target/riscv: Fix checks in hmode/hmode32

Add check for the implicit dependence between H and S

Csrs only existed in RV32 will not trigger virtual instruction fault
when not in RV32 based on section 8.6.1 of riscv-privileged spec
(draft-20220717)

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220718130955.11899-6-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu.c

@@ -733,6 +733,11 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
             return;
         }
 
+        if (cpu->cfg.ext_h && !cpu->cfg.ext_s) {
+            error_setg(errp, "H extension implicitly requires S-mode");
+            return;
+        }
+
         if (cpu->cfg.ext_f && !cpu->cfg.ext_icsr) {
             error_setg(errp, "F extension requires Zicsr");
             return;