/* We start running with guest_time == host_time */
uint64_t t = v3_get_host_time(&info->time_state);
- info->time_state.vm_enter_host_time = 0;
- info->time_state.vm_pause_host_time = t;
info->time_state.initial_host_time = t;
info->yield_start_cycle = t;
return 0;
}
-int v3_offset_time( struct guest_info * info, sint64_t offset )
-{
- struct vm_core_time * time_state = &(info->time_state);
- if (info->vm_info->time_state.follow_host_time) {
- PrintError("Cannot offset guest time passage while slaved to host clock.\n");
- return 1;
- } else {
- time_state->guest_cycles += offset;
- }
- return 0;
-}
+static sint64_t
+host_to_guest_cycles(struct guest_info * info, sint64_t host_cycles) {
+ struct vm_core_time * core_time_state = &(info->time_state);
+ uint32_t cl_num, cl_denom;
-int v3_skip_time(struct guest_info * info) {
- if (info->vm_info->time_state.follow_host_time) {
- PrintError("Cannot skip guest time passage while slaved to host clock.\n");
- return 1;
- } else {
- info->time_state.vm_pause_host_time = v3_get_host_time(&info->time_state);
- }
- return 0;
-}
+ cl_num = core_time_state->clock_ratio_num;
+ cl_denom = core_time_state->clock_ratio_denom;
-static sint64_t host_to_guest_cycles(struct guest_info * info, sint64_t host_cycles) {
- return (host_cycles * info->time_state.clock_ratio_num) / info->time_state.clock_ratio_denom;
+ return (host_cycles * cl_num) / cl_denom;
}
-int v3_time_advance_cycles(struct guest_info * info, uint64_t *host_cycles)
-{
- uint64_t t = v3_get_host_time(&info->time_state);
-
- info->time_state.vm_pause_host_time = t;
+/*
+static sint64_t
+guest_to_host_cycles(struct guest_info * info, sint64_t guest_cycles) {
+ struct vm_core_time * core_time_state = &(info->time_state);
+ uint32_t cl_num, cl_denom;
- if (info->vm_info->time_state.follow_host_time) {
- /* How many guest cycles should have elapsed? */
- sint64_t host_elapsed = t - info->time_state.initial_host_time;
- sint64_t guest_elapsed = host_to_guest_cycles(info, host_elapsed);
+ cl_num = core_time_state->clock_ratio_num;
+ cl_denom = core_time_state->clock_ratio_denom;
- info->time_state.guest_cycles = guest_elapsed;
- } else {
- uint64_t guest_cycles;
- if (*host_cycles) {
- guest_cycles = host_to_guest_cycles(info, *host_cycles);
- } else {
- guest_cycles = host_to_guest_cycles(info, (sint64_t)(t - info->time_state.vm_pause_host_time));
- }
- info->time_state.guest_cycles += guest_cycles;
- }
-
- return 0;
-}
-
-int v3_advance_time(struct guest_info * info) {
- return v3_time_advance_cycles(info, NULL);
-}
-
-/* Called immediately upon entry in the the VMM */
-int
-v3_time_exit_vm( struct guest_info * info, uint64_t * host_cycles )
-{
- return v3_time_advance_cycles(info, host_cycles);
+ return (guest_cycles * cl_denom) / cl_num;
}
+*/
-/* Called immediately prior to entry to the VM */
-int
-v3_time_enter_vm( struct guest_info * info )
+int v3_advance_time(struct guest_info * info, uint64_t *host_cycles)
{
- struct vm_core_time * time_state = &(info->time_state);
- uint64_t host_time = v3_get_host_time(&info->time_state);
+ uint64_t guest_cycles;
+
+ if (info->flags & VM_TIME_SLAVE_HOST) {
+ struct v3_time *vm_ts = &(info->vm_info->time_state);
+ uint64_t ht = v3_get_host_time(&info->time_state);
+ uint64_t host_elapsed = ht - info->time_state.initial_host_time;
+ uint64_t dilated_elapsed = (host_elapsed * vm_ts->td_num) / vm_ts->td_denom;
+ uint64_t guest_elapsed = host_to_guest_cycles(info, dilated_elapsed);
+ guest_cycles = guest_elapsed - v3_get_guest_time(&info->time_state);
+ } else if (*host_cycles) {
+ guest_cycles = host_to_guest_cycles(info, *host_cycles);
+ } else {
+ guest_cycles = 0;
+ }
+
+ info->time_state.guest_cycles += guest_cycles;
- time_state->vm_enter_host_time = host_time;
return 0;
-}
-
+}
-
struct v3_timer * v3_add_timer(struct guest_info * info,
struct v3_timer_ops * ops,
void * private_data) {
return;
}
- PrintDebug("Updating timers with %lld elapsed cycles.\n", cycles);
+ //PrintDebug("Updating timers with %lld elapsed cycles.\n", cycles);
list_for_each_entry(tmp_timer, &(time_state->timers), timer_link) {
tmp_timer->ops->update_timer(info, cycles, time_state->guest_cpu_freq, tmp_timer->private_data);
}
return 0;
}
+static int
+handle_time_configuration(struct v3_vm_info * vm, v3_cfg_tree_t *cfg) {
