/*
* Force a VCPU through a deschedule/reschedule path.
* For example, using this when setting the periodic timer period means that
* most periodic-timer state need only be touched from within the scheduler
* which can thus be done without need for synchronisation.
*/
void vcpu_force_reschedule(struct vcpu *v)
{
vcpu_schedule_lock_irq(v);
if ( v->is_running )
set_bit(_VPF_migrating, &v->pause_flags);
vcpu_schedule_unlock_irq(v);
if ( test_bit(_VPF_migrating, &v->pause_flags) )
{
vcpu_sleep_nosync(v);
vcpu_migrate(v);
}
}
static int __vcpu_set_affinity(
struct vcpu *v, cpumask_t *affinity,
bool_t old_lock_status, bool_t new_lock_status)
{
cpumask_t online_affinity, old_affinity;
cpus_and(online_affinity, *affinity, cpu_online_map);
if ( cpus_empty(online_affinity) )
return -EINVAL;
vcpu_schedule_lock_irq(v);
if ( v->affinity_locked != old_lock_status )
{
BUG_ON(!v->affinity_locked);
vcpu_schedule_unlock_irq(v);
return -EBUSY;
}
v->affinity_locked = new_lock_status;
old_affinity = v->cpu_affinity;
v->cpu_affinity = *affinity;
*affinity = old_affinity;
if ( !cpu_isset(v->processor, v->cpu_affinity) )
set_bit(_VPF_migrating, &v->pause_flags);
vcpu_schedule_unlock_irq(v);
if ( test_bit(_VPF_migrating, &v->pause_flags) )
{
vcpu_sleep_nosync(v);
vcpu_migrate(v);
}
return 0;
}
/*
* This function is used by cpu_hotplug code from stop_machine context.
* Hence we can avoid needing to take the
*/
void cpu_disable_scheduler(void)
{
struct domain *d;
struct vcpu *v;
unsigned int cpu = smp_processor_id();
for_each_domain ( d )
{
for_each_vcpu ( d, v )
{
if ( is_idle_vcpu(v) )
continue;
if ( (cpus_weight(v->cpu_affinity) == 1) &&
cpu_isset(cpu, v->cpu_affinity) )
{
printk("Breaking vcpu affinity for domain %d vcpu %d\n",
v->domain->domain_id, v->vcpu_id);
cpus_setall(v->cpu_affinity);
}
/*
* Migrate single-shot timers to CPU0. A new cpu will automatically
* be chosen when the timer is next re-set.
*/
if ( v->singleshot_timer.cpu == cpu )
migrate_timer(&v->singleshot_timer, 0);
if ( v->processor == cpu )
{
set_bit(_VPF_migrating, &v->pause_flags);
vcpu_sleep_nosync(v);
vcpu_migrate(v);
}
}
}
}