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linux/virt/kvm/irq_comm.c
Sheng Yang 5550af4df1 KVM: Fix guest shared interrupt with in-kernel irqchip
Every call of kvm_set_irq() should offer an irq_source_id, which is
allocated by kvm_request_irq_source_id(). Based on irq_source_id, we
identify the irq source and implement logical OR for shared level
interrupts.

The allocated irq_source_id can be freed by kvm_free_irq_source_id().

Currently, we support at most sizeof(unsigned long) different irq sources.

[Amit: - rebase to kvm.git HEAD
       - move definition of KVM_USERSPACE_IRQ_SOURCE_ID to common file
       - move kvm_request_irq_source_id to the update_irq ioctl]

[Xiantao: - Add kvm/ia64 stuff and make it work for kvm/ia64 guests]

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-28 14:21:34 +02:00

97 lines
2.9 KiB
C

/*
* irq_comm.c: Common API for in kernel interrupt controller
* Copyright (c) 2007, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
* Authors:
* Yaozu (Eddie) Dong <Eddie.dong@intel.com>
*
*/
#include <linux/kvm_host.h>
#include "irq.h"
#include "ioapic.h"
/* This should be called with the kvm->lock mutex held */
void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
{
unsigned long *irq_state = (unsigned long *)&kvm->arch.irq_states[irq];
/* Logical OR for level trig interrupt */
if (level)
set_bit(irq_source_id, irq_state);
else
clear_bit(irq_source_id, irq_state);
/* Not possible to detect if the guest uses the PIC or the
* IOAPIC. So set the bit in both. The guest will ignore
* writes to the unused one.
*/
kvm_ioapic_set_irq(kvm->arch.vioapic, irq, !!(*irq_state));
#ifdef CONFIG_X86
kvm_pic_set_irq(pic_irqchip(kvm), irq, !!(*irq_state));
#endif
}
void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi)
{
struct kvm_irq_ack_notifier *kian;
struct hlist_node *n;
hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
if (kian->gsi == gsi)
kian->irq_acked(kian);
}
void kvm_register_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian)
{
hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
}
void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian)
{
hlist_del(&kian->link);
}
/* The caller must hold kvm->lock mutex */
int kvm_request_irq_source_id(struct kvm *kvm)
{
unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
int irq_source_id = find_first_zero_bit(bitmap,
sizeof(kvm->arch.irq_sources_bitmap));
if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
irq_source_id = -EFAULT;
} else
set_bit(irq_source_id, bitmap);
return irq_source_id;
}
void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
{
int i;
if (irq_source_id <= 0 ||
irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
return;
}
for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
}