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![Anthony Liguori](/assets/img/avatar_default.png)
dynticks will provide equally good timer granularity on all modern Linux systems. This is more or less dead code these days. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
1168 lines
30 KiB
C
1168 lines
30 KiB
C
/*
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* QEMU System Emulator
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*
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* Copyright (c) 2003-2008 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "sysemu.h"
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#include "net.h"
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#include "monitor.h"
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#include "console.h"
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#include "hw/hw.h"
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#include <unistd.h>
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#include <fcntl.h>
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#include <time.h>
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#include <errno.h>
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#include <sys/time.h>
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#include <signal.h>
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#ifdef __FreeBSD__
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#include <sys/param.h>
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#endif
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#ifdef _WIN32
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#include <windows.h>
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#include <mmsystem.h>
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#endif
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#include "qemu-timer.h"
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/* Conversion factor from emulated instructions to virtual clock ticks. */
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int icount_time_shift;
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/* Arbitrarily pick 1MIPS as the minimum allowable speed. */
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#define MAX_ICOUNT_SHIFT 10
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/* Compensate for varying guest execution speed. */
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int64_t qemu_icount_bias;
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static QEMUTimer *icount_rt_timer;
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static QEMUTimer *icount_vm_timer;
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/***********************************************************/
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/* guest cycle counter */
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typedef struct TimersState {
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int64_t cpu_ticks_prev;
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int64_t cpu_ticks_offset;
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int64_t cpu_clock_offset;
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int32_t cpu_ticks_enabled;
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int64_t dummy;
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} TimersState;
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TimersState timers_state;
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/* return the host CPU cycle counter and handle stop/restart */
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int64_t cpu_get_ticks(void)
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{
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if (use_icount) {
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return cpu_get_icount();
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}
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if (!timers_state.cpu_ticks_enabled) {
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return timers_state.cpu_ticks_offset;
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} else {
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int64_t ticks;
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ticks = cpu_get_real_ticks();
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if (timers_state.cpu_ticks_prev > ticks) {
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/* Note: non increasing ticks may happen if the host uses
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software suspend */
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timers_state.cpu_ticks_offset += timers_state.cpu_ticks_prev - ticks;
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}
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timers_state.cpu_ticks_prev = ticks;
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return ticks + timers_state.cpu_ticks_offset;
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}
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}
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/* return the host CPU monotonic timer and handle stop/restart */
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static int64_t cpu_get_clock(void)
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{
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int64_t ti;
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if (!timers_state.cpu_ticks_enabled) {
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return timers_state.cpu_clock_offset;
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} else {
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ti = get_clock();
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return ti + timers_state.cpu_clock_offset;
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}
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}
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#ifndef CONFIG_IOTHREAD
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static int64_t qemu_icount_delta(void)
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{
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if (!use_icount) {
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return 5000 * (int64_t) 1000000;
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} else if (use_icount == 1) {
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/* When not using an adaptive execution frequency
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we tend to get badly out of sync with real time,
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so just delay for a reasonable amount of time. */
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return 0;
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} else {
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return cpu_get_icount() - cpu_get_clock();
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}
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}
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#endif
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/* enable cpu_get_ticks() */
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void cpu_enable_ticks(void)
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{
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if (!timers_state.cpu_ticks_enabled) {
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timers_state.cpu_ticks_offset -= cpu_get_real_ticks();
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timers_state.cpu_clock_offset -= get_clock();
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timers_state.cpu_ticks_enabled = 1;
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}
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}
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/* disable cpu_get_ticks() : the clock is stopped. You must not call
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cpu_get_ticks() after that. */
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void cpu_disable_ticks(void)
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{
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if (timers_state.cpu_ticks_enabled) {
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timers_state.cpu_ticks_offset = cpu_get_ticks();
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timers_state.cpu_clock_offset = cpu_get_clock();
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timers_state.cpu_ticks_enabled = 0;
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}
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}
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/***********************************************************/
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/* timers */
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#define QEMU_CLOCK_REALTIME 0
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#define QEMU_CLOCK_VIRTUAL 1
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#define QEMU_CLOCK_HOST 2
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struct QEMUClock {
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int type;
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int enabled;
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QEMUTimer *warp_timer;
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};
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struct QEMUTimer {
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QEMUClock *clock;
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int64_t expire_time; /* in nanoseconds */
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int scale;
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QEMUTimerCB *cb;
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void *opaque;
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struct QEMUTimer *next;
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};
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struct qemu_alarm_timer {
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char const *name;
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int (*start)(struct qemu_alarm_timer *t);
