static long evtchn_alloc_unbound(evtchn_alloc_unbound_t *alloc) { struct evtchn *chn; struct domain *d; int port; domid_t dom = alloc->dom; long rc; rc = rcu_lock_target_domain_by_id(dom, &d); if ( rc ) return rc; spin_lock(&d->event_lock); if ( (port = get_free_port(d)) < 0 ) ERROR_EXIT_DOM(port, d); chn = evtchn_from_port(d, port); rc = xsm_evtchn_unbound(d, chn, alloc->remote_dom); if ( rc ) goto out; chn->state = ECS_UNBOUND; if ( (chn->u.unbound.remote_domid = alloc->remote_dom) == DOMID_SELF ) chn->u.unbound.remote_domid = current->domain->domain_id; alloc->port = port; out: spin_unlock(&d->event_lock); rcu_unlock_domain(d); return rc; }
static long evtchn_bind_interdomain(evtchn_bind_interdomain_t *bind) { struct evtchn *lchn, *rchn; struct domain *ld = current->domain, *rd; int lport, rport = bind->remote_port; domid_t rdom = bind->remote_dom; long rc; if ( rdom == DOMID_SELF ) rdom = current->domain->domain_id; if ( (rd = rcu_lock_domain_by_id(rdom)) == NULL ) return -ESRCH; /* Avoid deadlock by first acquiring lock of domain with smaller id. */ if ( ld < rd ) { spin_lock(&ld->evtchn_lock); spin_lock(&rd->evtchn_lock); } else { if ( ld != rd ) spin_lock(&rd->evtchn_lock); spin_lock(&ld->evtchn_lock); } if ( (lport = get_free_port(ld)) < 0 ) ERROR_EXIT(lport); lchn = evtchn_from_port(ld, lport); if ( !port_is_valid(rd, rport) ) ERROR_EXIT_DOM(-EINVAL, rd); rchn = evtchn_from_port(rd, rport); if ( (rchn->state != ECS_UNBOUND) || (rchn->u.unbound.remote_domid != ld->domain_id) ) ERROR_EXIT_DOM(-EINVAL, rd); rc = xsm_evtchn_interdomain(ld, lchn, rd, rchn); if ( rc ) goto out; lchn->u.interdomain.remote_dom = rd; lchn->u.interdomain.remote_port = (u16)rport; lchn->state = ECS_INTERDOMAIN; rchn->u.interdomain.remote_dom = ld; rchn->u.interdomain.remote_port = (u16)lport; rchn->state = ECS_INTERDOMAIN; /* * We may have lost notifications on the remote unbound port. Fix that up * here by conservatively always setting a notification on the local port. */ evtchn_set_pending(ld->vcpu[lchn->notify_vcpu_id], lport); bind->local_port = lport; out: spin_unlock(&ld->evtchn_lock); if ( ld != rd ) spin_unlock(&rd->evtchn_lock); rcu_unlock_domain(rd); return rc; }