target/ppc: fix mtmsr instruction for icount

This patch fixes processing of mtmsr instructions in icount mode.
In this mode writing to interrupt/peripheral state is controlled
by can_do_io flag. This flag must be set explicitly before helper
function invocation.
Signed-off-by: NMaria Klimushenkova <maria.klimushenkova@ispras.ru>
Signed-off-by: NPavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

target/ppc/translate.c

@@ -4298,11 +4298,17 @@ static void gen_mtmsrd(DisasContext *ctx)
          *      if we enter power saving mode, we will exit the loop
          *      directly from ppc_store_msr
          */
+        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+            gen_io_start();
+        }
         gen_update_nip(ctx, ctx->base.pc_next);
         gen_helper_store_msr(cpu_env, cpu_gpr[rS(ctx->opcode)]);
         /* Must stop the translation as machine state (may have) changed */
         /* Note that mtmsr is not always defined as context-synchronizing */
         gen_stop_exception(ctx);
+        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+            gen_io_end();
+        }
     }
 #endif /* !defined(CONFIG_USER_ONLY) */
 }
@@ -4327,6 +4333,9 @@ static void gen_mtmsr(DisasContext *ctx)
          *      if we enter power saving mode, we will exit the loop
          *      directly from ppc_store_msr
          */
+        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+            gen_io_start();
+        }
         gen_update_nip(ctx, ctx->base.pc_next);
 #if defined(TARGET_PPC64)
         tcg_gen_deposit_tl(msr, cpu_msr, cpu_gpr[rS(ctx->opcode)], 0, 32);
@@ -4334,6 +4343,9 @@ static void gen_mtmsr(DisasContext *ctx)
         tcg_gen_mov_tl(msr, cpu_gpr[rS(ctx->opcode)]);
 #endif
         gen_helper_store_msr(cpu_env, msr);
+        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+            gen_io_end();
+        }
         tcg_temp_free(msr);
         /* Must stop the translation as machine state (may have) changed */
         /* Note that mtmsr is not always defined as context-synchronizing */