target/riscv/cpu.c: split kvm prop handling to its own helper

Future patches will split the existing Property arrays even further, and
the existing code in riscv_cpu_add_user_properties() will start to scale
bad with it because it's dealing with KVM constraints mixed in with TCG
constraints. We're going to pay a high price to share a couple of common
lines of code between the two.

Create a new kvm_riscv_cpu_add_kvm_properties() helper that will be
forked from riscv_cpu_add_user_properties() if we're running KVM. The
helper includes all properties that a KVM CPU will add. The rest of
riscv_cpu_add_user_properties() body will then be relieved from having
to deal with KVM constraints.

The helper was declared in kvm_stubs.h, while being implemented in
cpu.c, to allow '--enable-debug' builds to work. The compiler won't
remove the kvm_riscv_cpu_add_kvm_properties() reference when
'kvm_enabled()' is false if we end up with an unused function. Even
though being a KVM only helper we can't implement it in kvm.c due to its
many dependencies inside cpu.c, so make it public in kvm_riscv.h and
keep its implementation in cpu.c for now. We'll move it to kvm.c in the
near future.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20230912132423.268494-4-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu.c

@@ -1920,7 +1920,7 @@ static Property riscv_cpu_options[] = {
     DEFINE_PROP_UINT16("cboz_blocksize", RISCVCPU, cfg.cboz_blocksize, 64),
 };
 
-#ifndef CONFIG_USER_ONLY
+#ifdef CONFIG_KVM
 static void cpu_set_cfg_unavailable(Object *obj, Visitor *v,
                                     const char *name,
                                     void *opaque, Error **errp)
@@ -1937,6 +1937,44 @@ static void cpu_set_cfg_unavailable(Object *obj, Visitor *v,
                    propname);
     }
 }
+
+static void riscv_cpu_add_kvm_unavail_prop(Object *obj, const char *prop_name)
+{
+    /* Check if KVM created the property already */
+    if (object_property_find(obj, prop_name)) {
+        return;
+    }
+
+    /*
+     * Set the default to disabled for every extension
+     * unknown to KVM and error out if the user attempts
+     * to enable any of them.
+     */
+    object_property_add(obj, prop_name, "bool",
+                        NULL, cpu_set_cfg_unavailable,
+                        NULL, (void *)prop_name);
+}
+
+void kvm_riscv_cpu_add_kvm_properties(Object *obj)
+{
+    Property *prop;
+    DeviceState *dev = DEVICE(obj);
+
+    kvm_riscv_init_user_properties(obj);
+    riscv_cpu_add_misa_properties(obj);
+
+    for (prop = riscv_cpu_extensions; prop && prop->name; prop++) {
+        riscv_cpu_add_kvm_unavail_prop(obj, prop->name);
+    }
+
+    for (int i = 0; i < ARRAY_SIZE(riscv_cpu_options); i++) {
+        /* Check if KVM created the property already */
+        if (object_property_find(obj, riscv_cpu_options[i].name)) {
+            continue;
+        }
+        qdev_property_add_static(dev, &riscv_cpu_options[i]);
+    }
+}
 #endif
 
 /*
@@ -1954,39 +1992,18 @@ static void riscv_cpu_add_user_properties(Object *obj)
     riscv_add_satp_mode_properties(obj);
 
     if (kvm_enabled()) {
-        kvm_riscv_init_user_properties(obj);
+        kvm_riscv_cpu_add_kvm_properties(obj);
+        return;
     }
 #endif
 
     riscv_cpu_add_misa_properties(obj);
 
     for (prop = riscv_cpu_extensions; prop && prop->name; prop++) {
-#ifndef CONFIG_USER_ONLY
-        if (kvm_enabled()) {
-            /* Check if KVM created the property already */
-            if (object_property_find(obj, prop->name)) {
-                continue;
-            }
-
-            /*
-             * Set the default to disabled for every extension
-             * unknown to KVM and error out if the user attempts
-             * to enable any of them.
-             */
-            object_property_add(obj, prop->name, "bool",
-                                NULL, cpu_set_cfg_unavailable,
-                                NULL, (void *)prop->name);
-            continue;
-        }
-#endif
         qdev_property_add_static(dev, prop);
     }
 
     for (int i = 0; i < ARRAY_SIZE(riscv_cpu_options); i++) {
-        /* Check if KVM created the property already */
-        if (object_property_find(obj, riscv_cpu_options[i].name)) {
-            continue;
-        }
         qdev_property_add_static(dev, &riscv_cpu_options[i]);
     }
 }

target/riscv/kvm_riscv.h

@@ -19,6 +19,9 @@
 #ifndef QEMU_KVM_RISCV_H
 #define QEMU_KVM_RISCV_H
 
+/* Temporarily implemented in cpu.c */
+void kvm_riscv_cpu_add_kvm_properties(Object *obj);
+
 void kvm_riscv_init_user_properties(Object *cpu_obj);
 void kvm_riscv_reset_vcpu(RISCVCPU *cpu);
 void kvm_riscv_set_irq(RISCVCPU *cpu, int irq, int level);