Xen: register panic notifier to take crashes of xen guests on panic

Register a panic notifier so that when the guest crashes it can shut
down the domain and indicate it was a crash to the host.

Signed-off-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

3 files changed, 24 insertions, 0 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 90a3e802676..d99522e8f03 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1040,6 +1040,26 @@ static void xen_crash_shutdown(struct pt_regs *regs)
         xen_reboot(SHUTDOWN_crash);
 }
 
+static int
+xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+        struct sched_shutdown r = { .reason = SHUTDOWN_crash};
+
+        if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
+                BUG();
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block xen_panic_block = {
+        .notifier_call= xen_panic_event,
+};
+
+int xen_panic_handler_init(void)
+{
+        atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
+        return 0;
+}
+
 static const struct machine_ops __initdata xen_machine_ops = {
         .restart = xen_restart,
         .halt = xen_machine_halt,
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 9deb6bab6c7..328b0030542 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -226,6 +226,8 @@ void __init xen_arch_setup(void)
         struct physdev_set_iopl set_iopl;
         int rc;
 
+        xen_panic_handler_init();
+
         HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
         HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
 
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index f9153a300bc..00d59d608ed 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -101,4 +101,6 @@ void xen_sysret32(void);
 void xen_sysret64(void);
 void xen_adjust_exception_frame(void);
 
+extern int xen_panic_handler_init(void);
+
 #endif /* XEN_OPS_H */