1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * KVM paravirt_ops implementation
5 * Copyright (C) 2007, Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
6 * Copyright IBM Corporation, 2007
7 * Authors: Anthony Liguori <aliguori@us.ibm.com>
10 #include <linux/context_tracking.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/kvm_para.h>
14 #include <linux/cpu.h>
16 #include <linux/highmem.h>
17 #include <linux/hardirq.h>
18 #include <linux/notifier.h>
19 #include <linux/reboot.h>
20 #include <linux/hash.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/kprobes.h>
24 #include <linux/nmi.h>
25 #include <linux/swait.h>
26 #include <asm/timer.h>
28 #include <asm/traps.h>
30 #include <asm/tlbflush.h>
32 #include <asm/apicdef.h>
33 #include <asm/hypervisor.h>
35 #include <asm/cpuidle_haltpoll.h>
37 DEFINE_STATIC_KEY_FALSE(kvm_async_pf_enabled);
39 static int kvmapf = 1;
41 static int __init parse_no_kvmapf(char *arg)
47 early_param("no-kvmapf", parse_no_kvmapf);
49 static int steal_acc = 1;
50 static int __init parse_no_stealacc(char *arg)
56 early_param("no-steal-acc", parse_no_stealacc);
58 static DEFINE_PER_CPU_DECRYPTED(struct kvm_vcpu_pv_apf_data, apf_reason) __aligned(64);
59 DEFINE_PER_CPU_DECRYPTED(struct kvm_steal_time, steal_time) __aligned(64) __visible;
60 static int has_steal_clock = 0;
63 * No need for any "IO delay" on KVM
65 static void kvm_io_delay(void)
69 #define KVM_TASK_SLEEP_HASHBITS 8
70 #define KVM_TASK_SLEEP_HASHSIZE (1<<KVM_TASK_SLEEP_HASHBITS)
72 struct kvm_task_sleep_node {
73 struct hlist_node link;
74 struct swait_queue_head wq;
79 static struct kvm_task_sleep_head {
81 struct hlist_head list;
82 } async_pf_sleepers[KVM_TASK_SLEEP_HASHSIZE];
84 static struct kvm_task_sleep_node *_find_apf_task(struct kvm_task_sleep_head *b,
89 hlist_for_each(p, &b->list) {
90 struct kvm_task_sleep_node *n =
91 hlist_entry(p, typeof(*n), link);
92 if (n->token == token)
99 static bool kvm_async_pf_queue_task(u32 token, struct kvm_task_sleep_node *n)
101 u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
102 struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
103 struct kvm_task_sleep_node *e;
105 raw_spin_lock(&b->lock);
106 e = _find_apf_task(b, token);
108 /* dummy entry exist -> wake up was delivered ahead of PF */
110 raw_spin_unlock(&b->lock);
116 n->cpu = smp_processor_id();
117 init_swait_queue_head(&n->wq);
118 hlist_add_head(&n->link, &b->list);
119 raw_spin_unlock(&b->lock);
124 * kvm_async_pf_task_wait_schedule - Wait for pagefault to be handled
125 * @token: Token to identify the sleep node entry
127 * Invoked from the async pagefault handling code or from the VM exit page
128 * fault handler. In both cases RCU is watching.
130 void kvm_async_pf_task_wait_schedule(u32 token)
132 struct kvm_task_sleep_node n;
133 DECLARE_SWAITQUEUE(wait);
135 lockdep_assert_irqs_disabled();
137 if (!kvm_async_pf_queue_task(token, &n))
141 prepare_to_swait_exclusive(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
142 if (hlist_unhashed(&n.link))
149 finish_swait(&n.wq, &wait);
151 EXPORT_SYMBOL_GPL(kvm_async_pf_task_wait_schedule);
153 static void apf_task_wake_one(struct kvm_task_sleep_node *n)
155 hlist_del_init(&n->link);
156 if (swq_has_sleeper(&n->wq))
157 swake_up_one(&n->wq);
160 static void apf_task_wake_all(void)
164 for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++) {
165 struct kvm_task_sleep_head *b = &async_pf_sleepers[i];
166 struct kvm_task_sleep_node *n;
167 struct hlist_node *p, *next;
169 raw_spin_lock(&b->lock);
170 hlist_for_each_safe(p, next, &b->list) {
171 n = hlist_entry(p, typeof(*n), link);
172 if (n->cpu == smp_processor_id())
173 apf_task_wake_one(n);
175 raw_spin_unlock(&b->lock);
179 void kvm_async_pf_task_wake(u32 token)
181 u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
182 struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
183 struct kvm_task_sleep_node *n;
191 raw_spin_lock(&b->lock);
192 n = _find_apf_task(b, token);
195 * async PF was not yet handled.