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void (*stop)(struct qemu_alarm_timer *t);
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void (*rearm)(struct qemu_alarm_timer *t);
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#if defined(__linux__)
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int fd;
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timer_t timer;
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#elif defined(_WIN32)
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HANDLE timer;
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#endif
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char expired;
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char pending;
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};
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static struct qemu_alarm_timer *alarm_timer;
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static bool qemu_timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
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{
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return timer_head && (timer_head->expire_time <= current_time);
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}
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int qemu_alarm_pending(void)
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{
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return alarm_timer->pending;
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}
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static inline int alarm_has_dynticks(struct qemu_alarm_timer *t)
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{
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return !!t->rearm;
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}
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static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
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{
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if (!alarm_has_dynticks(t))
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return;
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t->rearm(t);
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}
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/* TODO: MIN_TIMER_REARM_NS should be optimized */
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#define MIN_TIMER_REARM_NS 250000
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#ifdef _WIN32
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static int mm_start_timer(struct qemu_alarm_timer *t);
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static void mm_stop_timer(struct qemu_alarm_timer *t);
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static void mm_rearm_timer(struct qemu_alarm_timer *t);
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static int win32_start_timer(struct qemu_alarm_timer *t);
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static void win32_stop_timer(struct qemu_alarm_timer *t);
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static void win32_rearm_timer(struct qemu_alarm_timer *t);
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#else
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static int unix_start_timer(struct qemu_alarm_timer *t);
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static void unix_stop_timer(struct qemu_alarm_timer *t);
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#ifdef __linux__
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static int dynticks_start_timer(struct qemu_alarm_timer *t);
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static void dynticks_stop_timer(struct qemu_alarm_timer *t);
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static void dynticks_rearm_timer(struct qemu_alarm_timer *t);
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#endif /* __linux__ */
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#endif /* _WIN32 */
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/* Correlation between real and virtual time is always going to be
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fairly approximate, so ignore small variation.
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When the guest is idle real and virtual time will be aligned in
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the IO wait loop. */
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#define ICOUNT_WOBBLE (get_ticks_per_sec() / 10)
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static void icount_adjust(void)
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{
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int64_t cur_time;
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int64_t cur_icount;
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int64_t delta;
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static int64_t last_delta;
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/* If the VM is not running, then do nothing. */
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if (!vm_running)
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return;
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cur_time = cpu_get_clock();
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cur_icount = qemu_get_clock_ns(vm_clock);
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delta = cur_icount - cur_time;
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/* FIXME: This is a very crude algorithm, somewhat prone to oscillation. */
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if (delta > 0
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&& last_delta + ICOUNT_WOBBLE < delta * 2
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&& icount_time_shift > 0) {
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/* The guest is getting too far ahead. Slow time down. */
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icount_time_shift--;
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}
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if (delta < 0
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&& last_delta - ICOUNT_WOBBLE > delta * 2
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&& icount_time_shift < MAX_ICOUNT_SHIFT) {
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/* The guest is getting too far behind. Speed time up. */
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icount_time_shift++;
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}
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last_delta = delta;
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qemu_icount_bias = cur_icount - (qemu_icount << icount_time_shift);
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}
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static void icount_adjust_rt(void * opaque)
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{
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qemu_mod_timer(icount_rt_timer,
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qemu_get_clock_ms(rt_clock) + 1000);
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icount_adjust();
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}
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static void icount_adjust_vm(void * opaque)
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{
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qemu_mod_timer(icount_vm_timer,
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qemu_get_clock_ns(vm_clock) + get_ticks_per_sec() / 10);
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icount_adjust();
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}
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int64_t qemu_icount_round(int64_t count)
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{
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return (count + (1 << icount_time_shift) - 1) >> icount_time_shift;
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}
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static struct qemu_alarm_timer alarm_timers[] = {
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#ifndef _WIN32
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#ifdef __linux__
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{"dynticks", dynticks_start_timer,
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dynticks_stop_timer, dynticks_rearm_timer},
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#endif
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{"unix", unix_start_timer, unix_stop_timer, NULL},
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#else
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{"mmtimer", mm_start_timer, mm_stop_timer, NULL},
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{"mmtimer2", mm_start_timer, mm_stop_timer, mm_rearm_timer},
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{"dynticks", win32_start_timer, win32_stop_timer, win32_rearm_timer},
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{"win32", win32_start_timer, win32_stop_timer, NULL},
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#endif
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{NULL, }
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};
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static void show_available_alarms(void)
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{
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int i;
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printf("Available alarm timers, in order of precedence:\n");
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for (i = 0; alarm_timers[i].name; i++)
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printf("%s\n", alarm_timers[i].name);
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}
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void configure_alarms(char const *opt)
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{
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int i;
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int cur = 0;
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int count = ARRAY_SIZE(alarm_timers) - 1;
