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cpus: extract out TCG-specific code to accel/tcg 

TCG is the first accelerator to register a "CpusAccel" interface
on initialization, providing functions for starting a vcpu,
kicking a vcpu, sychronizing state and getting virtual clock
and ticks.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[added const]
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Claudio Fontana 2020-07-06 19:39:45 +02:00 committed by Paolo Bonzini
parent 430065dab0
commit a77dabc33b
5 changed files with 576 additions and 510 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
accel/tcg/meson.build
View File

@ -12,4 +12,4 @@ tcg_ss.add(when: 'CONFIG_SOFTMMU', if_false: files('user-exec-stub.c'))
tcg_ss.add(when: 'CONFIG_PLUGIN', if_true: [files('plugin-gen.c'), libdl])
specific_ss.add_all(when: 'CONFIG_TCG', if_true: tcg_ss)
specific_ss.add(when: ['CONFIG_SOFTMMU', 'CONFIG_TCG'], if_true: files('tcg-all.c', 'cputlb.c'))
specific_ss.add(when: ['CONFIG_SOFTMMU', 'CONFIG_TCG'], if_true: files('tcg-all.c', 'cputlb.c', 'tcg-cpus.c'))

11
accel/tcg/tcg-all.c
View File

@ -24,18 +24,15 @@
*/
#include "qemu/osdep.h"
#include "sysemu/accel.h"
#include "qemu-common.h"
#include "sysemu/tcg.h"
#include "qom/object.h"
#include "cpu.h"
#include "sysemu/cpus.h"
#include "sysemu/cpu-timers.h"
#include "qemu/main-loop.h"
#include "tcg/tcg.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "hw/boards.h"
#include "qapi/qapi-builtin-visit.h"
#include "tcg-cpus.h"
struct TCGState {
AccelState parent_obj;
@ -124,6 +121,8 @@ static void tcg_accel_instance_init(Object *obj)
s->mttcg_enabled = default_mttcg_enabled();
}
bool mttcg_enabled;
static int tcg_init(MachineState *ms)
{
TCGState *s = TCG_STATE(current_accel());
@ -131,6 +130,8 @@ static int tcg_init(MachineState *ms)
tcg_exec_init(s->tb_size * 1024 * 1024);
cpu_interrupt_handler = tcg_handle_interrupt;
mttcg_enabled = s->mttcg_enabled;
cpus_register_accel(&tcg_cpus);
return 0;
}

551
accel/tcg/tcg-cpus.c Normal file
View File

@ -0,0 +1,551 @@
/*
* QEMU System Emulator
*
* 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 "qemu-common.h"
#include "sysemu/tcg.h"
#include "sysemu/replay.h"
#include "qemu/main-loop.h"
#include "qemu/guest-random.h"
#include "exec/exec-all.h"
#include "hw/boards.h"
#include "tcg-cpus.h"
/* Kick all RR vCPUs */
static void qemu_cpu_kick_rr_cpus(void)
{
CPUState *cpu;
CPU_FOREACH(cpu) {
cpu_exit(cpu);
};
}
static void tcg_kick_vcpu_thread(CPUState *cpu)
{
if (qemu_tcg_mttcg_enabled()) {
cpu_exit(cpu);
} else {
qemu_cpu_kick_rr_cpus();
}
}
/*
* TCG vCPU kick timer
*
* The kick timer is responsible for moving single threaded vCPU
* emulation on to the next vCPU. If more than one vCPU is running a
* timer event with force a cpu->exit so the next vCPU can get
* scheduled.
*
* The timer is removed if all vCPUs are idle and restarted again once
* idleness is complete.
