x86/S3: Restore broken vcpu affinity on resume

When in SYS_STATE_suspend, and going through the cpu_disable_scheduler
path, save a copy of the current cpu affinity, and mark a flag to
restore it later.

Later, in the resume process, when enabling nonboot cpus restore these
affinities.

Signed-off-by: Ben Guthro <benjamin.guthro@citrix.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Keir Fraser <keir@xen.org>

1 files changed, 42 insertions, 3 deletions

diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index 83fae4c9d2..7364ff8a7d 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -541,6 +541,38 @@ void vcpu_force_reschedule(struct vcpu *v)
     }
 }
 
+void restore_vcpu_affinity(struct domain *d)
+{
+    struct vcpu *v;
+
+    for_each_vcpu ( d, v )
+    {
+        vcpu_schedule_lock_irq(v);
+
+        if ( v->affinity_broken )
+        {
+            printk(XENLOG_DEBUG "Restoring affinity for d%dv%d\n",
+                   d->domain_id, v->vcpu_id);
+            cpumask_copy(v->cpu_affinity, v->cpu_affinity_saved);
+            v->affinity_broken = 0;
+        }
+
+        if ( v->processor == smp_processor_id() )
+        {
+            set_bit(_VPF_migrating, &v->pause_flags);
+            vcpu_schedule_unlock_irq(v);
+            vcpu_sleep_nosync(v);
+            vcpu_migrate(v);
+        }
+        else
+        {
+            vcpu_schedule_unlock_irq(v);
+        }
+    }
+
+    domain_update_node_affinity(d);
+}
+
 /*
  * This function is used by cpu_hotplug code from stop_machine context
  * and from cpupools to switch schedulers on a cpu.
@@ -554,7 +586,7 @@ int cpu_disable_scheduler(unsigned int cpu)
     int    ret = 0;
 
     c = per_cpu(cpupool, cpu);
-    if ( (c == NULL) || (system_state == SYS_STATE_suspend) )
+    if ( c == NULL )
         return ret;
 
     for_each_domain_in_cpupool ( d, c )
@@ -567,8 +599,15 @@ int cpu_disable_scheduler(unsigned int cpu)
             if ( cpumask_empty(&online_affinity) &&
                  cpumask_test_cpu(cpu, v->cpu_affinity) )
             {
-                printk("Breaking vcpu affinity for domain %d vcpu %d\n",
-                        v->domain->domain_id, v->vcpu_id);
+                printk(XENLOG_DEBUG "Breaking affinity for d%dv%d\n",
+                        d->domain_id, v->vcpu_id);
+
+                if (system_state == SYS_STATE_suspend)
+                {
+                    cpumask_copy(v->cpu_affinity_saved, v->cpu_affinity);
+                    v->affinity_broken = 1;
+                }
+
                 cpumask_setall(v->cpu_affinity);
             }