palacios/src/palacios/vmm_time.c

   1 /*
   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.
   5  *
   6  * The V3VEE Project is a joint project between Northwestern University
   7  * and the University of New Mexico.  You can find out more at
   8  * http://www.v3vee.org
   9  *
  10  * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
  11  * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
  12  * All rights reserved.
  13  *
  14  * Author: Jack Lange <jarusl@cs.northwestern.edu>
  15  *
  16  * This is free software.  You are permitted to use,
  17  * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
  18  */
  19
  20 #include <palacios/vmm_time.h>
  21 #include <palacios/vmm.h>
  22 #include <palacios/vm_guest.h>
  23
  24 #ifndef CONFIG_DEBUG_TIME
  25 #undef PrintDebug
  26 #define PrintDebug(fmt, args...)
  27 #endif
  28
  29 static int handle_cpufreq_hcall(struct guest_info * info, uint_t hcall_id, void * priv_data) {
  30     struct vm_time * time_state = &(info->time_state);
  31
  32     info->vm_regs.rbx = time_state->cpu_freq;
  33
  34     PrintDebug("Guest request cpu frequency: return %ld\n", (long)info->vm_regs.rbx);
  35
  36     return 0;
  37 }
  38
  39
  40
  41 void v3_init_time(struct guest_info * info) {
  42     struct vm_time * time_state = &(info->time_state);
  43
  44     time_state->cpu_freq = V3_CPU_KHZ();
  45
  46     time_state->pause_time = 0;
  47     time_state->last_update = 0;
  48     time_state->host_offset = 0;
  49
  50     INIT_LIST_HEAD(&(time_state->timers));
  51     time_state->num_timers = 0;
  52
  53     v3_register_hypercall(info->vm_info, TIME_CPUFREQ_HCALL, handle_cpufreq_hcall, NULL);
  54 }
  55
  56 uint64_t v3_get_host_time(struct guest_info * info) {
  57     uint64_t tmp;
  58     rdtscll(tmp);
  59     return tmp;
  60 }
  61
  62 uint64_t v3_get_guest_time(struct guest_info * info) {
  63     return v3_get_host_time(info) + info->time_state.host_offset;
  64 }
  65
  66
  67 int v3_start_time(struct guest_info * info) {
  68     /* We start running with guest_time == host_time */
  69     uint64_t t = v3_get_host_time(info);
  70
  71     PrintDebug("Starting initial guest time as %llu\n", t);
  72     info->time_state.last_update = t;
  73     info->time_state.pause_time = t;
  74     return 0;
  75 }
  76
  77 int v3_pause_time(struct guest_info * info) {
  78     V3_ASSERT(info->time_state.pause_time == 0);
  79     info->time_state.pause_time = v3_get_guest_time(info);
  80     PrintDebug("Time paused at guest time as %llu\n",
  81                info->time_state.pause_time);
  82     return 0;
  83 }
  84
  85 int v3_resume_time(struct guest_info * info) {
  86     uint64_t t = v3_get_host_time(info);
  87     V3_ASSERT(info->time_state.pause_time != 0);
  88     info->time_state.host_offset =
  89         (sint64_t)info->time_state.pause_time - (sint64_t)t;
  90 #ifdef OPTION_TIME_ADJUST_TSC_OFFSET
  91     /* XXX Adjust host_offset towards zero based on resolution/accuracy
  92      * constraints. */
  93 #endif
  94     info->time_state.pause_time = 0;
  95     PrintDebug("Time resumed paused at guest time as %llu "
  96                "offset %lld from host time.\n", t, info->time_state.host_offset);
  97
  98     return 0;
  99 }
 100
 101 int v3_add_timer(struct guest_info * info, struct vm_timer_ops * ops,
 102              void * private_data) {
 103     struct vm_timer * timer = NULL;
 104     timer = (struct vm_timer *)V3_Malloc(sizeof(struct vm_timer));
 105     V3_ASSERT(timer != NULL);
 106
 107     timer->ops = ops;
 108     timer->private_data = private_data;
 109
 110     list_add(&(timer->timer_link), &(info->time_state.timers));
 111     info->time_state.num_timers++;
 112
 113     return 0;
 114 }
 115
 116
 117 int v3_remove_timer(struct guest_info * info, struct vm_timer * timer) {
 118     list_del(&(timer->timer_link));
 119     info->time_state.num_timers--;
 120
 121     V3_Free(timer);
 122     return 0;
 123 }
 124
 125 void v3_update_timers(struct guest_info * info) {
 126     struct vm_timer * tmp_timer;
 127     uint64_t old_time = info->time_state.last_update;
 128     uint64_t cycles;
 129
 130     info->time_state.last_update = v3_get_guest_time(info);
 131     cycles = info->time_state.last_update - old_time;
 132
 133     list_for_each_entry(tmp_timer, &(info->time_state.timers), timer_link) {
 134         tmp_timer->ops->update_timer(info, cycles, info->time_state.cpu_freq, tmp_timer->private_data);
 135     }
 136 }