From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/arch/x86/kernel/kvm.c | 849 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 849 insertions(+) create mode 100644 kernel/arch/x86/kernel/kvm.c (limited to 'kernel/arch/x86/kernel/kvm.c') diff --git a/kernel/arch/x86/kernel/kvm.c b/kernel/arch/x86/kernel/kvm.c new file mode 100644 index 000000000..943562006 --- /dev/null +++ b/kernel/arch/x86/kernel/kvm.c @@ -0,0 +1,849 @@ +/* + * KVM paravirt_ops implementation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * Copyright (C) 2007, Red Hat, Inc., Ingo Molnar + * Copyright IBM Corporation, 2007 + * Authors: Anthony Liguori + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static int kvmapf = 1; + +static int parse_no_kvmapf(char *arg) +{ + kvmapf = 0; + return 0; +} + +early_param("no-kvmapf", parse_no_kvmapf); + +static int steal_acc = 1; +static int parse_no_stealacc(char *arg) +{ + steal_acc = 0; + return 0; +} + +early_param("no-steal-acc", parse_no_stealacc); + +static int kvmclock_vsyscall = 1; +static int parse_no_kvmclock_vsyscall(char *arg) +{ + kvmclock_vsyscall = 0; + return 0; +} + +early_param("no-kvmclock-vsyscall", parse_no_kvmclock_vsyscall); + +static DEFINE_PER_CPU(struct kvm_vcpu_pv_apf_data, apf_reason) __aligned(64); +static DEFINE_PER_CPU(struct kvm_steal_time, steal_time) __aligned(64); +static int has_steal_clock = 0; + +/* + * No need for any "IO delay" on KVM + */ +static void kvm_io_delay(void) +{ +} + +#define KVM_TASK_SLEEP_HASHBITS 8 +#define KVM_TASK_SLEEP_HASHSIZE (1<list) { + struct kvm_task_sleep_node *n = + hlist_entry(p, typeof(*n), link); + if (n->token == token) + return n; + } + + return NULL; +} + +void kvm_async_pf_task_wait(u32 token) +{ + 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); + + rcu_irq_enter(); + + 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); + + 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); + hlist_add_head(&n.link, &b->list); + spin_unlock(&b->lock); + + for (;;) { + if (!n.halted) + prepare_to_wait(&n.wq, &wait, TASK_UNINTERRUPTIBLE); + if (hlist_unhashed(&n.link)) + break; + + if (!n.halted) { + local_irq_enable(); + schedule(); + local_irq_disable(); + } else { + /* + * We cannot reschedule. So halt. + */ + rcu_irq_exit(); + native_safe_halt(); + rcu_irq_enter(); + local_irq_disable(); + } + } + if (!n.halted) + finish_wait(&n.wq, &wait); + + rcu_irq_exit(); + return; +} +EXPORT_SYMBOL_GPL(kvm_async_pf_task_wait); + +static void apf_task_wake_one(struct kvm_task_sleep_node *n) +{ + hlist_del_init(&n->link); + if (n->halted) + smp_send_reschedule(n->cpu); + else if (waitqueue_active(&n->wq)) + wake_up(&n->wq); +} + +static void apf_task_wake_all(void) +{ + int i; + + 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); + 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); + } +} + +void kvm_async_pf_task_wake(u32 token) +{ + 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; + + if (token == ~0) { + apf_task_wake_all(); + return; + } + +again: + spin_lock(&b->lock); + n = _find_apf_task(b, token); + if (!n) { + /* + * async PF was not yet handled. + * Add dummy entry for the token. + */ + n = kzalloc(sizeof(*n), GFP_ATOMIC); + if (!n) { + /* + * Allocation failed! Busy wait while other cpu + * handles async PF. + */ + spin_unlock(&b->lock); + cpu_relax(); + goto again; + } + n->token = token; + n->cpu = smp_processor_id(); + init_waitqueue_head(&n->wq); + hlist_add_head(&n->link, &b->list); + } else + apf_task_wake_one(n); + spin_unlock(&b->lock); + return; +} +EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake); + +u32 kvm_read_and_reset_pf_reason(void) +{ + u32 reason = 0; + + if (__this_cpu_read(apf_reason.enabled)) { + reason = __this_cpu_read(apf_reason.reason); + __this_cpu_write(apf_reason.reason, 0); + } + + return reason; +} +EXPORT_SYMBOL_GPL(kvm_read_and_reset_pf_reason); +NOKPROBE_SYMBOL(kvm_read_and_reset_pf_reason); + +dotraplinkage void +do_async_page_fault(struct pt_regs *regs, unsigned long error_code) +{ + enum ctx_state prev_state; + + switch (kvm_read_and_reset_pf_reason()) { + default: + trace_do_page_fault(regs, error_code); + break; + case KVM_PV_REASON_PAGE_NOT_PRESENT: + /* page is swapped out by the host. */ + prev_state = exception_enter(); + exit_idle(); + kvm_async_pf_task_wait((u32)read_cr2()); + exception_exit(prev_state); + break; + case KVM_PV_REASON_PAGE_READY: + rcu_irq_enter(); + exit_idle(); + kvm_async_pf_task_wake((u32)read_cr2()); + rcu_irq_exit(); + break; + } +} +NOKPROBE_SYMBOL(do_async_page_fault); + +static void __init paravirt_ops_setup(void) +{ + pv_info.name = "KVM"; + + /* + * KVM isn't paravirt in the sense of paravirt_enabled. A KVM + * guest kernel works like a bare metal kernel with additional + * features, and paravirt_enabled is about features that are + * missing. + */ + pv_info.paravirt_enabled = 0; + + if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY)) + pv_cpu_ops.io_delay = kvm_io_delay; + +#ifdef CONFIG_X86_IO_APIC + no_timer_check = 1; +#endif +} + +static void kvm_register_steal_time(void) +{ + int cpu = smp_processor_id(); + struct kvm_steal_time *st = &per_cpu(steal_time, cpu); + + if (!has_steal_clock) + return; + + memset(st, 0, sizeof(*st)); + + wrmsrl(MSR_KVM_STEAL_TIME, (slow_virt_to_phys(st) | KVM_MSR_ENABLED)); + pr_info("kvm-stealtime: cpu %d, msr %llx\n", + cpu, (unsigned long long) slow_virt_to_phys(st)); +} + +static DEFINE_PER_CPU(unsigned long, kvm_apic_eoi) = KVM_PV_EOI_DISABLED; + +static void kvm_guest_apic_eoi_write(u32 reg, u32 val) +{ + /** + * This relies on __test_and_clear_bit to modify the memory + * in a way that is atomic with respect to the local CPU. + * The hypervisor only accesses this memory from the local CPU so + * there's no need for lock or memory barriers. + * An optimization barrier is implied in apic write. + */ + if (__test_and_clear_bit(KVM_PV_EOI_BIT, this_cpu_ptr(&kvm_apic_eoi))) + return; + apic_write(APIC_EOI, APIC_EOI_ACK); +} + +void kvm_guest_cpu_init(void) +{ + if (!kvm_para_available()) + return; + + if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) { + u64 pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason)); + +#ifdef CONFIG_PREEMPT + pa |= KVM_ASYNC_PF_SEND_ALWAYS; +#endif + wrmsrl(MSR_KVM_ASYNC_PF_EN, pa | KVM_ASYNC_PF_ENABLED); + __this_cpu_write(apf_reason.enabled, 1); + printk(KERN_INFO"KVM setup async PF for cpu %d\n", + smp_processor_id()); + } + + if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) { + unsigned long pa; + /* Size alignment is implied but just to make it explicit. */ + BUILD_BUG_ON(__alignof__(kvm_apic_eoi) < 4); + __this_cpu_write(kvm_apic_eoi, 0); + pa = slow_virt_to_phys(this_cpu_ptr(&kvm_apic_eoi)) + | KVM_MSR_ENABLED; + wrmsrl(MSR_KVM_PV_EOI_EN, pa); + } + + if (has_steal_clock) + kvm_register_steal_time(); +} + +static void kvm_pv_disable_apf(void) +{ + if (!