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x86: kvmclock: abstract save/restore sched_clock_state

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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>
This commit is contained in:
Marcelo Tosatti 2012-02-13 11:07:27 -02:00 committed by Avi Kivity
parent 9587190107
commit b74f05d61b
6 changed files with 24 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/x86/include/asm/tsc.h
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@ -61,7 +61,7 @@ extern void check_tsc_sync_source(int cpu);
extern void check_tsc_sync_target(void);
extern int notsc_setup(char *);
extern void save_sched_clock_state(void);
extern void restore_sched_clock_state(void);
extern void tsc_save_sched_clock_state(void);
extern void tsc_restore_sched_clock_state(void);
#endif /* _ASM_X86_TSC_H */

4
arch/x86/include/asm/x86_init.h
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@ -162,6 +162,8 @@ struct x86_cpuinit_ops {
* @is_untracked_pat_range exclude from PAT logic
* @nmi_init enable NMI on cpus
* @i8042_detect pre-detect if i8042 controller exists
* @save_sched_clock_state: save state for sched_clock() on suspend
* @restore_sched_clock_state: restore state for sched_clock() on resume
*/
struct x86_platform_ops {
unsigned long (*calibrate_tsc)(void);
@ -173,6 +175,8 @@ struct x86_platform_ops {
void (*nmi_init)(void);
unsigned char (*get_nmi_reason)(void);
int (*i8042_detect)(void);
void (*save_sched_clock_state)(void);
void (*restore_sched_clock_state)(void);
};
struct pci_dev;

11
arch/x86/kernel/kvmclock.c
View File

@ -136,6 +136,15 @@ int kvm_register_clock(char *txt)
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 @@ void __init kvmclock_init(void)
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;

4
arch/x86/kernel/tsc.c
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@ -629,7 +629,7 @@ static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
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 @@ void save_sched_clock_state(void)
* 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;

4
arch/x86/kernel/x86_init.c
View File

@ -108,7 +108,9 @@ struct x86_platform_ops x86_platform = {
.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);

4
arch/x86/power/cpu.c
View File

@ -114,7 +114,7 @@ static void __save_processor_state(struct saved_context *ctxt)
void save_processor_state(void)
{
__save_processor_state(&saved_context);
save_sched_clock_state();
x86_platform.save_sched_clock_state();
}
#ifdef CONFIG_X86_32
EXPORT_SYMBOL(save_processor_state);
@ -230,8 +230,8 @@ static void __restore_processor_state(struct saved_context *ctxt)
/* Needed by apm.c */
void restore_processor_state(void)
{
x86_platform.restore_sched_clock_state();
__restore_processor_state(&saved_context);
restore_sched_clock_state();
}
#ifdef CONFIG_X86_32
EXPORT_SYMBOL(restore_processor_state);