Currently, when a `sret` is executed in virtual user mode, qemu raise an `illegal instruction exception`, but in this case the correct behavior is to raise a `virtual instruction exception` and the code already contains a check to it, but it's not enough to catch. This patch is useful to improve the correctness of the virtualization of the risc v architecture.
Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3622 Signed-off-by: Christian S. Lima <[email protected]> --- target/riscv/tcg/op_helper.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/target/riscv/tcg/op_helper.c b/target/riscv/tcg/op_helper.c index ba3c7da375..429a6186a7 100644 --- a/target/riscv/tcg/op_helper.c +++ b/target/riscv/tcg/op_helper.c @@ -293,6 +293,10 @@ target_ulong helper_sret(CPURISCVState *env) const privilege_mode_t src_priv = env->priv; const bool src_virt = env->virt_enabled; + if ((env->virt_enabled && env->priv < PRV_S) || (env->virt_enabled && get_field(env->hstatus, HSTATUS_VTSR))) { + riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC()); + } + if (!(env->priv >= PRV_S)) { riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC()); } @@ -308,10 +312,6 @@ target_ulong helper_sret(CPURISCVState *env) riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC()); } - if (env->virt_enabled && get_field(env->hstatus, HSTATUS_VTSR)) { - riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC()); - } - mstatus = env->mstatus; prev_priv = get_field(mstatus, MSTATUS_SPP); mstatus = set_field(mstatus, MSTATUS_SIE, -- 2.53.0
