Re: [PATCH RFC] target: riscv: Fix satp mode initialization based on profile

[Paolo Bonzini <pbonzini@redhat.com>]

On 5/19/25 14:07, Björn Töpel wrote:
> When realizing the cpus, the first cpu calls riscv_cpu_add_profiles()
> all profiles are disabled, whereas for the other cpu calls to
> riscv_cpu_add_profiles() have some profiles enabled. Having some
> profiles enabled, will issue a call to cpu_set_profile() that will
> enforce the satp code that Alex removes in this patch.
Ah so the problem is that *parent* profiles are not enabled until
riscv_cpu_add_profiles().

With my patches to introduce RISCVCPUDef, it's a pretty easy fix:

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 629ac37501e..04b929af41c 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1083,6 +1083,19 @@ static bool riscv_cpu_is_dynamic(Object *cpu_obj)
      return object_dynamic_cast(cpu_obj, TYPE_RISCV_DYNAMIC_CPU) != NULL;
  }
  
+static void riscv_cpu_enable_profile(RISCVCPU *cpu,
+                                     RISCVCPUProfile *profile)
+{
+    profile->enabled = true;
+
+    if (profile->u_parent) {
+        riscv_cpu_enable_profile(cpu, profile->u_parent);
+    }
+    if (profile->s_parent) {
+        riscv_cpu_enable_profile(cpu, profile->s_parent);
+    }
+}
+
  static void riscv_cpu_init(Object *obj)
  {
      RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(obj);
@@ -1121,7 +1134,7 @@ static void riscv_cpu_init(Object *obj)
      cpu->cfg.max_satp_mode = -1;
  
      if (mcc->def->profile) {
-        mcc->def->profile->enabled = true;
+        riscv_cpu_enable_profile(cpu, mcc->def->profile);
      }
  
      env->misa_ext_mask = env->misa_ext = mcc->def->misa_ext;

Since they're all reviewed and Alistair has flushed his queue, I'll
send them in my next pull request.

On top of them, probably profiles should also be converted to use
RISCVCPUCfg and riscv_cpu_enable_profile() can then enable all the
flags with riscv_cpu_cfg_merge().

In general a lot (if not all) of the profile code should be moved out
of tcg-cpu.c and into riscv_cpu_class_base_init().  I didn't do that
because I didn't want to balloon an already-large series, but it's a
pretty obvious extension of the RISCVCPUDef concept to include all
profile features.

Paolo