+ v3_cfg_tree_t * slave;
+
+ vm->time_state.flags = 0;
+ vm->time_state.td_num = vm->time_state.td_denom = 1;
+
+ if (!cfg) return 0;
+
+ slave = v3_cfg_subtree(cfg, "slave");
+
+ if (slave) {
+ char *source = v3_cfg_val(slave, "source");
+ v3_cfg_tree_t *dilation = v3_cfg_subtree(slave, "dilation");
+ if (source) {
+ if (strcasecmp(source, "host") == 0) {
+ PrintDebug("Slaving VM guest time to host time.\n");
+ vm->time_state.flags |= V3_TIME_SLAVE_HOST;
+ } else {
+ PrintError("Unknown time source for slaving.\n");
+ }
+ }
+ if (dilation && (vm->time_state.flags & V3_TIME_SLAVE_HOST)) {
+ char *str1, *str2;
+ uint32_t num = 1, denom = 1;
+ if ((str1 = v3_cfg_val(dilation, "value"))) {
+ denom = atoi(str1);
+ } else if ((str1 = v3_cfg_val(dilation, "num"))
+ && (str2 = v3_cfg_val(dilation, "denom"))) {
+ num = atoi(str1);
+ denom = atoi(str2);
+ }
+ if ((num > 0) && (denom > 0)) {
+ vm->time_state.td_num = num;
+ vm->time_state.td_denom = denom;
+ }
+ if ((vm->time_state.td_num != 1)
+ || (vm->time_state.td_denom != 1)) {
+ V3_Print("Time dilated from host time by a factor of %d/%d"
+ " in guest.\n", denom, num);
+ } else {
+ PrintError("Time dilation specifier in configuration did not"
+ " result in actual time dilation in VM.\n");
+ }
+ }
+ }
+ return 0;
+}
int v3_init_time_vm(struct v3_vm_info * vm) {
+ v3_cfg_tree_t * cfg_tree = vm->cfg_data->cfg;
int ret;
-
+
PrintDebug("Installing TSC MSR hook.\n");
ret = v3_hook_msr(vm, TSC_MSR,
tsc_msr_read_hook, tsc_msr_write_hook, NULL);
ret = v3_register_hypercall(vm, TIME_CPUFREQ_HCALL,
handle_cpufreq_hcall, NULL);
- vm->time_state.td_num = 1;
- vm->time_state.td_denom = 1;
- PrintDebug("Setting base time dilation factor to %d/%d.\n",
- vm->time_state.td_num, vm->time_state.td_denom);
+ handle_time_configuration(vm, v3_cfg_subtree(cfg_tree, "time"));
- vm->time_state.follow_host_time = 1;
- PrintDebug("Locking guest time to host time.\n");
return ret;
}
v3_remove_hypercall(vm, TIME_CPUFREQ_HCALL);
}
+static uint32_t
+gcd ( uint32_t a, uint32_t b )
+{
+ uint32_t c;
+ while ( a != 0 ) {
+ c = a; a = b%a; b = c;
+ }
+ return b;
+}
+
+static int compute_core_ratios(struct guest_info * info,
+ uint32_t hostKhz, uint32_t guestKhz)
+{
+ struct vm_core_time * time_state = &(info->time_state);
+ uint32_t khzGCD;
+
+ /* Compute these using the GCD() of the guest and host CPU freq.
+ * If the GCD is too small, make it "big enough" */
+ khzGCD = gcd(hostKhz, guestKhz);
+ if (khzGCD < 1024)
+ khzGCD = 1000;
+
+ time_state->clock_ratio_num = guestKhz / khzGCD;
+ time_state->clock_ratio_denom = hostKhz / khzGCD;
+
+ time_state->ipc_ratio_num = 1;
+ time_state->ipc_ratio_denom = 1;
+
+ return 0;
+}
+
void v3_init_time_core(struct guest_info * info) {
struct vm_core_time * time_state = &(info->time_state);
v3_cfg_tree_t * cfg_tree = info->core_cfg_data;
time_state->guest_cpu_freq = time_state->host_cpu_freq;
}
-
- /* Compute these using the GCD() of the guest and host CPU freq.
- * If the GCD is too small, make it "big enough" */
- time_state->clock_ratio_num = 1;
- time_state->clock_ratio_denom = 1;
-
PrintDebug("Logical Core %d (vcpu=%d) CPU frequency set to %d KHz (host CPU frequency = %d KHz).\n",
info->pcpu_id, info->vcpu_id,
time_state->guest_cpu_freq,
time_state->host_cpu_freq);
+ compute_core_ratios(info, time_state->host_cpu_freq,
+ time_state->guest_cpu_freq);
+
+ PrintDebug(" td_mult = %d/%d, cl_mult = %u/%u, ipc_mult = %u/%u.\n",
+ info->vm_info->time_state.td_num,
+ info->vm_info->time_state.td_denom,
+ time_state->clock_ratio_num, time_state->clock_ratio_denom,
+ time_state->ipc_ratio_num, time_state->ipc_ratio_denom);
time_state->guest_cycles = 0;
time_state->tsc_guest_offset = 0;
time_state->last_update = 0;
time_state->initial_host_time = 0;
- time_state->vm_enter_host_time = 0;
- time_state->vm_pause_host_time = 0;
- time_state->time_flags = 0; // XXX need to set trap TSC flag or not wisely
+ time_state->flags = 0;
+ if (info->vm_info->time_state.flags & V3_TIME_SLAVE_HOST) {
+ time_state->flags |= VM_TIME_SLAVE_HOST;
+ }
+ if ((time_state->clock_ratio_denom != 1) ||
+ (time_state->clock_ratio_num != 1)) {
+ time_state->flags |= VM_TIME_TRAP_RDTSC;
+ }
INIT_LIST_HEAD(&(time_state->timers));
time_state->num_timers = 0;
