/* * Kernel-based Virtual Machine driver for Linux * * This module enables machines with Intel VT-x extensions to run virtual * machines without emulation or binary translation. * * timer support * * Copyright 2010 Red Hat, Inc. and/or its affiliates. * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. */ #include #include #include #include #include "kvm_timer.h" static int __kvm_timer_fn(struct kvm_vcpu *vcpu, struct kvm_timer *ktimer) { int restart_timer = 0; wait_queue_head_t *q = &vcpu->wq; /* * There is a race window between reading and incrementing, but we do * not care about potentially loosing timer events in the !reinject * case anyway. Note: KVM_REQ_PENDING_TIMER is implicitly checked * in vcpu_enter_guest. */ if (ktimer->reinject || !atomic_read(&ktimer->pending)) { atomic_inc(&ktimer->pending); /* FIXME: this code should not know anything about vcpus */ kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu); } if (waitqueue_active(q)) wake_up_interruptible(q); if (ktimer->t_ops->is_periodic(ktimer)) { hrtimer_add_expires_ns(&ktimer->timer, ktimer->period); restart_timer = 1; } return restart_timer; } enum hrtimer_restart kvm_timer_fn(struct hrtimer *data) { int restart_timer; struct kvm_vcpu *vcpu; struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer); vcpu = ktimer->vcpu; if (!vcpu) return HRTIMER_NORESTART; restart_timer = __kvm_timer_fn(vcpu, ktimer); if (restart_timer) return HRTIMER_RESTART; else return HRTIMER_NORESTART; }