196 * Add dummy entry for the token.
198 n = kzalloc(sizeof(*n), GFP_ATOMIC);
201 * Allocation failed! Busy wait while other cpu
204 raw_spin_unlock(&b->lock);
209 n->cpu = smp_processor_id();
210 init_swait_queue_head(&n->wq);
211 hlist_add_head(&n->link, &b->list);
213 apf_task_wake_one(n);
215 raw_spin_unlock(&b->lock);
218 EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake);
220 noinstr u32 kvm_read_and_reset_apf_flags(void)
224 if (__this_cpu_read(apf_reason.enabled)) {
225 flags = __this_cpu_read(apf_reason.flags);
226 __this_cpu_write(apf_reason.flags, 0);
231 EXPORT_SYMBOL_GPL(kvm_read_and_reset_apf_flags);
233 noinstr bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token)
235 u32 reason = kvm_read_and_reset_apf_flags();
236 idtentry_state_t state;
239 case KVM_PV_REASON_PAGE_NOT_PRESENT:
240 case KVM_PV_REASON_PAGE_READY:
246 state = idtentry_enter(regs);
247 instrumentation_begin();
250 * If the host managed to inject an async #PF into an interrupt
251 * disabled region, then die hard as this is not going to end well
252 * and the host side is seriously broken.
254 if (unlikely(!(regs->flags & X86_EFLAGS_IF)))
255 panic("Host injected async #PF in interrupt disabled region\n");
257 if (reason == KVM_PV_REASON_PAGE_NOT_PRESENT) {
258 if (unlikely(!(user_mode(regs))))
259 panic("Host injected async #PF in kernel mode\n");
260 /* Page is swapped out by the host. */
261 kvm_async_pf_task_wait_schedule(token);
263 kvm_async_pf_task_wake(token);
266 instrumentation_end();
267 idtentry_exit(regs, state);
271 static void __init paravirt_ops_setup(void)
273 pv_info.name = "KVM";
275 if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY))
276 pv_ops.cpu.io_delay = kvm_io_delay;
278 #ifdef CONFIG_X86_IO_APIC
283 static void kvm_register_steal_time(void)
285 int cpu = smp_processor_id();
286 struct kvm_steal_time *st = &per_cpu(steal_time, cpu);
288 if (!has_steal_clock)
291 wrmsrl(MSR_KVM_STEAL_TIME, (slow_virt_to_phys(st) | KVM_MSR_ENABLED));
292 pr_info("kvm-stealtime: cpu %d, msr %llx\n",
293 cpu, (unsigned long long) slow_virt_to_phys(st));
296 static DEFINE_PER_CPU_DECRYPTED(unsigned long, kvm_apic_eoi) = KVM_PV_EOI_DISABLED;
298 static notrace void kvm_guest_apic_eoi_write(u32 reg, u32 val)
301 * This relies on __test_and_clear_bit to modify the memory
302 * in a way that is atomic with respect to the local CPU.
303 * The hypervisor only accesses this memory from the local CPU so
304 * there's no need for lock or memory barriers.
305 * An optimization barrier is implied in apic write.
