diff options
Diffstat (limited to 'include/qemu')
| -rw-r--r-- | include/qemu/chardev_open.h | 16 | ||||
| -rw-r--r-- | include/qemu/coroutine-core.h | 2 | ||||
| -rw-r--r-- | include/qemu/coroutine.h | 2 | ||||
| -rw-r--r-- | include/qemu/fifo8.h | 37 | ||||
| -rw-r--r-- | include/qemu/job.h | 20 | ||||
| -rw-r--r-- | include/qemu/main-loop.h | 68 | ||||
| -rw-r--r-- | include/qemu/osdep.h | 4 | ||||
| -rw-r--r-- | include/qemu/thread.h | 2 |
8 files changed, 87 insertions, 64 deletions
diff --git a/include/qemu/chardev_open.h b/include/qemu/chardev_open.h new file mode 100644 index 0000000000..64e8fcfdcb --- /dev/null +++ b/include/qemu/chardev_open.h @@ -0,0 +1,16 @@ +/* + * QEMU Chardev Helper + * + * Copyright (C) 2023 Intel Corporation. + * + * Authors: Yi Liu <yi.l.liu@intel.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ + +#ifndef QEMU_CHARDEV_OPEN_H +#define QEMU_CHARDEV_OPEN_H + +int open_cdev(const char *devpath, dev_t cdev); +#endif diff --git a/include/qemu/coroutine-core.h b/include/qemu/coroutine-core.h index 230bb56517..503bad6e0e 100644 --- a/include/qemu/coroutine-core.h +++ b/include/qemu/coroutine-core.h @@ -22,7 +22,7 @@ * rather than callbacks, for operations that need to give up control while * waiting for events to complete. * - * These functions are re-entrant and may be used outside the global mutex. + * These functions are re-entrant and may be used outside the BQL. * * Functions that execute in coroutine context cannot be called * directly from normal functions. Use @coroutine_fn to mark such diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h index a65be6697f..e6aff45301 100644 --- a/include/qemu/coroutine.h +++ b/include/qemu/coroutine.h @@ -26,7 +26,7 @@ * rather than callbacks, for operations that need to give up control while * waiting for events to complete. * - * These functions are re-entrant and may be used outside the global mutex. + * These functions are re-entrant and may be used outside the BQL. * * Functions that execute in coroutine context cannot be called * directly from normal functions. Use @coroutine_fn to mark such diff --git a/include/qemu/fifo8.h b/include/qemu/fifo8.h index 16be02f361..c6295c6ff0 100644 --- a/include/qemu/fifo8.h +++ b/include/qemu/fifo8.h @@ -71,7 +71,7 @@ uint8_t fifo8_pop(Fifo8 *fifo); * fifo8_pop_buf: * @fifo: FIFO to pop from * @max: maximum number of bytes to pop - * @num: actual number of returned bytes + * @numptr: pointer filled with number of bytes returned (can be NULL) * * Pop a number of elements from the FIFO up to a maximum of max. The buffer * containing the popped data is returned. This buffer points directly into @@ -82,16 +82,43 @@ uint8_t fifo8_pop(Fifo8 *fifo); * around in the ring buffer; in this case only a contiguous part of the data * is returned. * - * The number of valid bytes returned is populated in *num; will always return - * at least 1 byte. max must not be 0 or greater than the number of bytes in - * the FIFO. + * The number of valid bytes returned is populated in *numptr; will always + * return at least 1 byte. max must not be 0 or greater than the number of + * bytes in the FIFO. * * Clients are responsible for checking the availability of requested data * using fifo8_num_used(). * * Returns: A pointer to popped data. */ -const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num); +const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr); + +/** + * fifo8_peek_buf: read upto max bytes from the fifo + * @fifo: FIFO to read from + * @max: maximum number of bytes to peek + * @numptr: pointer filled with number of bytes returned (can be NULL) + * + * Peek into a number of elements from the FIFO up to a maximum of max. + * The buffer containing the data peeked into is returned. This buffer points + * directly into the FIFO backing store. Since data is invalidated once any + * of the fifo8_* APIs are called on the FIFO, it is the caller responsibility + * to access it before doing further API calls. + * + * The function may return fewer bytes than requested when the data wraps + * around in the ring buffer; in this case only a contiguous part of the data + * is returned. + * + * The number of valid bytes returned is populated in *numptr; will always + * return at least 1 byte. max must not be 0 or greater than the number of + * bytes in the FIFO. + * + * Clients are responsible for checking the availability of requested data + * using fifo8_num_used(). + * + * Returns: A pointer to