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