*/
static QEMUTimer *tcg_kick_vcpu_timer;
static CPUState *tcg_current_rr_cpu;
#define TCG_KICK_PERIOD (NANOSECONDS_PER_SECOND / 10)
static inline int64_t qemu_tcg_next_kick(void)
{
return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + TCG_KICK_PERIOD;
}
/* Kick the currently round-robin scheduled vCPU to next */
static void qemu_cpu_kick_rr_next_cpu(void)
{
CPUState *cpu;
do {
cpu = qatomic_mb_read(&tcg_current_rr_cpu);
if (cpu) {
cpu_exit(cpu);
}
} while (cpu != qatomic_mb_read(&tcg_current_rr_cpu));
}
static void kick_tcg_thread(void *opaque)
{
timer_mod(tcg_kick_vcpu_timer, qemu_tcg_next_kick());
qemu_cpu_kick_rr_next_cpu();
}
static void start_tcg_kick_timer(void)
{
assert(!mttcg_enabled);
if (!tcg_kick_vcpu_timer && CPU_NEXT(first_cpu)) {
tcg_kick_vcpu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
kick_tcg_thread, NULL);
}
if (tcg_kick_vcpu_timer && !timer_pending(tcg_kick_vcpu_timer)) {
timer_mod(tcg_kick_vcpu_timer, qemu_tcg_next_kick());
}
}
static void stop_tcg_kick_timer(void)
{
assert(!mttcg_enabled);
if (tcg_kick_vcpu_timer && timer_pending(tcg_kick_vcpu_timer)) {
timer_del(tcg_kick_vcpu_timer);
}
}
static void qemu_tcg_destroy_vcpu(CPUState *cpu)
{
}
static void qemu_tcg_rr_wait_io_event(void)
{
CPUState *cpu;
while (all_cpu_threads_idle()) {
stop_tcg_kick_timer();
qemu_cond_wait_iothread(first_cpu->halt_cond);
}
start_tcg_kick_timer();
CPU_FOREACH(cpu) {
qemu_wait_io_event_common(cpu);
}
}
static int64_t tcg_get_icount_limit(void)
{
int64_t deadline;
if (replay_mode != REPLAY_MODE_PLAY) {
/*
* Include all the timers, because they may need an attention.
* Too long CPU execution may create unnecessary delay in UI.
*/
deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL,
QEMU_TIMER_ATTR_ALL);
/* Check realtime timers, because they help with input processing */
deadline = qemu_soonest_timeout(deadline,
qemu_clock_deadline_ns_all(QEMU_CLOCK_REALTIME,
QEMU_TIMER_ATTR_ALL));
/*
* Maintain prior (possibly buggy) behaviour where if no deadline
* was set (as there is no QEMU_CLOCK_VIRTUAL timer) or it is more than
* INT32_MAX nanoseconds ahead, we still use INT32_MAX
* nanoseconds.
*/
if ((deadline < 0) || (deadline > INT32_MAX)) {
deadline = INT32_MAX;
}
return icount_round(deadline);
} else {
return replay_get_instructions();
}
}
static void notify_aio_contexts(void)
{
/* Wake up other AioContexts. */
qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL);
}
static void handle_icount_deadline(void)
{
assert(qemu_in_vcpu_thread());
if (icount_enabled()) {
int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL,
QEMU_TIMER_ATTR_ALL);
if (deadline == 0) {
notify_aio_contexts();
}
}
}
static void prepare_icount_for_run(CPUState *cpu)
{
if (icount_enabled()) {
int insns_left;
/*
* These should always be cleared by process_icount_data after
* each vCPU execution. However u16.high can be raised
* asynchronously by cpu_exit/cpu_interrupt/tcg_handle_interrupt
*/
g_assert(cpu_neg(cpu)->icount_decr.u16.low == 0);
g_assert(cpu->icount_extra == 0);
cpu->icount_budget = tcg_get_icount_limit();
insns_left = MIN(0xffff, cpu->icount_budget);
cpu_neg(cpu)->icount_decr.u16.low = insns_left;
cpu->icount_extra = cpu->icount_budget - insns_left;
replay_mutex_lock();
if (cpu->icount_budget == 0 && replay_has_checkpoint()) {
notify_aio_contexts();
}
}
}
static void process_icount_data(CPUState *cpu)
{
if (icount_enabled()) {
/* Account for executed instructions */
icount_update(cpu);
/* Reset the counters */
cpu_neg(cpu)->icount_decr.u16.low = 0;
cpu->icount_extra = 0;
cpu->icount_budget = 0;
replay_account_executed_instructions();
replay_mutex_unlock();
}
}
static int tcg_cpu_exec(CPUState *cpu)
{
int ret;
#ifdef CONFIG_PROFILER
int64_t ti;
#endif
assert(tcg_enabled());
#ifdef CONFIG_PROFILER
ti = profile_getclock();
#endif
cpu_exec_start(cpu);
ret = cpu_exec(cpu);
cpu_exec_end(cpu);
#ifdef CONFIG_PROFILER
qatomic_set(&tcg_ctx->prof.cpu_exec_time,
tcg_ctx->prof.cpu_exec_time + profile_getclock() - ti);
#endif
return ret;
}
/*
* Destroy any remaining vCPUs which have been unplugged and have
* finished running
*/
static void deal_with_unplugged_cpus(void)
{
CPUState *cpu;
CPU_FOREACH(cpu) {
if (cpu->unplug && !cpu_can_run(cpu)) {
qemu_tcg_destroy_vcpu(cpu);
cpu_thread_signal_destroyed(cpu);
break;
}
}
}
/*
* Single-threaded TCG
*
* In the single-threaded case each vCPU is simulated in turn. If
* there is more than a single vCPU we create a simple timer to kick
* the vCPU and ensure we don't get stuck in a tight loop in one vCPU.
