#include <linux/kprobes.h>
#include <linux/debugfs.h>
#include <linux/nmi.h>
+#include <linux/swait.h>
#include <asm/timer.h>
#include <asm/cpu.h>
#include <asm/traps.h>
struct kvm_task_sleep_node {
struct hlist_node link;
- wait_queue_head_t wq;
+ struct swait_queue_head wq;
u32 token;
int cpu;
bool halted;
};
static struct kvm_task_sleep_head {
- spinlock_t lock;
+ raw_spinlock_t lock;
struct hlist_head list;
} async_pf_sleepers[KVM_TASK_SLEEP_HASHSIZE];
u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
struct kvm_task_sleep_node n, *e;
- DEFINE_WAIT(wait);
+ DECLARE_SWAITQUEUE(wait);
rcu_irq_enter();
- spin_lock(&b->lock);
+ raw_spin_lock(&b->lock);
e = _find_apf_task(b, token);
if (e) {
/* dummy entry exist -> wake up was delivered ahead of PF */
hlist_del(&e->link);
kfree(e);
- spin_unlock(&b->lock);
+ raw_spin_unlock(&b->lock);
rcu_irq_exit();
return;
n.token = token;
n.cpu = smp_processor_id();
n.halted = is_idle_task(current) || preempt_count() > 1;
- init_waitqueue_head(&n.wq);
+ init_swait_queue_head(&n.wq);
hlist_add_head(&n.link, &b->list);
- spin_unlock(&b->lock);
+ raw_spin_unlock(&b->lock);
for (;;) {
if (!n.halted)
- prepare_to_wait(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
+ prepare_to_swait(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
if (hlist_unhashed(&n.link))
break;
}
}
if (!n.halted)
- finish_wait(&n.wq, &wait);
+ finish_swait(&n.wq, &wait);
rcu_irq_exit();
return;
hlist_del_init(&n->link);
if (n->halted)
smp_send_reschedule(n->cpu);
- else if (waitqueue_active(&n->wq))
- wake_up(&n->wq);
+ else if (swait_active(&n->wq))
+ swake_up(&n->wq);
}
static void apf_task_wake_all(void)
for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++) {
struct hlist_node *p, *next;
struct kvm_task_sleep_head *b = &async_pf_sleepers[i];
- spin_lock(&b->lock);
+ raw_spin_lock(&b->lock);
hlist_for_each_safe(p, next, &b->list) {
struct kvm_task_sleep_node *n =
hlist_entry(p, typeof(*n), link);
if (n->cpu == smp_processor_id())
apf_task_wake_one(n);
}
- spin_unlock(&b->lock);
+ raw_spin_unlock(&b->lock);
}
}
}
again:
- spin_lock(&b->lock);
+ raw_spin_lock(&b->lock);
n = _find_apf_task(b, token);
if (!n) {
/*
* Allocation failed! Busy wait while other cpu
* handles async PF.
*/
- spin_unlock(&b->lock);
+ raw_spin_unlock(&b->lock);
cpu_relax();
goto again;
}
n->token = token;
n->cpu = smp_processor_id();
- init_waitqueue_head(&n->wq);
+ init_swait_queue_head(&n->wq);
hlist_add_head(&n->link, &b->list);
} else
apf_task_wake_one(n);
- spin_unlock(&b->lock);
+ raw_spin_unlock(&b->lock);
return;
}
EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake);
apic_write(APIC_EOI, APIC_EOI_ACK);
}
-void kvm_guest_cpu_init(void)
+static void kvm_guest_cpu_init(void)
{
if (!kvm_para_available())
return;
paravirt_ops_setup();
register_reboot_notifier(&kvm_pv_reboot_nb);
for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++)
- spin_lock_init(&async_pf_sleepers[i].lock);
+ raw_spin_lock_init(&async_pf_sleepers[i].lock);
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF))
x86_init.irqs.trap_init = kvm_apf_trap_init;
kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid);
}
+
+#ifdef CONFIG_QUEUED_SPINLOCKS
+
+#include <asm/qspinlock.h>
+
+static void kvm_wait(u8 *ptr, u8 val)
+{
+ unsigned long flags;
+
+ if (in_nmi())
+ return;
+
+ local_irq_save(flags);
+
+ if (READ_ONCE(*ptr) != val)
+ goto out;
+
+ /*
+ * halt until it's our turn and kicked. Note that we do safe halt
+ * for irq enabled case to avoid hang when lock info is overwritten
+ * in irq spinlock slowpath and no spurious interrupt occur to save us.
+ */
+ if (arch_irqs_disabled_flags(flags))
+ halt();
+ else
+ safe_halt();
+
+out:
+ local_irq_restore(flags);
+}
+
+#else /* !CONFIG_QUEUED_SPINLOCKS */
+
enum kvm_contention_stat {
TAKEN_SLOW,
TAKEN_SLOW_PICKUP,
static struct dentry *d_spin_debug;
static struct dentry *d_kvm_debug;
-struct dentry *kvm_init_debugfs(void)
+static struct dentry *kvm_init_debugfs(void)
{
d_kvm_debug = debugfs_create_dir("kvm-guest", NULL);
if (!d_kvm_debug)
}
}
+#endif /* !CONFIG_QUEUED_SPINLOCKS */
+
/*
* Setup pv_lock_ops to exploit KVM_FEATURE_PV_UNHALT if present.
*/
if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT))
return;
+#ifdef CONFIG_QUEUED_SPINLOCKS
+ __pv_init_lock_hash();
+ pv_lock_ops.queued_spin_lock_slowpath = __pv_queued_spin_lock_slowpath;
+ pv_lock_ops.queued_spin_unlock = PV_CALLEE_SAVE(__pv_queued_spin_unlock);
+ pv_lock_ops.wait = kvm_wait;
+ pv_lock_ops.kick = kvm_kick_cpu;
+#else /* !CONFIG_QUEUED_SPINLOCKS */
pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(kvm_lock_spinning);
pv_lock_ops.unlock_kick = kvm_unlock_kick;
+#endif
}
static __init int kvm_spinlock_init_jump(void)