Andrew Fasano <fas...@mit.edu> writes:
> From: Elysia Witham <elysia.wit...@ll.mit.edu> > > Plugin callbacks and their registered functions are stored in a > separate struct which is accessible from the plugin's ctx. > In order for plugins to use another plugin's callbacks, we have > internal functions that resolve a plugin's name to its ctx and > find a target plugin. > > Signed-off-by: Elysia Witham <elysia.wit...@ll.mit.edu> > Signed-off-by: Andrew Fasano <fas...@mit.edu> > --- > include/qemu/qemu-plugin.h | 10 ++++++++++ > plugins/core.c | 23 +++++++++++++++++++++++ > plugins/loader.c | 10 ++++++++++ > plugins/plugin.h | 15 +++++++++++++++ > 4 files changed, 58 insertions(+) > > diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h > index 5326f33ce8..3ec82ce97f 100644 > --- a/include/qemu/qemu-plugin.h > +++ b/include/qemu/qemu-plugin.h > @@ -14,6 +14,7 @@ > #include <inttypes.h> > #include <stdbool.h> > #include <stddef.h> > +#include <gmodule.h> > > /* > * For best performance, build the plugin with -fvisibility=hidden so that > @@ -38,6 +39,15 @@ > */ > typedef uint64_t qemu_plugin_id_t; > > +/** > + * typedef cb_func_t - callback function pointer type > + * @evdata: plugin callback defined event data > + * @udata: plugin defined user data > + * > + * No return value. > + */ > +typedef void (*cb_func_t) (gpointer evdata, gpointer udata); > + > /* > * Versioning plugins: > * > diff --git a/plugins/core.c b/plugins/core.c > index 6a50b4a6e6..0415a55ec5 100644 > --- a/plugins/core.c > +++ b/plugins/core.c > @@ -236,6 +236,17 @@ void qemu_plugin_vcpu_exit_hook(CPUState *cpu) > qemu_rec_mutex_unlock(&plugin.lock); > } > This looks like another unused function. I was looking to see what locking was done before calling it as the suffix implies there should be some. > +struct qemu_plugin_ctx *plugin_name_to_ctx_locked(const char* name) > +{ > + struct qemu_plugin_ctx *ctx; > + QTAILQ_FOREACH(ctx, &plugin.ctxs, entry) { > + if (strcmp(ctx->name, name) == 0) { > + return plugin_id_to_ctx_locked(ctx->id); > + } > + } > + return NULL; > +} > + > int name_to_plugin_version(const char *name) > { > struct qemu_plugin_ctx *ctx; > @@ -260,6 +271,18 @@ const char *id_to_plugin_name(qemu_plugin_id_t id) > } > } > This one too. > +struct qemu_plugin_qpp_cb *plugin_find_qpp_cb(struct qemu_plugin_ctx *ctx, > + const char *name) > +{ > + struct qemu_plugin_qpp_cb *cb; > + QTAILQ_FOREACH(cb, &ctx->qpp_cbs, entry) { > + if (strcmp(cb->name, name) == 0) { > + return cb; > + } > + } > + return NULL; > +} > + > struct plugin_for_each_args { > struct qemu_plugin_ctx *ctx; > qemu_plugin_vcpu_simple_cb_t cb; > diff --git a/plugins/loader.c b/plugins/loader.c > index 12c0680e03..ab01d0753c 100644 > --- a/plugins/loader.c > +++ b/plugins/loader.c > @@ -277,6 +277,7 @@ static int plugin_load(struct qemu_plugin_desc *desc, > const qemu_info_t *info, E > break; > } > } > + QTAILQ_INIT(&ctx->qpp_cbs); > QTAILQ_INSERT_TAIL(&plugin.ctxs, ctx, entry); > ctx->installing = true; > rc = install(ctx->id, info, desc->argc, desc->argv); > @@ -303,6 +304,15 @@ static int plugin_load(struct qemu_plugin_desc *desc, > const qemu_info_t *info, E > return 1; > } > > +void plugin_add_qpp_cb(struct qemu_plugin_ctx *ctx, const char *name) > +{ > + struct qemu_plugin_qpp_cb *new_cb; > + new_cb = qemu_memalign(qemu_dcache_linesize, sizeof(*new_cb)); > + memset(new_cb, 0, sizeof(*new_cb)); Is there a reason to do aligned allocation here. Have you measured a difference between this and a normal g_new0() in performance? > + new_cb->name = name; > + QTAILQ_INSERT_TAIL(&ctx->qpp_cbs, new_cb, entry); > +} > + I think we need some rules for this that can be enforced. Can a plugin create a cb at any time? Or only during initialisation? If it's at any time we need some sort of serialisation to prevent races. > /* call after having removed @desc from the list */ > static void plugin_desc_free(struct qemu_plugin_desc *desc) > { > diff --git a/plugins/plugin.h b/plugins/plugin.h > index 9e710c23a7..fee4741bc6 100644 > --- a/plugins/plugin.h > +++ b/plugins/plugin.h > @@ -47,6 +47,14 @@ struct qemu_plugin_state { > struct qht dyn_cb_arr_ht; > }; > > +typedef void (*cb_func_t) (gpointer evdata, gpointer udata); > + > +struct qemu_plugin_qpp_cb { > + const char *name; > + cb_func_t registered_cb_funcs[QEMU_PLUGIN_EV_MAX]; > + int counter; > + QTAILQ_ENTRY(qemu_plugin_qpp_cb) entry; > +}; > > struct qemu_plugin_ctx { > GModule *handle; > @@ -54,6 +62,7 @@ struct qemu_plugin_ctx { > const char *name; > int version; > struct qemu_plugin_cb *callbacks[QEMU_PLUGIN_EV_MAX]; > + QTAILQ_HEAD(, qemu_plugin_qpp_cb) qpp_cbs; > QTAILQ_ENTRY(qemu_plugin_ctx) entry; > /* > * keep a reference to @desc until uninstall, so that plugins do not have > @@ -106,4 +115,10 @@ int name_to_plugin_version(const char *name); > > const char *id_to_plugin_name(qemu_plugin_id_t id); > > +struct qemu_plugin_qpp_cb *plugin_find_qpp_cb(struct qemu_plugin_ctx > *plugin_ctx, > + const char *cb_name); > + > +/* loader.c */ > +void plugin_add_qpp_cb(struct qemu_plugin_ctx *ctx, const char *name); > + > #endif /* PLUGIN_H */ -- Alex Bennée Virtualisation Tech Lead @ Linaro