* This is done explicitly rather than relying on side-effects
* elsewhere.
*/
static void *tcg_rr_cpu_thread_fn(void *arg)
{
CPUState *cpu = arg;
assert(tcg_enabled());
rcu_register_thread();
tcg_register_thread();
qemu_mutex_lock_iothread();
qemu_thread_get_self(cpu->thread);
cpu->thread_id = qemu_get_thread_id();
cpu->can_do_io = 1;
cpu_thread_signal_created(cpu);
qemu_guest_random_seed_thread_part2(cpu->random_seed);
/* wait for initial kick-off after machine start */
while (first_cpu->stopped) {
qemu_cond_wait_iothread(first_cpu->halt_cond);
/* process any pending work */
CPU_FOREACH(cpu) {
current_cpu = cpu;
qemu_wait_io_event_common(cpu);
}
}
start_tcg_kick_timer();
cpu = first_cpu;
/* process any pending work */
cpu->exit_request = 1;
while (1) {
qemu_mutex_unlock_iothread();
replay_mutex_lock();
qemu_mutex_lock_iothread();
/* Account partial waits to QEMU_CLOCK_VIRTUAL. */
icount_account_warp_timer();
/*
* Run the timers here. This is much more efficient than
* waking up the I/O thread and waiting for completion.
*/
handle_icount_deadline();
replay_mutex_unlock();
if (!cpu) {
cpu = first_cpu;
}
while (cpu && cpu_work_list_empty(cpu) && !cpu->exit_request) {
qatomic_mb_set(&tcg_current_rr_cpu, cpu);
current_cpu = cpu;
qemu_clock_enable(QEMU_CLOCK_VIRTUAL,
(cpu->singlestep_enabled & SSTEP_NOTIMER) == 0);
if (cpu_can_run(cpu)) {
int r;
qemu_mutex_unlock_iothread();
prepare_icount_for_run(cpu);
r = tcg_cpu_exec(cpu);
process_icount_data(cpu);
qemu_mutex_lock_iothread();
if (r == EXCP_DEBUG) {
cpu_handle_guest_debug(cpu);
break;
} else if (r == EXCP_ATOMIC) {
qemu_mutex_unlock_iothread();
cpu_exec_step_atomic(cpu);
qemu_mutex_lock_iothread();
break;
}
} else if (cpu->stop) {
if (cpu->unplug) {
cpu = CPU_NEXT(cpu);
}
break;
}
cpu = CPU_NEXT(cpu);
} /* while (cpu && !cpu->exit_request).. */
/* Does not need qatomic_mb_set because a spurious wakeup is okay. */
qatomic_set(&tcg_current_rr_cpu, NULL);
if (cpu && cpu->exit_request) {
qatomic_mb_set(&cpu->exit_request, 0);
}
if (icount_enabled() && all_cpu_threads_idle()) {
/*
* When all cpus are sleeping (e.g in WFI), to avoid a deadlock
* in the main_loop, wake it up in order to start the warp timer.
*/
qemu_notify_event();
}
qemu_tcg_rr_wait_io_event();
deal_with_unplugged_cpus();
}
rcu_unregister_thread();
return NULL;
}
/*
* Multi-threaded TCG
*
* In the multi-threaded case each vCPU has its own thread. The TLS
* variable current_cpu can be used deep in the code to find the
* current CPUState for a given thread.
*/
static void *tcg_cpu_thread_fn(void *arg)
{
CPUState *cpu = arg;
assert(tcg_enabled());
g_assert(!icount_enabled());
rcu_register_thread();
tcg_register_thread();
qemu_mutex_lock_iothread();
qemu_thread_get_self(cpu->thread);
cpu->thread_id = qemu_get_thread_id();
cpu->can_do_io = 1;
current_cpu = cpu;
cpu_thread_signal_created(cpu);
qemu_guest_random_seed_thread_part2(cpu->random_seed);
/* process any pending work */
cpu->exit_request = 1;
do {
if (cpu_can_run(cpu)) {
int r;
qemu_mutex_unlock_iothread();
r = tcg_cpu_exec(cpu);
qemu_mutex_lock_iothread();
switch (r) {
case EXCP_DEBUG:
cpu_handle_guest_debug(cpu);
break;
case EXCP_HALTED:
/*
* during start-up the vCPU is reset and the thread is
* kicked several times. If we don't ensure we go back
* to sleep in the halted state we won't cleanly
* start-up when the vCPU is enabled.