peekable data. + */ +const uint8_t *fifo8_peek_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr); /** * fifo8_reset: diff --git a/include/qemu/job.h b/include/qemu/job.h index e502787dd8..9ea98b5927 100644 --- a/include/qemu/job.h +++ b/include/qemu/job.h @@ -67,8 +67,6 @@ typedef struct Job { /** * The completion function that will be called when the job completes. - * Called with AioContext lock held, since many callback implementations - * use bdrv_* functions that require to hold the lock. */ BlockCompletionFunc *cb; @@ -264,9 +262,6 @@ struct JobDriver { * * This callback will not be invoked if the job has already failed. * If it fails, abort and then clean will be called. - * - * Called with AioContext lock held, since many callbacs implementations - * use bdrv_* functions that require to hold the lock. */ int (*prepare)(Job *job); @@ -277,9 +272,6 @@ struct JobDriver { * * All jobs will complete with a call to either .commit() or .abort() but * never both. - * - * Called with AioContext lock held, since many callback implementations - * use bdrv_* functions that require to hold the lock. */ void (*commit)(Job *job); @@ -290,9 +282,6 @@ struct JobDriver { * * All jobs will complete with a call to either .commit() or .abort() but * never both. - * - * Called with AioContext lock held, since many callback implementations - * use bdrv_* functions that require to hold the lock. */ void (*abort)(Job *job); @@ -301,9 +290,6 @@ struct JobDriver { * .commit() or .abort(). Regardless of which callback is invoked after * completion, .clean() will always be called, even if the job does not * belong to a transaction group. - * - * Called with AioContext lock held, since many callbacs implementations - * use bdrv_* functions that require to hold the lock. */ void (*clean)(Job *job); @@ -318,17 +304,12 @@ struct JobDriver { * READY). * (If the callback is NULL, the job is assumed to terminate * without I/O.) - * - * Called with AioContext lock held, since many callback implementations - * use bdrv_* functions that require to hold the lock. */ bool (*cancel)(Job *job, bool force); /** * Called when the job is freed. - * Called with AioContext lock held, since many callback implementations - * use bdrv_* functions that require to hold the lock. */ void (*free)(Job *job); }; @@ -424,7 +405,6 @@ void job_ref_locked(Job *job); * Release a reference that was previously acquired with job_ref_locked() or * job_create(). If it's the last reference to the object, it will be freed. * - * Takes AioContext lock internally to invoke a job->driver callback. * Called with job lock held. */ void job_unref_locked(Job *job); diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h index 68e70e61aa..5764db157c 100644 --- a/include/qemu/main-loop.h +++ b/include/qemu/main-loop.h @@ -248,19 +248,19 @@ GSource *iohandler_get_g_source(void); AioContext *iohandler_get_aio_context(void); /** - * qemu_mutex_iothread_locked: Return lock status of the main loop mutex. + * bql_locked: Return lock status of the Big QEMU Lock (BQL) * - * The main loop mutex is the coarsest lock in QEMU, and as such it + * The Big QEMU Lock (BQL) is the coarsest lock in QEMU, and as such it * must always be taken outside other locks. This function helps * functions take different paths depending on whether the current - * thread is running within the main loop mutex. + * thread is running within the BQL. * * This function should never be used in the block layer, because * unit tests, block layer tools and qemu-storage-daemon do not * have a BQL. * Please instead refer to qemu_in_main_thread(). */ -bool qemu_mutex_iothread_locked(void); +bool bql_locked(void); /** * qemu_in_main_thread: return whether it's possible to safely access @@ -312,78 +312,76 @@ bool qemu_in_main_thread(void); } while (0) /** - * qemu_mutex_lock_iothread: Lock the main loop mutex. + * bql_lock: Lock the Big QEMU Lock (BQL). * - * This function locks the main loop mutex. The mutex is taken by + * This function locks the Big QEMU Lock (BQL). The lock is taken by * main() in vl.c and always taken except while waiting on - * external events (such as with select). The mutex should be taken + * external events (such as with select). The lock should be taken * by threads other than the main loop thread when calling * qemu_bh_new(), qemu_set_fd_handler() and basically all other * functions documented in this file. * - * NOTE: tools currently are single-threaded and qemu_mutex_lock_iothread + * NOTE: tools currently are single-threaded and bql_lock * is a no-op there. */ -#define qemu_mutex_lock_iothread() \ - qemu_mutex_lock_iothread_impl(__FILE__, __LINE__) -void qemu_mutex_lock_iothread_impl(const char *file, int line); +#define bql_lock() bql_lock_impl(__FILE__, __LINE__) +void bql_lock_impl(const char *file, int line); /** - * qemu_mutex_unlock_iothread: Unlock the main loop mutex. + * bql_unlock: Unlock the Big QEMU Lock (BQL). * - * This function unlocks the main loop mutex. The mutex is taken by + * This function unlocks the Big QEMU Lock. The lock is taken by * main() in vl.c and always taken except while waiting on - * external events (such as with select). The mutex should be unlocked + * external events (such as with select). The lock should be unlocked * as soon as possible by threads other than the main loop thread, * because it prevents the main loop from processing callbacks, * including timers and bottom halves. * - * NOTE: tools currently are single-threaded and qemu_mutex_unlock_iothread + * NOTE: tools currently are single-threaded and bql_unlock * is a no-op there. */ -void qemu_mutex_unlock_iothread(void); +void bql_unlock(void); /** - * QEMU_IOTHREAD_LOCK_GUARD + * BQL_LOCK_GUARD * - * Wrap a block of code in a conditional qemu_mutex_{lock,unlock}_iothread. + * Wrap a block of code in a conditional bql_{lock,unlock}. */ -typedef struct IOThreadLockAuto IOThreadLockAuto; +typedef struct BQLLockAuto BQLLockAuto; -static inline IOThreadLockAuto *qemu_iothread_auto_lock(const char *file, - int line) +static inline BQLLockAuto *bql_auto_lock(const char *file, int line) { - if (qemu_mutex_iothread_locked()) { + if (bql_locked()) { return NULL; } - qemu_mutex_lock_iothread_impl(file, line); + bql_lock_impl(file, line); /* Anything non-NULL causes the cleanup function to be called */ - return (IOThreadLockAuto *)(uintptr_t)1; + return (BQLLockAuto *)(uintptr_t)1; } -static inline void qemu_iothread_auto_unlock(IOThreadLockAuto *l) +static inline void bql_auto_unlock(BQLLockAuto *l) { - qemu_mutex_unlock_iothread(); + bql_unlock(); } -G_DEFINE_AUTOPTR_CLEANUP_FUNC(IOThreadLockAuto, qemu_iothread_auto_unlock) +G_DEFINE_AUTOPTR_CLEANUP_FUNC(BQLLockAuto, bql_auto_unlock) -#define QEMU_IOTHREAD_LOCK_GUARD() \ - g_autoptr(IOThreadLockAuto) _iothread_lock_auto __attribute__((unused)) \ - = qemu_iothread_auto_lock(__FILE__, __LINE__) +#define BQL_LOCK_GUARD() \ + g_autoptr(BQLLockAuto) _bql_lock_auto __attribute__((unused)) \ + = bql_auto_lock(__FILE__, __LINE__) /* - * qemu_cond_wait_iothread: Wait on condition for the main loop mutex + * qemu_cond_wait_bql: Wait on condition for the Big QEMU Lock (BQL) * - * This function atomically releases the main loop mutex and causes + * This function atomically releases the Big QEMU Lock (BQL) and causes * the calling thread to block on the condition. */ -void qemu_cond_wait_iothread(QemuCond *cond); +void qemu_cond_wait_bql(QemuCond *cond); /* - * qemu_cond_timedwait_iothread: like the previous, but with timeout + * qemu_cond_timedwait_bql: like the previous, but with timeout */ -void qemu_cond_timedwait_iothread(QemuCond *cond, int ms); +void qemu_cond_timedwait_bql(QemuCond *cond, int ms); /* internal interfaces */ diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index d30ba73eda..db366d6796 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -678,8 +678,10 @@ typedef struct ThreadContext ThreadContext; * memory area starting at @area with the size of @sz. After a successful call, * each page in the area was faulted in writable at least once, for example, * after allocating file blocks for mapped files. + * + * Return: true on success, else false setting @errp with error. */ -void qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, +bool qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, ThreadContext *tc, Error **errp); /** diff --git a/include/qemu/thread.h b/include/qemu/thread.h index dd3822d7ce..fb74e21c08 100644 --- a/include/qemu/thread.h +++ b/include/qemu/thread.h @@ -47,7 +47,7 @@ typedef void (*QemuCondWaitFunc)(QemuCond *c, QemuMutex *m, const char *f, typedef bool (*QemuCondTimedWaitFunc)(QemuCond *c, QemuMutex *m, int ms, const char *f, int l); -extern QemuMutexLockFunc qemu_bql_mutex_lock_func; +extern QemuMutexLockFunc bql_mutex_lock_func; extern QemuMutexLockFunc qemu_mutex_lock_func; extern QemuMutexTrylockFunc qemu_mutex_trylock_func; extern QemuRecMutexLockFunc qemu_rec_mutex_lock_func; |