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linux/arch/x86/kvm/irq.h
Yi Wang e3c89f5dd1 KVM: x86: Don't re-setup empty IRQ routing when KVM_CAP_SPLIT_IRQCHIP
Now that KVM sets up empty IRQ routing during VM creation, don't recreate
empty routing during KVM_CAP_SPLIT_IRQCHIP.  Setting IRQ routes during
KVM_CAP_SPLIT_IRQCHIP can result in 20+ milliseconds of delay due to the
synchronize_srcu_expedited() call in kvm_set_irq_routing().

Note, the empty routing is guaranteed to be intact as KVM x86 only allows
changing the IRQ routing after an in-kernel IRQCHIP has been created, and
KVM_CAP_SPLIT_IRQCHIP is disallowed after creating an IRQCHIP.

Signed-off-by: Yi Wang <foxywang@tencent.com>
Link: https://lore.kernel.org/r/20240506101751.3145407-3-foxywang@tencent.com
[sean: massage changelog, remove unused empty_routing array]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-11 14:18:40 -07:00

114 lines
2.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* irq.h: in kernel interrupt controller related definitions
* Copyright (c) 2007, Intel Corporation.
*
* 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 "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_elcr;
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 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 pic_in_kernel(struct kvm *kvm)
{
return irqchip_kernel(kvm);
}
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_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
struct kvm_lapic_irq *irq,
struct dest_map *dest_map);
#endif