We'll add a new bare CPU type that won't have any default priv_ver. This
means that the CPU will default to priv_ver = 0, i.e. 1.10.0.

At the same we'll allow these CPUs to enable extensions at will, but
then, if the extension has a priv_ver newer than 1.10, we'll end up
disabling it. Users will then need to manually set priv_ver to something
other than 1.10 to enable the extensions they want, which is not ideal.

Change the setter() of extensions to allow user enabled extensions to
bump the priv_ver of the CPU. This will make it convenient for users to
enable extensions for CPUs that doesn't set a default priv_ver.

This change does not affect any existing CPU: vendor CPUs does not allow
extensions to be enabled, and generic CPUs are already set to priv_ver
LATEST.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
 target/riscv/tcg/tcg-cpu.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c
index 08f8dded56..3751f7711e 100644
--- a/target/riscv/tcg/tcg-cpu.c
+++ b/target/riscv/tcg/tcg-cpu.c
@@ -114,6 +114,26 @@ static int cpu_cfg_ext_get_min_version(uint32_t ext_offset)
     g_assert_not_reached();
 }
 
+static void cpu_validate_multi_ext_priv_ver(CPURISCVState *env,
+                                            uint32_t ext_offset)
+{
+    int ext_priv_ver;
+
+    if (env->priv_ver == PRIV_VERSION_LATEST) {
+        return;
+    }
+
+    ext_priv_ver = cpu_cfg_ext_get_min_version(ext_offset);
+
+    if (env->priv_ver < ext_priv_ver) {
+        /*
+         * Note: the 'priv_spec' command line option, if present,
+         * will take precedence over this priv_ver bump.
+         */
+        env->priv_ver = ext_priv_ver;
+    }
+}
+
 static void cpu_cfg_ext_auto_update(RISCVCPU *cpu, uint32_t ext_offset,
                                     bool value)
 {
@@ -742,6 +762,14 @@ static void cpu_set_misa_ext_cfg(Object *obj, Visitor *v, const char *name,
             return;
         }
 
+        if (misa_bit == RVH && env->priv_ver < PRIV_VERSION_1_12_0) {
+            /*
+             * Note: the 'priv_spec' command line option, if present,
+             * will take precedence over this priv_ver bump.
+             */
+            env->priv_ver = PRIV_VERSION_1_12_0;
+        }
+
         env->misa_ext |= misa_bit;
         env->misa_ext_mask |= misa_bit;
     } else {
@@ -871,6 +899,10 @@ static void cpu_set_multi_ext_cfg(Object *obj, Visitor *v, const char *name,
         return;
     }
 
+    if (value) {
+        cpu_validate_multi_ext_priv_ver(&cpu->env, multi_ext_cfg->offset);
+    }
+
     isa_ext_update_enabled(cpu, multi_ext_cfg->offset, value);
 }
 
-- 
2.41.0