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char *arg;
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char *name;
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struct qemu_alarm_timer tmp;
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if (!strcmp(opt, "?")) {
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show_available_alarms();
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exit(0);
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}
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arg = qemu_strdup(opt);
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/* Reorder the array */
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name = strtok(arg, ",");
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while (name) {
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for (i = 0; i < count && alarm_timers[i].name; i++) {
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if (!strcmp(alarm_timers[i].name, name))
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break;
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}
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if (i == count) {
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fprintf(stderr, "Unknown clock %s\n", name);
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goto next;
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}
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if (i < cur)
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/* Ignore */
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goto next;
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/* Swap */
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tmp = alarm_timers[i];
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alarm_timers[i] = alarm_timers[cur];
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alarm_timers[cur] = tmp;
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cur++;
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next:
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name = strtok(NULL, ",");
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}
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qemu_free(arg);
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if (cur) {
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/* Disable remaining timers */
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for (i = cur; i < count; i++)
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alarm_timers[i].name = NULL;
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} else {
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show_available_alarms();
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exit(1);
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}
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}
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#define QEMU_NUM_CLOCKS 3
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QEMUClock *rt_clock;
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QEMUClock *vm_clock;
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QEMUClock *host_clock;
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static QEMUTimer *active_timers[QEMU_NUM_CLOCKS];
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static QEMUClock *qemu_new_clock(int type)
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{
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QEMUClock *clock;
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clock = qemu_mallocz(sizeof(QEMUClock));
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clock->type = type;
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clock->enabled = 1;
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return clock;
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}
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void qemu_clock_enable(QEMUClock *clock, int enabled)
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{
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clock->enabled = enabled;
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}
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static int64_t vm_clock_warp_start;
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static void icount_warp_rt(void *opaque)
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{
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if (vm_clock_warp_start == -1) {
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return;
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}
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if (vm_running) {
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int64_t clock = qemu_get_clock_ns(rt_clock);
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int64_t warp_delta = clock - vm_clock_warp_start;
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if (use_icount == 1) {
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qemu_icount_bias += warp_delta;
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} else {
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/*
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* In adaptive mode, do not let the vm_clock run too
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* far ahead of real time.
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*/
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int64_t cur_time = cpu_get_clock();
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int64_t cur_icount = qemu_get_clock_ns(vm_clock);
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int64_t delta = cur_time - cur_icount;
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qemu_icount_bias += MIN(warp_delta, delta);
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}
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if (qemu_timer_expired(active_timers[QEMU_CLOCK_VIRTUAL],
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qemu_get_clock_ns(vm_clock))) {
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qemu_notify_event();
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}
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}
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vm_clock_warp_start = -1;
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}
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void qemu_clock_warp(QEMUClock *clock)
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{
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int64_t deadline;
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if (!clock->warp_timer) {
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return;
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}
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/*
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* There are too many global variables to make the "warp" behavior
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* applicable to other clocks. But a clock argument removes the
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* need for if statements all over the place.
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*/
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assert(clock == vm_clock);
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/*
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* If the CPUs have been sleeping, advance the vm_clock timer now. This
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* ensures that the deadline for the timer is computed correctly below.
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* This also makes sure that the insn counter is synchronized before the
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* CPU starts running, in case the CPU is woken by an event other than
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* the earliest vm_clock timer.
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*/
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icount_warp_rt(NULL);
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if (!all_cpu_threads_idle() || !active_timers[clock->type]) {
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qemu_del_timer(clock->warp_timer);
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return;
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}
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vm_clock_warp_start = qemu_get_clock_ns(rt_clock);
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deadline = qemu_next_icount_deadline();
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if (deadline > 0) {
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/*
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* Ensure the vm_clock proceeds even when the virtual CPU goes to
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* sleep. Otherwise, the CPU might be waiting for a future timer
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* interrupt to wake it up, but the interrupt never comes because
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* the vCPU isn't running any insns and thus doesn't advance the
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* vm_clock.
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*
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* An extreme solution for this problem would be to never let VCPUs
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* sleep in icount mode if there is a pending vm_clock timer; rather
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* time could just advance to the next vm_clock event. Instead, we
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* do stop VCPUs and only advance vm_clock after some "real" time,
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* (related to the time left until the next event) has passed. This
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* rt_clock timer will do this. This avoids that the warps are too
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* visible externally---for example, you will not be sending network
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* packets continously instead of every 100ms.
