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 "qemu/osdep.h"
  18 #include "sysemu/cpus.h"
  19
  20 extern void accel_blocker_init(void);
  21
  22 /*
  23  * accel_{cpu_}ioctl_begin/end:
  24  * Mark when ioctl is about to run or just finished.
  25  *
  26  * accel_{cpu_}ioctl_begin will block after accel_ioctl_inhibit_begin() is
  27  * called, preventing new ioctls to run. They will continue only after
  28  * accel_ioctl_inibith_end().
  29  */
  30 extern void accel_ioctl_begin(void);
  31 extern void accel_ioctl_end(void);
  32 extern void accel_cpu_ioctl_begin(CPUState *cpu);
  33 extern void accel_cpu_ioctl_end(CPUState *cpu);
  34
  35 /*
  36  * accel_ioctl_inhibit_begin: start critical section
  37  *
  38  * This function makes sure that:
  39  * 1) incoming accel_{cpu_}ioctl_begin() calls block
  40  * 2) wait that all ioctls that were already running reach
  41  *    accel_{cpu_}ioctl_end(), kicking vcpus if necessary.
  42  *
  43  * This allows the caller to access shared data or perform operations without
  44  * worrying of concurrent vcpus accesses.
  45  */
  46 extern void accel_ioctl_inhibit_begin(void);
  47
  48 /*
  49  * accel_ioctl_inhibit_end: end critical section started by
  50  * accel_ioctl_inhibit_begin()
  51  *
  52  * This function allows blocked accel_{cpu_}ioctl_begin() to continue.
  53  */
  54 extern void accel_ioctl_inhibit_end(void);
  55
  56 #endif /* ACCEL_BLOCKER_H */