plugins: add new inline op STORE_U64

This new operation can store an immediate u64 value to a given
scoreboard.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20240502211522.346467-4-pierrick.bouvier@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240514174253.694591-6-alex.bennee@linaro.org>

accel/tcg/plugin-gen.c

@@ -145,6 +145,16 @@ static void gen_inline_add_u64_cb(struct qemu_plugin_dyn_cb *cb)
     tcg_temp_free_ptr(ptr);
 }
 
+static void gen_inline_store_u64_cb(struct qemu_plugin_dyn_cb *cb)
+{
+    TCGv_ptr ptr = gen_plugin_u64_ptr(cb->inline_insn.entry);
+    TCGv_i64 val = tcg_constant_i64(cb->inline_insn.imm);
+
+    tcg_gen_st_i64(val, ptr, 0);
+
+    tcg_temp_free_ptr(ptr);
+}
+
 static void gen_mem_cb(struct qemu_plugin_dyn_cb *cb,
                        qemu_plugin_meminfo_t meminfo, TCGv_i64 addr)
 {
@@ -170,6 +180,9 @@ static void inject_cb(struct qemu_plugin_dyn_cb *cb)
     case PLUGIN_CB_INLINE_ADD_U64:
         gen_inline_add_u64_cb(cb);
         break;
+    case PLUGIN_CB_INLINE_STORE_U64:
+        gen_inline_store_u64_cb(cb);
+        break;
     default:
         g_assert_not_reached();
     }

include/qemu/plugin.h

@@ -70,6 +70,7 @@ enum plugin_dyn_cb_type {
     PLUGIN_CB_REGULAR,
     PLUGIN_CB_MEM_REGULAR,
     PLUGIN_CB_INLINE_ADD_U64,
+    PLUGIN_CB_INLINE_STORE_U64,
 };
 
 /*

include/qemu/qemu-plugin.h

@@ -305,12 +305,12 @@ void qemu_plugin_register_vcpu_tb_exec_cb(struct qemu_plugin_tb *tb,
  * enum qemu_plugin_op - describes an inline op
  *
  * @QEMU_PLUGIN_INLINE_ADD_U64: add an immediate value uint64_t
- *
- * Note: currently only a single inline op is supported.
+ * @QEMU_PLUGIN_INLINE_STORE_U64: store an immediate value uint64_t
  */
 
 enum qemu_plugin_op {
     QEMU_PLUGIN_INLINE_ADD_U64,
+    QEMU_PLUGIN_INLINE_STORE_U64,
 };
 
 /**

plugins/core.c

@@ -321,6 +321,8 @@ static enum plugin_dyn_cb_type op_to_cb_type(enum qemu_plugin_op op)
     switch (op) {
     case QEMU_PLUGIN_INLINE_ADD_U64:
         return PLUGIN_CB_INLINE_ADD_U64;
+    case QEMU_PLUGIN_INLINE_STORE_U64:
+        return PLUGIN_CB_INLINE_STORE_U64;
     default:
         g_assert_not_reached();
     }
@@ -535,6 +537,9 @@ void exec_inline_op(struct qemu_plugin_dyn_cb *cb, int cpu_index)
     case QEMU_PLUGIN_INLINE_ADD_U64:
         *val += cb->inline_insn.imm;
         break;
+    case QEMU_PLUGIN_INLINE_STORE_U64:
+        *val = cb->inline_insn.imm;
+        break;
     default:
         g_assert_not_reached();
     }
@@ -562,6 +567,7 @@ void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr,
                                    vaddr, cb->userp);
             break;
         case PLUGIN_CB_INLINE_ADD_U64:
+        case PLUGIN_CB_INLINE_STORE_U64:
             exec_inline_op(cb, cpu->cpu_index);
             break;
         default: