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/*
* QEMU System Emulator, accelerator interfaces
*
* Copyright (c) 2003-2008 Fabrice Bellard
* Copyright (c) 2014 Red Hat Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "sysemu/accel.h"
#include "sysemu/tcg.h"
#include "qom/object.h"
#include "cpu.h"
#include "sysemu/cpus.h"
#include "qemu/main-loop.h"
#include "tcg/tcg.h"
#include "include/qapi/error.h"
#include "include/qemu/error-report.h"
#include "include/hw/boards.h"
#include "qemu/option.h"
unsigned long tcg_tb_size;
/* mask must never be zero, except for A20 change call */
static void tcg_handle_interrupt(CPUState *cpu, int mask)
{
int old_mask;
g_assert(qemu_mutex_iothread_locked());
old_mask = cpu->interrupt_request;
cpu->interrupt_request |= mask;
/*
* If called from iothread context, wake the target cpu in
* case its halted.
*/
if (!qemu_cpu_is_self(cpu)) {
qemu_cpu_kick(cpu);
} else {
atomic_set(&cpu_neg(cpu)->icount_decr.u16.high, -1);
if (use_icount &&
!cpu->can_do_io
&& (mask & ~old_mask) != 0) {
cpu_abort(cpu, "Raised interrupt while not in I/O function");
}
}
}
/*
* We default to false if we know other options have been enabled
* which are currently incompatible with MTTCG. Otherwise when each
* guest (target) has been updated to support:
* - atomic instructions
* - memory ordering primitives (barriers)
* they can set the appropriate CONFIG flags in ${target}-softmmu.mak
*
* Once a guest architecture has been converted to the new primitives
* there are two remaining limitations to check.
*
* - The guest can't be oversized (e.g. 64 bit guest on 32 bit host)
* - The host must have a stronger memory order than the guest
*
* It may be possible in future to support strong guests on weak hosts
* but that will require tagging all load/stores in a guest with their
* implicit memory order requirements which would likely slow things
* down a lot.
*/
static bool check_tcg_memory_orders_compatible(void)
{
#if defined(TCG_GUEST_DEFAULT_MO) && defined(TCG_TARGET_DEFAULT_MO)
return (TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO) == 0;
#else
return false;
#endif
}
static bool default_mttcg_enabled(void)
{
if (use_icount || TCG_OVERSIZED_GUEST) {
return false;
} else {
#ifdef TARGET_SUPPORTS_MTTCG
return check_tcg_memory_orders_compatible();
#else
return false;
#endif
}
}
static void tcg_accel_instance_init(Object *obj)
{
mttcg_enabled = default_mttcg_enabled();
}
static int tcg_init(MachineState *ms)
{
tcg_exec_init(tcg_tb_size * 1024 * 1024);
cpu_interrupt_handler = tcg_handle_interrupt;
return 0;
}
void qemu_tcg_configure(QemuOpts *opts, Error **errp)
{
const char *t = qemu_opt_get(opts, "thread");
if (!t) {
return;
}
if (strcmp(t, "multi") == 0) {
if (TCG_OVERSIZED_GUEST) {
error_setg(errp, "No MTTCG when guest word size > hosts");
} else if (use_icount) {
error_setg(errp, "No MTTCG when icount is enabled");
} else {
#ifndef TARGET_SUPPORTS_MTTCG
warn_report("Guest not yet converted to MTTCG - "
"you may get unexpected results");
#endif
if (!check_tcg_memory_orders_compatible()) {
warn_report("Guest expects a stronger memory ordering "
"than the host provides");
error_printf("This may cause strange/hard to debug errors\n");
}
mttcg_enabled = true;
}
} else if (strcmp(t, "single") == 0) {
mttcg_enabled = false;
} else {
error_setg(errp, "Invalid 'thread' setting %s", t);
}
}
static void tcg_accel_class_init(ObjectClass *oc, void *data)
{
AccelClass *ac = ACCEL_CLASS(oc);
ac->name = "tcg";
ac->init_machine = tcg_init;
ac->allowed = &tcg_allowed;
}
#define TYPE_TCG_ACCEL ACCEL_CLASS_NAME("tcg")
static const TypeInfo tcg_accel_type = {
.name = TYPE_TCG_ACCEL,
.parent = TYPE_ACCEL,
.instance_init = tcg_accel_instance_init,
.class_init = tcg_accel_class_init,
};
static void register_accel_types(void)
{
type_register_static(&tcg_accel_type);
}
type_init(register_accel_types);
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