*
* cpu->halted should ensure we sleep in wait_io_event
*/
g_assert(cpu->halted);
break;
case EXCP_ATOMIC:
qemu_mutex_unlock_iothread();
cpu_exec_step_atomic(cpu);
qemu_mutex_lock_iothread();
default:
/* Ignore everything else? */
break;
}
}
qatomic_mb_set(&cpu->exit_request, 0);
qemu_wait_io_event(cpu);
} while (!cpu->unplug || cpu_can_run(cpu));
qemu_tcg_destroy_vcpu(cpu);
cpu_thread_signal_destroyed(cpu);
qemu_mutex_unlock_iothread();
rcu_unregister_thread();
return NULL;
}
static void tcg_start_vcpu_thread(CPUState *cpu)
{
char thread_name[VCPU_THREAD_NAME_SIZE];
static QemuCond *single_tcg_halt_cond;
static QemuThread *single_tcg_cpu_thread;
static int tcg_region_inited;
assert(tcg_enabled());
/*
* Initialize TCG regions--once. Now is a good time, because:
* (1) TCG's init context, prologue and target globals have been set up.
* (2) qemu_tcg_mttcg_enabled() works now (TCG init code runs before the
* -accel flag is processed, so the check doesn't work then).
*/
if (!tcg_region_inited) {
tcg_region_inited = 1;
tcg_region_init();
/*
* If MTTCG, and we will create multiple cpus,
* then we will have cpus running in parallel.
*/
if (qemu_tcg_mttcg_enabled()) {
MachineState *ms = MACHINE(qdev_get_machine());
if (ms->smp.max_cpus > 1) {
parallel_cpus = true;
}
}
}
if (qemu_tcg_mttcg_enabled() || !single_tcg_cpu_thread) {
cpu->thread = g_malloc0(sizeof(QemuThread));
cpu->halt_cond = g_malloc0(sizeof(QemuCond));
qemu_cond_init(cpu->halt_cond);
if (qemu_tcg_mttcg_enabled()) {
/* create a thread per vCPU with TCG (MTTCG) */
snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/TCG",
cpu->cpu_index);
qemu_thread_create(cpu->thread, thread_name, tcg_cpu_thread_fn,
cpu, QEMU_THREAD_JOINABLE);
} else {
/* share a single thread for all cpus with TCG */
snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "ALL CPUs/TCG");
qemu_thread_create(cpu->thread, thread_name,
tcg_rr_cpu_thread_fn,
cpu, QEMU_THREAD_JOINABLE);
single_tcg_halt_cond = cpu->halt_cond;
single_tcg_cpu_thread = cpu->thread;
}
#ifdef _WIN32
cpu->hThread = qemu_thread_get_handle(cpu->thread);
#endif
} else {
/* For non-MTTCG cases we share the thread */
cpu->thread = single_tcg_cpu_thread;
cpu->halt_cond = single_tcg_halt_cond;
cpu->thread_id = first_cpu->thread_id;
cpu->can_do_io = 1;
cpu->created = true;
}
}
static int64_t tcg_get_virtual_clock(void)
{
if (icount_enabled()) {
return icount_get();
}
return cpu_get_clock();
}
static int64_t tcg_get_elapsed_ticks(void)
{
if (icount_enabled()) {
return icount_get();
}
return cpu_get_ticks();
}
const CpusAccel tcg_cpus = {
.create_vcpu_thread = tcg_start_vcpu_thread,
.kick_vcpu_thread = tcg_kick_vcpu_thread,
.get_virtual_clock = tcg_get_virtual_clock,
.get_elapsed_ticks = tcg_get_elapsed_ticks,
};

17
accel/tcg/tcg-cpus.h Normal file
View File

@ -0,0 +1,17 @@
/*
* Accelerator CPUS Interface
*
* Copyright 2020 SUSE LLC
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef TCG_CPUS_H
#define TCG_CPUS_H
#include "sysemu/cpus.h"
extern const CpusAccel tcg_cpus;
#endif /* TCG_CPUS_H */

505
softmmu/cpus.c
View File

@ -24,27 +24,19 @@
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qemu/config-file.h"
#include "qemu/cutils.h"
#include "migration/vmstate.h"
#include "monitor/monitor.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-misc.h"
#include "qapi/qapi-events-run-state.h"
#include "qapi/qmp/qerror.h"
#include "qemu/error-report.h"
#include "qemu/qemu-print.h"
#include "sysemu/tcg.h"
#include "sysemu/block-backend.h"
#include "exec/gdbstub.h"
#include "sysemu/dma.h"
#include "sysemu/hw_accel.h"
#include "sysemu/kvm.h"
#include "sysemu/hax.h"
#include "sysemu/hvf.h"
#include "sysemu/whpx.h"
#include "exec/exec-all.h"
#include "qemu/thread.h"
#include "qemu/plugin.h"
#include "sysemu/cpus.h"
@ -124,79 +116,6 @@ bool all_cpu_threads_idle(void)
return true;
}
bool mttcg_enabled;
/***********************************************************/
/* TCG vCPU kick timer
*
* The kick timer is responsible for moving single threaded vCPU
* emulation on to the next vCPU. If more than one vCPU is running a
* timer event with force a cpu->exit so the next vCPU can get
* scheduled.
