diff options
| -rw-r--r-- | tests/plugin/Makefile | 1 | ||||
| -rw-r--r-- | tests/plugin/hotblocks.c | 143 |
2 files changed, 144 insertions, 0 deletions
diff --git a/tests/plugin/Makefile b/tests/plugin/Makefile index f9a3546ea3..e74940eaac 100644 --- a/tests/plugin/Makefile +++ b/tests/plugin/Makefile @@ -10,6 +10,7 @@ NAMES += bb NAMES += empty NAMES += insn NAMES += mem +NAMES += hotblocks SONAMES := $(addsuffix .so,$(addprefix lib,$(NAMES))) diff --git a/tests/plugin/hotblocks.c b/tests/plugin/hotblocks.c new file mode 100644 index 0000000000..1bd183849a --- /dev/null +++ b/tests/plugin/hotblocks.c @@ -0,0 +1,143 @@ +/* + * Copyright (C) 2019, Alex Bennée <alex.bennee@linaro.org> + * + * License: GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ +#include <inttypes.h> +#include <assert.h> +#include <stdlib.h> +#include <inttypes.h> +#include <string.h> +#include <unistd.h> +#include <stdio.h> +#include <glib.h> + +#include <qemu-plugin.h> + +static bool do_inline; + +/* Plugins need to take care of their own locking */ +static GMutex lock; +static GHashTable *hotblocks; +static guint64 limit = 20; + +/* + * Counting Structure + * + * The internals of the TCG are not exposed to plugins so we can only + * get the starting PC for each block. We cheat this slightly by + * xor'ing the number of instructions to the hash to help + * differentiate. + */ +typedef struct { + uint64_t start_addr; + uint64_t exec_count; + int trans_count; + unsigned long insns; +} ExecCount; + +static gint cmp_exec_count(gconstpointer a, gconstpointer b) +{ + ExecCount *ea = (ExecCount *) a; + ExecCount *eb = (ExecCount *) b; + return ea->exec_count > eb->exec_count ? -1 : 1; +} + +static void plugin_exit(qemu_plugin_id_t id, void *p) +{ + g_autoptr(GString) report = g_string_new("collected "); + GList *counts, *it; + int i; + + g_mutex_lock(&lock); + g_string_append_printf(report, "%d entries in the hash table\n", + g_hash_table_size(hotblocks)); + counts = g_hash_table_get_values(hotblocks); + it = g_list_sort(counts, cmp_exec_count); + + if (it) { + g_string_append_printf(report, "pc, tcount, icount, ecount\n"); + + for (i = 0; i < limit && it->next; i++, it = it->next) { + ExecCount *rec = (ExecCount *) it->data; + g_string_append_printf(report, "%#016"PRIx64", %d, %ld, %"PRId64"\n", + rec->start_addr, rec->trans_count, + rec->insns, rec->exec_count); + } + + g_list_free(it); + g_mutex_unlock(&lock); + } + + qemu_plugin_outs(report->str); +} + +static void plugin_init(void) +{ + hotblocks = g_hash_table_new(NULL, g_direct_equal); +} + +static void vcpu_tb_exec(unsigned int cpu_index, void *udata) +{ + ExecCount *cnt; + uint64_t hash = (uint64_t) udata; + + g_mutex_lock(&lock); + cnt = (ExecCount *) g_hash_table_lookup(hotblocks, (gconstpointer) hash); + /* should always succeed */ + g_assert(cnt); + cnt->exec_count++; + g_mutex_unlock(&lock); +} + +/* + * When do_inline we ask the plugin to increment the counter for us. + * Otherwise a helper is inserted which calls the vcpu_tb_exec + * callback. + */ +static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb) +{ + ExecCount *cnt; + uint64_t pc = qemu_plugin_tb_vaddr(tb); + unsigned long insns = qemu_plugin_tb_n_insns(tb); + uint64_t hash = pc ^ insns; + + g_mutex_lock(&lock); + cnt = (ExecCount *) g_hash_table_lookup(hotblocks, (gconstpointer) hash); + if (cnt) { + cnt->trans_count++; + } else { + cnt = g_new0(ExecCount, 1); + cnt->start_addr = pc; + cnt->trans_count = 1; + cnt->insns = insns; + g_hash_table_insert(hotblocks, (gpointer) hash, (gpointer) cnt); + } + + g_mutex_unlock(&lock); + + if (do_inline) { + qemu_plugin_register_vcpu_tb_exec_inline(tb, QEMU_PLUGIN_INLINE_ADD_U64, + &cnt->exec_count, 1); + } else { + qemu_plugin_register_vcpu_tb_exec_cb(tb, vcpu_tb_exec, + QEMU_PLUGIN_CB_NO_REGS, + (void *)hash); + } +} + +QEMU_PLUGIN_EXPORT +int qemu_plugin_install(qemu_plugin_id_t id, const qemu_info_t *info, + int argc, char **argv) +{ + if (argc && strcmp(argv[0], "inline") == 0) { + do_inline = true; + } + + plugin_init(); + + qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans); + qemu_plugin_register_atexit_cb(id, plugin_exit, NULL); + return 0; +} |