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*/
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qemu_mod_timer(clock->warp_timer, vm_clock_warp_start + deadline);
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} else {
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qemu_notify_event();
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}
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}
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QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
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QEMUTimerCB *cb, void *opaque)
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{
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QEMUTimer *ts;
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ts = qemu_mallocz(sizeof(QEMUTimer));
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ts->clock = clock;
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ts->cb = cb;
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ts->opaque = opaque;
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ts->scale = scale;
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return ts;
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}
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void qemu_free_timer(QEMUTimer *ts)
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{
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qemu_free(ts);
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}
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|
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/* stop a timer, but do not dealloc it */
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void qemu_del_timer(QEMUTimer *ts)
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{
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QEMUTimer **pt, *t;
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/* NOTE: this code must be signal safe because
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qemu_timer_expired() can be called from a signal. */
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pt = &active_timers[ts->clock->type];
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for(;;) {
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t = *pt;
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if (!t)
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break;
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if (t == ts) {
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*pt = t->next;
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break;
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}
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pt = &t->next;
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}
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}
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|
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/* modify the current timer so that it will be fired when current_time
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>= expire_time. The corresponding callback will be called. */
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static void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
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{
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QEMUTimer **pt, *t;
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|
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qemu_del_timer(ts);
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|
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/* add the timer in the sorted list */
|
|
/* NOTE: this code must be signal safe because
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qemu_timer_expired() can be called from a signal. */
|
|
pt = &active_timers[ts->clock->type];
|
|
for(;;) {
|
|
t = *pt;
|
|
if (!qemu_timer_expired_ns(t, expire_time)) {
|
|
break;
|
|
}
|
|
pt = &t->next;
|
|
}
|
|
ts->expire_time = expire_time;
