2 * This file is part of the Palacios Virtual Machine Monitor developed
3 * by the V3VEE Project with funding from the United States National
4 * Science Foundation and the Department of Energy.
6 * The V3VEE Project is a joint project between Northwestern University
7 * and the University of New Mexico. You can find out more at
10 * Copyright (c) 2008, Peter Dinda <pdinda@northwestern.edu>
11 * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
12 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
13 * All rights reserved.
15 * Author: Peter Dinda <pdinda@northwestern.edu>
17 * This is free software. You are permitted to use,
18 * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
21 #include <palacios/vmm_halt.h>
22 #include <palacios/vmm_intr.h>
25 #ifndef CONFIG_DEBUG_HALT
27 #define PrintDebug(fmt, args...)
33 // This should trigger a #GP if cpl != 0, otherwise, yield to host
36 int v3_handle_halt(struct guest_info * info) {
39 v3_raise_exception(info, GPF_EXCEPTION);
42 uint64_t yield_start = 0;
43 uint64_t yield_stop = 0;
46 PrintDebug("CPU Yield\n");
53 //v3_update_time(info, yield_stop - yield_start);
54 gap = yield_stop - yield_start;
56 /* WARNING!!! WARNING!!!
58 * DO NOT REMOVE THIS CONDITIONAL!!!
60 * It is common for an OS to issue an IO op, and then sit in a halt loop
61 * waiting for the device to complete and raise an irq.
62 * If you remove this then the timer interrupt will ALWAYS subvert the completion
63 * interrupt and stall the guest.
65 if (!v3_intr_pending(info)) {
66 v3_advance_time(info);
70 PrintDebug("CPU Yield Done (%d cycles)\n", gap);