diff options
| -rw-r--r-- | accel/tcg/meson.build | 2 | ||||
| -rw-r--r-- | accel/tcg/tcg-all.c | 11 | ||||
| -rw-r--r-- | accel/tcg/tcg-cpus.c | 551 | ||||
| -rw-r--r-- | accel/tcg/tcg-cpus.h | 17 | ||||
| -rw-r--r-- | softmmu/cpus.c | 505 |
5 files changed, 576 insertions, 510 deletions
diff --git a/accel/tcg/meson.build b/accel/tcg/meson.build index 96a76ed23d..19b9343d5b 100644 --- a/accel/tcg/meson.build +++ b/accel/tcg/meson.build @@ -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')) diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c index 2d13df3f72..000fe4dbd9 100644 --- a/accel/tcg/tcg-all.c +++ b/accel/tcg/tcg-all.c @@ -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; } diff --git a/accel/tcg/tcg-cpus.c b/accel/tcg/tcg-cpus.c new file mode 100644 index 0000000000..4f15c7f0de --- /dev/null +++ b/accel/tcg/tcg-cpus.c @@ -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, +}; diff --git a/accel/tcg/tcg-cpus.h b/accel/tcg/tcg-cpus.h new file mode 100644 index 0000000000..8b1d9d2abc --- /dev/null +++ b/accel/tcg/tcg-cpus.h @@ -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 */ diff --git a/softmmu/cpus.c b/softmmu/cpus.c index f932fc1f74..25f12e3ee9 100644 --- a/softmmu/cpus.c +++ b/softmmu/cpus.c @@ -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 { |