target/riscv: Fix sfence.vm/a both available in any priv version

sfence.vm has been replaced in priv v1.10 spec by sfence.vma.
Reported-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NBastian Koppelmann <kbastian@mail.uni-paderborn.de>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

target/riscv/translate.c

@@ -1292,10 +1292,14 @@ static void gen_system(CPURISCVState *env, DisasContext *ctx, uint32_t opc,
 #ifndef CONFIG_USER_ONLY
     /* Extract funct7 value and check whether it matches SFENCE.VMA */
     if ((opc == OPC_RISC_ECALL) && ((csr >> 5) == 9)) {
-        /* sfence.vma */
-        /* TODO: handle ASID specific fences */
-        gen_helper_tlb_flush(cpu_env);
-        return;
+        if (env->priv_ver == PRIV_VERSION_1_10_0) {
+            /* sfence.vma */
+            /* TODO: handle ASID specific fences */
+            gen_helper_tlb_flush(cpu_env);
+            return;
+        } else {
+            gen_exception_illegal(ctx);
+        }
     }
 #endif
 
@@ -1342,7 +1346,11 @@ static void gen_system(CPURISCVState *env, DisasContext *ctx, uint32_t opc,
             gen_helper_wfi(cpu_env);
             break;
         case 0x104: /* SFENCE.VM */
-            gen_helper_tlb_flush(cpu_env);
+            if (env->priv_ver <= PRIV_VERSION_1_09_1) {
+                gen_helper_tlb_flush(cpu_env);
+            } else {
+                gen_exception_illegal(ctx);
+            }
             break;
 #endif
         default: