Merge tag 'block-pull-request' of https://gitlab.com/stefanha/qemu into staging

Pull request

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# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
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* tag 'block-pull-request' of https://gitlab.com/stefanha/qemu:
  Rename "QEMU global mutex" to "BQL" in comments and docs
  Replace "iothread lock" with "BQL" in comments
  qemu/main-loop: rename qemu_cond_wait_iothread() to qemu_cond_wait_bql()
  qemu/main-loop: rename QEMU_IOTHREAD_LOCK_GUARD to BQL_LOCK_GUARD
  system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()
  iothread: Remove unused Error** argument in aio_context_set_aio_params

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

12 files changed, 50 insertions, 53 deletions

diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h
index 157f105916..cf5e8bde1c 100644
--- a/include/block/aio-wait.h
+++ b/include/block/aio-wait.h
@@ -143,7 +143,7 @@ static inline bool in_aio_context_home_thread(AioContext *ctx)
     }
 
     if (ctx == qemu_get_aio_context()) {
-        return qemu_mutex_iothread_locked();
+        return bql_locked();
     } else {
         return false;
     }
diff --git a/include/block/aio.h b/include/block/aio.h
index af05512a7d..c802a392e5 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -699,8 +699,7 @@ void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
  * @max_batch: maximum number of requests in a batch, 0 means that the
  *             engine will use its default
  */
-void aio_context_set_aio_params(AioContext *ctx, int64_t max_batch,
-                                Error **errp);
+void aio_context_set_aio_params(AioContext *ctx, int64_t max_batch);
 
 /**
  * aio_context_set_thread_pool_params:
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index e594c10d23..7061ab7201 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -54,7 +54,7 @@ typedef struct BlockJob {
 
     /**
      * Speed that was set with @block_job_set_speed.
-     * Always modified and read under QEMU global mutex (GLOBAL_STATE_CODE).
+     * Always modified and read under the BQL (GLOBAL_STATE_CODE).
      */
     int64_t speed;
 
@@ -66,7 +66,7 @@ typedef struct BlockJob {
 
     /**
      * Block other operations when block job is running.
-     * Always modified and read under QEMU global mutex (GLOBAL_STATE_CODE).
+     * Always modified and read under the BQL (GLOBAL_STATE_CODE).
      */
     Error *blocker;
 
@@ -89,7 +89,7 @@ typedef struct BlockJob {
 
     /**
      * BlockDriverStates that are involved in this block job.
-     * Always modified and read under QEMU global mutex (GLOBAL_STATE_CODE).
+     * Always modified and read under the BQL (GLOBAL_STATE_CODE).
      */
     GSList *nodes;
 } BlockJob;
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 41115d8919..fef3138d29 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -92,7 +92,7 @@ RAMBlock *qemu_ram_block_by_name(const char *name);
  *
  * By the time this function returns, the returned pointer is not protected
  * by RCU anymore.  If the caller is not within an RCU critical section and
- * does not hold the iothread lock, it must have other means of protecting the
+ * does not hold the BQL, it must have other means of protecting the
  * pointer, such as a reference to the memory region that owns the RAMBlock.
  */
 RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 48c11ca743..177be23db7 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -1982,7 +1982,7 @@ int memory_region_get_fd(MemoryRegion *mr);
  *
  * Use with care; by the time this function returns, the returned pointer is
  * not protected by RCU anymore.  If the caller is not within an RCU critical
- * section and does not hold the iothread lock, it must have other means of
+ * section and does not hold the BQL, it must have other means of
  * protecting the pointer, such as a reference to the region that includes
  * the incoming ram_addr_t.
  *
@@ -1999,7 +1999,7 @@ MemoryRegion *memory_region_from_host(void *ptr, ram_addr_t *offset);
  *
  * Use with care; by the time this function returns, the returned pointer is
  * not protected by RCU anymore.  If the caller is not within an RCU critical
- * section and does not hold the iothread lock, it must have other means of
+ * section and does not hold the BQL, it must have other means of
  * protecting the pointer, such as a reference to the region that includes
  * the incoming ram_addr_t.
  *
diff --git a/include/exec/ramblock.h b/include/exec/ramblock.h
index 69c6a53902..3eb79723c6 100644
--- a/include/exec/ramblock.h
+++ b/include/exec/ramblock.h
@@ -34,7 +34,7 @@ struct RAMBlock {
     ram_addr_t max_length;
     void (*resized)(const char*, uint64_t length, void *host);
     uint32_t flags;
-    /* Protected by iothread lock.  */
+    /* Protected by the BQL.  */
     char idstr[256];
     /* RCU-enabled, writes protected by the ramlist lock */
     QLIST_ENTRY(RAMBlock) next;
diff --git a/include/io/task.h b/include/io/task.h
index dc7d32ebd0..0b5342ee84 100644
--- a/include/io/task.h
+++ b/include/io/task.h
@@ -149,7 +149,7 @@ typedef void (*QIOTaskWorker)(QIOTask *task,
  * lookups) to be easily run non-blocking. Reporting the
  * results in the main thread context means that the caller
  * typically does not need to be concerned about thread
- * safety wrt the QEMU global mutex.
+ * safety wrt the BQL.
  *
  * For example, the socket_listen() method will block the caller
  * while DNS lookups take place if given a name, instead of IP
diff --git a/include/migration/register.h b/include/migration/register.h
index fed1d04a3c..9ab1f79512 100644
--- a/include/migration/register.h
+++ b/include/migration/register.h
@@ -17,7 +17,7 @@
 #include "hw/vmstate-if.h"
 
 typedef struct SaveVMHandlers {
-    /* This runs inside the iothread lock.  */
+    /* This runs inside the BQL.  */
     SaveStateHandler *save_state;
 
     /*
@@ -30,7 +30,7 @@ typedef struct SaveVMHandlers {
     int (*save_live_complete_postcopy)(QEMUFile *f, void *opaque);
     int (*save_live_complete_precopy)(QEMUFile *f, void *opaque);
 
-    /* This runs both outside and inside the iothread lock.  */
+    /* This runs both outside and inside the BQL.  */
     bool (*is_active)(void *opaque);
     bool (*has_postcopy)(void *opaque);
 
@@ -43,14 +43,14 @@ typedef struct SaveVMHandlers {
      */
     bool (*is_active_iterate)(void *opaque);
 
-    /* This runs outside the iothread lock in the migration case, and
+    /* This runs outside the BQL in the migration case, and
      * within the lock in the savevm case.  The callback had better only
      * use data that is local to the migration thread or protected
      * by other locks.
      */
     int (*save_live_iterate)(QEMUFile *f, void *opaque);
 
-    /* This runs outside the iothread lock!  */
+    /* This runs outside the BQL!  */
     /* Note for save_live_pending:
      * must_precopy:
      * - must be migrated in precopy or in stopped state
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/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/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;