|
|
ts->next = *pt;
|
|
*pt = ts;
|
|
|
|
/* Rearm if necessary */
|
|
if (pt == &active_timers[ts->clock->type]) {
|
|
if (!alarm_timer->pending) {
|
|
qemu_rearm_alarm_timer(alarm_timer);
|
|
}
|
|
/* Interrupt execution to force deadline recalculation. */
|
|
qemu_clock_warp(ts->clock);
|
|
if (use_icount) {
|
|
qemu_notify_event();
|
|
}
|
|
}
|
|
}
|
|
|
|
/* modify the current timer so that it will be fired when current_time
|
|
>= expire_time. The corresponding callback will be called. */
|
|
void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
|
|
{
|
|
qemu_mod_timer_ns(ts, expire_time * ts->scale);
|
|
}
|
|
|
|
int qemu_timer_pending(QEMUTimer *ts)
|
|
{
|
|
QEMUTimer *t;
|
|
for(t = active_timers[ts->clock->type]; t != NULL; t = t->next) {
|
|
if (t == ts)
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int qemu_timer_expired(QEMUTimer *timer_head, int64_t current_time)
|
|
{
|
|
return qemu_timer_expired_ns(timer_head, current_time * timer_head->scale);
|
|
}
|
|
|
|
static void qemu_run_timers(QEMUClock *clock)
|
|
{
|
|
QEMUTimer **ptimer_head, *ts;
|
|
int64_t current_time;
|
|
|
|
if (!clock->enabled)
|
|
return;
|
|
|
|
current_time = qemu_get_clock_ns(clock);
|
|
ptimer_head = &active_timers[clock->type];
|
|
for(;;) {
|
|
ts = *ptimer_head;
|
|
if (!qemu_timer_expired_ns(ts, current_time)) {
|
|
break;
|
|
}
|
|
/* remove timer from the list before calling the callback */
|
|
*ptimer_head = ts->next;
|
|
ts->next = NULL;
|
|
|
|
/* run the callback (the timer list can be modified) */
|
|
ts->cb(ts->opaque);
|
|
}
|
|
}
|
|
|
|
int64_t qemu_get_clock_ns(QEMUClock *clock)
|
|
{
|
|
switch(clock->type) {
|
|
case QEMU_CLOCK_REALTIME:
|
|
return get_clock();
|
|
default:
|
|
case QEMU_CLOCK_VIRTUAL:
|
|
if (use_icount) {
|
|
return cpu_get_icount();
|
|
} else {
|
|
return cpu_get_clock();
|
|
}
|
|
case QEMU_CLOCK_HOST:
|
|
return get_clock_realtime();
|
|
}
|
|
}
|
|
|
|
void init_clocks(void)
|
|
{
|
|
rt_clock = qemu_new_clock(QEMU_CLOCK_REALTIME);
|
|
vm_clock = qemu_new_clock(QEMU_CLOCK_VIRTUAL);
|
|
host_clock = qemu_new_clock(QEMU_CLOCK_HOST);
|
|
|
|
rtc_clock = host_clock;
|
|
}
|
|
|
|
/* save a timer */
|
|
void qemu_put_timer(QEMUFile *f, QEMUTimer *ts)
|
|
{
|
|
uint64_t expire_time;
|
|
|
|
if (qemu_timer_pending(ts)) {
|
|
expire_time = ts->expire_time;
|
|
} else {
|
|
expire_time = -1;
|
|
}
|
|
qemu_put_be64(f, expire_time);
|
|
}
|
|
|
|
void qemu_get_timer(QEMUFile *f, QEMUTimer *ts)
|
|
{
|
|
uint64_t expire_time;
|
|
|
|
expire_time = qemu_get_be64(f);
|
|
if (expire_time != -1) {
|
|
qemu_mod_timer_ns(ts, expire_time);
|
|
} else {
|
|
qemu_del_timer(ts);
|
|
}
|
|
}
|
|
|
|
static const VMStateDescription vmstate_timers = {
|
|
.name = "timer",
|
|
.version_id = 2,
|
|
.minimum_version_id = 1,
|
|
.minimum_version_id_old = 1,
|
|
.fields = (VMStateField []) {
|
|
VMSTATE_INT64(cpu_ticks_offset, TimersState),
|
|
VMSTATE_INT64(dummy, TimersState),
|
|
VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2),
|
|
VMSTATE_END_OF_LIST()
|
|
}
|
|
};
|
|
|
|
void configure_icount(const char *option)
|
|
{
|
|
vmstate_register(NULL, 0, &vmstate_timers, &timers_state);
|
|
if (!option)
|
|
return;
|
|
|
|
#ifdef CONFIG_IOTHREAD
|
|
vm_clock->warp_timer = qemu_new_timer_ns(rt_clock, icount_warp_rt, NULL);
|
|
#endif
|
|
|
|
if (strcmp(option, "auto") != 0) {
|
|
icount_time_shift = strtol(option, NULL, 0);
|
|
use_icount = 1;
|
|
return;
|
|
}
|
|
|
|
use_icount = 2;
|
|
|
|
/* 125MIPS seems a reasonable initial guess at the guest speed.
|
|
It will be corrected fairly quickly anyway. */
|
|
icount_time_shift = 3;
|
|
|
|
/* Have both realtime and virtual time triggers for speed adjustment.
|
|
The realtime trigger catches emulated time passing too slowly,
|
|
the virtual time trigger catches emulated time passing too fast.
|
|
Realtime triggers occur even when idle, so use them less frequently
|
|
than VM triggers. */
|
|
icount_rt_timer = qemu_new_timer_ms(rt_clock, icount_adjust_rt, NULL);
