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 extern 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 extern void accel_ioctl_begin(void); 30 extern void accel_ioctl_end(void); 31 extern void accel_cpu_ioctl_begin(CPUState *cpu); 32 extern 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 extern 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 extern void accel_ioctl_inhibit_end(void); 54 55 #endif /* ACCEL_BLOCKER_H */ 56