[PATCH] target/riscv: Fix itrigger when icount is used

[LIU Zhiwei]

When I boot a ubuntu image, QEMU output a "Bad icount read" message and exit.
The reason is that when execute helper_mret or helper_sret, it will
cause a call to icount_get_raw_locked (), which needs set can_do_io flag
on cpustate.

Thus we setting this flag when execute these two instructions.

Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
---
 target/riscv/insn_trans/trans_privileged.c.inc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/target/riscv/insn_trans/trans_privileged.c.inc 
b/target/riscv/insn_trans/trans_privileged.c.inc
index 59501b2780..e3bee971c6 100644
--- a/target/riscv/insn_trans/trans_privileged.c.inc
+++ b/target/riscv/insn_trans/trans_privileged.c.inc
@@ -77,6 +77,9 @@ static bool trans_sret(DisasContext *ctx, arg_sret *a)
 #ifndef CONFIG_USER_ONLY
     if (has_ext(ctx, RVS)) {
         decode_save_opc(ctx);
+        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+            gen_io_start();
+        }
         gen_helper_sret(cpu_pc, cpu_env);
         exit_tb(ctx); /* no chaining */
         ctx->base.is_jmp = DISAS_NORETURN;
@@ -93,6 +96,9 @@ static bool trans_mret(DisasContext *ctx, arg_mret *a)
 {
 #ifndef CONFIG_USER_ONLY
     decode_save_opc(ctx);
+    if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
+        gen_io_start();
+    }
     gen_helper_mret(cpu_pc, cpu_env);
     exit_tb(ctx); /* no chaining */
     ctx->base.is_jmp = DISAS_NORETURN;
-- 
2.17.1