linux/virt/kvm/irq_comm.c
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   1/*
   2 * irq_comm.c: Common API for in kernel interrupt controller
   3 * Copyright (c) 2007, Intel Corporation.
   4 *
   5 * This program is free software; you can redistribute it and/or modify it
   6 * under the terms and conditions of the GNU General Public License,
   7 * version 2, as published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope it will be useful, but WITHOUT
  10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12 * more details.
  13 *
  14 * You should have received a copy of the GNU General Public License along with
  15 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  16 * Place - Suite 330, Boston, MA 02111-1307 USA.
  17 * Authors:
  18 *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
  19 *
  20 */
  21
  22#include <linux/kvm_host.h>
  23#include "irq.h"
  24
  25#include "ioapic.h"
  26
  27/* This should be called with the kvm->lock mutex held */
  28void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
  29{
  30        unsigned long *irq_state = (unsigned long *)&kvm->arch.irq_states[irq];
  31
  32        /* Logical OR for level trig interrupt */
  33        if (level)
  34                set_bit(irq_source_id, irq_state);
  35        else
  36                clear_bit(irq_source_id, irq_state);
  37
  38        /* Not possible to detect if the guest uses the PIC or the
  39         * IOAPIC.  So set the bit in both. The guest will ignore
  40         * writes to the unused one.
  41         */
  42        kvm_ioapic_set_irq(kvm->arch.vioapic, irq, !!(*irq_state));
  43#ifdef CONFIG_X86
  44        kvm_pic_set_irq(pic_irqchip(kvm), irq, !!(*irq_state));
  45#endif
  46}
  47
  48void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi)
  49{
  50        struct kvm_irq_ack_notifier *kian;
  51        struct hlist_node *n;
  52
  53        hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
  54                if (kian->gsi == gsi)
  55                        kian->irq_acked(kian);
  56}
  57
  58void kvm_register_irq_ack_notifier(struct kvm *kvm,
  59                                   struct kvm_irq_ack_notifier *kian)
  60{
  61        hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
  62}
  63
  64void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
  65{
  66        hlist_del_init(&kian->link);
  67}
  68
  69/* The caller must hold kvm->lock mutex */
  70int kvm_request_irq_source_id(struct kvm *kvm)
  71{
  72        unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
  73        int irq_source_id = find_first_zero_bit(bitmap,
  74                                sizeof(kvm->arch.irq_sources_bitmap));
  75
  76        if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
  77                printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
  78                return -EFAULT;
  79        }
  80
  81        ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
  82        set_bit(irq_source_id, bitmap);
  83
  84        return irq_source_id;
  85}
  86
  87void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
  88{
  89        int i;
  90
  91        ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
  92
  93        if (irq_source_id < 0 ||
  94            irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
  95                printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
  96                return;
  97        }
  98        for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
  99                clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
 100        clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 101}
 102