|
|
qemu_mod_timer(icount_rt_timer,
|
|
qemu_get_clock_ms(rt_clock) + 1000);
|
|
icount_vm_timer = qemu_new_timer_ns(vm_clock, icount_adjust_vm, NULL);
|
|
qemu_mod_timer(icount_vm_timer,
|
|
qemu_get_clock_ns(vm_clock) + get_ticks_per_sec() / 10);
|
|
}
|
|
|
|
void qemu_run_all_timers(void)
|
|
{
|
|
alarm_timer->pending = 0;
|
|
|
|
/* rearm timer, if not periodic */
|
|
if (alarm_timer->expired) {
|
|
alarm_timer->expired = 0;
|
|
qemu_rearm_alarm_timer(alarm_timer);
|
|
}
|
|
|
|
/* vm time timers */
|
|
if (vm_running) {
|
|
qemu_run_timers(vm_clock);
|
|
}
|
|
|
|
qemu_run_timers(rt_clock);
|
|
qemu_run_timers(host_clock);
|
|
}
|
|
|
|
static int64_t qemu_next_alarm_deadline(void);
|
|
|
|
#ifdef _WIN32
|
|
static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused)
|
|
#else
|
|
static void host_alarm_handler(int host_signum)
|
|
#endif
|
|
{
|
|
struct qemu_alarm_timer *t = alarm_timer;
|
|
if (!t)
|
|
return;
|
|
|
|
#if 0
|
|
#define DISP_FREQ 1000
|
|
{
|
|
static int64_t delta_min = INT64_MAX;
|
|
static int64_t delta_max, delta_cum, last_clock, delta, ti;
|
|
static int count;
|
|
ti = qemu_get_clock_ns(vm_clock);
|
|
if (last_clock != 0) {
|
|
delta = ti - last_clock;
|
|
if (delta < delta_min)
|
|
delta_min = delta;
|
|
if (delta > delta_max)
|
|
delta_max = delta;
|
|
delta_cum += delta;
|
|
if (++count == DISP_FREQ) {
|
|
printf("timer: min=%" PRId64 " us max=%" PRId64 " us avg=%" PRId64 " us avg_freq=%0.3f Hz\n",
|
|
muldiv64(delta_min, 1000000, get_ticks_per_sec()),
|
|
muldiv64(delta_max, 1000000, get_ticks_per_sec()),
|
|
muldiv64(delta_cum, 1000000 / DISP_FREQ, get_ticks_per_sec()),
|
|
(double)get_ticks_per_sec() / ((double)delta_cum / DISP_FREQ));
|
|
count = 0;
|
|
delta_min = INT64_MAX;
|
|
delta_max = 0;
|
|
delta_cum = 0;
|
|
}
|
|
}
|
|
last_clock = ti;
|
|
}
|
|
#endif
|
|
if (alarm_has_dynticks(t) ||
|
|
qemu_next_alarm_deadline () <= 0) {
|
|
t->expired = alarm_has_dynticks(t);
|
|
t->pending = 1;
|
|
qemu_notify_event();
|
|
}
|
|
}
|
|
|
|
int64_t qemu_next_icount_deadline(void)
|
|
{
|
|
/* To avoid problems with overflow limit this to 2^32. */
|
|
int64_t delta = INT32_MAX;
|
|
|
|
assert(use_icount);
|
|
if (active_timers[QEMU_CLOCK_VIRTUAL]) {
|
|
delta = active_timers[QEMU_CLOCK_VIRTUAL]->expire_time -
|
|
qemu_get_clock_ns(vm_clock);
|
|
}
|
|
|
|
if (delta < 0)
|
|
delta = 0;
|
|
|
|
return delta;
|
|
}
|
|
|
|
static int64_t qemu_next_alarm_deadline(void)
|
|
{
|
|
int64_t delta;
|
|
int64_t rtdelta;
|
|
|
|
if (!use_icount && active_timers[QEMU_CLOCK_VIRTUAL]) {
|
|
delta = active_timers[QEMU_CLOCK_VIRTUAL]->expire_time -
|
|
qemu_get_clock_ns(vm_clock);
|
|
} else {
|
|
delta = INT32_MAX;
|
|
}
|
|
if (active_timers[QEMU_CLOCK_HOST]) {
|
|
int64_t hdelta = active_timers[QEMU_CLOCK_HOST]->expire_time -
|
|
qemu_get_clock_ns(host_clock);
|
|
if (hdelta < delta)
|
|
delta = hdelta;
|
|
}
|
|
if (active_timers[QEMU_CLOCK_REALTIME]) {
|
|
rtdelta = (active_timers[QEMU_CLOCK_REALTIME]->expire_time -
|
|
qemu_get_clock_ns(rt_clock));
|
|
if (rtdelta < delta)
|
|
delta = rtdelta;
|
|
}
|
|
|
|
return delta;
|
|
}
|
|
|
|
#if defined(__linux__)
|
|
|
|
static int dynticks_start_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
struct sigevent ev;
|
|
timer_t host_timer;
|
|
struct sigaction act;
|
|
|
|
sigfillset(&act.sa_mask);
|
|
act.sa_flags = 0;
|
|
act.sa_handler = host_alarm_handler;
|
|
|
|
sigaction(SIGALRM, &act, NULL);
|
|
|
|
/*
|
|
* Initialize ev struct to 0 to avoid valgrind complaining
|
|
* about uninitialized data in timer_create call
|
|
*/
|
|
memset(&ev, 0, sizeof(ev));
|
|
ev.sigev_value.sival_int = 0;
|
|
ev.sigev_notify = SIGEV_SIGNAL;
|
|
ev.sigev_signo = SIGALRM;
|
|
|
|
if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
|
|
perror("timer_create");
|
|
|
|
/* disable dynticks */
|
|
fprintf(stderr, "Dynamic Ticks disabled\n");
|
|
|
|
return -1;
|
|
}
|
|
|
|
