X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fvmm_time.c;h=38f5f6e637e719e0a2166e21956773113142dc04;hb=b91f96a59e8709a444eb345b0f2b255e9ed9b877;hp=727de3f22e3ff1d36c553f9b3814a8167c0aa1d1;hpb=569796250aabb415e296cb2b71afbb9cda512f69;p=palacios.git diff --git a/palacios/src/palacios/vmm_time.c b/palacios/src/palacios/vmm_time.c index 727de3f..38f5f6e 100644 --- a/palacios/src/palacios/vmm_time.c +++ b/palacios/src/palacios/vmm_time.c @@ -90,9 +90,9 @@ int v3_start_time(struct guest_info * info) { /* We start running with guest_time == host_time */ uint64_t t = v3_get_host_time(&info->time_state); - info->time_state.enter_time = 0; - info->time_state.pause_time = t; - info->time_state.initial_time = t; + 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; info->time_state.last_update = 0; @@ -106,51 +106,63 @@ int v3_start_time(struct guest_info * info) { int v3_offset_time( struct guest_info * info, sint64_t offset ) { struct vm_core_time * time_state = &(info->time_state); - time_state->guest_cycles += offset; + 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; } int v3_skip_time(struct guest_info * info) { if (info->vm_info->time_state.follow_host_time) { - PrintError("Cannot skip host time passage while slaved to host clock.\n"); + PrintError("Cannot skip guest time passage while slaved to host clock.\n"); return 1; } else { - info->time_state.pause_time = v3_get_host_time(&info->time_state); + info->time_state.vm_pause_host_time = v3_get_host_time(&info->time_state); } return 0; } -int v3_advance_time(struct guest_info * info) { +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; +} + +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; + 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_time; - sint64_t guest_target = (host_elapsed * info->time_state.guest_cpu_freq) / info->time_state.host_cpu_freq; - sint64_t cycle_lag = guest_target - info->time_state.guest_cycles; - v3_offset_time(info, cycle_lag); + sint64_t host_elapsed = t - info->time_state.initial_host_time; + sint64_t guest_elapsed = host_to_guest_cycles(info, host_elapsed); + + info->time_state.guest_cycles = guest_elapsed; } else { - v3_offset_time(info, (sint64_t)(t - info->time_state.pause_time)); - } - info->time_state.pause_time = t; + 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 * guest_cycles ) +v3_time_exit_vm( struct guest_info * info, uint64_t * host_cycles ) { - struct vm_core_time * time_state = &(info->time_state); - - time_state->pause_time = v3_get_host_time(time_state); - if (guest_cycles) { - time_state->guest_cycles += *guest_cycles; - } else { - sint64_t cycles_exec; - cycles_exec = (sint64_t)(time_state->pause_time - time_state->enter_time); - time_state->guest_cycles += cycles_exec; - } - return 0; + return v3_time_advance_cycles(info, host_cycles); } /* Called immediately prior to entry to the VM */ @@ -160,8 +172,7 @@ v3_time_enter_vm( struct guest_info * info ) struct vm_core_time * time_state = &(info->time_state); uint64_t host_time = v3_get_host_time(&info->time_state); - v3_advance_time(info); - time_state->enter_time = host_time; + time_state->vm_enter_host_time = host_time; return 0; } @@ -195,13 +206,17 @@ void v3_update_timers(struct guest_info * info) { struct vm_core_time *time_state = &info->time_state; struct v3_timer * tmp_timer; sint64_t cycles; - uint64_t old_time = info->time_state.last_update; + uint64_t old_time = time_state->last_update; time_state->last_update = v3_get_guest_time(time_state); cycles = (sint64_t)(time_state->last_update - old_time); - V3_ASSERT(cycles >= 0); + if (cycles < 0) { + PrintError("Cycles appears to have rolled over - old time %lld, current time %lld.\n", + old_time, time_state->last_update); + return; + } - // V3_Print("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); } @@ -349,8 +364,10 @@ int v3_init_time_vm(struct v3_vm_info * vm) { ret = v3_register_hypercall(vm, TIME_CPUFREQ_HCALL, handle_cpufreq_hcall, NULL); - vm->time_state.td_mult = 1; - PrintDebug("Setting base time dilation factor to %d.\n", vm->time_state.td_mult); + 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); vm->time_state.follow_host_time = 1; PrintDebug("Locking guest time to host time.\n"); @@ -385,17 +402,23 @@ void v3_init_time_core(struct guest_info * info) { 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); - time_state->initial_time = 0; - time_state->last_update = 0; - time_state->tsc_guest_offset = 0; - time_state->enter_time = 0; - time_state->pause_time = 0; 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; INIT_LIST_HEAD(&(time_state->timers)); time_state->num_timers = 0;