Add an opcode to find a code address within the current insn,
for later use with unwinding.  Generate the code generically
using tcg_reg_alloc_do_movi.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/tcg/tcg-op-common.h |  1 +
 include/tcg/tcg-opc.h       |  1 +
 tcg/tcg-op.c                |  5 +++++
 tcg/tcg.c                   | 10 ++++++++++
 4 files changed, 17 insertions(+)

diff --git a/include/tcg/tcg-op-common.h b/include/tcg/tcg-op-common.h
index 009e2778c5..a32c88a182 100644
--- a/include/tcg/tcg-op-common.h
+++ b/include/tcg/tcg-op-common.h
@@ -76,6 +76,7 @@ void tcg_gen_lookup_and_goto_ptr(void);
 
 void tcg_gen_plugin_cb(unsigned from);
 void tcg_gen_plugin_mem_cb(TCGv_i64 addr, unsigned meminfo);
+void tcg_gen_plugin_pc(TCGv_ptr);
 
 /* 32 bit ops */
 
diff --git a/include/tcg/tcg-opc.h b/include/tcg/tcg-opc.h
index 546eb49c11..087d1b82da 100644
--- a/include/tcg/tcg-opc.h
+++ b/include/tcg/tcg-opc.h
@@ -199,6 +199,7 @@ DEF(goto_ptr, 0, 1, 0, TCG_OPF_BB_EXIT | TCG_OPF_BB_END)
 
 DEF(plugin_cb, 0, 0, 1, TCG_OPF_NOT_PRESENT)
 DEF(plugin_mem_cb, 0, 1, 1, TCG_OPF_NOT_PRESENT)
+DEF(plugin_pc, 1, 0, 0, TCG_OPF_NOT_PRESENT)
 
 /* Replicate ld/st ops for 32 and 64-bit guest addresses. */
 DEF(qemu_ld_a32_i32, 1, 1, 1,
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index eff3728622..b8ca78cbe4 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -322,6 +322,11 @@ void tcg_gen_plugin_mem_cb(TCGv_i64 addr, unsigned meminfo)
     tcg_gen_op2(INDEX_op_plugin_mem_cb, tcgv_i64_arg(addr), meminfo);
 }
 
+void tcg_gen_plugin_pc(TCGv_ptr arg)
+{
+    tcg_gen_op1(INDEX_op_plugin_pc, tcgv_ptr_arg(arg));
+}
+
 /* 32 bit ops */
 
 void tcg_gen_discard_i32(TCGv_i32 arg)
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 34e3056380..b7c28d92a6 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -4689,6 +4689,13 @@ static void tcg_reg_alloc_mov(TCGContext *s, const TCGOp *op)
     }
 }
 
+static void tcg_reg_alloc_plugin_pc(TCGContext *s, const TCGOp *op)
+{
+    tcg_reg_alloc_do_movi(s, arg_temp(op->args[0]),
+                          (uintptr_t)tcg_splitwx_to_rx(s->code_ptr),
+                          op->life, output_pref(op, 0));
+}
+
 /*
  * Specialized code generation for INDEX_op_dup_vec.
  */
@@ -6196,6 +6203,9 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb, uint64_t pc_start)
         case INDEX_op_mov_vec:
             tcg_reg_alloc_mov(s, op);
             break;
+        case INDEX_op_plugin_pc:
+            tcg_reg_alloc_plugin_pc(s, op);
+            break;
         case INDEX_op_dup_vec:
             tcg_reg_alloc_dup(s, op);
             break;
-- 
2.34.1

Richard Henderson <richard.henderson@linaro.org> writes:

> Add an opcode to find a code address within the current insn,
> for later use with unwinding.  Generate the code generically
> using tcg_reg_alloc_do_movi.
>
> Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro