[PATCH v6 03/12] riscv-qmp-cmds.c: expose named features in cpu_model_expansion

[Daniel Henrique Barboza <dbarboza@ventanamicro.com>]

Named features (zic64b the sole example at this moment) aren't expose to
users, thus we need another way to expose them.

Go through each named feature, get its boolean value, do the needed
conversions (bool to qbool, qbool to QObject) and add it to output dict.

Another adjustment is needed: named features are evaluated during
finalize(), so riscv_cpu_finalize_features() needs to be mandatory
regardless of whether we have an input dict or not. Otherwise zic64b
will always return 'false', which is incorrect: the default values of
cache blocksizes (cbom_blocksize and cboz_blocksize) are set to 64,
satisfying the conditions for zic64b.

Here's an API usage example after this patch:

 $ ./build/qemu-system-riscv64 -S -M virt -display none
    -qmp tcp:localhost:1234,server,wait=off

 $ ./scripts/qmp/qmp-shell localhost:1234
Welcome to the QMP low-level shell!
Connected to QEMU 8.1.50

(QEMU) query-cpu-model-expansion type=full model={"name":"rv64"}
{"return": {"model":
    {"name": "rv64", "props": {... "zic64b": true, ...}}}}

zic64b is set to 'true', as expected, since all cache sizes are 64
bytes by default.

If we change one of the cache blocksizes, zic64b is returned as 'false':

(QEMU) query-cpu-model-expansion type=full model={"name":"rv64","props":{"cbom_blocksize":128}}
{"return": {"model":
    {"name": "rv64", "props": {... "zic64b": false, ...}}}}

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/riscv-qmp-cmds.c | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/target/riscv/riscv-qmp-cmds.c b/target/riscv/riscv-qmp-cmds.c
index 2f2dbae7c8..5ada279776 100644
--- a/target/riscv/riscv-qmp-cmds.c
+++ b/target/riscv/riscv-qmp-cmds.c
@@ -26,6 +26,7 @@
 
 #include "qapi/error.h"
 #include "qapi/qapi-commands-machine-target.h"
+#include "qapi/qmp/qbool.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qerror.h"
 #include "qapi/qobject-input-visitor.h"
@@ -99,6 +100,22 @@ static void riscv_obj_add_multiext_props(Object *obj, QDict *qdict_out,
     }
 }
 
+static void riscv_obj_add_named_feats_qdict(Object *obj, QDict *qdict_out)
+{
+    const RISCVCPUMultiExtConfig *named_cfg;
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    QObject *value;
+    bool flag_val;
+
+    for (int i = 0; riscv_cpu_named_features[i].name != NULL; i++) {
+        named_cfg = &riscv_cpu_named_features[i];
+        flag_val = isa_ext_is_enabled(cpu, named_cfg->offset);
+        value = QOBJECT(qbool_from_bool(flag_val));
+
+        qdict_put_obj(qdict_out, named_cfg->name, value);
+    }
+}
+
 static void riscv_cpuobj_validate_qdict_in(Object *obj, QObject *props,
                                            const QDict *qdict_in,
                                            Error **errp)
@@ -129,11 +146,6 @@ static void riscv_cpuobj_validate_qdict_in(Object *obj, QObject *props,
         goto err;
     }
 
-    riscv_cpu_finalize_features(RISCV_CPU(obj), &local_err);
-    if (local_err) {
-        goto err;
-    }
-
     visit_end_struct(visitor, NULL);
 
 err:
@@ -191,6 +203,13 @@ CpuModelExpansionInfo *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
         }
     }
 
+    riscv_cpu_finalize_features(RISCV_CPU(obj), &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        object_unref(obj);
+        return NULL;
+    }
+
     expansion_info = g_new0(CpuModelExpansionInfo, 1);
     expansion_info->model = g_malloc0(sizeof(*expansion_info->model));
     expansion_info->model->name = g_strdup(model->name);
@@ -200,6 +219,7 @@ CpuModelExpansionInfo *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
     riscv_obj_add_multiext_props(obj, qdict_out, riscv_cpu_extensions);
     riscv_obj_add_multiext_props(obj, qdict_out, riscv_cpu_experimental_exts);
     riscv_obj_add_multiext_props(obj, qdict_out, riscv_cpu_vendor_exts);
+    riscv_obj_add_named_feats_qdict(obj, qdict_out);
 
     /* Add our CPU boolean options too */
     riscv_obj_add_qdict_prop(obj, qdict_out, "mmu");
-- 
2.41.0