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| author | Eric B Munson <emunson@mgebm.net> | 2012-03-10 20:37:26 +0100 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-04-08 11:48:59 +0200 |
| commit | 3b5d56b9317fa7b5407dff1aa7b115bf6cdbd494 (patch) | |
| tree | d733bab15dcf193c3364d14fc2d973aa20a28fe3 /arch/x86 | |
| parent | x86: pvclock: Add flag to indicate that a vm was stopped by the host (diff) | |
| download | linux-3b5d56b9317fa7b5407dff1aa7b115bf6cdbd494.tar.xz linux-3b5d56b9317fa7b5407dff1aa7b115bf6cdbd494.zip | |
kvmclock: Add functions to check if the host has stopped the vm
When a host stops or suspends a VM it will set a flag to show this. The
watchdog will use these functions to determine if a softlockup is real, or the
result of a suspended VM.
Signed-off-by: Eric B Munson <emunson@mgebm.net>
asm-generic changes Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/kvm_para.h | 8 | ||||
| -rw-r--r-- | arch/x86/kernel/kvmclock.c | 21 |
2 files changed, 29 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 734c3767cfac..99c4bbe0cca2 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -95,6 +95,14 @@ struct kvm_vcpu_pv_apf_data { extern void kvmclock_init(void); extern int kvm_register_clock(char *txt); +#ifdef CONFIG_KVM_CLOCK +bool kvm_check_and_clear_guest_paused(void); +#else +static inline bool kvm_check_and_clear_guest_paused(void) +{ + return false; +} +#endif /* CONFIG_KVMCLOCK */ /* This instruction is vmcall. On non-VT architectures, it will generate a * trap that we will then rewrite to the appropriate instruction. diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index f8492da65bfc..4ba090ca689d 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -22,6 +22,7 @@ #include <asm/msr.h> #include <asm/apic.h> #include <linux/percpu.h> +#include <linux/hardirq.h> #include <asm/x86_init.h> #include <asm/reboot.h> @@ -114,6 +115,26 @@ static void kvm_get_preset_lpj(void) preset_lpj = lpj; } +bool kvm_check_and_clear_guest_paused(void) +{ + bool ret = false; + struct pvclock_vcpu_time_info *src; + + /* + * per_cpu() is safe here because this function is only called from + * timer functions where preemption is already disabled. + */ + WARN_ON(!in_atomic()); + src = &__get_cpu_var(hv_clock); + if ((src->flags & PVCLOCK_GUEST_STOPPED) != 0) { + __this_cpu_and(hv_clock.flags, ~PVCLOCK_GUEST_STOPPED); + ret = true; + } + + return ret; +} +EXPORT_SYMBOL_GPL(kvm_check_and_clear_guest_paused); + static struct clocksource kvm_clock = { .name = "kvm-clock", .read = kvm_clock_get_cycles, |