xen: implement CPU hotplugging
Note the changes from 2.6.18-xen CPU hotplugging:
A vcpu_down request from the remote admin via Xenbus both hotunplugs the
CPU, and disables it by removing it from the cpu_present map, and removing
its entry in /sys.
A vcpu_up request from the remote admin only re-enables the CPU, and does
not immediately bring the CPU up. A udev event is emitted, which can be
caught by the user if he wishes to automatically re-up CPUs when available,
or implement a more complex policy.
Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 20182d9..004ba86 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -450,6 +450,14 @@
setup_runstate_info(cpu);
}
+void xen_teardown_timer(int cpu)
+{
+ struct clock_event_device *evt;
+ BUG_ON(cpu == 0);
+ evt = &per_cpu(xen_clock_events, cpu);
+ unbind_from_irqhandler(evt->irq, NULL);
+}
+
void xen_setup_cpu_clockevents(void)
{
BUG_ON(preemptible());