void __init kvm_guest_init(void)
{
if (!kvm_para_available())
return;
paravirt_ops_setup();
register_reboot_notifier(&kvm_pv_reboot_nb);
if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
has_steal_clock = 1;
pv_time_ops.steal_clock = kvm_steal_clock;
paravirt_steal_enabled = true;
}
if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
apic_set_eoi_write(kvm_guest_apic_eoi_write);
#ifdef CONFIG_SMP
smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
register_cpu_notifier(&kvm_cpu_notifier);
#else
kvm_guest_cpu_init();
#endif
/*
* Hard lockup detection is enabled by default. Disable it, as guests
* can get false positives too easily, for example if the host is
* overcommitted.
*/
watchdog_enable_hardlockup_detector(false);
}
int proc_dowatchdog(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
int err, old_thresh, old_enabled;
bool old_hardlockup;
static DEFINE_MUTEX(watchdog_proc_mutex);
mutex_lock(&watchdog_proc_mutex);
old_thresh = ACCESS_ONCE(watchdog_thresh);
old_enabled = ACCESS_ONCE(watchdog_user_enabled);
old_hardlockup = watchdog_hardlockup_detector_is_enabled();
err = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (err || !write)
goto out;
set_sample_period();
/*
* Watchdog threads shouldn't be enabled if they are
* disabled. The 'watchdog_running' variable check in
* watchdog_*_all_cpus() function takes care of this.
*/
if (watchdog_user_enabled && watchdog_thresh) {
/*
* Prevent a change in watchdog_thresh accidentally overriding
* the enablement of the hardlockup detector.
*/
if (watchdog_user_enabled != old_enabled)
watchdog_enable_hardlockup_detector(true);
err = watchdog_enable_all_cpus(old_thresh != watchdog_thresh);
} else
watchdog_disable_all_cpus();
/* Restore old values on failure */
if (err) {
watchdog_thresh = old_thresh;
watchdog_user_enabled = old_enabled;
watchdog_enable_hardlockup_detector(old_hardlockup);
}
out:
mutex_unlock(&watchdog_proc_mutex);
return err;
}
static int __init hardlockup_panic_setup(char *str)
{
if (!strncmp(str, "panic", 5))
hardlockup_panic = 1;
else if (!strncmp(str, "nopanic", 7))
hardlockup_panic = 0;
else if (!strncmp(str, "0", 1))
watchdog_user_enabled = 0;
else if (!strncmp(str, "1", 1) || !strncmp(str, "2", 1)) {
/*
* Setting 'nmi_watchdog=1' or 'nmi_watchdog=2' (legacy option)
* has the same effect.
*/
watchdog_user_enabled = 1;
watchdog_enable_hardlockup_detector(true);
}
return 1;
}
