diff options
author | Philippe Mathieu-Daudé <philmd@linaro.org> | 2023-10-04 11:06:28 +0200 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-10-08 21:08:08 +0200 |
commit | 8d7f2e767d8cd058c817dbe31430b89f2e11535d (patch) | |
tree | 5b7c25cddf7e6c1b9dfc93c5169541e8c14e2901 /system/cpu-timers.c | |
parent | 01c85e60a4d0675f0ad203fe1fe119381e7ad15b (diff) |
system: Rename softmmu/ directory as system/
The softmmu/ directory contains files specific to system
emulation. Rename it as system/. Update meson rules, the
MAINTAINERS file and all the documentation and comments.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20231004090629.37473-14-philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'system/cpu-timers.c')
-rw-r--r-- | system/cpu-timers.c | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/system/cpu-timers.c b/system/cpu-timers.c new file mode 100644 index 0000000000..7452d97b67 --- /dev/null +++ b/system/cpu-timers.c @@ -0,0 +1,277 @@ +/* + * 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. + */ + +#include "qemu/osdep.h" +#include "qemu/cutils.h" +#include "migration/vmstate.h" +#include "qapi/error.h" +#include "qemu/error-report.h" +#include "sysemu/cpus.h" +#include "qemu/main-loop.h" +#include "qemu/option.h" +#include "qemu/seqlock.h" +#include "sysemu/replay.h" +#include "sysemu/runstate.h" +#include "hw/core/cpu.h" +#include "sysemu/cpu-timers.h" +#include "sysemu/cpu-throttle.h" +#include "sysemu/cpu-timers-internal.h" + +/* clock and ticks */ + +static int64_t cpu_get_ticks_locked(void) +{ + int64_t ticks = timers_state.cpu_ticks_offset; + if (timers_state.cpu_ticks_enabled) { + ticks += cpu_get_host_ticks(); + } + + if (timers_state.cpu_ticks_prev > ticks) { + /* Non increasing ticks may happen if the host uses software suspend. */ + timers_state.cpu_ticks_offset += timers_state.cpu_ticks_prev - ticks; + ticks = timers_state.cpu_ticks_prev; + } + + timers_state.cpu_ticks_prev = ticks; + return ticks; +} + +/* + * return the time elapsed in VM between vm_start and vm_stop. + * cpu_get_ticks() uses units of the host CPU cycle counter. + */ +int64_t cpu_get_ticks(void) +{ + int64_t ticks; + + qemu_spin_lock(&timers_state.vm_clock_lock); + ticks = cpu_get_ticks_locked(); + qemu_spin_unlock(&timers_state.vm_clock_lock); + return ticks; +} + +int64_t cpu_get_clock_locked(void) +{ + int64_t time; + + time = timers_state.cpu_clock_offset; + if (timers_state.cpu_ticks_enabled) { + time += get_clock(); + } + + return time; +} + +/* + * Return the monotonic time elapsed in VM, i.e., + * the time between vm_start and vm_stop + */ +int64_t cpu_get_clock(void) +{ + int64_t ti; + unsigned start; + + do { + start = seqlock_read_begin(&timers_state.vm_clock_seqlock); + ti = cpu_get_clock_locked(); + } while (seqlock_read_retry(&timers_state.vm_clock_seqlock, start)); + + return ti; +} + +/* + * enable cpu_get_ticks() + * Caller must hold BQL which serves as mutex for vm_clock_seqlock. + */ +void cpu_enable_ticks(void) +{ + seqlock_write_lock(&timers_state.vm_clock_seqlock, + &timers_state.vm_clock_lock); + if (!timers_state.cpu_ticks_enabled) { + timers_state.cpu_ticks_offset -= cpu_get_host_ticks(); + timers_state.cpu_clock_offset -= get_clock(); + timers_state.cpu_ticks_enabled = 1; + } + seqlock_write_unlock(&timers_state.vm_clock_seqlock, + &timers_state.vm_clock_lock); +} + +/* + * disable cpu_get_ticks() : the clock is stopped. You must not call + * cpu_get_ticks() after that. + * Caller must hold BQL which serves as mutex for vm_clock_seqlock. + */ +void cpu_disable_ticks(void) +{ + seqlock_write_lock(&timers_state.vm_clock_seqlock, + &timers_state.vm_clock_lock); + if (timers_state.cpu_ticks_enabled) { + timers_state.cpu_ticks_offset += cpu_get_host_ticks(); + timers_state.cpu_clock_offset = cpu_get_clock_locked(); + timers_state.cpu_ticks_enabled = 0; + } + seqlock_write_unlock(&timers_state.vm_clock_seqlock, + &timers_state.vm_clock_lock); +} + +static bool icount_state_needed(void *opaque) +{ + return icount_enabled(); +} + +static bool warp_timer_state_needed(void *opaque) +{ + TimersState *s = opaque; + return s->icount_warp_timer != NULL; +} + +static bool adjust_timers_state_needed(void *opaque) +{ + TimersState *s = opaque; + return s->icount_rt_timer != NULL; +} + +static bool icount_shift_state_needed(void *opaque) +{ + return icount_enabled() == 2; +} + +/* + * Subsection for warp timer migration is optional, because may not be created + */ +static const VMStateDescription icount_vmstate_warp_timer = { + .name = "timer/icount/warp_timer", + .version_id = 1, + .minimum_version_id = 1, + .needed = warp_timer_state_needed, + .fields = (VMStateField[]) { + VMSTATE_INT64(vm_clock_warp_start, TimersState), + VMSTATE_TIMER_PTR(icount_warp_timer, TimersState), + VMSTATE_END_OF_LIST() + } +}; + +static const VMStateDescription icount_vmstate_adjust_timers = { + .name = "timer/icount/timers", + .version_id = 1, + .minimum_version_id = 1, + .needed = adjust_timers_state_needed, + .fields = (VMStateField[]) { + VMSTATE_TIMER_PTR(icount_rt_timer, TimersState), + VMSTATE_TIMER_PTR(icount_vm_timer, TimersState), + VMSTATE_END_OF_LIST() + } +}; + +static const VMStateDescription icount_vmstate_shift = { + .name = "timer/icount/shift", + .version_id = 2, + .minimum_version_id = 2, + .needed = icount_shift_state_needed, + .fields = (VMStateField[]) { + VMSTATE_INT16(icount_time_shift, TimersState), + VMSTATE_INT64(last_delta, TimersState), + VMSTATE_END_OF_LIST() + } +}; + +/* + * This is a subsection for icount migration. + */ +static const VMStateDescription icount_vmstate_timers = { + .name = "timer/icount", + .version_id = 1, + .minimum_version_id = 1, + .needed = icount_state_needed, + .fields = (VMStateField[]) { + VMSTATE_INT64(qemu_icount_bias, TimersState), + VMSTATE_INT64(qemu_icount, TimersState), + VMSTATE_END_OF_LIST() + }, + .subsections = (const VMStateDescription * []) { + &icount_vmstate_warp_timer, + &icount_vmstate_adjust_timers, + &icount_vmstate_shift, + NULL + } +}; + +static const VMStateDescription vmstate_timers = { + .name = "timer", + .version_id = 2, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_INT64(cpu_ticks_offset, TimersState), + VMSTATE_UNUSED(8), + VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2), + VMSTATE_END_OF_LIST() + }, + .subsections = (const VMStateDescription * []) { + &icount_vmstate_timers, + NULL + } +}; + +static void do_nothing(CPUState *cpu, run_on_cpu_data unused) +{ +} + +void qemu_timer_notify_cb(void *opaque, QEMUClockType type) +{ + if (!icount_enabled() || type != QEMU_CLOCK_VIRTUAL) { + qemu_notify_event(); + return; + } + + if (qemu_in_vcpu_thread()) { + /* + * A CPU is currently running; kick it back out to the + * tcg_cpu_exec() loop so it will recalculate its + * icount deadline immediately. + */ + qemu_cpu_kick(current_cpu); + } else if (first_cpu) { + /* + * qemu_cpu_kick is not enough to kick a halted CPU out of + * qemu_tcg_wait_io_event. async_run_on_cpu, instead, + * causes cpu_thread_is_idle to return false. This way, + * handle_icount_deadline can run. + * If we have no CPUs at all for some reason, we don't + * need to do anything. + */ + async_run_on_cpu(first_cpu, do_nothing, RUN_ON_CPU_NULL); + } +} + +TimersState timers_state; + +/* initialize timers state and the cpu throttle for convenience */ +void cpu_timers_init(void) +{ + seqlock_init(&timers_state.vm_clock_seqlock); + qemu_spin_init(&timers_state.vm_clock_lock); + vmstate_register(NULL, 0, &vmstate_timers, &timers_state); + + cpu_throttle_init(); +} |