unicorn/qemu/cpus.c
Alex Bennée d56a4b0be4
tcg: handle EXCP_ATOMIC exception for system emulation
The patch enables handling atomic code in the guest. This should be
preferably done in cpu_handle_exception(), but the current assumptions
regarding when we can execute atomic sections cause a deadlock.

The current mechanism discards the flags which were set in atomic
execution. We ensure they are properly saved by calling the
cc->cpu_exec_enter/leave() functions around the loop.

As we are running cpu_exec_step_atomic() from the outermost loop we
need to avoid an abort() when single stepping over atomic code since
debug exception longjmp will point to the the setlongjmp in
cpu_exec(). We do this by setting a new jmp_env so that it jumps back
here on an exception.

Backports relevant parts of commit 08e73c48b053566bfe0c994f154f73991cd0ff0e from qemu
2018-03-02 09:56:43 -05:00

240 lines
5.8 KiB
C

/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* 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.
*/
/* Modified for Unicorn Engine by Nguyen Anh Quynh, 2015 */
/* Needed early for CONFIG_BSD etc. */
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "cpu.h"
#include "sysemu/sysemu.h"
#include "exec/exec-all.h"
#include "tcg.h"
#include "qemu/thread.h"
#include "sysemu/cpus.h"
#include "exec/address-spaces.h" // debug, can be removed later
#include "uc_priv.h"
static bool cpu_can_run(CPUState *cpu);
static void cpu_handle_guest_debug(CPUState *cpu);
static int tcg_cpu_exec(struct uc_struct *uc, CPUState *cpu);
static bool tcg_exec_all(struct uc_struct* uc);
static int qemu_tcg_init_vcpu(CPUState *cpu);
static void *qemu_tcg_cpu_loop(struct uc_struct *uc);
static bool default_mttcg_enabled(void)
{
return false;
}
void qemu_tcg_configure(struct uc_struct *uc)
{
uc->mttcg_enabled = default_mttcg_enabled();
}
int vm_start(struct uc_struct* uc)
{
if (resume_all_vcpus(uc)) {
return -1;
}
return 0;
}
bool cpu_is_stopped(CPUState *cpu)
{
return cpu->stopped;
}
void run_on_cpu(CPUState *cpu, run_on_cpu_func func, void *data)
{
func(cpu, data);
}
int resume_all_vcpus(struct uc_struct *uc)
{
CPUState *cpu = uc->cpu;
// Fix call multiple time (vu).
// We have to check whether this is the second time, then reset all CPU.
if (!cpu->created) {
cpu->created = true;
cpu->halted = 0;
if (qemu_init_vcpu(cpu))
return -1;
}
//qemu_clock_enable(QEMU_CLOCK_VIRTUAL, true);
cpu_resume(cpu);
qemu_tcg_cpu_loop(uc);
return 0;
}
int qemu_init_vcpu(CPUState *cpu)
{
cpu->nr_cores = smp_cores;
cpu->nr_threads = smp_threads;
cpu->stopped = true;
if (!cpu->as) {
/* If the target cpu hasn't set up any address spaces itself,
* give it the default one.
*/
AddressSpace *as = address_space_init_shareable(cpu->uc,
cpu->memory,
"cpu-memory");
cpu->num_ases = 1;
cpu_address_space_init(cpu, as, 0);
}
if (tcg_enabled(cpu->uc)) {
return qemu_tcg_init_vcpu(cpu);
}
return 0;
}
static void *qemu_tcg_cpu_loop(struct uc_struct *uc)
{
CPUState *cpu = uc->cpu;
//qemu_tcg_init_cpu_signals();
cpu->created = true;
while (1) {
if (tcg_exec_all(uc))
break;
}
cpu->created = false;
return NULL;
}
static int qemu_tcg_init_vcpu(CPUState *cpu)
{
return 0;
}
static int tcg_cpu_exec(struct uc_struct *uc, CPUState *cpu)
{
return cpu_exec(uc, cpu);
}
static bool tcg_exec_all(struct uc_struct* uc)
{
int r;
bool finish = false;
while (!uc->cpu->exit_request) {
CPUState *cpu = uc->cpu;
CPUArchState *env = cpu->env_ptr;
//qemu_clock_enable(QEMU_CLOCK_VIRTUAL,
// (cpu->singlestep_enabled & SSTEP_NOTIMER) == 0);
if (cpu_can_run(cpu)) {
uc->quit_request = false;
r = tcg_cpu_exec(uc, cpu);
// quit current TB but continue emulating?
if (uc->quit_request) {
// reset stop_request
uc->stop_request = false;
} else if (uc->stop_request) {
finish = true;
break;
}
// save invalid memory access error & quit
if (env->invalid_error) {
uc->invalid_addr = env->invalid_addr;
uc->invalid_error = env->invalid_error;
finish = true;
break;
}
if (r == EXCP_DEBUG) {
cpu_handle_guest_debug(cpu);
break;
}
if (r == EXCP_HLT) {
finish = true;
break;
} else if (r == EXCP_ATOMIC) {
cpu_exec_step_atomic(uc, cpu);
}
} else if (cpu->stop) {
printf(">>> got stopped!!!\n");
break;
}
}
if (uc->cpu && uc->cpu->exit_request) {
atomic_mb_set(&uc->cpu->exit_request, 0);
}
return finish;
}
static bool cpu_can_run(CPUState *cpu)
{
if (cpu->stop) {
return false;
}
if (cpu_is_stopped(cpu)) {
return false;
}
return true;
}
static void cpu_handle_guest_debug(CPUState *cpu)
{
cpu->stopped = true;
}
#if 0
#ifndef _WIN32
static void qemu_tcg_init_cpu_signals(void)
{
sigset_t set;
struct sigaction sigact;
memset(&sigact, 0, sizeof(sigact));
sigact.sa_handler = cpu_signal;
sigaction(SIG_IPI, &sigact, NULL);
sigemptyset(&set);
sigaddset(&set, SIG_IPI);
pthread_sigmask(SIG_UNBLOCK, &set, NULL);
}
#else /* _WIN32 */
static void qemu_tcg_init_cpu_signals(void)
{
}
#endif /* _WIN32 */
#endif