diff options
Diffstat (limited to 'arch/x86/kvm/ioapic.c')
| -rw-r--r-- | arch/x86/kvm/ioapic.c | 682 |
1 files changed, 682 insertions, 0 deletions
diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c new file mode 100644 index 000000000000..f0f7ef82b7a6 --- /dev/null +++ b/arch/x86/kvm/ioapic.c @@ -0,0 +1,682 @@ +/* + * Copyright (C) 2001 MandrakeSoft S.A. + * Copyright 2010 Red Hat, Inc. and/or its affiliates. + * + * MandrakeSoft S.A. + * 43, rue d'Aboukir + * 75002 Paris - France + * http://www.linux-mandrake.com/ + * http://www.mandrakesoft.com/ + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Yunhong Jiang <yunhong.jiang@intel.com> + * Yaozu (Eddie) Dong <eddie.dong@intel.com> + * Based on Xen 3.1 code. + */ + +#include <linux/kvm_host.h> +#include <linux/kvm.h> +#include <linux/mm.h> +#include <linux/highmem.h> +#include <linux/smp.h> +#include <linux/hrtimer.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <asm/processor.h> +#include <asm/page.h> +#include <asm/current.h> +#include <trace/events/kvm.h> + +#include "ioapic.h" +#include "lapic.h" +#include "irq.h" + +#if 0 +#define ioapic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg) +#else +#define ioapic_debug(fmt, arg...) +#endif +static int ioapic_service(struct kvm_ioapic *vioapic, int irq, + bool line_status); + +static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic, + unsigned long addr, + unsigned long length) +{ + unsigned long result = 0; + + switch (ioapic->ioregsel) { + case IOAPIC_REG_VERSION: + result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16) + | (IOAPIC_VERSION_ID & 0xff)); + break; + + case IOAPIC_REG_APIC_ID: + case IOAPIC_REG_ARB_ID: + result = ((ioapic->id & 0xf) << 24); + break; + + default: + { + u32 redir_index = (ioapic->ioregsel - 0x10) >> 1; + u64 redir_content; + + if (redir_index < IOAPIC_NUM_PINS) + redir_content = + ioapic->redirtbl[redir_index].bits; + else + redir_content = ~0ULL; + + result = (ioapic->ioregsel & 0x1) ? + (redir_content >> 32) & 0xffffffff : + redir_content & 0xffffffff; + break; + } + } + + return result; +} + +static void rtc_irq_eoi_tracking_reset(struct kvm_ioapic *ioapic) +{ + ioapic->rtc_status.pending_eoi = 0; + bitmap_zero(ioapic->rtc_status.dest_map, KVM_MAX_VCPUS); +} + +static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic); + +static void rtc_status_pending_eoi_check_valid(struct kvm_ioapic *ioapic) +{ + if (WARN_ON(ioapic->rtc_status.pending_eoi < 0)) + kvm_rtc_eoi_tracking_restore_all(ioapic); +} + +static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu) +{ + bool new_val, old_val; + struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic; + union kvm_ioapic_redirect_entry *e; + + e = &ioapic->redirtbl[RTC_GSI]; + if (!kvm_apic_match_dest(vcpu, NULL, 0, e->fields.dest_id, + e->fields.dest_mode)) + return; + + new_val = kvm_apic_pending_eoi(vcpu, e->fields.vector); + old_val = test_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map); + + if (new_val == old_val) + return; + + if (new_val) { + __set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map); + ioapic->rtc_status.pending_eoi++; + } else { + __clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map); + ioapic->rtc_status.pending_eoi--; + rtc_status_pending_eoi_check_valid(ioapic); + } +} + +void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu) +{ + struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic; + + spin_lock(&ioapic->lock); + __rtc_irq_eoi_tracking_restore_one(vcpu); + spin_unlock(&ioapic->lock); +} + +static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic) +{ + struct kvm_vcpu *vcpu; + int i; + + if (RTC_GSI >= IOAPIC_NUM_PINS) + return; + + rtc_irq_eoi_tracking_reset(ioapic); + kvm_for_each_vcpu(i, vcpu, ioapic->kvm) + __rtc_irq_eoi_tracking_restore_one(vcpu); +} + +static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu) +{ + if (test_and_clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map)) { + --ioapic->rtc_status.pending_eoi; + rtc_status_pending_eoi_check_valid(ioapic); + } +} + +static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic) +{ + if (ioapic->rtc_status.pending_eoi > 0) + return true; /* coalesced */ + + return false; +} + +static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq, + int irq_level, bool line_status) +{ + union