target/riscv/cpu.c: add riscv_cpu_validate_v()

The RVV verification will error out if fails and it's being done at the
end of riscv_cpu_validate_set_extensions(), after we've already set some
extensions that are dependent on RVV.  Let's put it in its own function
and do it earlier.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230517135714.211809-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu.c

@@ -834,13 +834,54 @@ static void riscv_cpu_disas_set_info(CPUState *s, disassemble_info *info)
     }
 }
 
+static void riscv_cpu_validate_v(CPURISCVState *env, RISCVCPUConfig *cfg,
+                                 Error **errp)
+{
+    int vext_version = VEXT_VERSION_1_00_0;
+
+    if (!is_power_of_2(cfg->vlen)) {
+        error_setg(errp, "Vector extension VLEN must be power of 2");
+        return;
+    }
+    if (cfg->vlen > RV_VLEN_MAX || cfg->vlen < 128) {
+        error_setg(errp,
+                   "Vector extension implementation only supports VLEN "
+                   "in the range [128, %d]", RV_VLEN_MAX);
+        return;
+    }
+    if (!is_power_of_2(cfg->elen)) {
+        error_setg(errp, "Vector extension ELEN must be power of 2");
+        return;
+    }
+    if (cfg->elen > 64 || cfg->elen < 8) {
+        error_setg(errp,
+                   "Vector extension implementation only supports ELEN "
+                   "in the range [8, 64]");
+        return;
+    }
+    if (cfg->vext_spec) {
+        if (!g_strcmp0(cfg->vext_spec, "v1.0")) {
+            vext_version = VEXT_VERSION_1_00_0;
+        } else {
+            error_setg(errp, "Unsupported vector spec version '%s'",
+                       cfg->vext_spec);
+            return;
+        }
+    } else {
+        qemu_log("vector version is not specified, "
+                 "use the default value v1.0\n");
+    }
+    set_vext_version(env, vext_version);
+}
+
 /*
  * Check consistency between chosen extensions while setting
  * cpu->cfg accordingly.
  */
 static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
 {
     CPURISCVState *env = &cpu->env;
+    Error *local_err = NULL;
 
     /* Do some ISA extension error checking */
     if (riscv_has_ext(env, RVG) &&
@@ -909,8 +950,14 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         return;
     }
 
-    /* The V vector extension depends on the Zve64d extension */
     if (riscv_has_ext(env, RVV)) {
+        riscv_cpu_validate_v(env, &cpu->cfg, &local_err);
+        if (local_err != NULL) {
+            error_propagate(errp, local_err);
+            return;
+        }
+
+        /* The V vector extension depends on the Zve64d extension */
         cpu->cfg.ext_zve64d = true;
     }
 
@@ -1045,46 +1092,6 @@ static void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         cpu->cfg.ext_zksed = true;
         cpu->cfg.ext_zksh = true;
     }
-
-    if (riscv_has_ext(env, RVV)) {
-        int vext_version = VEXT_VERSION_1_00_0;
-        if (!is_power_of_2(cpu->cfg.vlen)) {
-            error_setg(errp,
-                       "Vector extension VLEN must be power of 2");
-            return;
-        }
-        if (cpu->cfg.vlen > RV_VLEN_MAX || cpu->cfg.vlen < 128) {
-            error_setg(errp,
-                       "Vector extension implementation only supports VLEN "
-                       "in the range [128, %d]", RV_VLEN_MAX);
-            return;
-        }
-        if (!is_power_of_2(cpu->cfg.elen)) {
-            error_setg(errp,
-                       "Vector extension ELEN must be power of 2");
-            return;
-        }
-        if (cpu->cfg.elen > 64 || cpu->cfg.elen < 8) {
-            error_setg(errp,
-                       "Vector extension implementation only supports ELEN "
-                       "in the range [8, 64]");
-            return;
-        }
-        if (cpu->cfg.vext_spec) {
-            if (!g_strcmp0(cpu->cfg.vext_spec, "v1.0")) {
-                vext_version = VEXT_VERSION_1_00_0;
-            } else {
-                error_setg(errp,
-                           "Unsupported vector spec version '%s'",
-                           cpu->cfg.vext_spec);
-                return;
-            }
-        } else {
-            qemu_log("vector version is not specified, "
-                     "use the default value v1.0\n");
-        }
-        set_vext_version(env, vext_version);
-    }
 }
 
 #ifndef CONFIG_USER_ONLY