52 lines
1.7 KiB
Diff
52 lines
1.7 KiB
Diff
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From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
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Date: Mon, 25 Oct 2010 16:53:46 -0700
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Subject: [PATCH] x86/pvclock: zero last_value on resume
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If the guest domain has been suspend/resumed or migrated, then the
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system clock backing the pvclock clocksource may revert to a smaller
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value (ie, can be non-monotonic across the migration/save-restore).
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Make sure we zero last_value in that case so that the domain
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continues to see clock updates.
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Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
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diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
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index cd02f32..6226870 100644
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--- a/arch/x86/include/asm/pvclock.h
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+++ b/arch/x86/include/asm/pvclock.h
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@@ -11,5 +11,6 @@ unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
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void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
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struct pvclock_vcpu_time_info *vcpu,
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struct timespec *ts);
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+void pvclock_resume(void);
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#endif /* _ASM_X86_PVCLOCK_H */
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diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
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index 239427c..a4f07c1 100644
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--- a/arch/x86/kernel/pvclock.c
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+++ b/arch/x86/kernel/pvclock.c
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@@ -120,6 +120,11 @@ unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src)
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static atomic64_t last_value = ATOMIC64_INIT(0);
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+void pvclock_resume(void)
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+{
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+ atomic64_set(&last_value, 0);
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+}
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+
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cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src)
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{
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struct pvclock_shadow_time shadow;
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diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
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index b2bb5aa..5da5e53 100644
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--- a/arch/x86/xen/time.c
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+++ b/arch/x86/xen/time.c
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@@ -426,6 +426,8 @@ void xen_timer_resume(void)
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{
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int cpu;
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+ pvclock_resume();
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+
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if (xen_clockevent != &xen_vcpuop_clockevent)
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return;
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