@@ -20,6 +20,7 @@ enum qemu_plugin_event {
QEMU_PLUGIN_EV_VCPU_SYSCALL_RET,
QEMU_PLUGIN_EV_FLUSH,
QEMU_PLUGIN_EV_ATEXIT,
+ QEMU_PLUGIN_EV_GDBSTUB,
QEMU_PLUGIN_EV_MAX, /* total number of plugin events we support */
};
@@ -802,6 +802,22 @@ QEMU_PLUGIN_API
void qemu_plugin_register_atexit_cb(qemu_plugin_id_t id,
qemu_plugin_udata_cb_t cb, void *userdata);
+
+/**
+ * qemu_plugin_register_gdb_cb() - register a gdb callback
+ * @id: plugin ID
+ * @cb: callback
+ * @userdata: user data for callback
+ *
+ * When using the gdbstub to debug a guest you can send a command that
+ * will trigger the callback. This is useful if you want the plugin to
+ * print out collected state at particular points when debugging a
+ * program.
+ */
+QEMU_PLUGIN_API
+void qemu_plugin_register_gdb_cb(qemu_plugin_id_t id,
+ qemu_plugin_udata_cb_t cb, void *userdata);
+
/* returns how many vcpus were started at this point */
int qemu_plugin_num_vcpus(void);
@@ -118,4 +118,13 @@ struct qemu_plugin_scoreboard *plugin_scoreboard_new(size_t element_size);
void plugin_scoreboard_free(struct qemu_plugin_scoreboard *score);
+/**
+ * plugin_register_gdbstub_commands - register gdbstub commands
+ *
+ * This should only be called once to register gdbstub commands so we
+ * can trigger callbacks if needed.
+ */
+void plugin_register_gdbstub_commands(void);
+
+
#endif /* PLUGIN_H */
@@ -681,3 +681,21 @@ void qemu_plugin_update_ns(const void *handle, int64_t new_time)
}
#endif
}
+
+/*
+ * gdbstub hooks
+ */
+
+static bool gdbstub_callbacks;
+
+void qemu_plugin_register_gdb_cb(qemu_plugin_id_t id,
+ qemu_plugin_udata_cb_t cb,
+ void *udata)
+{
+ plugin_register_cb_udata(id, QEMU_PLUGIN_EV_GDBSTUB, cb, udata);
+
+ if (!gdbstub_callbacks) {
+ plugin_register_gdbstub_commands();
+ gdbstub_callbacks = true;
+ }
+}
@@ -23,6 +23,7 @@
#include "qemu/xxhash.h"
#include "qemu/rcu.h"
#include "hw/core/cpu.h"
+#include "gdbstub/commands.h"
#include "exec/exec-all.h"
#include "exec/tb-flush.h"
@@ -147,6 +148,7 @@ static void plugin_cb__udata(enum qemu_plugin_event ev)
switch (ev) {
case QEMU_PLUGIN_EV_ATEXIT:
+ case QEMU_PLUGIN_EV_GDBSTUB:
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_udata_cb_t func = cb->f.udata;
@@ -768,3 +770,38 @@ void plugin_scoreboard_free(struct qemu_plugin_scoreboard *score)
g_array_free(score->data, TRUE);
g_free(score);
}
+
+/*
+ * gdbstub integration
+ */
+
+static void handle_plugin_cb(GArray *params, void *user_ctx)
+{
+ plugin_cb__udata(QEMU_PLUGIN_EV_GDBSTUB);
+ gdb_put_packet("OK");
+}
+
+enum Command {
+ PluginCallback,
+ NUM_GDB_CMDS
+};
+
+static const GdbCmdParseEntry cmd_handler_table[NUM_GDB_CMDS] = {
+ [PluginCallback] = {
+ .handler = handle_plugin_cb,
+ .cmd_startswith = true,
+ .cmd = "qemu.plugin_cb",
+ .schema = "s?",
+ },
+};
+
+void plugin_register_gdbstub_commands(void)
+{
+ g_autoptr(GPtrArray) set_table = g_ptr_array_new();
+
+ for (int i = 0; i < NUM_GDB_CMDS; i++) {
+ g_ptr_array_add(set_table, (gpointer) &cmd_handler_table[PluginCallback]);
+ }
+
+ gdb_extend_set_table(set_table);
+}
@@ -66,8 +66,7 @@ static gint addr_order(gconstpointer a, gconstpointer b)
return na->region_address > nb->region_address ? 1 : -1;
}
-
-static void plugin_exit(qemu_plugin_id_t id, void *p)
+static void plugin_report(qemu_plugin_id_t id, void *p)
{
g_autoptr(GString) out = g_string_new("");
@@ -81,6 +80,7 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
}
qemu_plugin_outs(out->str);
+ g_mutex_lock(&lock);
if (do_region_summary) {
GList *counts = g_hash_table_get_values(regions);
@@ -105,6 +105,12 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
qemu_plugin_outs(out->str);
}
+ g_mutex_unlock(&lock);
+}
+
+static void plugin_exit(qemu_plugin_id_t id, void *p)
+{
+ plugin_report(id, p);
qemu_plugin_scoreboard_free(counts);
}
@@ -375,6 +381,7 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
counts, CPUCount, mem_count);
io_count = qemu_plugin_scoreboard_u64_in_struct(counts, CPUCount, io_count);
qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
+ qemu_plugin_register_gdb_cb(id, plugin_report, NULL);
qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
return 0;
}
@@ -25,6 +25,7 @@
qemu_plugin_read_register;
qemu_plugin_register_atexit_cb;
qemu_plugin_register_flush_cb;
+ qemu_plugin_register_gdb_cb;
qemu_plugin_register_vcpu_exit_cb;
qemu_plugin_register_vcpu_idle_cb;
qemu_plugin_register_vcpu_init_cb;
Now gdbstub has gained the ability to extend its command tables we can allow it to trigger plugin callbacks. This is probably most useful for QEMU developers debugging plugins themselves but might be useful for other stuff. Trigger the callback by sending: maintenance packet Qqemu.plugin_cb I've extended the memory plugin to report on the packet. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> --- include/qemu/plugin-event.h | 1 + include/qemu/qemu-plugin.h | 16 ++++++++++++++++ plugins/plugin.h | 9 +++++++++ plugins/api.c | 18 ++++++++++++++++++ plugins/core.c | 37 ++++++++++++++++++++++++++++++++++++ tests/tcg/plugins/mem.c | 11 +++++++++-- plugins/qemu-plugins.symbols | 1 + 7 files changed, 91 insertions(+), 2 deletions(-)