[PATCH] kvm: notify host when guest panicked

[Wen Congyang]

Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
 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     |    7 +++++++
 arch/x86/kernel/kvm.c               |   14 ++++++++++++++
 include/linux/kvm_para.h            |   13 +++++++++++++
 6 files changed, 49 insertions(+), 0 deletions(-)

diff --git a/arch/ia64/include/asm/kvm_para.h b/arch/ia64/include/asm/kvm_para.h
index 1588aee..a890096 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 unsigned int kvm_arch_pv_features(void)
+{
+	return 0;
+}
+
 #endif
 
 #endif
diff --git a/arch/powerpc/include/asm/kvm_para.h b/arch/powerpc/include/asm/kvm_para.h
index 7b754e7..b5f7c35 100644
--- a/arch/powerpc/include/asm/kvm_para.h
+++ b/arch/powerpc/include/asm/kvm_para.h
@@ -206,6 +206,11 @@ static inline unsigned int kvm_arch_para_features(void)
 	return r;
 }
 
+static inline unsigned int kvm_arch_pv_features(void)
+{
+	return 0;
+}
+
 #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..21a8d18 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 unsigned int kvm_arch_pv_features(void)
+{
+	return 0;
+}
+
 #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..02e214a 100644
--- a/arch/x86/include/asm/kvm_para.h
+++ b/arch/x86/include/asm/kvm_para.h
@@ -208,6 +208,13 @@ static inline void kvm_disable_steal_time(void)
 }
 #endif
 
+#define KVM_PV_PORT	(0x505UL)
+
+static inline unsigned int kvm_arch_pv_features(void)
+{
+	return inl(KVM_PV_PORT);
+}
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_X86_KVM_PARA_H */
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index b8ba6e4..adfde45 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -335,6 +335,17 @@ static struct notifier_block kvm_pv_reboot_nb = {
 	.notifier_call = kvm_pv_reboot_notify,
 };
 
+static int
+kvm_pv_panic_notify(struct notifier_block *nb, unsigned long code, void *unused)
+{
+	outl(KVM_PV_PANICKED, KVM_PV_PORT);
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block kvm_pv_panic_nb = {
+	.notifier_call = kvm_pv_panic_notify,
+};
+
 static u64 kvm_steal_clock(int cpu)
 {
 	u64 steal;
@@ -421,6 +432,9 @@ void __init kvm_guest_init(void)
 
 	paravirt_ops_setup();
 	register_reboot_notifier(&kvm_pv_reboot_nb);
+	if (kvm_pv_has_feature(KVM_PV_FEATURE_PANICKED))
+		atomic_notifier_chain_register(&panic_notifier_list,
+			&kvm_pv_panic_nb);
 	for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++)
 		spin_lock_init(&async_pf_sleepers[i].lock);
 	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF))
diff --git a/include/linux/kvm_para.h b/include/linux/kvm_para.h
index ff476dd..e73efcf 100644
--- a/include/linux/kvm_para.h
+++ b/include/linux/kvm_para.h
@@ -20,6 +20,12 @@
 #define KVM_HC_FEATURES			3
 #define KVM_HC_PPC_MAP_MAGIC_PAGE	4
 
+/* The bit of the value read from KVM_PV_PORT */
+#define KVM_PV_FEATURE_PANICKED	0
+
+/* The value writen to KVM_PV_PORT */
+#define KVM_PV_PANICKED		1
+
 /*
  * hypercalls use architecture specific
  */
@@ -33,5 +39,12 @@ static inline int kvm_para_has_feature(unsigned int feature)
 		return 1;
 	return 0;
 }
+
+static inline int kvm_pv_has_feature(unsigned int feature)
+{
+	if (kvm_arch_pv_features() & (1UL << feature))
+		return 1;
+	return 0;
+}
 #endif /* __KERNEL__ */
 #endif /* __LINUX_KVM_PARA_H */
-- 
1.7.1


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