#include <xen/xenbus.h>
#include <linux/cpu.h>
#include <linux/kthread.h>
+#include <xen/gnttab.h>
#include <xen/xencons.h>
#if defined(__i386__) || defined(__x86_64__)
static void __shutdown_handler(void *unused);
static DECLARE_WORK(shutdown_work, __shutdown_handler, NULL);
-#ifndef CONFIG_HOTPLUG_CPU
-#define cpu_down(x) (-EOPNOTSUPP)
-#define cpu_up(x) (-EOPNOTSUPP)
+#ifdef CONFIG_SMP
+int smp_suspend(void);
+void smp_resume(void);
+#else
+#define smp_suspend() (0)
+#define smp_resume() ((void)0)
#endif
-
static int __do_suspend(void *ignore)
{
- int i, j, k, fpp;
+ int i, j, k, fpp, err;
extern unsigned long max_pfn;
extern unsigned long *pfn_to_mfn_frame_list_list;
extern unsigned long *pfn_to_mfn_frame_list[];
- extern int gnttab_suspend(void);
- extern int gnttab_resume(void);
extern void time_resume(void);
-#ifdef CONFIG_SMP
- cpumask_t prev_online_cpus;
- int vcpu_prepare(int vcpu);
-#endif
-
- int err = 0;
-
BUG_ON(smp_processor_id() != 0);
BUG_ON(in_interrupt());
return -EOPNOTSUPP;
}
-#if defined(CONFIG_SMP) && !defined(CONFIG_HOTPLUG_CPU)
- if (num_online_cpus() > 1) {
- printk(KERN_WARNING "Can't suspend SMP guests "
- "without CONFIG_HOTPLUG_CPU\n");
- return -EOPNOTSUPP;
- }
-#endif
+ err = smp_suspend();
+ if (err)
+ return err;
xenbus_suspend();
- lock_cpu_hotplug();
-#ifdef CONFIG_SMP
- /*
- * Take all other CPUs offline. We hold the hotplug mutex to
- * avoid other processes bringing up CPUs under our feet.
- */
- cpus_clear(prev_online_cpus);
- while (num_online_cpus() > 1) {
- for_each_online_cpu(i) {
- if (i == 0)
- continue;
- unlock_cpu_hotplug();
- err = cpu_down(i);
- lock_cpu_hotplug();
- if (err != 0) {
- printk(KERN_CRIT "Failed to take all CPUs "
- "down: %d.\n", err);
- goto out_reenable_cpus;
- }
- cpu_set(i, prev_online_cpus);
- }
- }
-#endif
-
preempt_disable();
#ifdef __i386__
__cli();
preempt_enable();
- unlock_cpu_hotplug();
gnttab_suspend();
xencons_resume();
-#ifdef CONFIG_SMP
- for_each_cpu(i)
- vcpu_prepare(i);
-
-#endif
-
- /*
- * Only resume xenbus /after/ we've prepared our VCPUs; otherwise
- * the VCPU hotplug callback can race with our vcpu_prepare
- */
xenbus_resume();
-#ifdef CONFIG_SMP
- out_reenable_cpus:
- for_each_cpu_mask(i, prev_online_cpus) {
- j = cpu_up(i);
- if ((j != 0) && !cpu_online(i)) {
- printk(KERN_CRIT "Failed to bring cpu "
- "%d back up (%d).\n",
- i, j);
- err = j;
- }
- }
-#endif
+ smp_resume();
return err;
}
kfree(str);
}
-#ifdef CONFIG_MAGIC_SYSRQ
static void sysrq_handler(struct xenbus_watch *watch, const char **vec,
unsigned int len)
{
if (err == -EAGAIN)
goto again;
- if (sysrq_key != '\0') {
+#ifdef CONFIG_MAGIC_SYSRQ
+ if (sysrq_key != '\0')
handle_sysrq(sysrq_key, NULL, NULL);
- }
-}
#endif
+}
static struct xenbus_watch shutdown_watch = {
.node = "control/shutdown",
.callback = shutdown_handler
};
-#ifdef CONFIG_MAGIC_SYSRQ
static struct xenbus_watch sysrq_watch = {
.node ="control/sysrq",
.callback = sysrq_handler
};
-#endif
static int setup_shutdown_watcher(struct notifier_block *notifier,
unsigned long event,
void *data)
{
- int err1 = 0;
-#ifdef CONFIG_MAGIC_SYSRQ
- int err2 = 0;
-#endif
-
- err1 = register_xenbus_watch(&shutdown_watch);
-#ifdef CONFIG_MAGIC_SYSRQ
- err2 = register_xenbus_watch(&sysrq_watch);
-#endif
+ int err;
- if (err1)
+ err = register_xenbus_watch(&shutdown_watch);
+ if (err)
printk(KERN_ERR "Failed to set shutdown watcher\n");
-#ifdef CONFIG_MAGIC_SYSRQ
- if (err2)
+ err = register_xenbus_watch(&sysrq_watch);
+ if (err)
printk(KERN_ERR "Failed to set sysrq watcher\n");
-#endif
return NOTIFY_DONE;
}
unsigned int maxcpus = NR_CPUS;
#endif
+/*
+ * Set of CPUs that remote admin software will allow us to bring online.
