diff options
Diffstat (limited to 'arch/x86/kvm/i8254.c')
| -rw-r--r-- | arch/x86/kvm/i8254.c | 376 |
1 files changed, 235 insertions, 141 deletions
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 4d6f0d293ee..518d86471b7 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -5,6 +5,7 @@ * Copyright (c) 2006 Intel Corporation * Copyright (c) 2007 Keir Fraser, XenSource Inc * Copyright (c) 2008 Intel Corporation + * Copyright 2009 Red Hat, Inc. and/or its affiliates. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal @@ -29,10 +30,14 @@ * Based on QEMU and Xen. */ +#define pr_fmt(fmt) "pit: " fmt + #include <linux/kvm_host.h> +#include <linux/slab.h> #include "irq.h" #include "i8254.h" +#include "x86.h" #ifndef CONFIG_X86_64 #define mod_64(x, y) ((x) - (y) * div64_u64(x, y)) @@ -104,6 +109,9 @@ static s64 __kpit_elapsed(struct kvm *kvm) ktime_t remaining; struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; + if (!ps->period) + return 0; + /* * The Counter does not stop when it reaches zero. In * Modes 0, 1, 4, and 5 the Counter ``wraps around'' to @@ -113,9 +121,8 @@ static s64 __kpit_elapsed(struct kvm *kvm) * itself with the initial count and continues counting * from there. */ - remaining = hrtimer_expires_remaining(&ps->pit_timer.timer); - elapsed = ps->pit_timer.period - ktime_to_ns(remaining); - elapsed = mod_64(elapsed, ps->pit_timer.period); + remaining = hrtimer_get_remaining(&ps->timer); + elapsed = ps->period - ktime_to_ns(remaining); return elapsed; } @@ -224,22 +231,24 @@ static void pit_latch_status(struct kvm *kvm, int channel) } } -int pit_has_pending_timer(struct kvm_vcpu *vcpu) -{ - struct kvm_pit *pit = vcpu->kvm->arch.vpit; - - if (pit && vcpu->vcpu_id == 0 && pit->pit_state.irq_ack) - return atomic_read(&pit->pit_state.pit_timer.pending); - return 0; -} - static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian) { struct kvm_kpit_state *ps = container_of(kian, struct kvm_kpit_state, irq_ack_notifier); + int value; + spin_lock(&ps->inject_lock); - if (atomic_dec_return(&ps->pit_timer.pending) < 0) - atomic_inc(&ps->pit_timer.pending); + value = atomic_dec_return(&ps->pending); + if (value < 0) + /* spurious acks can be generated if, for example, the + * PIC is being reset. Handle it gracefully here + */ + atomic_inc(&ps->pending); + else if (value > 0) + /* in this case, we had multiple outstanding pit interrupts + * that we needed to inject. Reinject + */ + queue_kthread_work(&ps->pit->worker, &ps->pit->expired); ps->irq_ack = 1; spin_unlock(&ps->inject_lock); } @@ -249,54 +258,116 @@ void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu) struct kvm_pit *pit = vcpu->kvm->arch.vpit; struct hrtimer *timer; - if (vcpu->vcpu_id != 0 || !pit) + if (!kvm_vcpu_is_bsp(vcpu) || !pit) return; - timer = &pit->pit_state.pit_timer.timer; + timer = &pit->pit_state.timer; if (hrtimer_cancel(timer)) hrtimer_start_expires(timer, HRTIMER_MODE_ABS); } -static void destroy_pit_timer(struct kvm_timer *pt) +static void destroy_pit_timer(struct kvm_pit *pit) { - pr_debug("pit: execute del timer!