From: Daniel Henrique Barboza <dbarboza@ventanamicro.com>

Our current logic in get/setters of MISA and multi-letter extensions
works because we have only 2 CPU types, generic and vendor, and by using
"!generic" we're implying that we're talking about vendor CPUs. When adding
a third CPU type this logic will break so let's handle it beforehand.

In set_misa_ext_cfg() and set_multi_ext_cfg(), check for "vendor" cpu instead
of "not generic". The "generic CPU" checks remaining are from
riscv_cpu_add_misa_properties() and cpu_add_multi_ext_prop() before
applying default values for the extensions.

This leaves us with:

- vendor CPUs will not allow extension enablement, all other CPUs will;

- generic CPUs will inherit default values for extensions, all others
  won't.

And now we can add a new, third CPU type, that will allow extensions to
be enabled and will not inherit defaults, without changing the existing
logic.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20231218125334.37184-3-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/tcg/tcg-cpu.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c
index 29b5a88931..7174abb7f5 100644
--- a/target/riscv/tcg/tcg-cpu.c
+++ b/target/riscv/tcg/tcg-cpu.c
@@ -668,6 +668,11 @@ static bool riscv_cpu_is_generic(Object *cpu_obj)
     return object_dynamic_cast(cpu_obj, TYPE_RISCV_DYNAMIC_CPU) != NULL;
 }
 
+static bool riscv_cpu_is_vendor(Object *cpu_obj)
+{
+    return object_dynamic_cast(cpu_obj, TYPE_RISCV_VENDOR_CPU) != NULL;
+}
+
 /*
  * We'll get here via the following path:
  *
@@ -736,7 +741,7 @@ static void cpu_set_misa_ext_cfg(Object *obj, Visitor *v, const char *name,
     target_ulong misa_bit = misa_ext_cfg->misa_bit;
     RISCVCPU *cpu = RISCV_CPU(obj);
     CPURISCVState *env = &cpu->env;
-    bool generic_cpu = riscv_cpu_is_generic(obj);
+    bool vendor_cpu = riscv_cpu_is_vendor(obj);
     bool prev_val, value;
 
     if (!visit_type_bool(v, name, &value, errp)) {
@@ -750,7 +755,7 @@ static void cpu_set_misa_ext_cfg(Object *obj, Visitor *v, const char *name,
     }
 
     if (value) {
-        if (!generic_cpu) {
+        if (vendor_cpu) {
             g_autofree char *cpuname = riscv_cpu_get_name(cpu);
             error_setg(errp, "'%s' CPU does not allow enabling extensions",
                        cpuname);
@@ -855,7 +860,7 @@ static void cpu_set_multi_ext_cfg(Object *obj, Visitor *v, const char *name,
 {
     const RISCVCPUMultiExtConfig *multi_ext_cfg = opaque;
     RISCVCPU *cpu = RISCV_CPU(obj);
-    bool generic_cpu = riscv_cpu_is_generic(obj);
+    bool vendor_cpu = riscv_cpu_is_vendor(obj);
     bool prev_val, value;
 
     if (!visit_type_bool(v, name, &value, errp)) {
@@ -879,7 +884,7 @@ static void cpu_set_multi_ext_cfg(Object *obj, Visitor *v, const char *name,
         return;
     }
 
-    if (value && !generic_cpu) {
+    if (value && vendor_cpu) {
         g_autofree char *cpuname = riscv_cpu_get_name(cpu);
         error_setg(errp, "'%s' CPU does not allow enabling extensions",
                    cpuname);
-- 
2.43.0