+ * Notified to us via xenbus.
+ */
+static cpumask_t xenbus_allowed_cpumask;
+
+/* Set of CPUs that local admin will allow us to bring online. */
+static cpumask_t local_allowed_cpumask = CPU_MASK_ALL;
+
void __init prefill_possible_map(void)
{
int i, rc;
cpu_idle();
}
-void vcpu_prepare(int vcpu)
+static void vcpu_prepare(int vcpu)
{
vcpu_guest_context_t ctxt;
struct task_struct *idle = idle_task(vcpu);
vcpu_prepare(cpu);
}
+ xenbus_allowed_cpumask = cpu_present_map;
+
/* Currently, Xen gives no dynamic NUMA/HT info. */
for (cpu = 1; cpu < NR_CPUS; cpu++) {
cpu_sibling_map[cpu] = cpumask_of_cpu(cpu);
cpu_online_map = cpumask_of_cpu(0);
}
+static int local_cpu_hotplug_request(void)
+{
+ /*
+ * We assume a CPU hotplug request comes from local admin if it is made
+ * via a userspace process (i.e., one with a real mm_struct).
+ */
+ return (current->mm != NULL);
+}
+
#ifdef CONFIG_HOTPLUG_CPU
/*
}
if (strcmp(state, "online") == 0) {
+ cpu_set(cpu, xenbus_allowed_cpumask);
(void)cpu_up(cpu);
} else if (strcmp(state, "offline") == 0) {
+ cpu_clear(cpu, xenbus_allowed_cpumask);
(void)cpu_down(cpu);
} else {
printk(KERN_ERR "XENBUS: unknown state(%s) on CPU%d\n",
}
}
+static int smpboot_cpu_notify(struct notifier_block *notifier,
+ unsigned long action, void *hcpu)
+{
+ int cpu = (long)hcpu;
+
+ /*
+ * We do this in a callback notifier rather than __cpu_disable()
+ * because local_cpu_hotplug_request() does not work in the latter
+ * as it's always executed from within a stopmachine kthread.
+ */
+ if ((action == CPU_DOWN_PREPARE) && local_cpu_hotplug_request())
+ cpu_clear(cpu, local_allowed_cpumask);
+
+ return NOTIFY_OK;
+}
+
static int setup_cpu_watcher(struct notifier_block *notifier,
unsigned long event, void *data)
{
static struct xenbus_watch cpu_watch = {
.node = "cpu",
- .callback = handle_vcpu_hotplug_event };
+ .callback = handle_vcpu_hotplug_event,
+ .flags = XBWF_new_thread };
(void)register_xenbus_watch(&cpu_watch);
if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
static int __init setup_vcpu_hotplug_event(void)
{
+ static struct notifier_block hotplug_cpu = {
+ .notifier_call = smpboot_cpu_notify };
static struct notifier_block xsn_cpu = {
.notifier_call = setup_cpu_watcher };
+
+ register_cpu_notifier(&hotplug_cpu);
register_xenstore_notifier(&xsn_cpu);
+
return 0;
}
arch_initcall(setup_vcpu_hotplug_event);
+int smp_suspend(void)
+{
+ int i, err;
+
+ lock_cpu_hotplug();
+
+ /*
+ * Take all other CPUs offline. We hold the hotplug mutex to
+ * avoid other processes bringing up CPUs under our feet.
