virt/kvm/irq_comm.c

   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 */
  28 void 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
  48 void 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
  58 void 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
  64 void 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 */
  70 int 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
  87 void 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 }