include/sysemu/accel-blocker.h

   1 /*
   2  * Accelerator blocking API, to prevent new ioctls from starting and wait the
   3  * running ones finish.
   4  * This mechanism differs from pause/resume_all_vcpus() in that it does not
   5  * release the BQL.
   6  *
   7  *  Copyright (c) 2022 Red Hat Inc.
   8  *
   9  * Author: Emanuele Giuseppe Esposito       <eesposit@redhat.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  12  * See the COPYING file in the top-level directory.
  13  */
  14 #ifndef ACCEL_BLOCKER_H
  15 #define ACCEL_BLOCKER_H
  16
  17 #include "sysemu/cpus.h"
  18
  19 void accel_blocker_init(void);
  20
  21 /*
  22  * accel_{cpu_}ioctl_begin/end:
  23  * Mark when ioctl is about to run or just finished.
  24  *
  25  * accel_{cpu_}ioctl_begin will block after accel_ioctl_inhibit_begin() is
  26  * called, preventing new ioctls to run. They will continue only after
  27  * accel_ioctl_inibith_end().
  28  */
  29 void accel_ioctl_begin(void);
  30 void accel_ioctl_end(void);
  31 void accel_cpu_ioctl_begin(CPUState *cpu);
  32 void accel_cpu_ioctl_end(CPUState *cpu);
  33
  34 /*
  35  * accel_ioctl_inhibit_begin: start critical section
  36  *
  37  * This function makes sure that:
  38  * 1) incoming accel_{cpu_}ioctl_begin() calls block
  39  * 2) wait that all ioctls that were already running reach
  40  *    accel_{cpu_}ioctl_end(), kicking vcpus if necessary.
  41  *
  42  * This allows the caller to access shared data or perform operations without
  43  * worrying of concurrent vcpus accesses.
  44  */
  45 void accel_ioctl_inhibit_begin(void);
  46
  47 /*
  48  * accel_ioctl_inhibit_end: end critical section started by
  49  * accel_ioctl_inhibit_begin()
  50  *
  51  * This function allows blocked accel_{cpu_}ioctl_begin() to continue.
  52  */
  53 void accel_ioctl_inhibit_end(void);
  54
  55 #endif /* ACCEL_BLOCKER_H */