[PATCH 2/4] Add functions to check if the host has stopped the vm

2011-12-08 Thread Eric B Munson
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 emun...@mgebm.net
Cc: mi...@redhat.com
Cc: h...@zytor.com
Cc: a...@arndb.de
Cc: ry...@linux.vnet.ibm.com
Cc: aligu...@us.ibm.com
Cc: mtosa...@redhat.com
Cc: jeremy.fitzhardi...@citrix.com
Cc: kvm@vger.kernel.org
Cc: linux-a...@vger.kernel.org
Cc: x...@kernel.org
Cc: linux-ker...@vger.kernel.org
---
Changes from V5:
 Collapse generic stubs into this patch
 check_and_clear_guest_stopped() takes no args and uses __get_cpu_var()
 Include individual definitions in ia64, s390, and powerpc

 arch/ia64/include/asm/kvm_para.h|5 +
 arch/powerpc/include/asm/kvm_para.h |5 +
 arch/s390/include/asm/kvm_para.h|5 +
 arch/x86/include/asm/kvm_para.h |8 
 arch/x86/kernel/kvmclock.c  |   21 +
 include/asm-generic/kvm_para.h  |   14 ++
 6 files changed, 58 insertions(+), 0 deletions(-)
 create mode 100644 include/asm-generic/kvm_para.h

diff --git a/arch/ia64/include/asm/kvm_para.h b/arch/ia64/include/asm/kvm_para.h
index 1588aee..2019cb9 100644
--- a/arch/ia64/include/asm/kvm_para.h
+++ b/arch/ia64/include/asm/kvm_para.h
@@ -26,6 +26,11 @@ static inline unsigned int kvm_arch_para_features(void)
return 0;
 }
 
+static inline bool kvm_check_and_clear_guest_paused(void)
+{
+   return false;
+}
+
 #endif
 
 #endif
diff --git a/arch/powerpc/include/asm/kvm_para.h 
b/arch/powerpc/include/asm/kvm_para.h
index 50533f9..1f80293 100644
--- a/arch/powerpc/include/asm/kvm_para.h
+++ b/arch/powerpc/include/asm/kvm_para.h
@@ -169,6 +169,11 @@ static inline unsigned int kvm_arch_para_features(void)
return r;
 }
 
+static inline bool kvm_check_and_clear_guest_paused(void)
+{
+   return false;
+}
+
 #endif /* __KERNEL__ */
 
 #endif /* __POWERPC_KVM_PARA_H__ */
diff --git a/arch/s390/include/asm/kvm_para.h b/arch/s390/include/asm/kvm_para.h
index 6964db2..a988329 100644
--- a/arch/s390/include/asm/kvm_para.h
+++ b/arch/s390/include/asm/kvm_para.h
@@ -149,6 +149,11 @@ static inline unsigned int kvm_arch_para_features(void)
return 0;
 }
 
+static inline bool kvm_check_and_clear_guest_paused(void)
+{
+   return false;
+}
+
 #endif
 
 #endif /* __S390_KVM_PARA_H */
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 734c376..99c4bbe 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 44842d7..33d2e22 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) {
+   src-flags = src-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,
diff --git a/include/asm-generic/kvm_para.h b/include/asm-generic/kvm_para.h
new file mode 100644
index 000..05ef7e7
--- /dev/null
+++ b/include/asm-generic/kvm_para.h
@@ -0,0 +1,14 @@
+#ifndef _ASM_GENERIC_KVM_PARA_H
+#define _ASM_GENERIC_KVM_PARA_H
+
+
+/*
+ * This function is used by architectures that support kvm to avoid issuing
+ * false soft lockup messages.
+ */
+static inline bool kvm_check_and_clear_guest_paused(void)
+{
+   return false;
+}
+
+#endif
-- 
1.7.5.4

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[PATCH 2/4] Add functions to check if the host has stopped the vm

2011-08-29 Thread Eric B Munson
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 emun...@mgebm.net
---
 arch/x86/include/asm/pvclock.h |2 ++
 arch/x86/kernel/kvmclock.c |   14 ++
 2 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index a518c0a..dd59ad0 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..5f60d2b 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -113,6 +113,20 @@ 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;
+
+   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,
-- 
1.7.4.1

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