x86: kvmclock: abstract save/restore sched_clock_state
Upon resume from hibernation, CPU 0's hvclock area contains the old
values for system_time and tsc_timestamp. It is necessary for the
hypervisor to update these values with uptodate ones before the CPU uses
them.
Abstract TSC's save/restore sched_clock_state functions and use
restore_state to write to KVM_SYSTEM_TIME MSR, forcing an update.
Also move restore_sched_clock_state before __restore_processor_state,
since the later calls CONFIG_LOCK_STAT's lockstat_clock (also for TSC).
Thanks to Igor Mammedov for tracking it down.
Fixes suspend-to-disk with kvmclock.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index ca4e735..f8492da 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -136,6 +136,15 @@
return ret;
}
+static void kvm_save_sched_clock_state(void)
+{
+}
+
+static void kvm_restore_sched_clock_state(void)
+{
+ kvm_register_clock("primary cpu clock, resume");
+}
+
#ifdef CONFIG_X86_LOCAL_APIC
static void __cpuinit kvm_setup_secondary_clock(void)
{
@@ -195,6 +204,8 @@
x86_cpuinit.early_percpu_clock_init =
kvm_setup_secondary_clock;
#endif
+ x86_platform.save_sched_clock_state = kvm_save_sched_clock_state;
+ x86_platform.restore_sched_clock_state = kvm_restore_sched_clock_state;
machine_ops.shutdown = kvm_shutdown;
#ifdef CONFIG_KEXEC
machine_ops.crash_shutdown = kvm_crash_shutdown;
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index a62c201..aed2aa1 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -629,7 +629,7 @@
static unsigned long long cyc2ns_suspend;
-void save_sched_clock_state(void)
+void tsc_save_sched_clock_state(void)
{
if (!sched_clock_stable)
return;
@@ -645,7 +645,7 @@
* that sched_clock() continues from the point where it was left off during
* suspend.
*/
-void restore_sched_clock_state(void)
+void tsc_restore_sched_clock_state(void)
{
unsigned long long offset;
unsigned long flags;
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index 6f2ec53..e9f265f 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -108,7 +108,9 @@
.is_untracked_pat_range = is_ISA_range,
.nmi_init = default_nmi_init,
.get_nmi_reason = default_get_nmi_reason,
- .i8042_detect = default_i8042_detect
+ .i8042_detect = default_i8042_detect,
+ .save_sched_clock_state = tsc_save_sched_clock_state,
+ .restore_sched_clock_state = tsc_restore_sched_clock_state,
};
EXPORT_SYMBOL_GPL(x86_platform);