Add CPU status info and a status call to the CPU on/offline sysctls.

Signed-off-by: Frank van der Linden <frank.vanderlinden@sun.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/xen/arch/x86/sysctl.c b/xen/arch/x86/sysctl.c
index dbb54ede09..faf3f5157c 100644
--- a/xen/arch/x86/sysctl.c
+++ b/xen/arch/x86/sysctl.c
@@ -38,7 +38,7 @@ static long cpu_down_helper(void *data)
 long arch_do_sysctl(
     struct xen_sysctl *sysctl, XEN_GUEST_HANDLE(xen_sysctl_t) u_sysctl)
 {
-    long ret = 0;
+    long ret = 0, status;
 
     switch ( sysctl->cmd )
     {
@@ -102,19 +102,41 @@ long arch_do_sysctl(
     {
         unsigned int cpu = sysctl->u.cpu_hotplug.cpu;
 
+        if (cpu_present(cpu)) {
+            status = cpu_online(cpu) ? XEN_CPU_HOTPLUG_STATUS_ONLINE :
+                XEN_CPU_HOTPLUG_STATUS_OFFLINE;
+        } else {
+            status = -EINVAL;
+        }
+
         switch ( sysctl->u.cpu_hotplug.op )
         {
         case XEN_SYSCTL_CPU_HOTPLUG_ONLINE:
             ret = cpu_up(cpu);
+            /*
+             * In the case of a true hotplug, this CPU wasn't present
+             * before, so return the 'new' status for it.
+             */
+            if (ret == 0 && status == -EINVAL)
+                status = XEN_CPU_HOTPLUG_STATUS_NEW;
             break;
         case XEN_SYSCTL_CPU_HOTPLUG_OFFLINE:
             ret = continue_hypercall_on_cpu(
                 0, cpu_down_helper, (void *)(unsigned long)cpu);
             break;
+        case XEN_SYSCTL_CPU_HOTPLUG_STATUS:
+            ret = 0;
+            break;
         default:
             ret = -EINVAL;
             break;
         }
+
+        /*
+         * If the operation was successful, return the old status.
+         */
+        if (ret >= 0)
+            ret = status;
     }
     break;