target/ppc: Use gen_io_start/end around DARN

Generating a random number counts as I/O, as it cannot be
replayed and produce the same results.

Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index b5217f632f0afc9779213a7d5b3395142b14c2ba..4a5de280365b240b8959ef391af72f28afd7b950 100644 (file)
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -1847,13 +1847,22 @@ static void gen_darn(DisasContext *ctx)
 {
     int l = L(ctx->opcode);
 
-    if (l == 0) {
-        gen_helper_darn32(cpu_gpr[rD(ctx->opcode)]);
-    } else if (l <= 2) {
-        /* Return 64-bit random for both CRN and RRN */
-        gen_helper_darn64(cpu_gpr[rD(ctx->opcode)]);
-    } else {
+    if (l > 2) {
         tcg_gen_movi_i64(cpu_gpr[rD(ctx->opcode)], -1);
+    } else {
+        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+            gen_io_start();
+        }
+        if (l == 0) {
+            gen_helper_darn32(cpu_gpr[rD(ctx->opcode)]);
+        } else {
+            /* Return 64-bit random for both CRN and RRN */
+            gen_helper_darn64(cpu_gpr[rD(ctx->opcode)]);
+        }
+        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+            gen_io_end();
+            gen_stop_exception(ctx);
+        }
     }
 }
 #endif