1 files changed, 65 insertions, 0 deletions

diff --git a/arch/x86/kvm/timer.c b/arch/x86/kvm/timer.c
new file mode 100644
index 00000000000..ae432ea1cd8
--- /dev/null
+++ b/arch/x86/kvm/timer.c
@@ -0,0 +1,65 @@
+/*
+ * 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 <linux/kvm_host.h>
+#include <linux/kvm.h>
+#include <linux/hrtimer.h>
+#include <linux/atomic.h>
+#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 losing 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;
+}
+