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-rw-r--r--tests/plugin/lockstep.c340
1 files changed, 0 insertions, 340 deletions
diff --git a/tests/plugin/lockstep.c b/tests/plugin/lockstep.c
deleted file mode 100644
index a696673dff..0000000000
--- a/tests/plugin/lockstep.c
+++ /dev/null
@@ -1,340 +0,0 @@
-/*
- * Lockstep Execution Plugin
- *
- * Allows you to execute two QEMU instances in lockstep and report
- * when their execution diverges. This is mainly useful for developers
- * who want to see where a change to TCG code generation has
- * introduced a subtle and hard to find bug.
- *
- * Caveats:
- * - single-threaded linux-user apps only with non-deterministic syscalls
- * - no MTTCG enabled system emulation (icount may help)
- *
- * While icount makes things more deterministic it doesn't mean a
- * particular run may execute the exact same sequence of blocks. An
- * asynchronous event (for example X11 graphics update) may cause a
- * block to end early and a new partial block to start. This means
- * serial only test cases are a better bet. -d nochain may also help.
- *
- * This code is not thread safe!
- *
- * Copyright (c) 2020 Linaro Ltd
- *
- * SPDX-License-Identifier: GPL-2.0-or-later
- */
-
-#include <glib.h>
-#include <inttypes.h>
-#include <unistd.h>
-#include <sys/socket.h>
-#include <sys/un.h>
-#include <stdio.h>
-#include <errno.h>
-
-#include <qemu-plugin.h>
-
-QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
-
-/* saved so we can uninstall later */
-static qemu_plugin_id_t our_id;
-
-static unsigned long bb_count;
-static unsigned long insn_count;
-
-/* Information about a translated block */
-typedef struct {
- uint64_t pc;
- uint64_t insns;
-} BlockInfo;
-
-/* Information about an execution state in the log */
-typedef struct {
- BlockInfo *block;
- unsigned long insn_count;
- unsigned long block_count;
-} ExecInfo;
-
-/* The execution state we compare */
-typedef struct {
- uint64_t pc;
- unsigned long insn_count;
-} ExecState;
-
-typedef struct {
- GSList *log_pos;
- int distance;
-} DivergeState;
-
-/* list of translated block info */
-static GSList *blocks;
-
-/* execution log and points of divergence */
-static GSList *log, *divergence_log;
-
-static int socket_fd;
-static char *path_to_unlink;
-
-static bool verbose;
-
-static void plugin_cleanup(qemu_plugin_id_t id)
-{
- /* Free our block data */
- g_slist_free_full(blocks, &g_free);
- g_slist_free_full(log, &g_free);
- g_slist_free(divergence_log);
-
- close(socket_fd);
- if (path_to_unlink) {
- unlink(path_to_unlink);
- }
-}
-
-static void plugin_exit(qemu_plugin_id_t id, void *p)
-{
- g_autoptr(GString) out = g_string_new("No divergence :-)\n");
- g_string_append_printf(out, "Executed %ld/%d blocks\n",
- bb_count, g_slist_length(log));
- g_string_append_printf(out, "Executed ~%ld instructions\n", insn_count);
- qemu_plugin_outs(out->str);
-
- plugin_cleanup(id);
-}
-
-static void report_divergance(ExecState *us, ExecState *them)
-{
- DivergeState divrec = { log, 0 };
- g_autoptr(GString) out = g_string_new("");
- bool diverged = false;
-
- /*
- * If we have diverged before did we get back on track or are we
- * totally loosing it?
- */
- if (divergence_log) {
- DivergeState *last = (DivergeState *) divergence_log->data;
- GSList *entry;
-
- for (entry = log; g_slist_next(entry); entry = g_slist_next(entry)) {
- if (entry == last->log_pos) {
- break;
- }
- divrec.distance++;
- }
-
- /*
- * If the last two records are so close it is likely we will
- * not recover synchronisation with the other end.
- */
- if (divrec.distance == 1 && last->distance == 1) {
- diverged = true;
- }
- }
- divergence_log = g_slist_prepend(divergence_log,
- g_memdup(&divrec, sizeof(divrec)));
-
- /* Output short log entry of going out of sync... */
- if (verbose || divrec.distance == 1 || diverged) {
- g_string_printf(out, "@ %#016lx vs %#016lx (%d/%d since last)\n",
- us->pc, them->pc, g_slist_length(divergence_log),
- divrec.distance);
- qemu_plugin_outs(out->str);
- }
-
- if (diverged) {
- int i;
- GSList *entry;
-
- g_string_printf(out, "Δ insn_count @ %#016lx (%ld) vs %#016lx (%ld)\n",
- us->pc, us->insn_count, them->pc, them->insn_count);
-
- for (entry = log, i = 0;
- g_slist_next(entry) && i < 5;
- entry = g_slist_next(entry), i++) {
- ExecInfo *prev = (ExecInfo *) entry->data;
- g_string_append_printf(out,
- " previously @ %#016lx/%ld (%ld insns)\n",
- prev->block->pc, prev->block->insns,
- prev->insn_count);
- }
- qemu_plugin_outs(out->str);
- qemu_plugin_outs("too much divergence... giving up.");
- qemu_plugin_uninstall(our_id, plugin_cleanup);
- }
-}
-
-static void vcpu_tb_exec(unsigned int cpu_index, void *udata)
-{
- BlockInfo *bi = (BlockInfo *) udata;
- ExecState us, them;
- ssize_t bytes;
- ExecInfo *exec;
-
- us.pc = bi->pc;
- us.insn_count = insn_count;
-
- /*
- * Write our current position to the other end. If we fail the
- * other end has probably died and we should shut down gracefully.
