diff options
Diffstat (limited to 'arch/x86/kvm/ioapic.c')
| -rw-r--r-- | arch/x86/kvm/ioapic.c | 114 |
1 files changed, 79 insertions, 35 deletions
diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c index 765943d7cfa5..2c2783296aed 100644 --- a/arch/x86/kvm/ioapic.c +++ b/arch/x86/kvm/ioapic.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: LGPL-2.1-or-later /* * Copyright (C) 2001 MandrakeSoft S.A. * Copyright 2010 Red Hat, Inc. and/or its affiliates. @@ -8,24 +9,11 @@ * 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. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kvm_host.h> #include <linux/kvm.h> @@ -40,11 +28,11 @@ #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" +#include "trace.h" static int ioapic_service(struct kvm_ioapic *vioapic, int irq, bool line_status); @@ -295,11 +283,8 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, ulong *ioapic_handled_vectors) index == RTC_GSI) { u16 dm = kvm_lapic_irq_dest_mode(!!e->fields.dest_mode); - if (kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT, - e->fields.dest_id, dm) || - kvm_apic_pending_eoi(vcpu, e->fields.vector)) - __set_bit(e->fields.vector, - ioapic_handled_vectors); + kvm_scan_ioapic_irq(vcpu, e->fields.dest_id, dm, + e->fields.vector, ioapic_handled_vectors); } } spin_unlock(&ioapic->lock); @@ -312,6 +297,42 @@ void kvm_arch_post_irq_ack_notifier_list_update(struct kvm *kvm) kvm_make_scan_ioapic_request(kvm); } +void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq, + struct kvm_irq_mask_notifier *kimn) +{ + struct kvm_ioapic *ioapic = kvm->arch.vioapic; + + mutex_lock(&kvm->irq_lock); + kimn->irq = irq; + hlist_add_head_rcu(&kimn->link, &ioapic->mask_notifier_list); + mutex_unlock(&kvm->irq_lock); +} + +void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq, + struct kvm_irq_mask_notifier *kimn) +{ + mutex_lock(&kvm->irq_lock); + hlist_del_rcu(&kimn->link); + mutex_unlock(&kvm->irq_lock); + synchronize_srcu(&kvm->irq_srcu); +} + +void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin, + bool mask) +{ + struct kvm_ioapic *ioapic = kvm->arch.vioapic; + struct kvm_irq_mask_notifier *kimn; + int idx, gsi; + + idx = srcu_read_lock(&kvm->irq_srcu); + gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin); + if (gsi != -1) + hlist_for_each_entry_rcu(kimn, &ioapic->mask_notifier_list, link) + if (kimn->irq == gsi) + kimn->func(kimn, mask); + srcu_read_unlock(&kvm->irq_srcu, idx); +} + static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) { unsigned index; @@ -367,9 +388,39 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) 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); + if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG && + ioapic->irr & (1 << index) && !e->fields.mask && !e->fields.remote_irr) { + /* + * Pending status in irr may be outdated: the IRQ line may have + * already been deasserted by a device while the IRQ was masked. + * This occurs, for instance, if the interrupt is handled in a + * Linux guest as a oneshot interrupt (IRQF_ONESHOT). In this + * case the guest acknowledges the interrupt to the device in + * its threaded irq handler, i.e. after the EOI but before + * unmasking, so at the time of unmasking the IRQ line is + * already down but our pending irr bit is still set. In such + * cases, injecting this pending interrupt to the guest is + * buggy: the guest will receive an extra unwanted interrupt. + * + * So we need to check here if the IRQ is actually still pending. + * As we are generally not able to probe the IRQ line status + * directly, we do it through irqfd resampler. Namely, we clear + * the pending status and notify the resampler that this interrupt + * is done, without actually injecting it into the guest. If the + * IRQ line is actually already deasserted, we are done. If it is + * still asserted, a new interrupt will be shortly triggered + * through irqfd and injected into the guest. + * + * If, however, it's not possible to resample (no irqfd resampler + * registered for this irq), then unconditionally inject this + * pending interrupt into the guest, so the guest will not miss + * an interrupt, although may get an extra unwanted interrupt. + */ + if (kvm_notify_irqfd_resampler(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index)) + ioapic->irr &= ~(1 << index); + else + ioapic_service(ioapic, index, false); + } if (e->fields.delivery_mode == APIC_DM_FIXED) { struct kvm_lapic_irq irq; @@ -451,9 +502,11 @@ static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status) return ret; } -int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id, - int level, bool line_status) +int kvm_ioapic_set_irq(struct kvm_kernel_irq_routing_entry *e, struct kvm *kvm, + int irq_source_id, int level, bool line_status) { + struct kvm_ioapic *ioapic = kvm->arch.vioapic; + int irq = e->irqchip.pin; int ret, irq_level; BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS); @@ -468,16 +521,6 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id, 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; @@ -690,6 +733,7 @@ int kvm_ioapic_init(struct kvm *kvm) return -ENOMEM; spin_lock_init(&ioapic->lock); INIT_DELAYED_WORK(&ioapic->eoi_inject, kvm_ioapic_eoi_inject_work); + INIT_HLIST_HEAD(&ioapic->mask_notifier_list); kvm->arch.vioapic = ioapic; kvm_ioapic_reset(ioapic); kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops); |