alistair23-linux/arch/x86/kvm/irq.h
David Hildenbrand 5c0aea0e8d KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING
We needed the lock to avoid racing with creation of the irqchip on x86. As
kvm_set_irq_routing() calls srcu_synchronize_expedited(), this lock
might be held for a longer time.

Let's introduce an arch specific callback to check if we can actually
add irq routes. For x86, all we have to do is check if we have an
irqchip in the kernel. We don't need kvm->lock at that point as the
irqchip is marked as inititalized only when actually fully created.

Reported-by: Steve Rutherford <srutherford@google.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Fixes: 1df6ddede1 ("KVM: x86: race between KVM_SET_GSI_ROUTING and KVM_CREATE_IRQCHIP")
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-02 14:45:45 +02:00

130 lines
3.5 KiB
C

/*
* irq.h: in kernel interrupt controller related definitions
* 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>
*
*/
#ifndef __IRQ_H
#define __IRQ_H
#include <linux/mm_types.h>
#include <linux/hrtimer.h>
#include <linux/kvm_host.h>
#include <linux/spinlock.h>
#include <kvm/iodev.h>
#include "ioapic.h"
#include "lapic.h"
#define PIC_NUM_PINS 16
#define SELECT_PIC(irq) \
((irq) < 8 ? KVM_IRQCHIP_PIC_MASTER : KVM_IRQCHIP_PIC_SLAVE)
struct kvm;
struct kvm_vcpu;
struct kvm_kpic_state {
u8 last_irr; /* edge detection */
u8 irr; /* interrupt request register */
u8 imr; /* interrupt mask register */
u8 isr; /* interrupt service register */
u8 priority_add; /* highest irq priority */
u8 irq_base;
u8 read_reg_select;
u8 poll;
u8 special_mask;
u8 init_state;
u8 auto_eoi;
u8 rotate_on_auto_eoi;
u8 special_fully_nested_mode;
u8 init4; /* true if 4 byte init */
u8 elcr; /* PIIX edge/trigger selection */
u8 elcr_mask;
u8 isr_ack; /* interrupt ack detection */
struct kvm_pic *pics_state;
};
struct kvm_pic {
spinlock_t lock;
bool wakeup_needed;
unsigned pending_acks;
struct kvm *kvm;
struct kvm_kpic_state pics[2]; /* 0 is master pic, 1 is slave pic */
int output; /* intr from master PIC */
struct kvm_io_device dev_master;
struct kvm_io_device dev_slave;
struct kvm_io_device dev_eclr;
void (*ack_notifier)(void *opaque, int irq);
unsigned long irq_states[PIC_NUM_PINS];
};
int kvm_pic_init(struct kvm *kvm);
void kvm_pic_destroy(struct kvm *kvm);
int kvm_pic_read_irq(struct kvm *kvm);
void kvm_pic_update_irq(struct kvm_pic *s);
static inline int pic_in_kernel(struct kvm *kvm)
{
int mode = kvm->arch.irqchip_mode;
/* Matches smp_wmb() when setting irqchip_mode */
smp_rmb();
return mode == KVM_IRQCHIP_KERNEL;
}
static inline int irqchip_split(struct kvm *kvm)
{
int mode = kvm->arch.irqchip_mode;
/* Matches smp_wmb() when setting irqchip_mode */
smp_rmb();
return mode == KVM_IRQCHIP_SPLIT;
}
static inline int irqchip_kernel(struct kvm *kvm)
{
int mode = kvm->arch.irqchip_mode;
/* Matches smp_wmb() when setting irqchip_mode */
smp_rmb();
return mode == KVM_IRQCHIP_KERNEL;
}
static inline int irqchip_in_kernel(struct kvm *kvm)
{
int mode = kvm->arch.irqchip_mode;
/* Matches smp_wmb() when setting irqchip_mode */
smp_rmb();
return mode != KVM_IRQCHIP_NONE;
}
void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu);
void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu);
void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu);
void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu);
void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu);
void __kvm_migrate_timers(struct kvm_vcpu *vcpu);
int apic_has_pending_timer(struct kvm_vcpu *vcpu);
int kvm_setup_default_irq_routing(struct kvm *kvm);
int kvm_setup_empty_irq_routing(struct kvm *kvm);
#endif