48 lines
1.4 KiB
C
48 lines
1.4 KiB
C
/*
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* Kernel-based Virtual Machine driver for Linux
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*
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* This module enables machines with Intel VT-x extensions to run virtual
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* machines without emulation or binary translation.
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*
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* timer support
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*
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* Copyright 2010 Red Hat, Inc. and/or its affiliates.
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*/
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#include <linux/kvm_host.h>
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#include <linux/kvm.h>
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#include <linux/hrtimer.h>
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#include <linux/atomic.h>
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#include "kvm_timer.h"
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enum hrtimer_restart kvm_timer_fn(struct hrtimer *data)
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{
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struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
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struct kvm_vcpu *vcpu = ktimer->vcpu;
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wait_queue_head_t *q = &vcpu->wq;
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/*
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* There is a race window between reading and incrementing, but we do
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* not care about potentially losing timer events in the !reinject
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* case anyway. Note: KVM_REQ_PENDING_TIMER is implicitly checked
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* in vcpu_enter_guest.
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*/
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if (ktimer->reinject || !atomic_read(&ktimer->pending)) {
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atomic_inc(&ktimer->pending);
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/* FIXME: this code should not know anything about vcpus */
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kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
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}
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if (waitqueue_active(q))
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wake_up_interruptible(q);
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if (ktimer->t_ops->is_periodic(ktimer)) {
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hrtimer_add_expires_ns(&ktimer->timer, ktimer->period);
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return HRTIMER_RESTART;
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} else
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return HRTIMER_NORESTART;
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}
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