kvm_ioapic_redirect_entry entry; + u32 mask = 1 << irq; + u32 old_irr; + int edge, ret; + + entry = ioapic->redirtbl[irq]; + edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG); + + if (!irq_level) { + ioapic->irr &= ~mask; + ret = 1; + goto out; + } + + /* + * Return 0 for coalesced interrupts; for edge-triggered interrupts, + * this only happens if a previous edge has not been delivered due + * do masking. For level interrupts, the remote_irr field tells + * us if the interrupt is waiting for an EOI. + * + * RTC is special: it is edge-triggered, but userspace likes to know + * if it has been already ack-ed via EOI because coalesced RTC + * interrupts lead to time drift in Windows guests. So we track + * EOI manually for the RTC interrupt. + */ + if (irq == RTC_GSI && line_status && + rtc_irq_check_coalesced(ioapic)) { + ret = 0; + goto out; + } + + old_irr = ioapic->irr; + ioapic->irr |= mask; + if ((edge && old_irr == ioapic->irr) || + (!edge && entry.fields.remote_irr)) { + ret = 0; + goto out; + } + + ret = ioapic_service(ioapic, irq, line_status); + +out: + trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0); + return ret; +} + +static void kvm_ioapic_inject_all(struct kvm_ioapic *ioapic, unsigned long irr) +{ + u32 idx; + + rtc_irq_eoi_tracking_reset(ioapic); + for_each_set_bit(idx, &irr, IOAPIC_NUM_PINS) + ioapic_set_irq(ioapic, idx, 1, true); + + kvm_rtc_eoi_tracking_restore_all(ioapic); +} + + +static void update_handled_vectors(struct kvm_ioapic *ioapic) +{ + DECLARE_BITMAP(handled_vectors, 256); + int i; + + memset(handled_vectors, 0, sizeof(handled_vectors)); + for (i = 0; i < IOAPIC_NUM_PINS; ++i) + __set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors); + memcpy(ioapic->handled_vectors, handled_vectors, + sizeof(handled_vectors)); + smp_wmb(); +} + +void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap, + u32 *tmr) +{ + struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic; + union kvm_ioapic_redirect_entry *e; + int index; + + spin_lock(&ioapic->lock); + for (index = 0; index < IOAPIC_NUM_PINS; index++) { + e = &ioapic->redirtbl[index]; + if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG || + kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) || + index == RTC_GSI) { + if (kvm_apic_match_dest(vcpu, NULL, 0, + e->fields.dest_id, e->fields.dest_mode)) { + __set_bit(e->fields.vector, + (unsigned long *)eoi_exit_bitmap); + if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG) + __set_bit(e->fields.vector, + (unsigned long *)tmr); + } + } + } + spin_unlock(&ioapic->lock); +} + +#ifdef CONFIG_X86 +void kvm_vcpu_request_scan_ioapic(struct kvm *kvm) +{ + struct kvm_ioapic *ioapic = kvm->arch.vioapic; + + if (!ioapic) + return; + kvm_make_scan_ioapic_request(kvm); +} +#else +void kvm_vcpu_request_scan_ioapic(struct kvm *kvm) +{ + return; +} +#endif + +static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) +{ + unsigned index; + bool mask_before, mask_after; + union kvm_ioapic_redirect_entry *e; + + switch (ioapic->ioregsel) { + case IOAPIC_REG_VERSION: + /* Writes are ignored. */ + break; + + case IOAPIC_REG_APIC_ID: + ioapic->id = (val >> 24) & 0xf; + break; + + case IOAPIC_REG_ARB_ID: + break; + + default: + index = (ioapic->ioregsel - 0x10) >> 1; + + ioapic_debug("change redir index %x val %x\n", index, val); + if (index >= IOAPIC_NUM_PINS) + return; + e = &ioapic->redirtbl[index]; + mask_before = e->fields.mask; + if (ioapic->ioregsel & 1) { + e->bits &= 0xffffffff; + e->bits |= (u64) val << 32; + } else { + e->bits &= ~0xffffffffULL; + e->bits |= (u32) val; + e->fields.remote_irr = 0; + } + update_handled_vectors(ioapic); + mask_after = e->fields.mask; + if (mask_before != mask_after) + kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after); + if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG + && ioapic->irr & (1 << index)) + ioapic_service(ioapic, index, false); + kvm_vcpu_request_scan_ioapic(ioapic->kvm); + break; + } +} + +static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status) +{ + union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq]; + struct kvm_lapic_irq irqe; + int ret; + + if (entry->fields.mask) + return -1; + + ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x " + "vector=%x