We define a scoreboard that will hold our data per cpu. As well, we define a buffer per cpu that will be used to read registers and memories in a thread-safe way.
For now, we just instrument all instructions with an empty callback. Reviewed-by: Manos Pitsidianakis <manos.pitsidiana...@linaro.org> Signed-off-by: Pierrick Bouvier <pierrick.bouv...@linaro.org> --- contrib/plugins/uftrace.c | 73 +++++++++++++++++++++++++++++++++++++ contrib/plugins/meson.build | 3 +- 2 files changed, 75 insertions(+), 1 deletion(-) create mode 100644 contrib/plugins/uftrace.c diff --git a/contrib/plugins/uftrace.c b/contrib/plugins/uftrace.c new file mode 100644 index 00000000000..4af0130b159 --- /dev/null +++ b/contrib/plugins/uftrace.c @@ -0,0 +1,73 @@ +/* + * Copyright (C) 2025, Pierrick Bouvier <pierrick.bouv...@linaro.org> + * + * Generates a trace compatible with uftrace (similar to uftrace record). + * https://github.com/namhyung/uftrace + * + * See docs/about/emulation.rst|Uftrace for details and examples. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include <qemu-plugin.h> +#include <glib.h> + +QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION; + +typedef struct Cpu { + GByteArray *buf; +} Cpu; + +static struct qemu_plugin_scoreboard *score; + +static void track_callstack(unsigned int cpu_index, void *udata) +{ +} + +static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb) +{ + size_t n_insns = qemu_plugin_tb_n_insns(tb); + + for (size_t i = 0; i < n_insns; i++) { + struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i); + + uintptr_t pc = qemu_plugin_insn_vaddr(insn); + qemu_plugin_register_vcpu_insn_exec_cb(insn, track_callstack, + QEMU_PLUGIN_CB_R_REGS, + (void *) pc); + } +} + +static void vcpu_init(qemu_plugin_id_t id, unsigned int vcpu_index) +{ + Cpu *cpu = qemu_plugin_scoreboard_find(score, vcpu_index); + cpu->buf = g_byte_array_new(); +} + +static void vcpu_end(unsigned int vcpu_index) +{ + Cpu *cpu = qemu_plugin_scoreboard_find(score, vcpu_index); + g_byte_array_free(cpu->buf, true); + memset(cpu, 0, sizeof(Cpu)); +} + +static void at_exit(qemu_plugin_id_t id, void *data) +{ + for (size_t i = 0; i < qemu_plugin_num_vcpus(); ++i) { + vcpu_end(i); + } + + qemu_plugin_scoreboard_free(score); +} + +QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id, + const qemu_info_t *info, + int argc, char **argv) +{ + score = qemu_plugin_scoreboard_new(sizeof(Cpu)); + qemu_plugin_register_vcpu_init_cb(id, vcpu_init); + qemu_plugin_register_atexit_cb(id, at_exit, NULL); + qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans); + + return 0; +} diff --git a/contrib/plugins/meson.build b/contrib/plugins/meson.build index 1876bc78438..7eb3629c95d 100644 --- a/contrib/plugins/meson.build +++ b/contrib/plugins/meson.build @@ -1,5 +1,6 @@ contrib_plugins = ['bbv', 'cache', 'cflow', 'drcov', 'execlog', 'hotblocks', - 'hotpages', 'howvec', 'hwprofile', 'ips', 'stoptrigger'] + 'hotpages', 'howvec', 'hwprofile', 'ips', 'stoptrigger', + 'uftrace'] if host_os != 'windows' # lockstep uses socket.h contrib_plugins += 'lockstep' -- 2.47.2
