[RFC PATCH 2/3] Add functions to check if the host has stopped the vm

Eric B Munson
2011-08-03T14:25:15Z

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 | 3 +++
arch/x86/kernel/kvmclock.c | 12 ++++++++++++
2 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index a518c0a..a9e9b4f 100644
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -13,6 +13,9 @@ void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
struct timespec *ts);
void pvclock_resume(void);

+bool kvm_check_host_stopped(void);
+void kvm_clear_host_stopped(void);
+
/*
* 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..5a42582 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -113,6 +113,18 @@ static void kvm_get_preset_lpj(void)
preset_lpj = lpj;
}

+bool kvm_check_host_stopped()
+{
+ struct pvclock_vcpu_time_info *src = &per_cpu(hv_clock, 0);
+ return (src->flags & PVCLOCK_STOPPED) != 0;
+}
+
+void kvm_clear_host_stopped()
+{
+ struct pvclock_vcpu_time_info *src = &per_cpu(hv_clock, 0);
+ src->flags = src->flags & (~PVCLOCK_STOPPED);
+}
+
static struct clocksource kvm_clock = {
.name = "kvm-clock",
.read = kvm_clock_get_cycles,
--
1.7.4.1