3d80840d96
Timers that fire between guest hlt and vcpu_block's add_wait_queue() are
ignored, possibly resulting in hangs.
Also make sure that atomic_inc and waitqueue_active tests happen in the
specified order, otherwise the following race is open:
CPU0 CPU1
if (waitqueue_active(wq))
add_wait_queue()
if (!atomic_read(pit_timer->pending))
schedule()
atomic_inc(pit_timer->pending)
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
96 lines
2.3 KiB
C
96 lines
2.3 KiB
C
/*
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* irq.c: API for in kernel interrupt controller
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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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#include <linux/module.h>
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#include <linux/kvm_host.h>
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#include "irq.h"
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#include "i8254.h"
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/*
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* check if there are pending timer events
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* to be processed.
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*/
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int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
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{
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int ret;
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ret = pit_has_pending_timer(vcpu);
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ret |= apic_has_pending_timer(vcpu);
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return ret;
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}
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EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
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/*
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* check if there is pending interrupt without
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* intack.
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*/
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int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
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{
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struct kvm_pic *s;
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if (kvm_apic_has_interrupt(v) == -1) { /* LAPIC */
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if (kvm_apic_accept_pic_intr(v)) {
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s = pic_irqchip(v->kvm); /* PIC */
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return s->output;
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} else
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return 0;
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}
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return 1;
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}
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EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
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/*
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* Read pending interrupt vector and intack.
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*/
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int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
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{
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struct kvm_pic *s;
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int vector;
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vector = kvm_get_apic_interrupt(v); /* APIC */
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if (vector == -1) {
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if (kvm_apic_accept_pic_intr(v)) {
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s = pic_irqchip(v->kvm);
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s->output = 0; /* PIC */
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vector = kvm_pic_read_irq(s);
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}
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}
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return vector;
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}
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EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
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void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
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{
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kvm_inject_apic_timer_irqs(vcpu);
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kvm_inject_pit_timer_irqs(vcpu);
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/* TODO: PIT, RTC etc. */
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}
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EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
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void kvm_timer_intr_post(struct kvm_vcpu *vcpu, int vec)
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{
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kvm_apic_timer_intr_post(vcpu, vec);
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kvm_pit_timer_intr_post(vcpu, vec);
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/* TODO: PIT, RTC etc. */
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}
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EXPORT_SYMBOL_GPL(kvm_timer_intr_post);
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