[PULL 1/6] target/riscv: Correctly implement TSR trap

[Palmer Dabbelt]

From: Alistair Francis <address@hidden>

As reported in: https://bugs.launchpad.net/qemu/+bug/1851939 we weren't
correctly handling illegal instructions based on the value of MSTATUS_TSR
and the current privledge level.

This patch fixes the issue raised in the bug by raising an illegal
instruction if TSR is set and we are in S-Mode.

Signed-off-by: Alistair Francis <address@hidden>
Reviewed-by: Jonathan Behrens <address@hidden
Signed-off-by: Palmer Dabbelt <address@hidden>
---
 target/riscv/op_helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index 8736f689c2..c6412f680c 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -85,7 +85,7 @@ target_ulong helper_sret(CPURISCVState *env, target_ulong 
cpu_pc_deb)
     }
 
     if (env->priv_ver >= PRIV_VERSION_1_10_0 &&
-        get_field(env->mstatus, MSTATUS_TSR)) {
+        get_field(env->mstatus, MSTATUS_TSR) && !(env->priv >= PRV_M)) {
         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
     }
 
-- 
2.25.1.481.gfbce0eb801-goog