unicorn/qemu/qom/cpu.c
Alex Bennée d4cb954102
cpu: atomically modify cpu->exit_request
ThreadSanitizer picks up potential races although we already use
barriers to ensure things are in the correct order when processing exit
requests. For true C11 defined behaviour across threads we need to use
relaxed atomic_set/atomic_read semantics to reassure tsan.

Backports commit 027d9a7d2911e993cdcbd21c7c35d1dd058f05bb from qemu
2018-02-26 05:11:18 -05:00

306 lines
7.4 KiB
C

/*
* QEMU CPU model
*
* Copyright (c) 2012-2014 SUSE LINUX Products GmbH
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see
* <http://www.gnu.org/licenses/gpl-2.0.html>
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "qemu/log.h"
#include "uc_priv.h"
bool cpu_exists(struct uc_struct* uc, int64_t id)
{
CPUState *cpu = uc->cpu;
CPUClass *cc = CPU_GET_CLASS(uc, cpu);
if (cc->get_arch_id(cpu) == id) {
return true;
}
return false;
}
CPUState *cpu_generic_init(struct uc_struct *uc, const char *typename, const char *cpu_model)
{
char *str, *name, *featurestr;
CPUState *cpu;
ObjectClass *oc;
CPUClass *cc;
Error *err = NULL;
str = g_strdup(cpu_model);
name = strtok(str, ",");
oc = cpu_class_by_name(uc, typename, name);
if (oc == NULL) {
g_free(str);
return NULL;
}
cpu = CPU(object_new(uc, object_class_get_name(oc)));
cc = CPU_GET_CLASS(uc, cpu);
featurestr = strtok(NULL, ",");
cc->parse_features(cpu, featurestr, &err);
g_free(str);
if (err != NULL) {
goto out;
}
object_property_set_bool(uc, OBJECT(cpu), true, "realized", &err);
out:
if (err != NULL) {
error_free(err);
object_unref(uc, OBJECT(cpu));
return NULL;
}
return cpu;
}
bool cpu_paging_enabled(const CPUState *cpu)
{
CPUClass *cc = CPU_GET_CLASS(cpu->uc, cpu);
return cc->get_paging_enabled(cpu);
}
static bool cpu_common_get_paging_enabled(const CPUState *cpu)
{
return false;
}
void cpu_get_memory_mapping(CPUState *cpu, MemoryMappingList *list,
Error **errp)
{
CPUClass *cc = CPU_GET_CLASS(cpu->uc, cpu);
cc->get_memory_mapping(cpu, list, errp);
}
static void cpu_common_get_memory_mapping(CPUState *cpu,
MemoryMappingList *list,
Error **errp)
{
error_setg(errp, "Obtaining memory mappings is unsupported on this CPU.");
}
void cpu_reset_interrupt(CPUState *cpu, int mask)
{
cpu->interrupt_request &= ~mask;
}
void cpu_exit(CPUState *cpu)
{
atomic_set(&cpu->exit_request, 1);
/* Ensure cpu_exec will see the exit request after TCG has exited. */
smp_wmb();
atomic_set(&cpu->tcg_exit_req, 1);
}
static void cpu_common_noop(CPUState *cpu)
{
}
static bool cpu_common_exec_interrupt(CPUState *cpu, int int_req)
{
return false;
}
void cpu_dump_state(CPUState *cpu, FILE *f, fprintf_function cpu_fprintf,
int flags)
{
CPUClass *cc = CPU_GET_CLASS(cpu->uc, cpu);
if (cc->dump_state) {
cc->dump_state(cpu, f, cpu_fprintf, flags);
}
}
void cpu_dump_statistics(CPUState *cpu, FILE *f, fprintf_function cpu_fprintf,
int flags)
{
CPUClass *cc = CPU_GET_CLASS(cpu->uc, cpu);
if (cc->dump_statistics) {
cc->dump_statistics(cpu, f, cpu_fprintf, flags);
}
}
void cpu_reset(CPUState *cpu)
{
CPUClass *klass = CPU_GET_CLASS(cpu->uc, cpu);
if (klass->reset != NULL) {
(*klass->reset)(cpu);
}
}
static void cpu_common_reset(CPUState *cpu)
{
CPUClass *cc = CPU_GET_CLASS(cpu->uc, cpu);