*
* The timer is removed if all vCPUs are idle and restarted again once
* idleness is complete.
*/
static QEMUTimer *tcg_kick_vcpu_timer;
static CPUState *tcg_current_rr_cpu;
#define TCG_KICK_PERIOD (NANOSECONDS_PER_SECOND / 10)
static inline int64_t qemu_tcg_next_kick(void)
{
return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + TCG_KICK_PERIOD;
}
/* Kick the currently round-robin scheduled vCPU to next */
static void qemu_cpu_kick_rr_next_cpu(void)
{
CPUState *cpu;
do {
cpu = qatomic_mb_read(&tcg_current_rr_cpu);
if (cpu) {
cpu_exit(cpu);
}
} while (cpu != qatomic_mb_read(&tcg_current_rr_cpu));
}
/* Kick all RR vCPUs */
static void qemu_cpu_kick_rr_cpus(void)
{
CPUState *cpu;
CPU_FOREACH(cpu) {
cpu_exit(cpu);
};
}
static void kick_tcg_thread(void *opaque)
{
timer_mod(tcg_kick_vcpu_timer, qemu_tcg_next_kick());
qemu_cpu_kick_rr_next_cpu();
}
static void start_tcg_kick_timer(void)
{
assert(!mttcg_enabled);
if (!tcg_kick_vcpu_timer && CPU_NEXT(first_cpu)) {
tcg_kick_vcpu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
kick_tcg_thread, NULL);
}
if (tcg_kick_vcpu_timer && !timer_pending(tcg_kick_vcpu_timer)) {
timer_mod(tcg_kick_vcpu_timer, qemu_tcg_next_kick());
}
}
static void stop_tcg_kick_timer(void)
{
assert(!mttcg_enabled);
if (tcg_kick_vcpu_timer && timer_pending(tcg_kick_vcpu_timer)) {
timer_del(tcg_kick_vcpu_timer);
}
}
/***********************************************************/
void hw_error(const char *fmt, ...)
{
@ -328,9 +247,7 @@ int64_t cpus_get_virtual_clock(void)
if (cpus_accel && cpus_accel->get_virtual_clock) {
return cpus_accel->get_virtual_clock();
}
if (icount_enabled()) {
return icount_get();
} else if (qtest_enabled()) { /* for qtest_clock_warp */
if (qtest_enabled()) { /* for qtest_clock_warp */
return qtest_get_virtual_clock();
}
return cpu_get_clock();
@ -346,9 +263,6 @@ int64_t cpus_get_elapsed_ticks(void)
if (cpus_accel && cpus_accel->get_elapsed_ticks) {
return cpus_accel->get_elapsed_ticks();
}
if (icount_enabled()) {
return icount_get();
}
return cpu_get_ticks();
}
@ -482,10 +396,6 @@ static void qemu_kvm_destroy_vcpu(CPUState *cpu)
}
}
static void qemu_tcg_destroy_vcpu(CPUState *cpu)
{
}
static void qemu_cpu_stop(CPUState *cpu, bool exit)
{
g_assert(qemu_cpu_is_self(cpu));
@ -506,22 +416,6 @@ void qemu_wait_io_event_common(CPUState *cpu)
process_queued_cpu_work(cpu);
}
static void qemu_tcg_rr_wait_io_event(void)
{
CPUState *cpu;
while (all_cpu_threads_idle()) {
stop_tcg_kick_timer();
qemu_cond_wait(first_cpu->halt_cond, &qemu_global_mutex);
}
start_tcg_kick_timer();
CPU_FOREACH(cpu) {
qemu_wait_io_event_common(cpu);
}
}
void qemu_wait_io_event(CPUState *cpu)
{
bool slept = false;
@ -633,259 +527,6 @@ static void *qemu_dummy_cpu_thread_fn(void *arg)
#endif
}
static int64_t tcg_get_icount_limit(void)
{
int64_t deadline;
if (replay_mode != REPLAY_MODE_PLAY) {
/*
* Include all the timers, because they may need an attention.
