'event-loop-base' provides basic property handling for all 'AioContext' based event loops. So let's define a new 'MainLoopClass' that inherits from it. This will permit tweaking the main loop's properties through qapi as well as through the command line using the '-object' keyword[1]. Only one instance of 'MainLoopClass' might be created at any time.
'EventLoopBaseClass' learns a new callback, 'can_be_deleted()' so as to mark 'MainLoop' as non-deletable. Signed-off-by: Nicolas Saenz Julienne <nsaen...@redhat.com> [1] For example: -object main-loop,id=main-loop,aio-max-batch=<value> --- Changes since v1: - Fix json files to differentiate between iothread and main-loop - Use OBJECT_DECLARE_TYPE() - Fix build dependencies event-loop-base.c | 13 ++++++++ include/qemu/main-loop.h | 10 ++++++ include/sysemu/event-loop-base.h | 1 + meson.build | 3 +- qapi/qom.json | 16 +++++++++ util/main-loop.c | 56 ++++++++++++++++++++++++++++++++ 6 files changed, 98 insertions(+), 1 deletion(-) diff --git a/event-loop-base.c b/event-loop-base.c index a924c73a7c..e7f99a6ec8 100644 --- a/event-loop-base.c +++ b/event-loop-base.c @@ -73,10 +73,23 @@ static void event_loop_base_complete(UserCreatable *uc, Error **errp) } } +static bool event_loop_base_can_be_deleted(UserCreatable *uc) +{ + EventLoopBaseClass *bc = EVENT_LOOP_BASE_GET_CLASS(uc); + EventLoopBase *backend = EVENT_LOOP_BASE(uc); + + if (bc->can_be_deleted) { + return bc->can_be_deleted(backend); + } + + return true; +} + static void event_loop_base_class_init(ObjectClass *klass, void *class_data) { UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass); ucc->complete = event_loop_base_complete; + ucc->can_be_deleted = event_loop_base_can_be_deleted; object_class_property_add(klass, "aio-max-batch", "int", event_loop_base_get_param, diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h index 8dbc6fcb89..71231729c2 100644 --- a/include/qemu/main-loop.h +++ b/include/qemu/main-loop.h @@ -26,9 +26,19 @@ #define QEMU_MAIN_LOOP_H #include "block/aio.h" +#include "qom/object.h" +#include "sysemu/event-loop-base.h" #define SIG_IPI SIGUSR1 +#define TYPE_MAIN_LOOP "main-loop" +OBJECT_DECLARE_TYPE(MainLoop, MainLoopClass, MAIN_LOOP) + +struct MainLoop { + EventLoopBase parent_obj; +}; +typedef struct MainLoop MainLoop; + /** * qemu_init_main_loop: Set up the process so that it can run the main loop. * diff --git a/include/sysemu/event-loop-base.h b/include/sysemu/event-loop-base.h index 8e77d8b69f..fced4c9fea 100644 --- a/include/sysemu/event-loop-base.h +++ b/include/sysemu/event-loop-base.h @@ -25,6 +25,7 @@ struct EventLoopBaseClass { void (*init)(EventLoopBase *base, Error **errp); void (*update_params)(EventLoopBase *base, Error **errp); + bool (*can_be_deleted)(EventLoopBase *base); }; struct EventLoopBase { diff --git a/meson.build b/meson.build index 3c90b4f2aa..2b9b7202ac 100644 --- a/meson.build +++ b/meson.build @@ -2745,7 +2745,8 @@ libqemuutil = static_library('qemuutil', sources: util_ss.sources() + stub_ss.sources() + genh, dependencies: [util_ss.dependencies(), libm, threads, glib, socket, malloc, pixman]) qemuutil = declare_dependency(link_with: libqemuutil, - sources: genh + version_res) + sources: genh + version_res, + dependencies: [event_loop_base]) if have_system or have_user decodetree = generator(find_program('scripts/decodetree.py'), diff --git a/qapi/qom.json b/qapi/qom.json index eeb5395ff3..c8eb192772 100644 --- a/qapi/qom.json +++ b/qapi/qom.json @@ -528,6 +528,20 @@ '*poll-shrink': 'int', '*aio-max-batch': 'int' } } +## +# @MainLoopProperties: +# +# Properties for the main-loop object. +# +# @aio-max-batch: maximum number of requests in a batch for the AIO engine, +# 0 means that the engine will use its default +# (default:0, since 6.1) +# +# Since: 2.0 +## +{ 'struct': 'MainLoopProperties', + 'data': { '*aio-max-batch': 'int' } } + ## # @MemoryBackendProperties: # @@ -818,6 +832,7 @@ { 'name': 'input-linux', 'if': 'CONFIG_LINUX' }, 'iothread', + 'main-loop', { 'name': 'memory-backend-epc', 'if': 'CONFIG_LINUX' }, 'memory-backend-file', @@ -883,6 +898,7 @@ 'input-linux': { 'type': 'InputLinuxProperties', 'if': 'CONFIG_LINUX' }, 'iothread': 'IothreadProperties', + 'main-loop': 'MainLoopProperties', 'memory-backend-epc': { 'type': 'MemoryBackendEpcProperties', 'if': 'CONFIG_LINUX' }, 'memory-backend-file': 'MemoryBackendFileProperties', diff --git a/util/main-loop.c b/util/main-loop.c index 4d5a5b9943..3bf5709374 100644 --- a/util/main-loop.c +++ b/util/main-loop.c @@ -33,6 +33,7 @@ #include "qemu/error-report.h" #include "qemu/queue.h" #include "qemu/compiler.h" +#include "qom/object.h" #ifndef _WIN32 #include <sys/wait.h> @@ -184,6 +185,61 @@ int qemu_init_main_loop(Error **errp) return 0; } +static void main_loop_update_params(EventLoopBase *base, Error **errp) +{ + if (!qemu_aio_context) { + error_setg(errp, "qemu aio context not ready"); + return; + } + + aio_context_set_aio_params(qemu_aio_context, base->aio_max_batch, errp); +} + +MainLoop *mloop; + +static void main_loop_init(EventLoopBase *base, Error **errp) +{ + MainLoop *m = MAIN_LOOP(base); + + if (mloop) { + error_setg(errp, "only one main-loop instance allowed"); + return; + } + + main_loop_update_params(base, errp); + + mloop = m; + return; +} + +static bool main_loop_can_be_deleted(EventLoopBase *base) +{ + return false; +} + +static void main_loop_class_init(ObjectClass *oc, void *class_data) +{ + EventLoopBaseClass *bc = EVENT_LOOP_BASE_CLASS(oc); + + bc->init = main_loop_init; + bc->update_params = main_loop_update_params; + bc->can_be_deleted = main_loop_can_be_deleted; +} + +static const TypeInfo main_loop_info = { + .name = TYPE_MAIN_LOOP, + .parent = TYPE_EVENT_LOOP_BASE, + .class_init = main_loop_class_init, + .instance_size = sizeof(MainLoop), +}; + +static void main_loop_register_types(void) +{ + type_register_static(&main_loop_info); +} + +type_init(main_loop_register_types) + static int max_priority; #ifndef _WIN32 -- 2.35.1