diff options
| -rw-r--r-- | arch/x86/kernel/kvmclock.c | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index b5991d53fc0e..cb3d0ca1fa22 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -87,6 +87,27 @@ static u64 kvm_clock_get_cycles(struct clocksource *cs) return kvm_clock_read(); } +static u64 kvm_clock_get_cycles_snapshot(struct clocksource *cs, + struct clocksource_hw_snapshot *chs) +{ + struct pvclock_vcpu_time_info *src; + unsigned version; + u64 ret, tsc; + + preempt_disable_notrace(); + src = this_cpu_pvti(); + do { + version = pvclock_read_begin(src); + tsc = rdtsc_ordered(); + ret = __pvclock_read_cycles(src, tsc); + } while (pvclock_read_retry(src, version)); + preempt_enable_notrace(); + + chs->hw_cycles = tsc; + chs->hw_csid = CSID_X86_TSC; + return ret; +} + static noinstr u64 kvm_sched_clock_read(void) { return pvclock_clocksource_read_nowd(this_cpu_pvti()) - kvm_sched_clock_offset; @@ -156,13 +177,14 @@ static int kvm_cs_enable(struct clocksource *cs) } static struct clocksource kvm_clock = { - .name = "kvm-clock", - .read = kvm_clock_get_cycles, - .rating = 400, - .mask = CLOCKSOURCE_MASK(64), - .flags = CLOCK_SOURCE_IS_CONTINUOUS, - .id = CSID_X86_KVM_CLK, - .enable = kvm_cs_enable, + .name = "kvm-clock", + .read = kvm_clock_get_cycles, + .read_snapshot = kvm_clock_get_cycles_snapshot, + .rating = 400, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .id = CSID_X86_KVM_CLK, + .enable = kvm_cs_enable, }; static void kvm_register_clock(char *txt) |