307 if (__test_and_clear_bit(KVM_PV_EOI_BIT, this_cpu_ptr(&kvm_apic_eoi)))
309 apic->native_eoi_write(APIC_EOI, APIC_EOI_ACK);
312 static void kvm_guest_cpu_init(void)
314 if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) {
317 WARN_ON_ONCE(!static_branch_likely(&kvm_async_pf_enabled));
319 pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason));
320 pa |= KVM_ASYNC_PF_ENABLED;
322 if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_VMEXIT))
323 pa |= KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;
325 wrmsrl(MSR_KVM_ASYNC_PF_EN, pa);
326 __this_cpu_write(apf_reason.enabled, 1);
327 pr_info("KVM setup async PF for cpu %d\n", smp_processor_id());
330 if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) {
333 /* Size alignment is implied but just to make it explicit. */
334 BUILD_BUG_ON(__alignof__(kvm_apic_eoi) < 4);
335 __this_cpu_write(kvm_apic_eoi, 0);
336 pa = slow_virt_to_phys(this_cpu_ptr(&kvm_apic_eoi))
338 wrmsrl(MSR_KVM_PV_EOI_EN, pa);
342 kvm_register_steal_time();
345 static void kvm_pv_disable_apf(void)
347 if (!__this_cpu_read(apf_reason.enabled))
350 wrmsrl(MSR_KVM_ASYNC_PF_EN, 0);
351 __this_cpu_write(apf_reason.enabled, 0);
353 pr_info("Unregister pv shared memory for cpu %d\n", smp_processor_id());
356 static void kvm_pv_guest_cpu_reboot(void *unused)
359 * We disable PV EOI before we load a new kernel by kexec,
360 * since MSR_KVM_PV_EOI_EN stores a pointer into old kernel's memory.
361 * New kernel can re-enable when it boots.
363 if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
364 wrmsrl(MSR_KVM_PV_EOI_EN, 0);
365 kvm_pv_disable_apf();
366 kvm_disable_steal_time();
369 static int kvm_pv_reboot_notify(struct notifier_block *nb,
370 unsigned long code, void *unused)
372 if (code == SYS_RESTART)
373 on_each_cpu(kvm_pv_guest_cpu_reboot, NULL, 1);
377 static struct notifier_block kvm_pv_reboot_nb = {
378 .notifier_call = kvm_pv_reboot_notify,
381 static u64 kvm_steal_clock(int cpu)
384 struct kvm_steal_time *src;
387 src = &per_cpu(steal_time, cpu);
389 version = src->version;
393 } while ((version & 1) || (version != src->version));
398 void kvm_disable_steal_time(void)
400 if (!has_steal_clock)
403 wrmsr(MSR_KVM_STEAL_TIME, 0, 0);
406 static inline void __set_percpu_decrypted(void *ptr, unsigned long size)
408 early_set_memory_decrypted((unsigned long) ptr, size);
412 * Iterate through all possible CPUs and map the memory region pointed
413 * by apf_reason, steal_time and kvm_apic_eoi as decrypted at once.
415 * Note: we iterate through all possible CPUs to ensure that CPUs
416 * hotplugged will have their per-cpu variable already mapped as
419 static void __init sev_map_percpu_data(void)
426 for_each_possible_cpu(cpu) {
427 __set_percpu_decrypted(&per_cpu(apf_reason, cpu), sizeof(apf_reason));
428 __set_percpu_decrypted(&per_cpu(steal_time, cpu), sizeof(steal_time));
429 __set_percpu_decrypted(&per_cpu(kvm_apic_eoi, cpu), sizeof(kvm_apic_eoi));
433 static bool pv_tlb_flush_supported(void)
435 return (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
436 !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
437 kvm_para_has_feature(KVM_FEATURE_STEAL_TIME));
440 static DEFINE_PER_CPU(cpumask_var_t, __pv_cpu_mask);
444 static bool pv_ipi_supported(void)
446 return kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI);
449 static bool pv_sched_yield_supported(void)
451 return (kvm_para_has_feature(KVM_FEATURE_PV_SCHED_YIELD) &&
452 !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
453 kvm_para_has_feature(KVM_FEATURE_STEAL_TIME));
456 #define KVM_IPI_CLUSTER_SIZE (2 * BITS_PER_LONG)
458 static void __send_ipi_mask(const struct cpumask *mask, int vector)
461 int cpu, apic_id, icr;
462 int min = 0, max = 0;
464 __uint128_t ipi_bitmap = 0;
470 if (cpumask_empty(mask))
473 local_irq_save(flags);
477 icr = APIC_DM_FIXED | vector;
484 for_each_cpu(cpu, mask) {
485 apic_id = per_cpu(x86_cpu_to_apicid, cpu);
488 } else if (apic_id < min && max - apic_id < KVM_IPI_CLUSTER_SIZE) {
489 ipi_bitmap <<= min - apic_id;
491 } else if (apic_id < min + KVM_IPI_CLUSTER_SIZE) {
492 max = apic_id < max ? max : apic_id;
494 ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
495 (unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr);
496 WARN_ONCE(ret < 0, "KVM: failed to send PV IPI: %ld", ret);
500 __set_bit(apic_id - min, (unsigned long *)&ipi_bitmap);
504 ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
505 (unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr);
506 WARN_ONCE(ret < 0, "KVM: failed to send PV IPI: %ld", ret);
509 local_irq_restore(flags);
512 static void kvm_send_ipi_mask(const struct cpumask *mask, int vector)
514 __send_ipi_mask(mask, vector);
517 static void kvm_send_ipi_mask_allbutself(const struct cpumask *mask, int vector)
519 unsigned int this_cpu = smp_processor_id();
520 struct cpumask *new_mask = this_cpu_cpumask_var_ptr(__pv_cpu_mask);
521 const struct cpumask *local_mask;
523 cpumask_copy(new_mask, mask);
524 cpumask_clear_cpu(this_cpu, new_mask);
525 local_mask = new_mask;
526 __send_ipi_mask(local_mask, vector);
530 * Set the IPI entry points
532 static void kvm_setup_pv_ipi(void)
534 apic->send_IPI_mask = kvm_send_ipi_mask;
535 apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
536 pr_info("KVM setup pv IPIs\n");
539 static void kvm_smp_send_call_func_ipi(const struct cpumask *mask)
543 native_send_call_func_ipi(mask);
545 /* Make sure other vCPUs get a chance to run if they need to. */
546 for_each_cpu(cpu, mask) {
547 if (vcpu_is_preempted(cpu)) {
548 kvm_hypercall1(KVM_HC_SCHED_YIELD, per_cpu(x86_cpu_to_apicid, cpu));
554 static void __init kvm_smp_prepare_cpus(unsigned int max_cpus)
556 native_smp_prepare_cpus(max_cpus);
557 if (kvm_para_has_hint(KVM_HINTS_REALTIME))
558 static_branch_disable(&virt_spin_lock_key);
561 static void __init kvm_smp_prepare_boot_cpu(void)
564 * Map the per-cpu variables as decrypted before kvm_guest_cpu_init()
565 * shares the guest physical address with the hypervisor.
567 sev_map_percpu_data();
569 kvm_guest_cpu_init();
570 native_smp_prepare_boot_cpu();
574 static void kvm_guest_cpu_offline(void)
576 kvm_disable_steal_time();
577 if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
578 wrmsrl(MSR_KVM_PV_EOI_EN, 0);
579 kvm_pv_disable_apf();
583 static int kvm_cpu_online(unsigned int cpu)
586 kvm_guest_cpu_init();
591 static int kvm_cpu_down_prepare(unsigned int cpu)
594 kvm_guest_cpu_offline();
600 static void kvm_flush_tlb_others(const struct cpumask *cpumask,
601 const struct flush_tlb_info *info)
605 struct kvm_steal_time *src;
606 struct cpumask *flushmask = this_cpu_cpumask_var_ptr(__pv_cpu_mask);
608 cpumask_copy(flushmask, cpumask);
610 * We have to call flush only on online vCPUs. And
611 * queue flush_on_enter for pre-empted vCPUs
613 for_each_cpu(cpu, flushmask) {
614 src = &per_cpu(steal_time, cpu);
615 state = READ_ONCE(src->preempted);
616 if ((state & KVM_VCPU_PREEMPTED)) {
617 if (try_cmpxchg(&src->preempted, &state,
618 state | KVM_VCPU_FLUSH_TLB))
619 __cpumask_clear_cpu(cpu, flushmask);
623 native_flush_tlb_others(flushmask, info);
626 static void __init kvm_guest_init(void)
630 paravirt_ops_setup();
631 register_reboot_notifier(&kvm_pv_reboot_nb);
632 for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++)
633 raw_spin_lock_init(&async_pf_sleepers[i].lock);