\n"); - hrtimer_cancel(&pt->timer); + hrtimer_cancel(&pit->pit_state.timer); + flush_kthread_work(&pit->expired); } -static bool kpit_is_periodic(struct kvm_timer *ktimer) +static void pit_do_work(struct kthread_work *work) { - struct kvm_kpit_state *ps = container_of(ktimer, struct kvm_kpit_state, - pit_timer); - return ps->is_periodic; + struct kvm_pit *pit = container_of(work, struct kvm_pit, expired); + struct kvm *kvm = pit->kvm; + struct kvm_vcpu *vcpu; + int i; + struct kvm_kpit_state *ps = &pit->pit_state; + int inject = 0; + + /* Try to inject pending interrupts when + * last one has been acked. + */ + spin_lock(&ps->inject_lock); + if (ps->irq_ack) { + ps->irq_ack = 0; + inject = 1; + } + spin_unlock(&ps->inject_lock); + if (inject) { + kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1, false); + kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0, false); + + /* + * Provides NMI watchdog support via Virtual Wire mode. + * The route is: PIT -> PIC -> LVT0 in NMI mode. + * + * Note: Our Virtual Wire implementation is simplified, only + * propagating PIT interrupts to all VCPUs when they have set + * LVT0 to NMI delivery. Other PIC interrupts are just sent to + * VCPU0, and only if its LVT0 is in EXTINT mode. + */ + if (kvm->arch.vapics_in_nmi_mode > 0) + kvm_for_each_vcpu(i, vcpu, kvm) + kvm_apic_nmi_wd_deliver(vcpu); + } } -static struct kvm_timer_ops kpit_ops = { - .is_periodic = kpit_is_periodic, -}; +static enum hrtimer_restart pit_timer_fn(struct hrtimer *data) +{ + struct kvm_kpit_state *ps = container_of(data, struct kvm_kpit_state, timer); + struct kvm_pit *pt = ps->kvm->arch.vpit; -static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period) + if (ps->reinject || !atomic_read(&ps->pending)) { + atomic_inc(&ps->pending); + queue_kthread_work(&pt->worker, &pt->expired); + } + + if (ps->is_periodic) { + hrtimer_add_expires_ns(&ps->timer, ps->period); + return HRTIMER_RESTART; + } else + return HRTIMER_NORESTART; +} + +static void create_pit_timer(struct kvm *kvm, u32 val, int is_period) { - struct kvm_timer *pt = &ps->pit_timer; + struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; s64 interval; + if (!irqchip_in_kernel(kvm) || ps->flags & KVM_PIT_FLAGS_HPET_LEGACY) + return; + interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ); - pr_debug("pit: create pit timer, interval is %llu nsec\n", interval); + pr_debug("create pit timer, interval is %llu nsec\n", interval); /* TODO The new value only affected after the retriggered */ - hrtimer_cancel(&pt->timer); - pt->period = interval; + hrtimer_cancel(&ps->timer); + flush_kthread_work(&ps->pit->expired); + ps->period = interval; ps->is_periodic = is_period; - pt->timer.function = kvm_timer_fn; - pt->t_ops = &kpit_ops; - pt->kvm = ps->pit->kvm; - pt->vcpu_id = 0; + ps->timer.function = pit_timer_fn; + ps->kvm = ps->pit->kvm; - atomic_set(&pt->pending, 0); + atomic_set(&ps->pending, 0); ps->irq_ack = 1; - hrtimer_start(&pt->timer, ktime_add_ns(ktime_get(), interval), + /* + * Do not allow the guest to program periodic timers with small + * interval, since the hrtimers are not throttled by the host + * scheduler. + */ + if (ps->is_periodic) { + s64 min_period = min_timer_period_us * 1000LL; + + if (ps->period < min_period) { + pr_info_ratelimited( + "kvm: requested %lld ns " + "i8254 timer period limited to %lld ns\n", + ps->period, min_period); + ps->period = min_period; + } + } + + hrtimer_start(&ps->timer, ktime_add_ns(ktime_get(), interval), HRTIMER_MODE_ABS); } @@ -306,7 +377,7 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val) WARN_ON(!mutex_is_locked(&ps->lock)); - pr_debug("pit: load_count val is %d, channel is %d\n", val, channel); + pr_debug("load_count val is %d, channel is %d\n", val, channel); /* * The largest possible initial count is 0; this is equivalent @@ -329,33 +400,58 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val) case 1: /* FIXME: enhance mode 4 precision */ case 4: - create_pit_timer(ps, val, 0); + create_pit_timer(kvm, val, 0); break; case 2: case 3: - create_pit_timer(ps, val, 1); + create_pit_timer(kvm, val, 1); break; default: - destroy_pit_timer(&ps->pit_timer); + destroy_pit_timer(kvm->arch.vpit); } } -void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val) +void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start) +{ + u8 saved_mode; + if (hpet_legacy_start) { + /* save existing mode for later reenablement */ + saved_mode = kvm->arch.vpit->pit_state.channels[0].mode; + kvm->arch.vpit->pit_state.channels[0].mode = 0xff; /* disable timer */ + pit_load_count(kvm, channel, val); + kvm->arch.vpit->pit_state.channels[0].mode = saved_mode; + } else { + pit_load_count(kvm, channel, val); + } +} + +static inline struct kvm_pit *dev_to_pit(struct kvm_io_device *dev) +{ + return container_of(dev, struct kvm_pit, dev); +} + +static inline struct kvm_pit *speaker_to_pit(struct kvm_io_device *dev) +{ + return container_of(dev, struct kvm_pit, speaker_dev); +} + +static inline int pit_in_range(gpa_t addr) { - mutex_lock(&kvm->arch.vpit->pit_state.lock); - pit_load_count(kvm, channel, val); - mutex_unlock(&kvm->arch.vpit->pit_state.lock); + return ((addr >= KVM_PIT_BASE_ADDRESS) && + (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH)); } -static void pit_ioport_write(struct kvm_io_device *this, - gpa_t addr, int len, const void *data) +static int pit_ioport_write(struct kvm_io_device *this, + gpa_t addr, int len, const void *data) { - struct kvm_pit *pit = (struct kvm_pit *)this->private; + struct kvm_pit *pit = dev_to_pit(this); struct kvm_kpit_state *pit_state = &pit->pit_state; struct kvm *kvm = pit->kvm; int channel, access; struct kvm_kpit_channel_state *s; u32 val = *(u32 *) data; + if (!pit_in_range(addr)) + return -EOPNOTSUPP; val &= 0xff; addr &= KVM_PIT_CHANNEL_MASK; @@ -363,8 +459,8 @@ static void pit_ioport_write(struct kvm_io_device *this, mutex_lock(&pit_state->lock); if (val != 0) - pr_debug("pit: write addr is 0x%x, len is %d, val is 0x%x\n", - (unsigned int)addr, len, val); + pr_debug("write addr is 0x%x, len is %d, val is 0x%x\n", + (unsigned int)addr, len, val); if (addr == 3) { channel = val >> 6; @@ -418,18 +514,24 @@ static void pit_ioport_write(struct kvm_io_device *this, } mutex_unlock(&pit_state->lock); + return 0; } -static void pit_ioport_read(struct kvm_io_device *this, - gpa_t addr, int len, void *data) +static int pit_ioport_read(struct kvm_io_device *this, + gpa_t addr, int len, void *data) { - struct kvm_pit *pit = (struct kvm_pit *)this->private; + struct kvm_pit *pit = dev_to_pit(this); struct kvm_kpit_state *pit_state = &pit->pit_state; struct kvm *kvm = pit->kvm; int ret, count; struct kvm_kpit_channel_state *s; + if (!pit_in_range(addr)) + return -EOPNOTSUPP; addr &= KVM_PIT_CHANNEL_MASK; + if (addr == 3) + return 0; + s = &pit_state->channels[addr]; mutex_lock(&pit_state->lock); @@ -482,37 +584,36 @@ static void pit_ioport_read(struct kvm_io_device *this, memcpy(data, (char *)&ret, len); mutex_unlock(&pit_state->lock); + return 0; } -static int pit_in_range(struct kvm_io_device *this, gpa_t addr, - int len, int is_write) -{ - return ((addr >= KVM_PIT_BASE_ADDRESS) && - (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH)); -} - -static void speaker_ioport_write(struct kvm_io_device *this, - gpa_t addr, int len, const void *data) +static int speaker_ioport_write(struct kvm_io_device *this, + gpa_t addr, int len, const void *data) { - struct kvm_pit *pit = (struct kvm_pit *)this->private; + struct kvm_pit *pit = speaker_to_pit(this); struct kvm_kpit_state *pit_state = &pit->pit_state; struct kvm *kvm = pit->kvm; u32 val = *(u32 *) data; + if (addr != KVM_SPEAKER_BASE_ADDRESS) + return -EOPNOTSUPP; mutex_lock(&pit_state->lock); pit_state->speaker_data_on = (val >> 1) & 1; pit_set_gate(kvm, 2, val & 1); mutex_unlock(&pit_state->lock); + return 0; } -static void speaker_ioport_read(struct kvm_io_device *this, - gpa_t addr, int len, void *data) +static int speaker_ioport_read(struct kvm_io_device *this, + gpa_t addr, int len, void *data) { - struct kvm_pit *pit = (struct kvm_pit *)this->private; + struct kvm_pit *pit = speaker_to_pit(this); struct kvm_kpit_state *pit_state = &pit->pit_state; struct kvm *kvm = pit->kvm; unsigned int refresh_clock; int ret; + if (addr != KVM_SPEAKER_BASE_ADDRESS) + return -EOPNOTSUPP; /* Refresh clock toggles at about 15us. We approximate as 2^14ns. */ refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1; @@ -524,12 +625,7 @@ static void speaker_ioport_read(struct kvm_io_device *this, len = sizeof(ret); memcpy(data, (char *)&ret, len); mutex_unlock(&pit_state->lock); -} - -static int speaker_in_range(struct kvm_io_device *this, gpa_t addr, - int len, int is_write) -{ - return (addr == KVM_SPEAKER_BASE_ADDRESS); + return 0; } void kvm_pit_reset(struct kvm_pit *pit) @@ -538,6 +634,7 @@ void kvm_pit_reset(struct kvm_pit *pit) struct kvm_kpit_channel_state *c; mutex_lock(&pit->pit_state.lock); + pit->pit_state.flags = 0; for (i = 0; i < 3; i++) { c = &pit->pit_state.channels[i]; c->mode = 0xff; @@ -546,7 +643,7 @@ void kvm_pit_reset(struct kvm_pit *pit) } mutex_unlock(&pit->pit_state.lock); - atomic_set(&pit->pit_state.pit_timer.pending, 0); + atomic_set(&pit->pit_state.pending, 0); pit->pit_state.irq_ack = 1; } @@ -555,15 +652,29 @@ static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, bool mask) struct kvm_pit *pit = container_of(kimn, struct kvm_pit, mask_notifier); if (!mask) { - atomic_set(&pit->pit_state.pit_timer.pending, 0); + atomic_set(&pit->pit_state.pending, 0); pit->pit_state.irq_ack = 1; } } -struct kvm_pit *kvm_create_pit(struct kvm *kvm) +static const struct kvm_io_device_ops pit_dev_ops = { + .read = pit_ioport_read, + .write = pit_ioport_write, +}; + +static const struct kvm_io_device_ops speaker_dev_ops = { + .read = speaker_ioport_read, + .write = speaker_ioport_write, +}; + +/* Caller must hold slots_lock */ +struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) { struct kvm_pit *pit; struct kvm_kpit_state *pit_state; + struct pid *pid; + pid_t pid_nr; + int ret; pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL); if (!pit) @@ -579,30 +690,31 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm) mutex_lock(&pit->pit_state.lock); spin_lock_init(&pit->pit_state.inject_lock); - /* Initialize PIO device */ - pit->dev.read = pit_ioport_read; - pit->dev.write = pit_ioport_write; - pit->dev.in_range = pit_in_range; - pit->dev.private = pit; - kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev); + pid = get_pid(task_tgid(current)); + pid_nr = pid_vnr(pid); + put_pid(pid); - pit->speaker_dev.read = speaker_ioport_read; - pit->speaker_dev.write = speaker_ioport_write; - pit->speaker_dev.in_range = speaker_in_range; - pit->speaker_dev.private = pit; - kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev); + init_kthread_worker(&pit->worker); + pit->worker_task = kthread_run(kthread_worker_fn, &pit->worker, + "kvm-pit/%d", pid_nr); + if (IS_ERR(pit->worker_task)) { + mutex_unlock(&pit->pit_state.lock); + kvm_free_irq_source_id(kvm, pit->irq_source_id); + kfree(pit); + return NULL; + } + init_kthread_work(&pit->expired, pit_do_work); kvm->arch.vpit = pit; pit->kvm = kvm; pit_state = &pit->pit_state; pit_state->pit = pit; - hrtimer_init(&pit_state->pit_timer.timer, - CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + hrtimer_init(&pit_state->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); pit_state->irq_ack_notifier.gsi = 0; pit_state->irq_ack_notifier.irq_acked = kvm_pit_ack_irq; kvm_register_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier); - pit_state->pit_timer.reinject = true; + pit_state->reinject = true; mutex_unlock(&pit->pit_state.lock); kvm_pit_reset(pit); @@ -610,7 +722,33 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm) pit->mask_notifier.func = pit_mask_notifer; kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier); + kvm_iodevice_init(&pit->dev, &pit_dev_ops); + ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, KVM_PIT_BASE_ADDRESS, + KVM_PIT_MEM_LENGTH, &pit->dev); + if (ret < 0) + goto fail; + + if (flags & KVM_PIT_SPEAKER_DUMMY) { + kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops); + ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, + KVM_SPEAKER_BASE_ADDRESS, 4, + &pit->speaker_dev); + if (ret < 0) + goto fail_unregister; + } + return pit; + +fail_unregister: + kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &pit->dev); + +fail: + kvm_unregister_irq_mask_notifier(kvm, 0, &pit->mask_notifier); + kvm_unregister_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier); + kvm_free_irq_source_id(kvm, pit->irq_source_id); + kthread_stop(pit->worker_task); + kfree(pit); + return NULL; } void kvm_free_pit(struct kvm *kvm) @@ -618,64 +756,20 @@ void kvm_free_pit(struct kvm *kvm) struct hrtimer *timer; if (kvm->arch.vpit) { + kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &kvm->arch.vpit->dev); + kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, + &kvm->arch.vpit->speaker_dev); kvm_unregister_irq_mask_notifier(kvm, 0, &kvm->arch.vpit->mask_notifier); + kvm_unregister_irq_ack_notifier(kvm, + &kvm->arch.vpit->pit_state.irq_ack_notifier); mutex_lock(&kvm->arch.vpit->pit_state.lock); - timer = &kvm->arch.vpit->pit_state.pit_timer.timer; + timer = &kvm->arch.vpit->pit_state.timer; hrtimer_cancel(timer); + flush_kthread_work(&kvm->arch.vpit->expired); + kthread_stop(kvm->arch.vpit->worker_task); kvm_free_irq_source_id(kvm, kvm->arch.vpit->irq_source_id); mutex_unlock(&kvm->arch.vpit->pit_state.lock); kfree(kvm->arch.vpit); } } - -static void __inject_pit_timer_intr(struct kvm *kvm) -{ - struct kvm_vcpu *vcpu; - int i; - - mutex_lock(&kvm->lock); - kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1); - kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0); - mutex_unlock(&kvm->lock); - - /* - * Provides NMI watchdog support via Virtual Wire mode. - * The route is: PIT -> PIC -> LVT0 in NMI mode. - * - * Note: Our Virtual Wire implementation is simplified, only - * propagating PIT interrupts to all VCPUs when they have set - * LVT0 to NMI delivery. Other PIC interrupts are just sent to - * VCPU0, and only if its LVT0 is in EXTINT mode. - */ - if (kvm->arch.vapics_in_nmi_mode > 0) - for (i = 0; i < KVM_MAX_VCPUS; ++i) { - vcpu = kvm->vcpus[i]; - if (vcpu) - kvm_apic_nmi_wd_deliver(vcpu); - } -} - -void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu) -{ - struct kvm_pit *pit = vcpu->kvm->arch.vpit; - struct kvm *kvm = vcpu->kvm; - struct kvm_kpit_state *ps; - - if (vcpu && pit) { - int inject = 0; - ps = &pit->pit_state; - - /* Try to inject pending interrupts when - * last one has been acked. - */ - spin_lock(&ps->inject_lock); - if (atomic_read(&ps->pit_timer.pending) && ps->irq_ack) { - ps->irq_ack = 0; - inject = 1; - } - spin_unlock(&ps->inject_lock); - if (inject) - __inject_pit_timer_intr(kvm); - } -} |