__this_cpu_read(apf_reason.enabled)) + return; + + wrmsrl(MSR_KVM_ASYNC_PF_EN, 0); + __this_cpu_write(apf_reason.enabled, 0); + + printk(KERN_INFO"Unregister pv shared memory for cpu %d\n", + smp_processor_id()); +} + +static void kvm_pv_guest_cpu_reboot(void *unused) +{ + /* + * We disable PV EOI before we load a new kernel by kexec, + * since MSR_KVM_PV_EOI_EN stores a pointer into old kernel's memory. + * New kernel can re-enable when it boots. + */ + if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) + wrmsrl(MSR_KVM_PV_EOI_EN, 0); + kvm_pv_disable_apf(); + kvm_disable_steal_time(); +} + +static int kvm_pv_reboot_notify(struct notifier_block *nb, + unsigned long code, void *unused) +{ + if (code == SYS_RESTART) + on_each_cpu(kvm_pv_guest_cpu_reboot, NULL, 1); + return NOTIFY_DONE; +} + +static struct notifier_block kvm_pv_reboot_nb = { + .notifier_call = kvm_pv_reboot_notify, +}; + +static u64 kvm_steal_clock(int cpu) +{ + u64 steal; + struct kvm_steal_time *src; + int version; + + src = &per_cpu(steal_time, cpu); + do { + version = src->version; + rmb(); + steal = src->steal; + rmb(); + } while ((version & 1) || (version != src->version)); + + return steal; +} + +void kvm_disable_steal_time(void) +{ + if (!has_steal_clock) + return; + + wrmsr(MSR_KVM_STEAL_TIME, 0, 0); +} + +#ifdef CONFIG_SMP +static void __init kvm_smp_prepare_boot_cpu(void) +{ + kvm_guest_cpu_init(); + native_smp_prepare_boot_cpu(); + kvm_spinlock_init(); +} + +static void kvm_guest_cpu_online(void *dummy) +{ + kvm_guest_cpu_init(); +} + +static void kvm_guest_cpu_offline(void *dummy) +{ + kvm_disable_steal_time(); + if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) + wrmsrl(MSR_KVM_PV_EOI_EN, 0); + kvm_pv_disable_apf(); + apf_task_wake_all(); +} + +static int kvm_cpu_notify(struct notifier_block *self, unsigned long action, + void *hcpu) +{ + int cpu = (unsigned long)hcpu; + switch (action) { + case CPU_ONLINE: + case CPU_DOWN_FAILED: + case CPU_ONLINE_FROZEN: + smp_call_function_single(cpu, kvm_guest_cpu_online, NULL, 0); + break; + case CPU_DOWN_PREPARE: + case CPU_DOWN_PREPARE_FROZEN: + smp_call_function_single(cpu, kvm_guest_cpu_offline, NULL, 1); + break; + default: + break; + } + return NOTIFY_OK; +} + +static struct notifier_block kvm_cpu_notifier = { + .notifier_call = kvm_cpu_notify, +}; +#endif + +static void __init kvm_apf_trap_init(void) +{ + set_intr_gate(14, async_page_fault); +} + +void __init kvm_guest_init(void) +{ + int i; + + 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); + if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF)) + x86_init.irqs.trap_init = kvm_apf_trap_init; + + if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) { + has_steal_clock = 1; + pv_time_ops.steal_clock = kvm_steal_clock; + } + + if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) + apic_set_eoi_write(kvm_guest_apic_eoi_write); + + if (kvmclock_vsyscall) + kvm_setup_vsyscall_timeinfo(); + +#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. + */ + hardlockup_detector_disable(); +} + +static noinline uint32_t __kvm_cpuid_base(void) +{ + if (boot_cpu_data.cpuid_level < 0) + return 0; /* So we don't blow up on old processors */ + + if (cpu_has_hypervisor) + return hypervisor_cpuid_base("KVMKVMKVM\0\0\0", 0); + + return 0; +} + +static inline uint32_t kvm_cpuid_base(void) +{ + static int kvm_cpuid_base = -1; + + if (kvm_cpuid_base == -1) + kvm_cpuid_base = __kvm_cpuid_base(); + + return kvm_cpuid_base; +} + +bool kvm_para_available(void) +{ + return kvm_cpuid_base() != 