mirror of
https://github.com/torvalds/linux.git
synced 2024-11-11 06:31:49 +00:00
743eeb0b01
Currently the method of dealing with an IO operation on a bus (PIO/MMIO) is to call the read or write callback for each device registered on the bus until we find a device which handles it. Since the number of devices on a bus can be significant due to ioeventfds and coalesced MMIO zones, this leads to a lot of overhead on each IO operation. Instead of registering devices, we now register ranges which points to a device. Lookup is done using an efficient bsearch instead of a linear search. Performance test was conducted by comparing exit count per second with 200 ioeventfds created on one byte and the guest is trying to access a different byte continuously (triggering usermode exits). Before the patch the guest has achieved 259k exits per second, after the patch the guest does 274k exits per second. Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
107 lines
2.9 KiB
C
107 lines
2.9 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 "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[16];
|
|
};
|
|
|
|
struct kvm_pic *kvm_create_pic(struct kvm *kvm);
|
|
void kvm_destroy_pic(struct kvm *kvm);
|
|
int kvm_pic_read_irq(struct kvm *kvm);
|
|
void kvm_pic_update_irq(struct kvm_pic *s);
|
|
|
|
static inline struct kvm_pic *pic_irqchip(struct kvm *kvm)
|
|
{
|
|
return kvm->arch.vpic;
|
|
}
|
|
|
|
static inline int irqchip_in_kernel(struct kvm *kvm)
|
|
{
|
|
int ret;
|
|
|
|
ret = (pic_irqchip(kvm) != NULL);
|
|
smp_rmb();
|
|
return ret;
|
|
}
|
|
|
|
void kvm_pic_reset(struct kvm_kpic_state *s);
|
|
|
|
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);
|
|
|
|
#endif
|