xemu/include/qemu/module.h
Daniel P. Berrange fe4db84d49 trace: provide mechanism for registering trace events
Remove the notion of there being a single global array
of trace events, by introducing a method for registering
groups of events.

The module_call_init() needs to be invoked at the start
of any program that wants to make use of the trace
support. Currently this covers system emulators qemu-nbd,
qemu-img and qemu-io.

[Squashed the following fix from Daniel P. Berrange
<berrange@redhat.com>:

linux-user/bsd-user: initialize trace events subsystem

The bsd-user/linux-user programs make use of the CPU emulation
code and this now requires that the trace events subsystem
is enabled, otherwise it'll crash trying to allocate an empty
trace events bitmap for the CPU object.

--Stefan]

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-14-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-10-12 09:52:50 +02:00

66 lines
2.2 KiB
C

/*
* QEMU Module Infrastructure
*
* Copyright IBM, Corp. 2009
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.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_MODULE_H
#define QEMU_MODULE_H
#define DSO_STAMP_FUN glue(qemu_stamp, CONFIG_STAMP)
#define DSO_STAMP_FUN_STR stringify(DSO_STAMP_FUN)
#ifdef BUILD_DSO
void DSO_STAMP_FUN(void);
/* This is a dummy symbol to identify a loaded DSO as a QEMU module, so we can
* distinguish "version mismatch" from "not a QEMU module", when the stamp
* check fails during module loading */
void qemu_module_dummy(void);
#define module_init(function, type) \
static void __attribute__((constructor)) do_qemu_init_ ## function(void) \
{ \
register_dso_module_init(function, type); \
}
#else
/* This should not be used directly. Use block_init etc. instead. */
#define module_init(function, type) \
static void __attribute__((constructor)) do_qemu_init_ ## function(void) \
{ \
register_module_init(function, type); \
}
#endif
typedef enum {
MODULE_INIT_BLOCK,
MODULE_INIT_OPTS,
MODULE_INIT_QAPI,
MODULE_INIT_QOM,
MODULE_INIT_TRACE,
MODULE_INIT_MAX
} module_init_type;
#define block_init(function) module_init(function, MODULE_INIT_BLOCK)
#define opts_init(function) module_init(function, MODULE_INIT_OPTS)
#define qapi_init(function) module_init(function, MODULE_INIT_QAPI)
#define type_init(function) module_init(function, MODULE_INIT_QOM)
#define trace_init(function) module_init(function, MODULE_INIT_TRACE)
#define block_module_load_one(lib) module_load_one("block-", lib)
void register_module_init(void (*fn)(void), module_init_type type);
void register_dso_module_init(void (*fn)(void), module_init_type type);
void module_call_init(module_init_type type);
void module_load_one(const char *prefix, const char *lib_name);
#endif