+ */
+ while (num_online_cpus() > 1) {
+ unlock_cpu_hotplug();
+ for_each_online_cpu(i) {
+ if (i == 0)
+ continue;
+ err = cpu_down(i);
+ if (err) {
+ printk(KERN_CRIT "Failed to take all CPUs "
+ "down: %d.\n", err);
+ for_each_cpu(i)
+ vcpu_hotplug(i);
+ return err;
+ }
+ }
+ lock_cpu_hotplug();
+ }
+
+ return 0;
+}
+
+void smp_resume(void)
+{
+ int i;
+
+ for_each_cpu(i)
+ vcpu_prepare(i);
+
+ unlock_cpu_hotplug();
+
+ for_each_cpu(i)
+ vcpu_hotplug(i);
+}
+
int __cpu_disable(void)
{
cpumask_t map = cpu_online_map;
#else /* !CONFIG_HOTPLUG_CPU */
+int smp_suspend(void)
+{
+ if (num_online_cpus() > 1) {
+ printk(KERN_WARNING "Can't suspend SMP guests "
+ "without CONFIG_HOTPLUG_CPU\n");
+ return -EOPNOTSUPP;
+ }
+ return 0;
+}
+
+void smp_resume(void)
+{
+}
+
int __cpu_disable(void)
{
return -ENOSYS;
int __devinit __cpu_up(unsigned int cpu)
{
+ int rc;
+
+ if (local_cpu_hotplug_request()) {
+ cpu_set(cpu, local_allowed_cpumask);
+ if (!cpu_isset(cpu, xenbus_allowed_cpumask)) {
+ printk("%s: attempt to bring up CPU %u disallowed by "
+ "remote admin.\n", __FUNCTION__, cpu);
+ return -EBUSY;
+ }
+ } else if (!cpu_isset(cpu, local_allowed_cpumask) ||
+ !cpu_isset(cpu, xenbus_allowed_cpumask)) {
+ return -EBUSY;
+ }
+
#ifdef CONFIG_SMP_ALTERNATIVES
if (num_online_cpus() == 1)
prepare_for_smp();
xen_smp_intr_init(cpu);
cpu_set(cpu, cpu_online_map);
- if (HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL) != 0)
+
+ rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
+ if (rc != 0)
BUG();
return 0;
{
struct pciback_device *pdev;
- pdev = kmalloc(sizeof(struct pciback_device), GFP_KERNEL);
+ pdev = kzalloc(sizeof(struct pciback_device), GFP_KERNEL);
if (pdev == NULL)
goto out;
dev_dbg(&xdev->dev, "allocated pdev @ 0x%p\n", pdev);
up_write(&xs_state.suspend_mutex);
}
+static int xenwatch_handle_callback(void *data)
+{
+ struct xs_stored_msg *msg = data;
+
+ msg->u.watch.handle->callback(msg->u.watch.handle,
+ (const char **)msg->u.watch.vec,
+ msg->u.watch.vec_size);
+
+ kfree(msg->u.watch.vec);
+ kfree(msg);
+
+ /* Kill this kthread if we were spawned just for this callback. */
+ if (current->pid != xenwatch_pid)
+ do_exit(0);
+
+ return 0;
+}
+
static int xenwatch_thread(void *unused)
{
struct list_head *ent;
if (ent != &watch_events) {
msg = list_entry(ent, struct xs_stored_msg, list);
- msg->u.watch.handle->callback(
- msg->u.watch.handle,
- (const char **)msg->u.watch.vec,
- msg->u.watch.vec_size);
- kfree(msg->u.watch.vec);
- kfree(msg);
+ if (msg->u.watch.handle->flags & XBWF_new_thread)
+ kthread_run(xenwatch_handle_callback,
+ msg, "xenwatch_cb");
+ else
+ xenwatch_handle_callback(msg);
}
mutex_unlock(&xenwatch_mutex);
#define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
#endif
+int gnttab_suspend(void);
+int gnttab_resume(void);
+
#endif /* __ASM_GNTTAB_H__ */
/*
/* Callback (executed in a process context with no locks held). */
void (*callback)(struct xenbus_watch *,
const char **vec, unsigned int len);
+
+ /* See XBWF_ definitions below. */
+ unsigned long flags;
};
+/*
+ * Execute callback in its own kthread. Useful if the callback is long
+ * running or heavily serialised, to avoid taking out the main xenwatch thread
+ * for a long period of time (or even unwittingly causing a deadlock).
+ */
+#define XBWF_new_thread 1
/* A xenbus device. */
struct xenbus_device {
projects / xen.git / commitdiff