From b74f05d61b73af584d0c39121980171389ecfaaa Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Mon, 13 Feb 2012 11:07:27 -0200 Subject: 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 Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity 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..f8492da6 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; } +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; 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 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; 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 @@ 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); diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index f10c0af..0e76a28 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -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); -- cgit v0.10.2