[Qemu-devel] [PATCH v8 23/25] target/ppc: Use gen_io_start/end around DARN

[Richard Henderson]

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

Acked-by: David Gibson <address@hidden>
Reviewed-by: Laurent Vivier <address@hidden>
Suggested-by: Peter Maydell <address@hidden>
Signed-off-by: Richard Henderson <address@hidden>
---
 target/ppc/translate.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index b5217f632f..4a5de28036 100644
--- 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
-- 
2.17.1