xref: /openbmc/qemu/hw/core/cpu-common.c (revision 43610f3184f846da948e8ab9dbc0c5de1e9bde79)
1 /*
2  * QEMU CPU model
3  *
4  * Copyright (c) 2012-2014 SUSE LINUX Products GmbH
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version 2
9  * of the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see
18  * <http://www.gnu.org/licenses/gpl-2.0.html>
19  */
20 
21 #include "qemu/osdep.h"
22 #include "qapi/error.h"
23 #include "hw/core/cpu.h"
24 #include "system/hw_accel.h"
25 #include "qemu/log.h"
26 #include "qemu/main-loop.h"
27 #include "qemu/lockcnt.h"
28 #include "exec/log.h"
29 #include "exec/gdbstub.h"
30 #include "system/tcg.h"
31 #include "hw/boards.h"
32 #include "hw/qdev-properties.h"
33 #include "trace.h"
34 #ifdef CONFIG_PLUGIN
35 #include "qemu/plugin.h"
36 #endif
37 
38 CPUState *cpu_by_arch_id(int64_t id)
39 {
40     CPUState *cpu;
41 
42     CPU_FOREACH(cpu) {
43         CPUClass *cc = CPU_GET_CLASS(cpu);
44 
45         if (cc->get_arch_id(cpu) == id) {
46             return cpu;
47         }
48     }
49     return NULL;
50 }
51 
52 bool cpu_exists(int64_t id)
53 {
54     return !!cpu_by_arch_id(id);
55 }
56 
57 CPUState *cpu_create(const char *typename)
58 {
59     Error *err = NULL;
60     CPUState *cpu = CPU(object_new(typename));
61     if (!qdev_realize(DEVICE(cpu), NULL, &err)) {
62         error_report_err(err);
63         object_unref(OBJECT(cpu));
64         exit(EXIT_FAILURE);
65     }
66     return cpu;
67 }
68 
69 /* Resetting the IRQ comes from across the code base so we take the
70  * BQL here if we need to.  cpu_interrupt assumes it is held.*/
71 void cpu_reset_interrupt(CPUState *cpu, int mask)
72 {
73     bool need_lock = !bql_locked();
74 
75     if (need_lock) {
76         bql_lock();
77     }
78     cpu->interrupt_request &= ~mask;
79     if (need_lock) {
80         bql_unlock();
81     }
82 }
83 
84 void cpu_exit(CPUState *cpu)
85 {
86     qatomic_set(&cpu->exit_request, 1);
87     /* Ensure cpu_exec will see the exit request after TCG has exited.  */
88     smp_wmb();
89     qatomic_set(&cpu->neg.icount_decr.u16.high, -1);
90 }
91 
92 static int cpu_common_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg)
93 {
94     return 0;
95 }
96 
97 static int cpu_common_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg)
98 {
99     return 0;
100 }
101 
102 void cpu_dump_state(CPUState *cpu, FILE *f, int flags)
103 {
104     CPUClass *cc = CPU_GET_CLASS(cpu);
105 
106     if (cc->dump_state) {
107         cpu_synchronize_state(cpu);
108         cc->dump_state(cpu, f, flags);
109     }
110 }
111 
112 void cpu_reset(CPUState *cpu)
113 {
114     device_cold_reset(DEVICE(cpu));
115 
116     trace_cpu_reset(cpu->cpu_index);
117 }
118 
119 static void cpu_common_reset_hold(Object *obj, ResetType type)
120 {
121     CPUState *cpu = CPU(obj);
122     CPUClass *cc = CPU_GET_CLASS(cpu);
123 
124     if (qemu_loglevel_mask(CPU_LOG_RESET)) {
125         qemu_log("CPU Reset (CPU %d)\n", cpu->cpu_index);
126         log_cpu_state(cpu, cc->reset_dump_flags);
127     }
128 
129     cpu->interrupt_request = 0;
130     cpu->halted = cpu->start_powered_off;
131     cpu->mem_io_pc = 0;
132     cpu->icount_extra = 0;
133     qatomic_set(&cpu->neg.icount_decr.u32, 0);
134     cpu->neg.can_do_io = true;
135     cpu->exception_index = -1;
136     cpu->crash_occurred = false;
137     cpu->cflags_next_tb = -1;
138 
139     cpu_exec_reset_hold(cpu);
140 }
141 
142 static bool cpu_common_has_work(CPUState *cs)
143 {
144     return false;
145 }
146 
