xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()

This call has always been missing from xen_play dead() but until
recently this was rather benign. With new cpu hotplug framework
(commit 8df3e07e7f21 ("cpu/hotplug: Let upcoming cpu bring itself fully up").
however this call is required, otherwise a hot-plugged CPU will not
be properly brough up (by never calling cpuhp_online_idle())

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 3c6d17fd423a82006d89c71e7345bb6a566aec09..719cf291dcdf195e68e52c97dd054686192aa936 100644 (file)
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -545,6 +545,8 @@ static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
         * data back is to call:
         */
        tick_nohz_idle_enter();
+
+       cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 }
 
 #else /* !CONFIG_HOTPLUG_CPU */