravirt/sys/x86/x86/kvm_clock.c
==============================================================================
--- projects/paravirt/sys/x86/x86/kvm_clock.c	Wed Dec 31 06:54:28 2014	(r276453)
+++ projects/paravirt/sys/x86/x86/kvm_clock.c	Wed Dec 31 06:59:22 2014	(r276454)
@@ -58,6 +58,20 @@ static struct timecounter kvm_clock_time
 static uint32_t kvm_clock_wall_clock_msr;
 static uint32_t kvm_clock_system_time_msr;
 
+uint64_t
+kvm_clock_tsc_freq(void)
+{
+	struct pvclock_vcpu_time_info *ti;
+	uint64_t freq;
+
+	critical_enter();
+	ti = DPCPU_PTR(kvm_clock_vcpu_time_info);
+	freq = pvclock_tsc_freq(ti);
+	critical_exit();
+
+	return (freq);
+}
+
 static u_int
 kvm_clock_get_timecounter(struct timecounter *tc)
 {

Modified: projects/paravirt/sys/x86/x86/pvclock.c
==============================================================================
--- projects/paravirt/sys/x86/x86/pvclock.c	Wed Dec 31 06:54:28 2014	(r276453)
+++ projects/paravirt/sys/x86/x86/pvclock.c	Wed Dec 31 06:59:22 2014	(r276454)
@@ -50,6 +50,21 @@ pvclock_resume(void)
 	atomic_store_rel_64(&pvclock_last_cycles, 0);
 }
 
+uint64_t
+pvclock_tsc_freq(struct pvclock_vcpu_time_info *ti)
+{
+	uint64_t freq;
+
+	freq = (1000000000ULL << 32) / ti->tsc_to_system_mul;
+
+	if (ti->tsc_shift < 0)
+		freq <<= -ti->tsc_shift;
+	else
+		freq >>= ti->tsc_shift;
+
+	return (freq);
+}
+
 /*
  * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
  * yielding a 64-bit result.