include/sysemu/cpu-timers.h

   1 /*
   2  * CPU timers state API
   3  *
   4  * Copyright 2020 SUSE LLC
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10 #ifndef SYSEMU_CPU_TIMERS_H
  11 #define SYSEMU_CPU_TIMERS_H
  12
  13 #include "qemu/timer.h"
  14
  15 /* init the whole cpu timers API, including icount, ticks, and cpu_throttle */
  16 void cpu_timers_init(void);
  17
  18 /* icount - Instruction Counter API */
  19
  20 /*
  21  * icount enablement state:
  22  *
  23  * 0 = Disabled - Do not count executed instructions.
  24  * 1 = Enabled - Fixed conversion of insn to ns via "shift" option
  25  * 2 = Enabled - Runtime adaptive algorithm to compute shift
  26  */
  27 #ifdef CONFIG_TCG
  28 extern int use_icount;
  29 #define icount_enabled() (use_icount)
  30 #else
  31 #define icount_enabled() 0
  32 #endif
  33
  34 /*
  35  * Update the icount with the executed instructions. Called by
  36  * cpus-tcg vCPU thread so the main-loop can see time has moved forward.
  37  */
  38 void icount_update(CPUState *cpu);
  39
  40 /* get raw icount value */
  41 int64_t icount_get_raw(void);
  42
  43 /* return the virtual CPU time in ns, based on the instruction counter. */
  44 int64_t icount_get(void);
  45 /*
  46  * convert an instruction counter value to ns, based on the icount shift.
  47  * This shift is set as a fixed value with the icount "shift" option
  48  * (precise mode), or it is constantly approximated and corrected at
  49  * runtime in adaptive mode.
  50  */
  51 int64_t icount_to_ns(int64_t icount);
  52
  53 /* configure the icount options, including "shift" */
  54 void icount_configure(QemuOpts *opts, Error **errp);
  55
  56 /* used by tcg vcpu thread to calc icount budget */
  57 int64_t icount_round(int64_t count);
  58
  59 /* if the CPUs are idle, start accounting real time to virtual clock. */
  60 void icount_start_warp_timer(void);
  61 void icount_account_warp_timer(void);
  62 void icount_notify_exit(void);
  63
  64 /*
  65  * CPU Ticks and Clock
  66  */
  67
  68 /* Caller must hold BQL */
  69 void cpu_enable_ticks(void);
  70 /* Caller must hold BQL */
  71 void cpu_disable_ticks(void);
  72
  73 /*
  74  * return the time elapsed in VM between vm_start and vm_stop.
  75  * cpu_get_ticks() uses units of the host CPU cycle counter.
  76  */
  77 int64_t cpu_get_ticks(void);
  78
  79 /*
  80  * Returns the monotonic time elapsed in VM, i.e.,
  81  * the time between vm_start and vm_stop
  82  */
  83 int64_t cpu_get_clock(void);
  84
  85 void qemu_timer_notify_cb(void *opaque, QEMUClockType type);
  86
  87 /* get the VIRTUAL clock and VM elapsed ticks via the cpus accel interface */
  88 int64_t cpus_get_virtual_clock(void);
  89 int64_t cpus_get_elapsed_ticks(void);
  90
  91 #endif /* SYSEMU_CPU_TIMERS_H */