accel/tcg: Handle gdb singlestep in cpu_tb_exec

Currently the change in cpu_tb_exec is masked by the debug exception
being raised by the translators.  But this allows us to remove that code.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 5fd1ed3422..c9764c1325 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -383,6 +383,17 @@ cpu_tb_exec(CPUState *cpu, TranslationBlock *itb, int *tb_exit)
             cc->set_pc(cpu, last_tb->pc);
         }
     }
+
+    /*
+     * If gdb single-step, and we haven't raised another exception,
+     * raise a debug exception.  Single-step with another exception
+     * is handled in cpu_handle_exception.
+     */
+    if (unlikely(cpu->singlestep_enabled) && cpu->exception_index == -1) {
+        cpu->exception_index = EXCP_DEBUG;
+        cpu_loop_exit(cpu);
+    }
+
     return last_tb;
 }