plugins: Use translator_st for qemu_plugin_insn_data

Use the bytes that we record for the entire TB, rather than
a per-insn GByteArray.  Record the length of the insn in
plugin_gen_insn_end rather than infering from the length
of the array.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

accel/tcg/plugin-gen.c

@@ -346,11 +346,9 @@ void plugin_gen_insn_start(CPUState *cpu, const DisasContextBase *db)
     ptb->n = n;
     if (n <= ptb->insns->len) {
         insn = g_ptr_array_index(ptb->insns, n - 1);
-        g_byte_array_set_size(insn->data, 0);
     } else {
         assert(n - 1 == ptb->insns->len);
         insn = g_new0(struct qemu_plugin_insn, 1);
-        insn->data = g_byte_array_sized_new(4);
         g_ptr_array_add(ptb->insns, insn);
     }
 
@@ -389,6 +387,11 @@ void plugin_gen_insn_start(CPUState *cpu, const DisasContextBase *db)
 
 void plugin_gen_insn_end(void)
 {
+    const DisasContextBase *db = tcg_ctx->plugin_db;
+    struct qemu_plugin_insn *pinsn = tcg_ctx->plugin_insn;
+
+    pinsn->len = db->fake_insn ? db->record_len : db->pc_next - pinsn->vaddr;
+
     tcg_gen_plugin_cb(PLUGIN_GEN_AFTER_INSN);
 }
 

accel/tcg/translator.c

@@ -409,27 +409,6 @@ bool translator_st(const DisasContextBase *db, void *dest,
     return false;
 }
 
-static void plugin_insn_append(vaddr pc, const void *from, size_t size)
-{
-#ifdef CONFIG_PLUGIN
-    struct qemu_plugin_insn *insn = tcg_ctx->plugin_insn;
-    size_t off;
-
-    if (insn == NULL) {
-        return;
-    }
-    off = pc - insn->vaddr;
-    if (off < insn->data->len) {
-        g_byte_array_set_size(insn->data, off);
-    } else if (off > insn->data->len) {
-        /* we have an unexpected gap */
-        g_assert_not_reached();
-    }
-
-    insn->data = g_byte_array_append(insn->data, from, size);
-#endif
-}
-
 uint8_t translator_ldub(CPUArchState *env, DisasContextBase *db, vaddr pc)
 {
     uint8_t raw;
@@ -438,7 +417,6 @@ uint8_t translator_ldub(CPUArchState *env, DisasContextBase *db, vaddr pc)
         raw = cpu_ldub_code(env, pc);
         record_save(db, pc, &raw, sizeof(raw));
     }
-    plugin_insn_append(pc, &raw, sizeof(raw));
     return raw;
 }
 
@@ -453,7 +431,6 @@ uint16_t translator_lduw(CPUArchState *env, DisasContextBase *db, vaddr pc)
         raw = tswap16(tgt);
         record_save(db, pc, &raw, sizeof(raw));
     }
-    plugin_insn_append(pc, &raw, sizeof(raw));
     return tgt;
 }
 
@@ -468,7 +445,6 @@ uint32_t translator_ldl(CPUArchState *env, DisasContextBase *db, vaddr pc)
         raw = tswap32(tgt);
         record_save(db, pc, &raw, sizeof(raw));
     }
-    plugin_insn_append(pc, &raw, sizeof(raw));
     return tgt;
 }
 
@@ -483,7 +459,6 @@ uint64_t translator_ldq(CPUArchState *env, DisasContextBase *db, vaddr pc)
         raw = tswap64(tgt);
         record_save(db, pc, &raw, sizeof(raw));
     }
-    plugin_insn_append(pc, &raw, sizeof(raw));
     return tgt;
 }
 
@@ -492,5 +467,4 @@ void translator_fake_ldb(DisasContextBase *db, vaddr pc, uint8_t insn8)
     assert(pc >= db->pc_first);
     db->fake_insn = true;
     record_save(db, pc, &insn8, sizeof(insn8));
-    plugin_insn_append(pc, &insn8, sizeof(insn8));
 }

include/qemu/plugin.h

@@ -98,11 +98,11 @@ struct qemu_plugin_dyn_cb {
 
 /* Internal context for instrumenting an instruction */
 struct qemu_plugin_insn {
-    GByteArray *data;
     uint64_t vaddr;
     void *haddr;
     GArray *insn_cbs;
     GArray *mem_cbs;
+    uint8_t len;
     bool calls_helpers;
 
     /* if set, the instruction calls helpers that might access guest memory */
@@ -117,18 +117,6 @@ struct qemu_plugin_scoreboard {
     QLIST_ENTRY(qemu_plugin_scoreboard) entry;
 };
 
-/*
- * qemu_plugin_insn allocate and cleanup functions. We don't expect to
- * cleanup many of these structures. They are reused for each fresh
- * translation.
- */
-
-static inline void qemu_plugin_insn_cleanup_fn(gpointer data)
-{
-    struct qemu_plugin_insn *insn = (struct qemu_plugin_insn *) data;
-    g_byte_array_free(insn->data, true);
-}
-
 /* Internal context for this TranslationBlock */
 struct qemu_plugin_tb {
     GPtrArray *insns;

plugins/api.c

@@ -42,6 +42,7 @@
 #include "tcg/tcg.h"
 #include "exec/exec-all.h"
 #include "exec/gdbstub.h"
+#include "exec/translator.h"
 #include "disas/disas.h"
 #include "plugin.h"
 #ifndef CONFIG_USER_ONLY
@@ -219,14 +220,15 @@ qemu_plugin_tb_get_insn(const struct qemu_plugin_tb *tb, size_t idx)
 size_t qemu_plugin_insn_data(const struct qemu_plugin_insn *insn,
                              void *dest, size_t len)
 {
-    len = MIN(len, insn->data->len);
-    memcpy(dest, insn->data->data, len);
-    return len;
+    const DisasContextBase *db = tcg_ctx->plugin_db;
+
+    len = MIN(len, insn->len);
+    return translator_st(db, dest, insn->vaddr, len) ? len : 0;
 }
 
 size_t qemu_plugin_insn_size(const struct qemu_plugin_insn *insn)
 {
-    return insn->data->len;
+    return insn->len;
 }
 
 uint64_t qemu_plugin_insn_vaddr(const struct qemu_plugin_insn *insn)
@@ -242,7 +244,7 @@ void *qemu_plugin_insn_haddr(const struct qemu_plugin_insn *insn)
 char *qemu_plugin_insn_disas(const struct qemu_plugin_insn *insn)
 {
     CPUState *cpu = current_cpu;
-    return plugin_disas(cpu, insn->vaddr, insn->data->len);
+    return plugin_disas(cpu, insn->vaddr, insn->len);
 }
 
 const char *qemu_plugin_insn_symbol(const struct qemu_plugin_insn *insn)

tcg/tcg.c

@@ -765,8 +765,7 @@ static void alloc_tcg_plugin_context(TCGContext *s)
 {
 #ifdef CONFIG_PLUGIN
     s->plugin_tb = g_new0(struct qemu_plugin_tb, 1);
-    s->plugin_tb->insns =
-        g_ptr_array_new_with_free_func(qemu_plugin_insn_cleanup_fn);
+    s->plugin_tb->insns = g_ptr_array_new();
 #endif
 }