[PULL 18/24] i386/tdx: Error and exit when named cpu model is requested

[Paolo Bonzini <pbonzini@redhat.com>]

From: Xiaoyao Li <xiaoyao.li@intel.com>

Currently, it gets below error when requesting any named cpu model with
"-cpu" to boot a TDX VM:

  qemu-system-x86_64: KVM_TDX_INIT_VM failed: Invalid argument

It misleads people to think it's the bug of KVM or QEMU. It is just that
current QEMU doesn't support named cpu model for TDX.

To support named cpu models for TDX guest, there are opens to be
finalized and needs a mount of additional work.

For now, explicitly check the case when named cpu model is requested.
Error report a hint and exit.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20250612133801.2238342-1-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/kvm/tdx.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 820ca3614e2..2b52de9d71b 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -739,8 +739,14 @@ static int tdx_kvm_type(X86ConfidentialGuest *cg)
 
 static void tdx_cpu_instance_init(X86ConfidentialGuest *cg, CPUState *cpu)
 {
+    X86CPUClass *xcc = X86_CPU_GET_CLASS(cpu);
     X86CPU *x86cpu = X86_CPU(cpu);
 
+    if (xcc->model) {
+        error_report("Named cpu model is not supported for TDX yet!");
+        exit(1);
+    }
+
     object_property_set_bool(OBJECT(cpu), "pmu", false, &error_abort);
 
     /* invtsc is fixed1 for TD guest */
-- 
2.49.0