xen: restore vcpu_info mapping
If we're using vcpu_info mapping, then make sure its restored on all
processors before relasing them from stop_machine.
The only complication is that if this fails, we can't continue because
we've already made assumptions that the mapping is available (baked in
calls to the _direct versions of the functions, for example).
Fortunately this can only happen with a 32-bit hypervisor, which may
possibly run out of mapping space. On a 64-bit hypervisor, this is a
non-issue.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index ed9f04b..8e6152e 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -98,7 +98,7 @@
*/
static int have_vcpu_info_placement = 1;
-static void __init xen_vcpu_setup(int cpu)
+static void xen_vcpu_setup(int cpu)
{
struct vcpu_register_vcpu_info info;
int err;
@@ -136,6 +136,34 @@
}
}
+/*
+ * On restore, set the vcpu placement up again.
+ * If it fails, then we're in a bad state, since
+ * we can't back out from using it...
+ */
+void xen_vcpu_restore(void)
+{
+ if (have_vcpu_info_placement) {
+ int cpu;
+
+ for_each_online_cpu(cpu) {
+ bool other_cpu = (cpu != smp_processor_id());
+
+ if (other_cpu &&
+ HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
+ BUG();
+
+ xen_vcpu_setup(cpu);
+
+ if (other_cpu &&
+ HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
+ BUG();
+ }
+
+ BUG_ON(!have_vcpu_info_placement);
+ }
+}
+
static void __init xen_banner(void)
{
printk(KERN_INFO "Booting paravirtualized kernel on %s\n",