commit 5fb7ad8d1220101e69a87014d5a485d19aea9917
Author: Dario Faggioli <dfaggioli@xxxxxxxx>
Date:   Wed Apr 11 09:04:33 2018 +0200

    xen: credit: implement SCHED_OP(migrate)
    
    with just sanity checking in it, to catch a race.
    
    Signed-off-by: Dario Faggioli <dfaggioli@xxxxxxxx>

diff --git a/xen/common/sched_credit.c b/xen/common/sched_credit.c
index 9bc638c09c..7a909376e6 100644
--- a/xen/common/sched_credit.c
+++ b/xen/common/sched_credit.c
@@ -867,6 +867,17 @@ _csched_cpu_pick(const struct scheduler *ops, struct vcpu *vc, bool_t commit)
     return cpu;
 }
 
+static void
+csched_vcpu_migrate(const struct scheduler *ops, struct vcpu *vc,
+		    unsigned int new_cpu)
+{
+    BUG_ON(vc->is_running);
+    BUG_ON(test_bit(_VPF_migrating, &vc->pause_flags));
+    BUG_ON(__vcpu_on_runq(CSCHED_VCPU(vc)));
+    BUG_ON(CSCHED_VCPU(vc) == CSCHED_VCPU(curr_on_cpu(vc->processor)));
+    vc->processor = new_cpu;
+}
+
 static int
 csched_cpu_pick(const struct scheduler *ops, struct vcpu *vc)
 {
@@ -2278,6 +2289,7 @@ static const struct scheduler sched_credit_def = {
     .adjust_global  = csched_sys_cntl,
 
     .pick_cpu       = csched_cpu_pick,
+    .migrate        = csched_vcpu_migrate,
     .do_schedule    = csched_schedule,
 
     .dump_cpu_state = csched_dump_pcpu,