635 if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
637 pv_ops.time.steal_clock = kvm_steal_clock;
640 if (pv_tlb_flush_supported()) {
641 pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others;
642 pv_ops.mmu.tlb_remove_table = tlb_remove_table;
643 pr_info("KVM setup pv remote TLB flush\n");
646 if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
647 apic_set_eoi_write(kvm_guest_apic_eoi_write);
649 if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf)
650 static_branch_enable(&kvm_async_pf_enabled);
653 smp_ops.smp_prepare_cpus = kvm_smp_prepare_cpus;
654 smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
655 if (pv_sched_yield_supported()) {
656 smp_ops.send_call_func_ipi = kvm_smp_send_call_func_ipi;
657 pr_info("KVM setup pv sched yield\n");
659 if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/kvm:online",
660 kvm_cpu_online, kvm_cpu_down_prepare) < 0)
661 pr_err("kvm_guest: Failed to install cpu hotplug callbacks\n");
663 sev_map_percpu_data();
664 kvm_guest_cpu_init();
668 * Hard lockup detection is enabled by default. Disable it, as guests
669 * can get false positives too easily, for example if the host is
672 hardlockup_detector_disable();
675 static noinline uint32_t __kvm_cpuid_base(void)
677 if (boot_cpu_data.cpuid_level < 0)
678 return 0; /* So we don't blow up on old processors */
680 if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
681 return hypervisor_cpuid_base("KVMKVMKVM\0\0\0", 0);
686 static inline uint32_t kvm_cpuid_base(void)
688 static int kvm_cpuid_base = -1;
690 if (kvm_cpuid_base == -1)
691 kvm_cpuid_base = __kvm_cpuid_base();
693 return kvm_cpuid_base;
696 bool kvm_para_available(void)
698 return kvm_cpuid_base() != 0;
700 EXPORT_SYMBOL_GPL(kvm_para_available);
702 unsigned int kvm_arch_para_features(void)
704 return cpuid_eax(kvm_cpuid_base() | KVM_CPUID_FEATURES);
707 unsigned int kvm_arch_para_hints(void)
709 return cpuid_edx(kvm_cpuid_base() | KVM_CPUID_FEATURES);
711 EXPORT_SYMBOL_GPL(kvm_arch_para_hints);
713 static uint32_t __init kvm_detect(void)
715 return kvm_cpuid_base();
718 static void __init kvm_apic_init(void)
720 #if defined(CONFIG_SMP)
721 if (pv_ipi_supported())
726 static void __init kvm_init_platform(void)
729 x86_platform.apic_post_init = kvm_apic_init;
732 const __initconst struct hypervisor_x86 x86_hyper_kvm = {
734 .detect = kvm_detect,
735 .type = X86_HYPER_KVM,
736 .init.guest_late_init = kvm_guest_init,
737 .init.x2apic_available = kvm_para_available,
738 .init.init_platform = kvm_init_platform,
741 static __init int activate_jump_labels(void)
743 if (has_steal_clock) {
744 static_key_slow_inc(¶virt_steal_enabled);
746 static_key_slow_inc(¶virt_steal_rq_enabled);
751 arch_initcall(activate_jump_labels);
753 static __init int kvm_alloc_cpumask(void)
758 if (!kvm_para_available() || nopv)
761 if (pv_tlb_flush_supported())
764 #if defined(CONFIG_SMP)
765 if (pv_ipi_supported())
770 for_each_possible_cpu(cpu) {
771 zalloc_cpumask_var_node(per_cpu_ptr(&__pv_cpu_mask, cpu),
772 GFP_KERNEL, cpu_to_node(cpu));
777 arch_initcall(kvm_alloc_cpumask);
779 #ifdef CONFIG_PARAVIRT_SPINLOCKS
781 /* Kick a cpu by its apicid. Used to wake up a halted vcpu */
782 static void kvm_kick_cpu(int cpu)
785 unsigned long flags = 0;
787 apicid = per_cpu(x86_cpu_to_apicid, cpu);
788 kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid);
791 #include <asm/qspinlock.h>
793 static void kvm_wait(u8 *ptr, u8 val)
800 local_irq_save(flags);
802 if (READ_ONCE(*ptr) != val)
806 * halt until it's our turn and kicked. Note that we do safe halt
807 * for irq enabled case to avoid hang when lock info is overwritten
808 * in irq spinlock slowpath and no spurious interrupt occur to save us.