147 ObjectClass *cpu_class_by_name(const char *typename, const char *cpu_model)
148 {
149     ObjectClass *oc;
150     CPUClass *cc;
151 
152     oc = object_class_by_name(typename);
153     cc = CPU_CLASS(oc);
154     assert(cc->class_by_name);
155     assert(cpu_model);
156     oc = cc->class_by_name(cpu_model);
157     if (object_class_dynamic_cast(oc, typename) &&
158         !object_class_is_abstract(oc)) {
159         return oc;
160     }
161 
162     return NULL;
163 }
164 
165 static void cpu_common_parse_features(const char *typename, char *features,
166                                       Error **errp)
167 {
168     char *val;
169     static bool cpu_globals_initialized;
170     /* Single "key=value" string being parsed */
171     char *featurestr = features ? strtok(features, ",") : NULL;
172 
173     /* should be called only once, catch invalid users */
174     assert(!cpu_globals_initialized);
175     cpu_globals_initialized = true;
176 
177     while (featurestr) {
178         val = strchr(featurestr, '=');
179         if (val) {
180             GlobalProperty *prop = g_new0(typeof(*prop), 1);
181             *val = 0;
182             val++;
183             prop->driver = typename;
184             prop->property = g_strdup(featurestr);
185             prop->value = g_strdup(val);
186             qdev_prop_register_global(prop);
187         } else {
188             error_setg(errp, "Expected key=value format, found %s.",
189                        featurestr);
190             return;
191         }
192         featurestr = strtok(NULL, ",");
193     }
194 }
195 
196 bool cpu_exec_realizefn(CPUState *cpu, Error **errp)
197 {
198     if (!accel_cpu_common_realize(cpu, errp)) {
199         return false;
200     }
201 
202     /* Wait until cpu initialization complete before exposing cpu. */
203     cpu_list_add(cpu);
204 
205     cpu_vmstate_register(cpu);
206 
207     return true;
208 }
209 
210 static void cpu_common_realizefn(DeviceState *dev, Error **errp)
211 {
212     CPUState *cpu = CPU(dev);
213     Object *machine = qdev_get_machine();
214 
215     /* qdev_get_machine() can return something that's not TYPE_MACHINE
216      * if this is one of the user-only emulators; in that case there's
217      * no need to check the ignore_memory_transaction_failures board flag.
218      */
219     if (object_dynamic_cast(machine, TYPE_MACHINE)) {
220         MachineClass *mc = MACHINE_GET_CLASS(machine);
221 
222         if (mc) {
223             cpu->ignore_memory_transaction_failures =
224                 mc->ignore_memory_transaction_failures;
225         }
226     }
227 
228     if (dev->hotplugged) {
229         cpu_synchronize_post_init(cpu);
230         cpu_resume(cpu);
231     }
232 
233     /* NOTE: latest generic point where the cpu is fully realized */
234 }
235 
236 static void cpu_common_unrealizefn(DeviceState *dev)
237 {
238     CPUState *cpu = CPU(dev);
239 
240     /* Call the plugin hook before clearing the cpu is fully unrealized */
241 #ifdef CONFIG_PLUGIN
242     if (tcg_enabled()) {
243         qemu_plugin_vcpu_exit_hook(cpu);
244     }
245 #endif
246 
247     /* NOTE: latest generic point before the cpu is fully unrealized */
248     cpu_exec_unrealizefn(cpu);
249 }
250 
251 void cpu_exec_unrealizefn(CPUState *cpu)
252 {
253     cpu_vmstate_unregister(cpu);
254 
255     cpu_list_remove(cpu);
256     /*
257      * Now that the vCPU has been removed from the RCU list, we can call
258      * accel_cpu_common_unrealize, which may free fields using call_rcu.
259      */
260     accel_cpu_common_unrealize(cpu);
261 }
262 
263 static void cpu_common_initfn(Object *obj)
264 {
265     CPUState *cpu = CPU(obj);
266 
267     /* cache the cpu class for the hotpath */
268     cpu->cc = CPU_GET_CLASS(cpu);
269 
270     gdb_init_cpu(cpu);
271     cpu->cpu_index = UNASSIGNED_CPU_INDEX;
272     cpu->cluster_index = UNASSIGNED_CLUSTER_INDEX;
273     cpu->as = NULL;
274     cpu->num_ases = 0;
275     /* user-mode doesn't have configurable SMP topology */
276     /* the default value is changed by qemu_init_vcpu() for system-mode */
277     cpu->nr_threads = 1;
278 
279     /* allocate storage for thread info, initialise condition variables */
280     cpu->thread = g_new0(QemuThread, 1);
281     cpu->halt_cond = g_new0(QemuCond, 1);
282     qemu_cond_init(cpu->halt_cond);
283 
284     qemu_mutex_init(&cpu->work_mutex);
285     qemu_lockcnt_init(&cpu->in_ioctl_lock);
286     QSIMPLEQ_INIT(&cpu->work_list);
287     QTAILQ_INIT(&cpu->breakpoints);
288     QTAILQ_INIT(&cpu->watchpoints);
289 
290     cpu_exec_initfn(cpu);
291 
292     /*
293      * Plugin initialization must wait until the cpu start executing
294      * code, but we must queue this work before the threads are
295      * created to ensure we don't race.
296      */
297 #ifdef CONFIG_PLUGIN
298     if (tcg_enabled()) {
299         cpu->plugin_state = qemu_plugin_create_vcpu_state();
300         qemu_plugin_vcpu_init_hook(cpu);
301     }
302 #endif
303 }
304 
305 static void cpu_common_finalize(Object *obj)
306 {
307     CPUState *cpu = CPU(obj);
308 
309 #ifdef CONFIG_PLUGIN
310     if (tcg_enabled()) {
311         g_free(cpu->plugin_state);
312     }
313 #endif
314     free_queued_cpu_work(cpu);
315     /* If cleanup didn't happen in context to gdb_unregister_coprocessor_all */
316     if (cpu->gdb_regs) {
317         g_array_free(cpu->gdb_regs, TRUE);
318     }
319     qemu_lockcnt_destroy(&cpu->in_ioctl_lock);
320     qemu_mutex_destroy(&cpu->work_mutex);
321     qemu_cond_destroy(cpu->halt_cond);
322     g_free(cpu->halt_cond);
323     g_free(cpu->thread);
324 }
325 
326 static int64_t cpu_common_get_arch_id(CPUState *cpu)
327 {
328     return cpu->cpu_index;
329 }
330 
331 static void cpu_common_class_init(ObjectClass *klass, void *data)
332 {
333     DeviceClass *dc = DEVICE_CLASS(klass);
334     ResettableClass *rc = RESETTABLE_CLASS(klass);
335     CPUClass *k = CPU_CLASS(klass);
336 
337     k->parse_features = cpu_common_parse_features;
338     k->get_arch_id = cpu_common_get_arch_id;
339     k->has_work = cpu_common_has_work;
340     k->gdb_read_register = cpu_common_gdb_read_register;
341     k->gdb_write_register = cpu_common_gdb_write_register;
342     set_bit(DEVICE_CATEGORY_CPU, dc->categories);
343     dc->realize = cpu_common_realizefn;
344     dc->unrealize = cpu_common_unrealizefn;
345     rc->phases.hold = cpu_common_reset_hold;
346     cpu_class_init_props(dc);
347     /*
348      * Reason: CPUs still need special care by board code: wiring up
349      * IRQs, adding reset handlers, halting non-first CPUs, ...
350      */
351     dc->user_creatable = false;
352 }
353 
354 static const TypeInfo cpu_type_info = {
355     .name = TYPE_CPU,
356     .parent = TYPE_DEVICE,
357     .instance_size = sizeof(CPUState),
358     .instance_init = cpu_common_initfn,
359     .instance_finalize = cpu_common_finalize,
360     .abstract = true,
361     .class_size = sizeof(CPUClass),
362     .class_init = cpu_common_class_init,
363 };
364 
365 static void cpu_register_types(void)
366 {
367     type_register_static(&cpu_type_info);
368 }
369 
370 type_init(cpu_register_types)
371