* Too long CPU execution may create unnecessary delay in UI.
*/
deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL,
QEMU_TIMER_ATTR_ALL);
/* Check realtime timers, because they help with input processing */
deadline = qemu_soonest_timeout(deadline,
qemu_clock_deadline_ns_all(QEMU_CLOCK_REALTIME,
QEMU_TIMER_ATTR_ALL));
/* Maintain prior (possibly buggy) behaviour where if no deadline
* was set (as there is no QEMU_CLOCK_VIRTUAL timer) or it is more than
* INT32_MAX nanoseconds ahead, we still use INT32_MAX
* nanoseconds.
*/
if ((deadline < 0) || (deadline > INT32_MAX)) {
deadline = INT32_MAX;
}
return icount_round(deadline);
} else {
return replay_get_instructions();
}
}
static void notify_aio_contexts(void)
{
/* Wake up other AioContexts. */
qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL);
}
static void handle_icount_deadline(void)
{
assert(qemu_in_vcpu_thread());
if (icount_enabled()) {
int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL,
QEMU_TIMER_ATTR_ALL);
if (deadline == 0) {
notify_aio_contexts();
}
}
}
static void prepare_icount_for_run(CPUState *cpu)
{
if (icount_enabled()) {
int insns_left;
/* These should always be cleared by process_icount_data after
* each vCPU execution. However u16.high can be raised
* asynchronously by cpu_exit/cpu_interrupt/tcg_handle_interrupt
*/
g_assert(cpu_neg(cpu)->icount_decr.u16.low == 0);
g_assert(cpu->icount_extra == 0);
cpu->icount_budget = tcg_get_icount_limit();
insns_left = MIN(0xffff, cpu->icount_budget);
cpu_neg(cpu)->icount_decr.u16.low = insns_left;
cpu->icount_extra = cpu->icount_budget - insns_left;
replay_mutex_lock();
if (cpu->icount_budget == 0 && replay_has_checkpoint()) {
notify_aio_contexts();
}
}
}
static void process_icount_data(CPUState *cpu)
{
if (icount_enabled()) {
/* Account for executed instructions */
icount_update(cpu);
/* Reset the counters */
cpu_neg(cpu)->icount_decr.u16.low = 0;
cpu->icount_extra = 0;
cpu->icount_budget = 0;
replay_account_executed_instructions();
replay_mutex_unlock();
}
}
static int tcg_cpu_exec(CPUState *cpu)
{
int ret;
#ifdef CONFIG_PROFILER
int64_t ti;
#endif
assert(tcg_enabled());
#ifdef CONFIG_PROFILER
ti = profile_getclock();
#endif
cpu_exec_start(cpu);
ret = cpu_exec(cpu);
cpu_exec_end(cpu);
#ifdef CONFIG_PROFILER
qatomic_set(&tcg_ctx->prof.cpu_exec_time,
tcg_ctx->prof.cpu_exec_time + profile_getclock() - ti);
#endif
return ret;
}
/* Destroy any remaining vCPUs which have been unplugged and have
* finished running
*/
static void deal_with_unplugged_cpus(void)
{
CPUState *cpu;
CPU_FOREACH(cpu) {
if (cpu->unplug && !cpu_can_run(cpu)) {
qemu_tcg_destroy_vcpu(cpu);
cpu_thread_signal_destroyed(cpu);
break;
}
}
}
/* Single-threaded TCG
*
* In the single-threaded case each vCPU is simulated in turn. If
* there is more than a single vCPU we create a simple timer to kick
* the vCPU and ensure we don't get stuck in a tight loop in one vCPU.
* This is done explicitly rather than relying on side-effects
* elsewhere.