810 if (arch_irqs_disabled_flags(flags))
816 local_irq_restore(flags);
820 __visible bool __kvm_vcpu_is_preempted(long cpu)
822 struct kvm_steal_time *src = &per_cpu(steal_time, cpu);
824 return !!(src->preempted & KVM_VCPU_PREEMPTED);
826 PV_CALLEE_SAVE_REGS_THUNK(__kvm_vcpu_is_preempted);
830 #include <asm/asm-offsets.h>
832 extern bool __raw_callee_save___kvm_vcpu_is_preempted(long);
835 * Hand-optimize version for x86-64 to avoid 8 64-bit register saving and
836 * restoring to/from the stack.
839 ".pushsection .text;"
840 ".global __raw_callee_save___kvm_vcpu_is_preempted;"
841 ".type __raw_callee_save___kvm_vcpu_is_preempted, @function;"
842 "__raw_callee_save___kvm_vcpu_is_preempted:"
843 "movq __per_cpu_offset(,%rdi,8), %rax;"
844 "cmpb $0, " __stringify(KVM_STEAL_TIME_preempted) "+steal_time(%rax);"
847 ".size __raw_callee_save___kvm_vcpu_is_preempted, .-__raw_callee_save___kvm_vcpu_is_preempted;"
853 * Setup pv_lock_ops to exploit KVM_FEATURE_PV_UNHALT if present.
855 void __init kvm_spinlock_init(void)
857 /* Does host kernel support KVM_FEATURE_PV_UNHALT? */
858 if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT))
861 if (kvm_para_has_hint(KVM_HINTS_REALTIME))
864 /* Don't use the pvqspinlock code if there is only 1 vCPU. */
865 if (num_possible_cpus() == 1)
868 __pv_init_lock_hash();
869 pv_ops.lock.queued_spin_lock_slowpath = __pv_queued_spin_lock_slowpath;
870 pv_ops.lock.queued_spin_unlock =
871 PV_CALLEE_SAVE(__pv_queued_spin_unlock);
872 pv_ops.lock.wait = kvm_wait;
873 pv_ops.lock.kick = kvm_kick_cpu;
875 if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
876 pv_ops.lock.vcpu_is_preempted =
877 PV_CALLEE_SAVE(__kvm_vcpu_is_preempted);
881 #endif /* CONFIG_PARAVIRT_SPINLOCKS */
883 #ifdef CONFIG_ARCH_CPUIDLE_HALTPOLL
885 static void kvm_disable_host_haltpoll(void *i)
887 wrmsrl(MSR_KVM_POLL_CONTROL, 0);
890 static void kvm_enable_host_haltpoll(void *i)
892 wrmsrl(MSR_KVM_POLL_CONTROL, 1);
895 void arch_haltpoll_enable(unsigned int cpu)
897 if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL)) {
898 pr_err_once("kvm: host does not support poll control\n");
899 pr_err_once("kvm: host upgrade recommended\n");
903 /* Enable guest halt poll disables host halt poll */
904 smp_call_function_single(cpu, kvm_disable_host_haltpoll, NULL, 1);
906 EXPORT_SYMBOL_GPL(arch_haltpoll_enable);
908 void arch_haltpoll_disable(unsigned int cpu)
910 if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL))
913 /* Enable guest halt poll disables host halt poll */
914 smp_call_function_single(cpu, kvm_enable_host_haltpoll, NULL, 1);
916 EXPORT_SYMBOL_GPL(arch_haltpoll_disable);