tests/plugin: add sample plugins

Pass arguments with -plugin=libfoo.so,arg=bar,arg=baz
Signed-off-by: NEmilio G. Cota <cota@braap.org>
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>

configure

@@ -7903,6 +7903,7 @@ DIRS="$DIRS roms/seabios roms/vgabios"
 LINKS="Makefile"
 LINKS="$LINKS tests/tcg/lm32/Makefile po/Makefile"
 LINKS="$LINKS tests/tcg/Makefile.target tests/fp/Makefile"
+LINKS="$LINKS tests/plugin/Makefile"
 LINKS="$LINKS pc-bios/optionrom/Makefile pc-bios/keymaps"
 LINKS="$LINKS pc-bios/s390-ccw/Makefile"
 LINKS="$LINKS roms/seabios/Makefile roms/vgabios/Makefile"

tests/plugin/Makefile

+BUILD_DIR := $(CURDIR)/../..
+
+include $(BUILD_DIR)/config-host.mak
+include $(SRC_PATH)/rules.mak
+
+$(call set-vpath, $(SRC_PATH)/tests/plugin)
+
+NAMES :=
+NAMES += bb
+NAMES += empty
+NAMES += insn
+NAMES += mem
+
+SONAMES := $(addsuffix .so,$(addprefix lib,$(NAMES)))
+
+QEMU_CFLAGS += -fPIC
+QEMU_CFLAGS += -I$(SRC_PATH)/include/qemu
+
+all: $(SONAMES)
+
+lib%.so: %.o
+	$(CC) -shared -Wl,-soname,$@ -o $@ $^ $(LDLIBS)
+
+clean:
+	rm -f *.o *.so *.d
+	rm -Rf .libs
+
+.PHONY: all clean

tests/plugin/bb.c

+/*
+ * Copyright (C) 2018, Emilio G. Cota <cota@braap.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 <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <glib.h>
+
+#include <qemu-plugin.h>
+
+static uint64_t bb_count;
+static uint64_t insn_count;
+static bool do_inline;
+
+static void plugin_exit(qemu_plugin_id_t id, void *p)
+{
+    g_autofree gchar *out;
+    out = g_strdup_printf("bb's: %" PRIu64", insns: %" PRIu64 "\n",
+                          bb_count, insn_count);
+    qemu_plugin_outs(out);
+}
+
+static void vcpu_tb_exec(unsigned int cpu_index, void *udata)
+{
+    unsigned long n_insns = (unsigned long)udata;
+
+    insn_count += n_insns;
+    bb_count++;
+}
+
+static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
+{
+    unsigned long n_insns = qemu_plugin_tb_n_insns(tb);
+
+    if (do_inline) {
+        qemu_plugin_register_vcpu_tb_exec_inline(tb, QEMU_PLUGIN_INLINE_ADD_U64,
+                                                 &bb_count, 1);
+        qemu_plugin_register_vcpu_tb_exec_inline(tb, QEMU_PLUGIN_INLINE_ADD_U64,
+                                                 &insn_count, n_insns);
+    } else {
+        qemu_plugin_register_vcpu_tb_exec_cb(tb, vcpu_tb_exec,
+                                             QEMU_PLUGIN_CB_NO_REGS,
+                                             (void *)n_insns);
+    }
+}
+
+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;
+    }
+
+    qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
+    qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
+    return 0;
+}

tests/plugin/empty.c

+/*
+ * Copyright (C) 2018, Emilio G. Cota <cota@braap.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 <string.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#include <qemu-plugin.h>
+
+/*
+ * Empty TB translation callback.
+ * This allows us to measure the overhead of injecting and then
+ * removing empty instrumentation.
+ */
+static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
+{ }
+
+QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
+                                           const qemu_info_t *info,
+                                           int argc, char **argv)
+{
+    qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
+    return 0;
+}

