xemu/accel/tcg/tcg-all.c
Emilio G. Cota fff42f183e tcg: access cpu->icount_decr.u16.high with atomics
Consistently access u16.high with atomics to avoid
undefined behaviour in MTTCG.

Note that icount_decr.u16.low is only used in icount mode,
so regular accesses to it are OK.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20181010144853.13005-2-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18 18:58:10 -07:00

93 lines
2.7 KiB
C

/*
* 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/sysemu.h"
#include "qom/object.h"
#include "qemu-common.h"
#include "qom/cpu.h"
#include "sysemu/cpus.h"
#include "qemu/main-loop.h"
unsigned long tcg_tb_size;
#ifndef CONFIG_USER_ONLY
/* 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->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");
}
}
}
#endif
static int tcg_init(MachineState *ms)
{
tcg_exec_init(tcg_tb_size * 1024 * 1024);
cpu_interrupt_handler = tcg_handle_interrupt;
return 0;
}
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,
.class_init = tcg_accel_class_init,
};
static void register_accel_types(void)
{
type_register_static(&tcg_accel_type);
}
type_init(register_accel_types);