*/
static void *qemu_tcg_rr_cpu_thread_fn(void *arg)
{
CPUState *cpu = arg;
assert(tcg_enabled());
rcu_register_thread();
tcg_register_thread();
qemu_mutex_lock_iothread();
qemu_thread_get_self(cpu->thread);
cpu->thread_id = qemu_get_thread_id();
cpu->can_do_io = 1;
cpu_thread_signal_created(cpu);
qemu_guest_random_seed_thread_part2(cpu->random_seed);
/* wait for initial kick-off after machine start */
while (first_cpu->stopped) {
qemu_cond_wait(first_cpu->halt_cond, &qemu_global_mutex);
/* process any pending work */
CPU_FOREACH(cpu) {
current_cpu = cpu;
qemu_wait_io_event_common(cpu);
}
}
start_tcg_kick_timer();
cpu = first_cpu;
/* process any pending work */
cpu->exit_request = 1;
while (1) {
qemu_mutex_unlock_iothread();
replay_mutex_lock();
qemu_mutex_lock_iothread();
/* Account partial waits to QEMU_CLOCK_VIRTUAL. */
icount_account_warp_timer();
/* Run the timers here. This is much more efficient than
* waking up the I/O thread and waiting for completion.
*/
handle_icount_deadline();
replay_mutex_unlock();
if (!cpu) {
cpu = first_cpu;
}
while (cpu && cpu_work_list_empty(cpu) && !cpu->exit_request) {
qatomic_mb_set(&tcg_current_rr_cpu, cpu);
current_cpu = cpu;
qemu_clock_enable(QEMU_CLOCK_VIRTUAL,
(cpu->singlestep_enabled & SSTEP_NOTIMER) == 0);
if (cpu_can_run(cpu)) {
int r;
qemu_mutex_unlock_iothread();
prepare_icount_for_run(cpu);
r = tcg_cpu_exec(cpu);
process_icount_data(cpu);
qemu_mutex_lock_iothread();
if (r == EXCP_DEBUG) {
cpu_handle_guest_debug(cpu);
break;
} else if (r == EXCP_ATOMIC) {
qemu_mutex_unlock_iothread();
cpu_exec_step_atomic(cpu);
qemu_mutex_lock_iothread();
break;
}
} else if (cpu->stop) {
if (cpu->unplug) {
cpu = CPU_NEXT(cpu);
}
break;
}
cpu = CPU_NEXT(cpu);
} /* while (cpu && !cpu->exit_request).. */
/* Does not need qatomic_mb_set because a spurious wakeup is okay. */
qatomic_set(&tcg_current_rr_cpu, NULL);
if (cpu && cpu->exit_request) {
qatomic_mb_set(&cpu->exit_request, 0);
}
if (icount_enabled() && all_cpu_threads_idle()) {
/*
* When all cpus are sleeping (e.g in WFI), to avoid a deadlock
* in the main_loop, wake it up in order to start the warp timer.
*/
qemu_notify_event();
}
qemu_tcg_rr_wait_io_event();
deal_with_unplugged_cpus();
}
rcu_unregister_thread();
return NULL;
}
static void *qemu_hax_cpu_thread_fn(void *arg)
{
CPUState *cpu = arg;
@ -1005,76 +646,6 @@ static void CALLBACK dummy_apc_func(ULONG_PTR unused)
}
#endif
/* Multi-threaded TCG
*
* In the multi-threaded case each vCPU has its own thread. The TLS
* variable current_cpu can be used deep in the code to find the
* current CPUState for a given thread.
*/
static void *qemu_tcg_cpu_thread_fn(void *arg)
{
CPUState *cpu = arg;
assert(tcg_enabled());
g_assert(!icount_enabled());
rcu_register_thread();
tcg_register_thread();
qemu_mutex_lock_iothread();
qemu_thread_get_self(cpu->thread);
cpu->thread_id = qemu_get_thread_id();
cpu->can_do_io = 1;
current_cpu = cpu;
cpu_thread_signal_created(cpu);
qemu_guest_random_seed_thread_part2(cpu->random_seed);
/* process any pending work */
cpu->exit_request = 1;
do {
if (cpu_can_run(cpu)) {
int r;
qemu_mutex_unlock_iothread();
r = tcg_cpu_exec(cpu);
qemu_mutex_lock_iothread();
switch (r) {
case EXCP_DEBUG:
cpu_handle_guest_debug(cpu);
break;
case EXCP_HALTED:
/* during start-up the vCPU is reset and the thread is
* kicked several times. If we don't ensure we go back
* to sleep in the halted state we won't cleanly
* start-up when the vCPU is enabled.
