plugins: Drop tcg_flags from struct qemu_plugin_dyn_cb

As noted by qemu-plugins.h, enum qemu_plugin_cb_flags is
currently unused -- plugins can neither read nor write
guest registers.

Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

accel/tcg/plugin-gen.c

@@ -384,7 +384,7 @@ static TCGOp *copy_st_ptr(TCGOp **begin_op, TCGOp *op)
 }
 
 static TCGOp *copy_call(TCGOp **begin_op, TCGOp *op, void *empty_func,
-                        void *func, unsigned tcg_flags, int *cb_idx)
+                        void *func, int *cb_idx)
 {
     /* copy all ops until the call */
     do {
@@ -411,7 +411,7 @@ static TCGOp *copy_call(TCGOp **begin_op, TCGOp *op, void *empty_func,
         tcg_debug_assert(i < MAX_OPC_PARAM_ARGS);
     }
     op->args[*cb_idx] = (uintptr_t)func;
-    op->args[*cb_idx + 1] = tcg_flags;
+    op->args[*cb_idx + 1] = (*begin_op)->args[*cb_idx + 1];
 
     return op;
 }
@@ -438,7 +438,7 @@ static TCGOp *append_udata_cb(const struct qemu_plugin_dyn_cb *cb,
 
     /* call */
     op = copy_call(&begin_op, op, HELPER(plugin_vcpu_udata_cb),
-                   cb->f.vcpu_udata, cb->tcg_flags, cb_idx);
+                   cb->f.vcpu_udata, cb_idx);
 
     return op;
 }
@@ -489,7 +489,7 @@ static TCGOp *append_mem_cb(const struct qemu_plugin_dyn_cb *cb,
     if (type == PLUGIN_GEN_CB_MEM) {
         /* call */
         op = copy_call(&begin_op, op, HELPER(plugin_vcpu_mem_cb),
-                       cb->f.vcpu_udata, cb->tcg_flags, cb_idx);
+                       cb->f.vcpu_udata, cb_idx);
     }
 
     return op;

accel/tcg/plugin-helpers.h

@@ -1,5 +1,4 @@
 #ifdef CONFIG_PLUGIN
-/* Note: no TCG flags because those are overwritten later */
 DEF_HELPER_2(plugin_vcpu_udata_cb, void, i32, ptr)
 DEF_HELPER_4(plugin_vcpu_mem_cb, void, i32, i32, i64, ptr)
 #endif

include/qemu/plugin.h

@@ -79,7 +79,6 @@ enum plugin_dyn_cb_subtype {
 struct qemu_plugin_dyn_cb {
     union qemu_plugin_cb_sig f;
     void *userp;
-    unsigned tcg_flags;
     enum plugin_dyn_cb_subtype type;
     /* @rw applies to mem callbacks only (both regular and inline) */
     enum qemu_plugin_mem_rw rw;

plugins/core.c

@@ -295,33 +295,15 @@ void plugin_register_inline_op(GArray **arr,
     dyn_cb->inline_insn.imm = imm;
 }
 
-static inline uint32_t cb_to_tcg_flags(enum qemu_plugin_cb_flags flags)
-{
-    uint32_t ret;
-
-    switch (flags) {
-    case QEMU_PLUGIN_CB_RW_REGS:
-        ret = 0;
-        break;
-    case QEMU_PLUGIN_CB_R_REGS:
-        ret = TCG_CALL_NO_WG;
-        break;
-    case QEMU_PLUGIN_CB_NO_REGS:
-    default:
-        ret = TCG_CALL_NO_RWG;
-    }
-    return ret;
-}
-
-inline void
-plugin_register_dyn_cb__udata(GArray **arr,
-                              qemu_plugin_vcpu_udata_cb_t cb,
-                              enum qemu_plugin_cb_flags flags, void *udata)
+void plugin_register_dyn_cb__udata(GArray **arr,
+                                   qemu_plugin_vcpu_udata_cb_t cb,
+                                   enum qemu_plugin_cb_flags flags,
+                                   void *udata)
 {
     struct qemu_plugin_dyn_cb *dyn_cb = plugin_get_dyn_cb(arr);
 
     dyn_cb->userp = udata;
-    dyn_cb->tcg_flags = cb_to_tcg_flags(flags);
+    /* Note flags are discarded as unused. */
     dyn_cb->f.vcpu_udata = cb;
     dyn_cb->type = PLUGIN_CB_REGULAR;
 }
@@ -336,7 +318,7 @@ void plugin_register_vcpu_mem_cb(GArray **arr,
 
     dyn_cb = plugin_get_dyn_cb(arr);
     dyn_cb->userp = udata;
-    dyn_cb->tcg_flags = cb_to_tcg_flags(flags);
+    /* Note flags are discarded as unused. */
     dyn_cb->type = PLUGIN_CB_REGULAR;
     dyn_cb->rw = rw;
     dyn_cb->f.generic = cb;