t->timer = host_timer;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void dynticks_stop_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
timer_t host_timer = t->timer;
|
|
|
|
timer_delete(host_timer);
|
|
}
|
|
|
|
static void dynticks_rearm_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
timer_t host_timer = t->timer;
|
|
struct itimerspec timeout;
|
|
int64_t nearest_delta_ns = INT64_MAX;
|
|
int64_t current_ns;
|
|
|
|
assert(alarm_has_dynticks(t));
|
|
if (!active_timers[QEMU_CLOCK_REALTIME] &&
|
|
!active_timers[QEMU_CLOCK_VIRTUAL] &&
|
|
!active_timers[QEMU_CLOCK_HOST])
|
|
return;
|
|
|
|
nearest_delta_ns = qemu_next_alarm_deadline();
|
|
if (nearest_delta_ns < MIN_TIMER_REARM_NS)
|
|
nearest_delta_ns = MIN_TIMER_REARM_NS;
|
|
|
|
/* check whether a timer is already running */
|
|
if (timer_gettime(host_timer, &timeout)) {
|
|
perror("gettime");
|
|
fprintf(stderr, "Internal timer error: aborting\n");
|
|
exit(1);
|
|
}
|
|
current_ns = timeout.it_value.tv_sec * 1000000000LL + timeout.it_value.tv_nsec;
|
|
if (current_ns && current_ns <= nearest_delta_ns)
|
|
return;
|
|
|
|
timeout.it_interval.tv_sec = 0;
|
|
timeout.it_interval.tv_nsec = 0; /* 0 for one-shot timer */
|
|
timeout.it_value.tv_sec = nearest_delta_ns / 1000000000;
|
|
timeout.it_value.tv_nsec = nearest_delta_ns % 1000000000;
|
|
if (timer_settime(host_timer, 0 /* RELATIVE */, &timeout, NULL)) {
|
|
perror("settime");
|
|
fprintf(stderr, "Internal timer error: aborting\n");
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
#endif /* defined(__linux__) */
|
|
|
|
#if !defined(_WIN32)
|
|
|
|
static int unix_start_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
struct sigaction act;
|
|
struct itimerval itv;
|
|
int err;
|
|
|
|
/* timer signal */
|
|
sigfillset(&act.sa_mask);
|
|
act.sa_flags = 0;
|
|
act.sa_handler = host_alarm_handler;
|
|
|
|
sigaction(SIGALRM, &act, NULL);
|
|
|
|
itv.it_interval.tv_sec = 0;
|
|
/* for i386 kernel 2.6 to get 1 ms */
|
|
itv.it_interval.tv_usec = 999;
|
|
itv.it_value.tv_sec = 0;
|
|
itv.it_value.tv_usec = 10 * 1000;
|
|
|
|
err = setitimer(ITIMER_REAL, &itv, NULL);
|
|
if (err)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void unix_stop_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
struct itimerval itv;
|
|
|
|
memset(&itv, 0, sizeof(itv));
|
|
setitimer(ITIMER_REAL, &itv, NULL);
|
|
}
|
|
|
|
#endif /* !defined(_WIN32) */
|
|
|
|
|
|
#ifdef _WIN32
|
|
|
|
static MMRESULT mm_timer;
|
|
static unsigned mm_period;
|
|
|
|
static void CALLBACK mm_alarm_handler(UINT uTimerID, UINT uMsg,
|
|
DWORD_PTR dwUser, DWORD_PTR dw1,
|
|
DWORD_PTR dw2)
|
|
{
|
|
struct qemu_alarm_timer *t = alarm_timer;
|
|
if (!t) {
|
|
return;
|
|
}
|
|
if (alarm_has_dynticks(t) || qemu_next_alarm_deadline() <= 0) {
|
|
t->expired = alarm_has_dynticks(t);
|
|
t->pending = 1;
|
|
qemu_notify_event();
|
|
}
|
|
}
|
|
|
|
static int mm_start_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
TIMECAPS tc;
|
|
UINT flags;
|
|
|
|
memset(&tc, 0, sizeof(tc));
|
|
timeGetDevCaps(&tc, sizeof(tc));
|
|
|
|
mm_period = tc.wPeriodMin;
|
|
timeBeginPeriod(mm_period);
|
|
|
|
flags = TIME_CALLBACK_FUNCTION;
|
|
if (alarm_has_dynticks(t)) {
|
|
flags |= TIME_ONESHOT;
|
|
} else {
|
|
flags |= TIME_PERIODIC;
|
|
}
|
|
|
|
mm_timer = timeSetEvent(1, /* interval (ms) */
|
|
mm_period, /* resolution */
|
|
mm_alarm_handler, /* function */
|
|
(DWORD_PTR)t, /* parameter */
|
|
flags);
|
|
|
|
if (!mm_timer) {
|
|
fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
|
|
GetLastError());
|
|
timeEndPeriod(mm_period);
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void mm_stop_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
timeKillEvent(mm_timer);
|
|
timeEndPeriod(mm_period);
|
|
}
|
|
|
|
static void mm_rearm_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
int nearest_delta_ms;
|
|
|
|
assert(alarm_has_dynticks(t));
|
|
if (!active_timers[QEMU_CLOCK_REALTIME] &&
|
|
!active_timers[QEMU_CLOCK_VIRTUAL] &&
|
|
!active_timers[QEMU_CLOCK_HOST]) {
|
|
return;
|
|
}
|
|
|
|
timeKillEvent(mm_timer);
|
|
|
|
nearest_delta_ms = (qemu_next_alarm_deadline() + 999999) / 1000000;
|
|
if (nearest_delta_ms < 1) {
|
|
nearest_delta_ms = 1;
|
|
}
|
|
mm_timer = timeSetEvent(nearest_delta_ms,
|
|
mm_period,
|
|
mm_alarm_handler,
|
|
(DWORD_PTR)t,
|
|
TIME_ONESHOT | TIME_CALLBACK_FUNCTION);
|
|
|
|
if (!mm_timer) {
|
|
fprintf(stderr, "Failed to re-arm win32 alarm timer %ld\n",
|
|
GetLastError());
|
|
|
|
timeEndPeriod(mm_period);
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
static int win32_start_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
HANDLE hTimer;
|
|
BOOLEAN success;
|
|
|
|
/* If you call ChangeTimerQueueTimer on a one-shot timer (its period
|
|
is zero) that has already expired, the timer is not updated. Since
|
|
creating a new timer is relatively expensive, set a bogus one-hour
|
|
interval in the dynticks case. */
|
|
success = CreateTimerQueueTimer(&hTimer,
|
|
NULL,
|
|
host_alarm_handler,
|
|
t,
|
|
1,
|
|
alarm_has_dynticks(t) ? 3600000 : 1,
|
|
WT_EXECUTEINTIMERTHREAD);
|
|
|
|
if (!success) {
|
|
fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
|
|
GetLastError());
|
|
return -1;
|
|
}
|
|
|
|
t->timer = hTimer;
|
|
return 0;
|
|
}
|
|
|
|
static void win32_stop_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
HANDLE hTimer = t->timer;
|
|
|
|
if (hTimer) {
|
|
DeleteTimerQueueTimer(NULL, hTimer, NULL);
|
|
}
|
|
}
|
|
|
|
static void win32_rearm_timer(struct qemu_alarm_timer *t)
|
|
{
|
|
HANDLE hTimer = t->timer;
|
|
int nearest_delta_ms;
|
|
BOOLEAN success;
|
|
|
|
assert(alarm_has_dynticks(t));
|
|
if (!active_timers[QEMU_CLOCK_REALTIME] &&
|
|
!active_timers[QEMU_CLOCK_VIRTUAL] &&
|
|
!active_timers[QEMU_CLOCK_HOST])
|
|
return;
|
|
|
|
nearest_delta_ms = (qemu_next_alarm_deadline() + 999999) / 1000000;
|
|
if (nearest_delta_ms < 1) {
|
|
nearest_delta_ms = 1;
|
|
}
|
|
success = ChangeTimerQueueTimer(NULL,
|
|
hTimer,
|
|
nearest_delta_ms,
|
|
3600000);
|
|
|
|
if (!success) {
|
|
fprintf(stderr, "Failed to rearm win32 alarm timer: %ld\n",
|
|
GetLastError());
|
|
exit(-1);
|
|
}
|
|
|
|
}
|
|
|
|
#endif /* _WIN32 */
|
|
|
|
static void alarm_timer_on_change_state_rearm(void *opaque, int running, int reason)
|
|
{
|
|
if (running)
|
|
qemu_rearm_alarm_timer((struct qemu_alarm_timer *) opaque);
|
|
}
|
|
|
|
int init_timer_alarm(void)
|
|
{
|
|
struct qemu_alarm_timer *t = NULL;
|
|
int i, err = -1;
|
|
|
|
for (i = 0; alarm_timers[i].name; i++) {
|
|
t = &alarm_timers[i];
|
|
|
|
err = t->start(t);
|
|
if (!err)
|
|
break;
|
|
}
|
|
|
|
if (err) {
|
|
err = -ENOENT;
|
|
goto fail;
|
|
}
|
|
|
|
/* first event is at time 0 */
|
|
t->pending = 1;
|
|
alarm_timer = t;
|
|
qemu_add_vm_change_state_handler(alarm_timer_on_change_state_rearm, t);
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
return err;
|
|
}
|
|
|
|
void quit_timers(void)
|
|
{
|
|
struct qemu_alarm_timer *t = alarm_timer;
|
|
alarm_timer = NULL;
|
|
t->stop(t);
|
|
}
|
|
|
|
int qemu_calculate_timeout(void)
|
|
{
|
|
#ifndef CONFIG_IOTHREAD
|
|
int timeout;
|
|
|
|
if (!vm_running)
|
|
timeout = 5000;
|
|
else {
|
|
/* XXX: use timeout computed from timers */
|
|
int64_t add;
|
|
int64_t delta;
|
|
/* Advance virtual time to the next event. */
|
|
delta = qemu_icount_delta();
|
|
if (delta > 0) {
|
|
/* If virtual time is ahead of real time then just
|
|
wait for IO. */
|
|
timeout = (delta + 999999) / 1000000;
|
|
} else {
|
|
/* Wait for either IO to occur or the next
|
|
timer event. */
|
|
add = qemu_next_icount_deadline();
|
|
/* We advance the timer before checking for IO.
|
|
Limit the amount we advance so that early IO
|
|
activity won't get the guest too far ahead. */
|
|
if (add > 10000000)
|
|
add = 10000000;
|
|
delta += add;
|
|
qemu_icount += qemu_icount_round (add);
|
|
timeout = delta / 1000000;
|
|
if (timeout < 0)
|
|
timeout = 0;
|
|
}
|
|
}
|
|
|
|
return timeout;
|
|
#else /* CONFIG_IOTHREAD */
|
|
return 1000;
|
|
#endif
|
|
}
|
|
|