Base on the riscv-privileged spec, vstvec substitutes for the usual stvec. Therefore, the encoding of the MODE should also be restricted to 0 and 1.
Signed-off-by: Jiayi Li <liji...@eswincomputing.com> --- target/riscv/csr.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/target/riscv/csr.c b/target/riscv/csr.c index 432c59dc66..f9229d92ab 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -3791,7 +3791,12 @@ static RISCVException read_vstvec(CPURISCVState *env, int csrno, static RISCVException write_vstvec(CPURISCVState *env, int csrno, target_ulong val) { - env->vstvec = val; + /* bits [1:0] encode mode; 0 = direct, 1 = vectored, 2 >= reserved */ + if ((val & 3) < 2) { + env->vstvec = val; + } else { + qemu_log_mask(LOG_UNIMP, "CSR_VSTVEC: reserved mode not supported\n"); + } return RISCV_EXCP_NONE; } -- 2.25.1