*
* cpu->halted should ensure we sleep in wait_io_event
*/
g_assert(cpu->halted);
break;
case EXCP_ATOMIC:
qemu_mutex_unlock_iothread();
cpu_exec_step_atomic(cpu);
qemu_mutex_lock_iothread();
default:
/* Ignore everything else? */
break;
}
}
qatomic_mb_set(&cpu->exit_request, 0);
qemu_wait_io_event(cpu);
} while (!cpu->unplug || cpu_can_run(cpu));
qemu_tcg_destroy_vcpu(cpu);
cpu_thread_signal_destroyed(cpu);
qemu_mutex_unlock_iothread();
rcu_unregister_thread();
return NULL;
}
void cpus_kick_thread(CPUState *cpu)
{
#ifndef _WIN32
@ -1105,15 +676,8 @@ void cpus_kick_thread(CPUState *cpu)
void qemu_cpu_kick(CPUState *cpu)
{
qemu_cond_broadcast(cpu->halt_cond);
if (cpus_accel && cpus_accel->kick_vcpu_thread) {
cpus_accel->kick_vcpu_thread(cpu);
} else if (tcg_enabled()) {
if (qemu_tcg_mttcg_enabled()) {
cpu_exit(cpu);
} else {
qemu_cpu_kick_rr_cpus();
}
} else {
if (hax_enabled()) {
/*
@ -1269,71 +833,6 @@ void cpu_remove_sync(CPUState *cpu)
qemu_mutex_lock_iothread();
}
static void qemu_tcg_init_vcpu(CPUState *cpu)
{
char thread_name[VCPU_THREAD_NAME_SIZE];
static QemuCond *single_tcg_halt_cond;
static QemuThread *single_tcg_cpu_thread;
static int tcg_region_inited;
assert(tcg_enabled());
/*
* Initialize TCG regions--once. Now is a good time, because:
* (1) TCG's init context, prologue and target globals have been set up.
* (2) qemu_tcg_mttcg_enabled() works now (TCG init code runs before the
* -accel flag is processed, so the check doesn't work then).
*/
if (!tcg_region_inited) {
tcg_region_inited = 1;
tcg_region_init();
/*
* If MTTCG, and we will create multiple cpus,
* then we will have cpus running in parallel.
*/
if (qemu_tcg_mttcg_enabled()) {
MachineState *ms = MACHINE(qdev_get_machine());
if (ms->smp.max_cpus > 1) {
parallel_cpus = true;
}
}
}
if (qemu_tcg_mttcg_enabled() || !single_tcg_cpu_thread) {
cpu->thread = g_malloc0(sizeof(QemuThread));
cpu->halt_cond = g_malloc0(sizeof(QemuCond));
qemu_cond_init(cpu->halt_cond);
if (qemu_tcg_mttcg_enabled()) {
/* create a thread per vCPU with TCG (MTTCG) */
snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/TCG",
cpu->cpu_index);
qemu_thread_create(cpu->thread, thread_name, qemu_tcg_cpu_thread_fn,
cpu, QEMU_THREAD_JOINABLE);
} else {
/* share a single thread for all cpus with TCG */
snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "ALL CPUs/TCG");
qemu_thread_create(cpu->thread, thread_name,
qemu_tcg_rr_cpu_thread_fn,
cpu, QEMU_THREAD_JOINABLE);
single_tcg_halt_cond = cpu->halt_cond;
single_tcg_cpu_thread = cpu->thread;
}
#ifdef _WIN32
cpu->hThread = qemu_thread_get_handle(cpu->thread);
#endif
} else {
/* For non-MTTCG cases we share the thread */
cpu->thread = single_tcg_cpu_thread;
cpu->halt_cond = single_tcg_halt_cond;
cpu->thread_id = first_cpu->thread_id;
cpu->can_do_io = 1;
cpu->created = true;
}
}
static void qemu_hax_start_vcpu(CPUState *cpu)
{
char thread_name[VCPU_THREAD_NAME_SIZE];
@ -1444,8 +943,6 @@ void qemu_init_vcpu(CPUState *cpu)
qemu_hax_start_vcpu(cpu);
} else if (hvf_enabled()) {
qemu_hvf_start_vcpu(cpu);
} else if (tcg_enabled()) {
qemu_tcg_init_vcpu(cpu);
} else if (whpx_enabled()) {
qemu_whpx_start_vcpu(cpu);
} else {