tests/plugin/insn.c

+/*
+ * Copyright (C) 2018, Emilio G. Cota <cota@braap.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 <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <glib.h>
+
+#include <qemu-plugin.h>
+
+static uint64_t insn_count;
+static bool do_inline;
+
+static void vcpu_insn_exec_before(unsigned int cpu_index, void *udata)
+{
+    insn_count++;
+}
+
+static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
+{
+    size_t n = qemu_plugin_tb_n_insns(tb);
+    size_t i;
+
+    for (i = 0; i < n; i++) {
+        struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
+
+        if (do_inline) {
+            qemu_plugin_register_vcpu_insn_exec_inline(
+                insn, QEMU_PLUGIN_INLINE_ADD_U64, &insn_count, 1);
+        } else {
+            qemu_plugin_register_vcpu_insn_exec_cb(
+                insn, vcpu_insn_exec_before, QEMU_PLUGIN_CB_NO_REGS, NULL);
+        }
+    }
+}
+
+static void plugin_exit(qemu_plugin_id_t id, void *p)
+{
+    g_autofree gchar *out;
+    out = g_strdup_printf("insns: %" PRIu64 "\n", insn_count);
+    qemu_plugin_outs(out);
+}
+
+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")) {
+        do_inline = true;
+    }
+
+    qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
+    qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
+    return 0;
+}

tests/plugin/mem.c

+/*
+ * Copyright (C) 2018, Emilio G. Cota <cota@braap.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 <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <glib.h>
+
+#include <qemu-plugin.h>
+
+static uint64_t mem_count;
+static uint64_t io_count;
+static bool do_inline;
+static bool do_haddr;
+static enum qemu_plugin_mem_rw rw = QEMU_PLUGIN_MEM_RW;
+
+static void plugin_exit(qemu_plugin_id_t id, void *p)
+{
+    g_autoptr(GString) out = g_string_new("");
+
+    g_string_printf(out, "mem accesses: %" PRIu64 "\n", mem_count);
+    if (do_haddr) {
+        g_string_append_printf(out, "io accesses: %" PRIu64 "\n", mem_count);
+    }
+    qemu_plugin_outs(out->str);
+}
+
+static void vcpu_mem(unsigned int cpu_index, qemu_plugin_meminfo_t meminfo,
+                     uint64_t vaddr, void *udata)
+{
+    if (do_haddr) {
+        struct qemu_plugin_hwaddr *hwaddr;
+        hwaddr = qemu_plugin_get_hwaddr(meminfo, vaddr);
+        if (qemu_plugin_hwaddr_is_io(hwaddr)) {
+            io_count++;
+        } else {
+            mem_count++;
+        }
+    } else {
+        mem_count++;
+    }
+}
+
+static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
+{
+    size_t n = qemu_plugin_tb_n_insns(tb);
+    size_t i;
+
+    for (i = 0; i < n; i++) {
+        struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
+
+        if (do_inline) {
+            qemu_plugin_register_vcpu_mem_inline(insn, rw,
+                                                 QEMU_PLUGIN_INLINE_ADD_U64,
+                                                 &mem_count, 1);
+        } else {
+            qemu_plugin_register_vcpu_mem_cb(insn, vcpu_mem,
+                                             QEMU_PLUGIN_CB_NO_REGS,
+                                             rw, NULL);
+        }
+    }
+}
+
+QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
+                                           const qemu_info_t *info,
+                                           int argc, char **argv)
+{
+    if (argc) {
+        if (argc >= 3) {
+            if (!strcmp(argv[2], "haddr")) {
+                do_haddr = true;
+            }
+        }
+        if (argc >= 2) {
+            const char *str = argv[1];
+
+            if (!strcmp(str, "r")) {
+                rw = QEMU_PLUGIN_MEM_R;
+            } else if (!strcmp(str, "w")) {
+                rw = QEMU_PLUGIN_MEM_W;
+            }
+        }
+        if (!strcmp(argv[0], "inline")) {
+            do_inline = true;
+        }
+    }
+
+    qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
+    qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
+    return 0;
+}