Messages in this thread Patch in this message | | | From | Eric B Munson <> | Subject | [PATCH 2/6 V2] Add functions to check if the host has stopped the vm | Date | Mon, 31 Oct 2011 16:07:26 -0400 |
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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> --- arch/x86/include/asm/pvclock.h | 2 ++ arch/x86/kernel/kvmclock.c | 19 +++++++++++++++++++ 2 files changed, 21 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index c59cc97..7d3ba41 100644 --- a/arch/x86/include/asm/pvclock.h +++ b/arch/x86/include/asm/pvclock.h @@ -13,6 +13,8 @@ void pvclock_read_wallclock(struct pvclock_wall_clock *wall, struct timespec *ts); void pvclock_resume(void); +bool kvm_check_and_clear_host_stopped(int cpu); + /* * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, * yielding a 64-bit result. diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index c1a0188..8ddcfaf 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -113,6 +113,25 @@ static void kvm_get_preset_lpj(void) preset_lpj = lpj; } +bool kvm_check_and_clear_host_stopped(int cpu) +{ + 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 = &per_cpu(hv_clock, cpu); + if ((src->flags & PVCLOCK_GUEST_STOPPED) != 0) { + src->flags = src->flags & (~PVCLOCK_GUEST_STOPPED); + ret = true; + } + + return ret; +} + static struct clocksource kvm_clock = { .name = "kvm-clock", .read = kvm_clock_get_cycles, -- 1.7.5.4
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