trig_mode=%x\n", + entry->fields.dest_id, entry->fields.dest_mode, + entry->fields.delivery_mode, entry->fields.vector, + entry->fields.trig_mode); + + irqe.dest_id = entry->fields.dest_id; + irqe.vector = entry->fields.vector; + irqe.dest_mode = entry->fields.dest_mode; + irqe.trig_mode = entry->fields.trig_mode; + irqe.delivery_mode = entry->fields.delivery_mode << 8; + irqe.level = 1; + irqe.shorthand = 0; + + if (irqe.trig_mode == IOAPIC_EDGE_TRIG) + ioapic->irr &= ~(1 << irq); + + if (irq == RTC_GSI && line_status) { + /* + * pending_eoi cannot ever become negative (see + * rtc_status_pending_eoi_check_valid) and the caller + * ensures that it is only called if it is >= zero, namely + * if rtc_irq_check_coalesced returns false). + */ + BUG_ON(ioapic->rtc_status.pending_eoi != 0); + ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, + ioapic->rtc_status.dest_map); + ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret); + } else + ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL); + + if (ret && irqe.trig_mode == IOAPIC_LEVEL_TRIG) + entry->fields.remote_irr = 1; + + return ret; +} + +int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id, + int level, bool line_status) +{ + int ret, irq_level; + + BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS); + + spin_lock(&ioapic->lock); + irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq], + irq_source_id, level); + ret = ioapic_set_irq(ioapic, irq, irq_level, line_status); + + spin_unlock(&ioapic->lock); + + return ret; +} + +void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id) +{ + int i; + + spin_lock(&ioapic->lock); + for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++) + __clear_bit(irq_source_id, &ioapic->irq_states[i]); + spin_unlock(&ioapic->lock); +} + +static void kvm_ioapic_eoi_inject_work(struct work_struct *work) +{ + int i; + struct kvm_ioapic *ioapic = container_of(work, struct kvm_ioapic, + eoi_inject.work); + spin_lock(&ioapic->lock); + for (i = 0; i < IOAPIC_NUM_PINS; i++) { + union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i]; + + if (ent->fields.trig_mode != IOAPIC_LEVEL_TRIG) + continue; + + if (ioapic->irr & (1 << i) && !ent->fields.remote_irr) + ioapic_service(ioapic, i, false); + } + spin_unlock(&ioapic->lock); +} + +#define IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT 10000 + +static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, + struct kvm_ioapic *ioapic, int vector, int trigger_mode) +{ + int i; + + for (i = 0; i < IOAPIC_NUM_PINS; i++) { + union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i]; + + if (ent->fields.vector != vector) + continue; + + if (i == RTC_GSI) + rtc_irq_eoi(ioapic, vcpu); + /* + * We are dropping lock while calling ack notifiers because ack + * notifier callbacks for assigned devices call into IOAPIC + * recursively. Since remote_irr is cleared only after call + * to notifiers if the same vector will be delivered while lock + * is dropped it will be put into irr and will be delivered + * after ack notifier returns. + */ + spin_unlock(&ioapic->lock); + kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i); + spin_lock(&ioapic->lock); + + if (trigger_mode != IOAPIC_LEVEL_TRIG) + continue; + + ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG); + ent->fields.remote_irr = 0; + if (!ent->fields.mask && (ioapic->irr & (1 << i))) { + ++ioapic->irq_eoi[i]; + if (ioapic->irq_eoi[i] == IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT) { + /* + * Real hardware does not deliver the interrupt + * immediately during eoi broadcast, and this + * lets a buggy guest make slow progress + * even if it does not correctly handle a + * level-triggered interrupt. Emulate this + * behavior if we detect an interrupt storm. + */ + schedule_delayed_work(&ioapic->eoi_inject, HZ / 100); + ioapic->irq_eoi[i] = 0; + trace_kvm_ioapic_delayed_eoi_inj(ent->bits); + } else { + ioapic_service(ioapic, i, false); + } + } else { + ioapic->irq_eoi[i] = 0; + } + } +} + +bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector) +{ + struct kvm_ioapic *ioapic = kvm->arch.vioapic; + smp_rmb(); + return test_bit(vector, ioapic->handled_vectors); +} + +void kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, int vector, int trigger_mode) +{ + struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic; + + spin_lock(&ioapic->lock); + __kvm_ioapic_update_eoi(vcpu, ioapic, vector, trigger_mode); + spin_unlock(&ioapic->lock); +} + +static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev) +{ + return container_of(dev, struct kvm_ioapic, dev); +} + +static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr) +{ + return ((addr >= ioapic->base_address && + (addr < ioapic->base_address + IOAPIC_MEM_LENGTH))); +} + +static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len, + void *val) +{ + struct kvm_ioapic *ioapic = to_ioapic(this); + u32 result; + if (!ioapic_in_range(ioapic, addr)) + return -EOPNOTSUPP; + + ioapic_debug("addr %lx\n", (unsigned long)addr); + ASSERT(!(addr & 0xf)); /* check alignment */ + + addr &= 0xff; + spin_lock(&ioapic->lock); + switch (addr) { + case IOAPIC_REG_SELECT: + result = ioapic->ioregsel; + break; + + case IOAPIC_REG_WINDOW: + result = ioapic_read_indirect(ioapic, addr, len); + break; + + default: + result = 0; + break; + } + spin_unlock(&ioapic->lock); + + switch (len) { + case 8: + *(u64 *) val = result; + break; + case 1: + case 2: + case 4: + memcpy(val, (char *)&result, len); + break; + default: + printk(KERN_WARNING "ioapic: wrong length %d\n", len); + } + return 0; +} + +static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len, + const void *val) +{ + struct kvm_ioapic *ioapic = to_ioapic(this); + u32 data; + if (!ioapic_in_range(ioapic, addr)) + return -EOPNOTSUPP; + + ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n", + (void*)addr, len, val); + ASSERT(!(addr & 0xf)); /* check alignment */ + + switch (len) { + case 8: + case 4: + data = *(u32 *) val; + break; + case 2: + data = *(u16 *) val; + break; + case 1: + data = *(u8 *) val; + break; + default: + printk(KERN_WARNING "ioapic: Unsupported size %d\n", len); + return 0; + } + + addr &= 0xff; + spin_lock(&ioapic->lock); + switch (addr) { + case IOAPIC_REG_SELECT: + ioapic->ioregsel = data & 0xFF; /* 8-bit register */ + break; + + case IOAPIC_REG_WINDOW: + ioapic_write_indirect(ioapic, data); + break; + + default: + break; + } + spin_unlock(&ioapic->lock); + return 0; +} + +static void kvm_ioapic_reset(struct kvm_ioapic *ioapic) +{ + int i; + + cancel_delayed_work_sync(&ioapic->eoi_inject); + for (i = 0; i < IOAPIC_NUM_PINS; i++) + ioapic->redirtbl[i].fields.mask = 1; + ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS; + ioapic->ioregsel = 0; + ioapic->irr = 0; + ioapic->id = 0; + memset(ioapic->irq_eoi, 0x00, IOAPIC_NUM_PINS); + rtc_irq_eoi_tracking_reset(ioapic); + update_handled_vectors(ioapic); +} + +static const struct kvm_io_device_ops ioapic_mmio_ops = { + .read = ioapic_mmio_read, + .write = ioapic_mmio_write, +}; + +int kvm_ioapic_init(struct kvm *kvm) +{ + struct kvm_ioapic *ioapic; + int ret; + + ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL); + if (!ioapic) + return -ENOMEM; + spin_lock_init(&ioapic->lock); + INIT_DELAYED_WORK(&ioapic->eoi_inject, kvm_ioapic_eoi_inject_work); + kvm->arch.vioapic = ioapic; + kvm_ioapic_reset(ioapic); + kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops); + ioapic->kvm = kvm; + mutex_lock(&kvm->slots_lock); + ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address, + IOAPIC_MEM_LENGTH, &ioapic->dev); + mutex_unlock(&kvm->slots_lock); + if (ret < 0) { + kvm->arch.vioapic = NULL; + kfree(ioapic); + } + + return ret; +} + +void kvm_ioapic_destroy(struct kvm *kvm) +{ + struct kvm_ioapic *ioapic = kvm->arch.vioapic; + + cancel_delayed_work_sync(&ioapic->eoi_inject); + if (ioapic) { + kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev); + kvm->arch.vioapic = NULL; + kfree(ioapic); + } +} + +int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state) +{ + struct kvm_ioapic *ioapic = ioapic_irqchip(kvm); + if (!ioapic) + return -EINVAL; + + spin_lock(&ioapic->lock); + memcpy(state, ioapic, sizeof(struct kvm_ioapic_state)); + spin_unlock(&ioapic->lock); + return 0; +} + +int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state) +{ + struct kvm_ioapic *ioapic = ioapic_irqchip(kvm); + if (!ioapic) + return -EINVAL; + + spin_lock(&ioapic->lock); + memcpy(ioapic, state, sizeof(struct kvm_ioapic_state)); + ioapic->irr = 0; + update_handled_vectors(ioapic); + kvm_vcpu_request_scan_ioapic(kvm); + kvm_ioapic_inject_all(ioapic, state->irr); + spin_unlock(&ioapic->lock); + return 0; +} |