int i;
if (qemu_loglevel_mask(CPU_LOG_RESET)) {
qemu_log("CPU Reset (CPU %d)\n", cpu->cpu_index);
log_cpu_state(cpu, cc->reset_dump_flags);
}
cpu->interrupt_request = 0;
cpu->halted = 0;
cpu->mem_io_pc = 0;
cpu->mem_io_vaddr = 0;
cpu->icount_extra = 0;
cpu->icount_decr.u32 = 0;
cpu->can_do_io = 0;
cpu->exception_index = -1;
cpu->crash_occurred = false;
for (i = 0; i < TB_JMP_CACHE_SIZE; ++i) {
atomic_set(&cpu->tb_jmp_cache[i], NULL);
}
}
static bool cpu_common_has_work(CPUState *cs)
{
return false;
}
static bool cpu_common_debug_check_watchpoint(CPUState *cpu, CPUWatchpoint *wp)
{
/* If no extra check is required, QEMU watchpoint match can be considered
* as an architectural match.
*/
return true;
}
ObjectClass *cpu_class_by_name(struct uc_struct *uc, const char *typename, const char *cpu_model)
{
CPUClass *cc = CPU_CLASS(uc, object_class_by_name(uc, typename));
return cc->class_by_name(uc, cpu_model);
}
static ObjectClass *cpu_common_class_by_name(struct uc_struct *uc, const char *cpu_model)
{
return NULL;
}
static void cpu_common_parse_features(CPUState *cpu, char *features,
Error **errp)
{
char *featurestr; /* Single "key=value" string being parsed */
char *val;
Error *err = NULL;
featurestr = features ? strtok(features, ",") : NULL;
while (featurestr) {
val = strchr(featurestr, '=');
if (val) {
*val = 0;
val++;
object_property_parse(cpu->uc, OBJECT(cpu), val, featurestr, &err);
if (err) {
error_propagate(errp, err);
return;
}
} else {
error_setg(errp, "Expected key=value format, found %s.",
featurestr);
return;
}
featurestr = strtok(NULL, ",");
}
}
static int cpu_common_realizefn(struct uc_struct *uc, DeviceState *dev, Error **errp)
{
CPUState *cpu = CPU(dev);
if (dev->hotplugged) {
cpu_resume(cpu);
}
return 0;
}
static void cpu_common_initfn(struct uc_struct *uc, Object *obj, void *opaque)
{
CPUState *cpu = CPU(obj);
QTAILQ_INIT(&cpu->breakpoints);
QTAILQ_INIT(&cpu->watchpoints);
}
static int64_t cpu_common_get_arch_id(CPUState *cpu)
{
return cpu->cpu_index;
}
static void cpu_class_init(struct uc_struct *uc, ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(uc, klass);
CPUClass *k = CPU_CLASS(uc, klass);
k->class_by_name = cpu_common_class_by_name;
k->parse_features = cpu_common_parse_features;
k->reset = cpu_common_reset;
k->get_arch_id = cpu_common_get_arch_id;
k->has_work = cpu_common_has_work;
k->get_paging_enabled = cpu_common_get_paging_enabled;
k->get_memory_mapping = cpu_common_get_memory_mapping;
k->debug_excp_handler = cpu_common_noop;
k->debug_check_watchpoint = cpu_common_debug_check_watchpoint;
k->cpu_exec_enter = cpu_common_noop;
k->cpu_exec_exit = cpu_common_noop;
k->cpu_exec_interrupt = cpu_common_exec_interrupt;
dc->realize = cpu_common_realizefn;
/*
* Reason: CPUs still need special care by board code: wiring up
* IRQs, adding reset handlers, halting non-first CPUs, ...
*/
dc->cannot_instantiate_with_device_add_yet = true;
}
static const TypeInfo cpu_type_info = {
TYPE_CPU,
TYPE_DEVICE,
sizeof(CPUClass),
sizeof(CPUState),
NULL,
cpu_common_initfn,
NULL,
NULL,
NULL,
cpu_class_init,
NULL,
NULL,
true,
};
void cpu_register_types(struct uc_struct *uc)
{
type_register_static(uc, &cpu_type_info);
}