forked from mirrors/linux
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>
106 lines
2.9 KiB
C
106 lines
2.9 KiB
C
/*
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* irq.h: in kernel interrupt controller related definitions
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* Copyright (c) 2007, Intel Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
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* Place - Suite 330, Boston, MA 02111-1307 USA.
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* Authors:
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* Yaozu (Eddie) Dong <Eddie.dong@intel.com>
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*
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*/
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#ifndef __IRQ_H
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#define __IRQ_H
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#include <linux/mm_types.h>
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#include <linux/hrtimer.h>
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#include <linux/kvm_host.h>
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#include <linux/spinlock.h>
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#include "iodev.h"
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#include "ioapic.h"
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#include "lapic.h"
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#define PIC_NUM_PINS 16
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#define SELECT_PIC(irq) \
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((irq) < 8 ? KVM_IRQCHIP_PIC_MASTER : KVM_IRQCHIP_PIC_SLAVE)
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struct kvm;
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struct kvm_vcpu;
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struct kvm_kpic_state {
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u8 last_irr; /* edge detection */
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u8 irr; /* interrupt request register */
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u8 imr; /* interrupt mask register */
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u8 isr; /* interrupt service register */
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u8 priority_add; /* highest irq priority */
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u8 irq_base;
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u8 read_reg_select;
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u8 poll;
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u8 special_mask;
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u8 init_state;
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u8 auto_eoi;
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u8 rotate_on_auto_eoi;
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u8 special_fully_nested_mode;
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u8 init4; /* true if 4 byte init */
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u8 elcr; /* PIIX edge/trigger selection */
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u8 elcr_mask;
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u8 isr_ack; /* interrupt ack detection */
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struct kvm_pic *pics_state;
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};
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struct kvm_pic {
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spinlock_t lock;
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bool wakeup_needed;
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unsigned pending_acks;
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struct kvm *kvm;
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struct kvm_kpic_state pics[2]; /* 0 is master pic, 1 is slave pic */
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int output; /* intr from master PIC */
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struct kvm_io_device dev_master;
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struct kvm_io_device dev_slave;
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struct kvm_io_device dev_eclr;
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void (*ack_notifier)(void *opaque, int irq);
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unsigned long irq_states[16];
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};
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struct kvm_pic *kvm_create_pic(struct kvm *kvm);
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void kvm_destroy_pic(struct kvm *kvm);
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int kvm_pic_read_irq(struct kvm *kvm);
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void kvm_pic_update_irq(struct kvm_pic *s);
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static inline struct kvm_pic *pic_irqchip(struct kvm *kvm)
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{
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return kvm->arch.vpic;
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}
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static inline int irqchip_in_kernel(struct kvm *kvm)
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{
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int ret;
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ret = (pic_irqchip(kvm) != NULL);
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smp_rmb();
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return ret;
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}
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void kvm_pic_reset(struct kvm_kpic_state *s);
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void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu);
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void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu);
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void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu);
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void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu);
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void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu);
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void __kvm_migrate_timers(struct kvm_vcpu *vcpu);
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int apic_has_pending_timer(struct kvm_vcpu *vcpu);
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#endif
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