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-rw-r--r--system/cpu-timers.c277
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diff --git a/system/cpu-timers.c b/system/cpu-timers.c
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+++ b/system/cpu-timers.c
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+/*
+ * 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();
+}
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