static int setup_shutdown_watcher(void)
{
int err;
(void)xenbus_scanf(XBT_NIL, "control",
"platform-feature-multiprocessor-suspend",
"%d", &fast_suspend);
err = register_xenbus_watch(&shutdown_watch);
if (err) {
printk(KERN_ERR "Failed to set shutdown watcher\n");
return err;
}
err = register_xenbus_watch(&sysrq_watch);
if (err) {
printk(KERN_ERR "Failed to set sysrq watcher\n");
return err;
}
/* suspend event channel */
err = setup_suspend_evtchn();
if (err) {
printk(KERN_ERR "Failed to register suspend event channel\n");
return err;
}
return 0;
}
static int xen_suspend(void *__unused)
{
int err, old_state;
daemonize("suspend");
err = set_cpus_allowed(current, cpumask_of_cpu(0));
if (err) {
printk(KERN_ERR "Xen suspend can't run on CPU0 (%d)\n", err);
goto fail;
}
do {
err = __xen_suspend(fast_suspend, xen_resume_notifier);
if (err) {
printk(KERN_ERR "Xen suspend failed (%d)\n", err);
goto fail;
}
if (!suspend_cancelled)
setup_suspend_evtchn();
old_state = cmpxchg(
&shutting_down, SHUTDOWN_RESUMING, SHUTDOWN_INVALID);
} while (old_state == SHUTDOWN_SUSPEND);
switch (old_state) {
case SHUTDOWN_INVALID:
case SHUTDOWN_SUSPEND:
BUG();
case SHUTDOWN_RESUMING:
break;
default:
schedule_work(&shutdown_work);
break;
}
return 0;
fail:
old_state = xchg(&shutting_down, SHUTDOWN_INVALID);
BUG_ON(old_state != SHUTDOWN_SUSPEND);
return 0;
}
/* open a checkpoint session to guest domid */
int checkpoint_open(checkpoint_state* s, unsigned int domid)
{
xc_dominfo_t dominfo;
unsigned long pvirq;
s->domid = domid;
s->xch = xc_interface_open();
if (s->xch < 0) {
s->errstr = "could not open control interface (are you root?)";
return -1;
}
s->xsh = xs_daemon_open();
if (!s->xsh) {
checkpoint_close(s);
s->errstr = "could not open xenstore handle";
return -1;
}
s->xce = xc_evtchn_open();
if (s->xce < 0) {
checkpoint_close(s);
s->errstr = "could not open event channel handle";
return -1;
}
if (xc_domain_getinfo(s->xch, s->domid, 1, &dominfo) < 0) {
checkpoint_close(s);
s->errstr = "could not get domain info";
return -1;
}
if (dominfo.hvm) {
if (xc_get_hvm_param(s->xch, s->domid, HVM_PARAM_CALLBACK_IRQ, &pvirq)) {
checkpoint_close(s);
s->errstr = "could not get HVM callback IRQ";
return -1;
}
s->domtype = pvirq ? dt_pvhvm : dt_hvm;
} else
s->domtype = dt_pv;
if (setup_shutdown_watch(s) < 0) {
checkpoint_close(s);
return -1;
}
if (s->domtype == dt_pv) {
if (setup_suspend_evtchn(s) < 0) {
fprintf(stderr, "WARNING: suspend event channel unavailable, "
"falling back to slow xenstore signalling\n");
}
} else if (s->domtype == dt_pvhvm) {
checkpoint_close(s);
s->errstr = "PV-on-HVM is unsupported";
return -1;
}
return 0;
}
