On Tue, 7 Feb 2012, Marcelo Tosatti wrote:
>
> 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.
>
> Fixes suspend-to-disk with kvmclock.
>
> Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
>
> diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
> index 15d9915..c91e8b9 100644
> --- a/arch/x86/include/asm/tsc.h
> +++ b/arch/x86/include/asm/tsc.h
> @@ -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 */
> diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
> index 5d0afac..baaca8d 100644
> --- a/arch/x86/include/asm/x86_init.h
> +++ b/arch/x86/include/asm/x86_init.h
> @@ -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;
> diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
> index ca4e735..57e6b78 100644
> --- a/arch/x86/kernel/kvmclock.c
> +++ b/arch/x86/kernel/kvmclock.c
> @@ -136,6 +136,15 @@ int kvm_register_clock(char *txt)
> return ret;
> }
>
> +void kvm_save_sched_clock_state(void)
static ?
> +{
> +}
> +
> +void kvm_restore_sched_clock_state(void)
Ditto
> +{
> + kvm_register_clock("primary cpu clock, resume");
> +}
> +
Otherwise: Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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