0; +} +EXPORT_SYMBOL_GPL(kvm_para_available); + +unsigned int kvm_arch_para_features(void) +{ + return cpuid_eax(kvm_cpuid_base() | KVM_CPUID_FEATURES); +} + +static uint32_t __init kvm_detect(void) +{ + return kvm_cpuid_base(); +} + +const struct hypervisor_x86 x86_hyper_kvm __refconst = { + .name = "KVM", + .detect = kvm_detect, + .x2apic_available = kvm_para_available, +}; +EXPORT_SYMBOL_GPL(x86_hyper_kvm); + +static __init int activate_jump_labels(void) +{ + if (has_steal_clock) { + static_key_slow_inc(¶virt_steal_enabled); + if (steal_acc) + static_key_slow_inc(¶virt_steal_rq_enabled); + } + + return 0; +} +arch_initcall(activate_jump_labels); + +#ifdef CONFIG_PARAVIRT_SPINLOCKS + +/* Kick a cpu by its apicid. Used to wake up a halted vcpu */ +static void kvm_kick_cpu(int cpu) +{ + int apicid; + unsigned long flags = 0; + + apicid = per_cpu(x86_cpu_to_apicid, cpu); + kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); +} + +enum kvm_contention_stat { + TAKEN_SLOW, + TAKEN_SLOW_PICKUP, + RELEASED_SLOW, + RELEASED_SLOW_KICKED, + NR_CONTENTION_STATS +}; + +#ifdef CONFIG_KVM_DEBUG_FS +#define HISTO_BUCKETS 30 + +static struct kvm_spinlock_stats +{ + u32 contention_stats[NR_CONTENTION_STATS]; + u32 histo_spin_blocked[HISTO_BUCKETS+1]; + u64 time_blocked; +} spinlock_stats; + +static u8 zero_stats; + +static inline void check_zero(void) +{ + u8 ret; + u8 old; + + old = READ_ONCE(zero_stats); + if (unlikely(old)) { + ret = cmpxchg(&zero_stats, old, 0); + /* This ensures only one fellow resets the stat */ + if (ret == old) + memset(&spinlock_stats, 0, sizeof(spinlock_stats)); + } +} + +static inline void add_stats(enum kvm_contention_stat var, u32 val) +{ + check_zero(); + spinlock_stats.contention_stats[var] += val; +} + + +static inline u64 spin_time_start(void) +{ + return sched_clock(); +} + +static void __spin_time_accum(u64 delta, u32 *array) +{ + unsigned index; + + index = ilog2(delta); + check_zero(); + + if (index < HISTO_BUCKETS) + array[index]++; + else + array[HISTO_BUCKETS]++; +} + +static inline void spin_time_accum_blocked(u64 start) +{ + u32 delta; + + delta = sched_clock() - start; + __spin_time_accum(delta, spinlock_stats.histo_spin_blocked); + spinlock_stats.time_blocked += delta; +} + +static struct dentry *d_spin_debug; +static struct dentry *d_kvm_debug; + +struct dentry *kvm_init_debugfs(void) +{ + d_kvm_debug = debugfs_create_dir("kvm-guest", NULL); + if (!d_kvm_debug) + printk(KERN_WARNING "Could not create 'kvm' debugfs directory\n"); + + return d_kvm_debug; +} + +static int __init kvm_spinlock_debugfs(void) +{ + struct dentry *d_kvm; + + d_kvm = kvm_init_debugfs(); + if (d_kvm == NULL) + return -ENOMEM; + + d_spin_debug = debugfs_create_dir("spinlocks", d_kvm); + + debugfs_create_u8("zero_stats", 0644, d_spin_debug, &zero_stats); + + debugfs_create_u32("taken_slow", 0444, d_spin_debug, + &spinlock_stats.contention_stats[TAKEN_SLOW]); + debugfs_create_u32("taken_slow_pickup", 0444, d_spin_debug, + &spinlock_stats.contention_stats[TAKEN_SLOW_PICKUP]); + + debugfs_create_u32("released_slow", 0444, d_spin_debug, + &spinlock_stats.contention_stats[RELEASED_SLOW]); + debugfs_create_u32("released_slow_kicked", 0444, d_spin_debug, + &spinlock_stats.contention_stats[RELEASED_SLOW_KICKED]); + + debugfs_create_u64("time_blocked", 0444, d_spin_debug, + &spinlock_stats.time_blocked); + + debugfs_create_u32_array("histo_blocked", 0444, d_spin_debug, + spinlock_stats.histo_spin_blocked, HISTO_BUCKETS + 1); + + return 0; +} +fs_initcall(kvm_spinlock_debugfs); +#else /* !CONFIG_KVM_DEBUG_FS */ +static inline void add_stats(enum kvm_contention_stat var, u32 val) +{ +} + +static inline u64 spin_time_start(void) +{ + return 0; +} + +static inline void spin_time_accum_blocked(u64 start) +{ +} +#endif /* CONFIG_KVM_DEBUG_FS */ + +struct kvm_lock_waiting { + struct arch_spinlock *lock; + __ticket_t want; +}; + +/* cpus 'waiting' on a spinlock to become available */ +static cpumask_t waiting_cpus; + +/* Track spinlock on which a cpu is waiting */ +static DEFINE_PER_CPU(struct kvm_lock_waiting, klock_waiting); + +__visible void kvm_lock_spinning(struct arch_spinlock *lock, __ticket_t want) +{ + struct kvm_lock_waiting *w; + int cpu; + u64 start; + unsigned long flags; + __ticket_t head; + + if (in_nmi()) + return; + + w = this_cpu_ptr(&klock_waiting); + cpu = smp_processor_id(); + start = spin_time_start(); + + /* + * Make sure an interrupt handler can't upset things in a + * partially setup state. + */ + local_irq_save(flags); + + /* + * The ordering protocol on this is that the "lock" pointer + * may only be set non-NULL if the "want" ticket is correct. + * If we're updating "want", we must first clear "lock". + */ + w->lock = NULL; + smp_wmb(); + w->want = want; + smp_wmb(); + w->lock = lock; + + add_stats(TAKEN_SLOW, 1); + + /* + * This uses set_bit, which is atomic but we should not rely on its + * reordering gurantees. So barrier is needed after this call. + */ + cpumask_set_cpu(cpu, &waiting_cpus); + + barrier(); + + /* + * Mark entry to slowpath before doing the pickup test to make + * sure we don't deadlock with an unlocker. + */ + __ticket_enter_slowpath(lock); + + /* make sure enter_slowpath, which is atomic does not cross the read */ + smp_mb__after_atomic(); + + /* + * check again make sure it didn't become free while + * we weren't looking. + */ + head = READ_ONCE(lock->tickets.head); + if (__tickets_equal(head, want)) { + add_stats(TAKEN_SLOW_PICKUP, 1); + 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: + cpumask_clear_cpu(cpu, &waiting_cpus); + w->lock = NULL; + local_irq_restore(flags); + spin_time_accum_blocked(start); +} +PV_CALLEE_SAVE_REGS_THUNK(kvm_lock_spinning); + +/* Kick vcpu waiting on @lock->head to reach value @ticket */ +static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) +{ + int cpu; + + add_stats(RELEASED_SLOW, 1); + for_each_cpu(cpu, &waiting_cpus) { + const struct kvm_lock_waiting *w = &per_cpu(klock_waiting, cpu); + if (READ_ONCE(w->lock) == lock && + READ_ONCE(w->want) == ticket) { + add_stats(RELEASED_SLOW_KICKED, 1); + kvm_kick_cpu(cpu); + break; + } + } +} + +/* + * Setup pv_lock_ops to exploit KVM_FEATURE_PV_UNHALT if present. + */ +void __init kvm_spinlock_init(void) +{ + if (!kvm_para_available()) + return; + /* Does host kernel support KVM_FEATURE_PV_UNHALT? */ + if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) + return; + + pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(kvm_lock_spinning); + pv_lock_ops.unlock_kick = kvm_unlock_kick; +} + +static __init int kvm_spinlock_init_jump(void) +{ + if (!kvm_para_available()) + return 0; + if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) + return 0; + + static_key_slow_inc(¶virt_ticketlocks_enabled); + printk(KERN_INFO "KVM setup paravirtual spinlock\n"); + + return 0; +} +early_initcall(kvm_spinlock_init_jump); + +#endif /* CONFIG_PARAVIRT_SPINLOCKS */ -- cgit 1.2.3-korg