- */
- bytes = write(socket_fd, &us, sizeof(ExecState));
- if (bytes < sizeof(ExecState)) {
- qemu_plugin_outs(bytes < 0 ?
- "problem writing to socket" :
- "wrote less than expected to socket");
- qemu_plugin_uninstall(our_id, plugin_cleanup);
- return;
- }
-
- /*
- * Now read where our peer has reached. Again a failure probably
- * indicates the other end died and we should close down cleanly.
- */
- bytes = read(socket_fd, &them, sizeof(ExecState));
- if (bytes < sizeof(ExecState)) {
- qemu_plugin_outs(bytes < 0 ?
- "problem reading from socket" :
- "read less than expected");
- qemu_plugin_uninstall(our_id, plugin_cleanup);
- return;
- }
-
- /*
- * Compare and report if we have diverged.
- */
- if (us.pc != them.pc) {
- report_divergance(&us, &them);
- }
-
- /*
- * Assume this block will execute fully and record it
- * in the execution log.
- */
- insn_count += bi->insns;
- bb_count++;
- exec = g_new0(ExecInfo, 1);
- exec->block = bi;
- exec->insn_count = insn_count;
- exec->block_count = bb_count;
- log = g_slist_prepend(log, exec);
-}
-
-static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
-{
- BlockInfo *bi = g_new0(BlockInfo, 1);
- bi->pc = qemu_plugin_tb_vaddr(tb);
- bi->insns = qemu_plugin_tb_n_insns(tb);
-
- /* save a reference so we can free later */
- blocks = g_slist_prepend(blocks, bi);
- qemu_plugin_register_vcpu_tb_exec_cb(tb, vcpu_tb_exec,
- QEMU_PLUGIN_CB_NO_REGS, (void *)bi);
-}
-
-
-/*
- * Instead of encoding master/slave status into what is essentially
- * two peers we shall just take the simple approach of checking for
- * the existence of the pipe and assuming if it's not there we are the
- * first process.
- */
-static bool setup_socket(const char *path)
-{
- struct sockaddr_un sockaddr;
- int fd;
-
- fd = socket(AF_UNIX, SOCK_STREAM, 0);
- if (fd < 0) {
- perror("create socket");
- return false;
- }
-
- sockaddr.sun_family = AF_UNIX;
- g_strlcpy(sockaddr.sun_path, path, sizeof(sockaddr.sun_path) - 1);
- if (bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)) < 0) {
- perror("bind socket");
- close(fd);
- return false;
- }
-
- /* remember to clean-up */
- path_to_unlink = g_strdup(path);
-
- if (listen(fd, 1) < 0) {
- perror("listen socket");
- close(fd);
- return false;
- }
-
- socket_fd = accept(fd, NULL, NULL);
- if (socket_fd < 0 && errno != EINTR) {
- perror("accept socket");
- return false;
- }
-
- qemu_plugin_outs("setup_socket::ready\n");
-
- return true;
-}
-
-static bool connect_socket(const char *path)
-{
- int fd;
- struct sockaddr_un sockaddr;
-
- fd = socket(AF_UNIX, SOCK_STREAM, 0);
- if (fd < 0) {
- perror("create socket");
- return false;
- }
-
- sockaddr.sun_family = AF_UNIX;
- g_strlcpy(sockaddr.sun_path, path, sizeof(sockaddr.sun_path) - 1);
-
- if (connect(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)) < 0) {
- perror("failed to connect");
- return false;
- }
-
- qemu_plugin_outs("connect_socket::ready\n");
-
- socket_fd = fd;
- return true;
-}
-
-static bool setup_unix_socket(const char *path)
-{
- if (g_file_test(path, G_FILE_TEST_EXISTS)) {
- return connect_socket(path);
- } else {
- return setup_socket(path);
- }
-}
-
-
-QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
- const qemu_info_t *info,
- int argc, char **argv)
-{
- int i;
-
- if (!argc || !argv[0]) {
- qemu_plugin_outs("Need a socket path to talk to other instance.");
- return -1;
- }
-
- for (i = 0; i < argc; i++) {
- char *p = argv[i];
- if (strcmp(p, "verbose") == 0) {
- verbose = true;
- } else if (!setup_unix_socket(argv[0])) {
- qemu_plugin_outs("Failed to setup socket for communications.");
- return -1;
- }
- }
-
- our_id = id;
-
- qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
- qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
- return 0;
-}
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