Re: [PATCH v14 15/22] KVM: selftests: Call KVM_TDX_INIT_VCPU when creating a new TDX vcpu
Binbin Wu <[email protected]>
| Newsgroups | dev.linux.lists.linux-coco,org.kernel.vger.kvm,org.kernel.vger.linux-kernel,org.kernel.vger.linux-kselftest |
|---|---|
| Message-ID | <[email protected]> |
On 8/14/2026 4:32 PM, Xiaoyao Li wrote:
[...]
>> +static void tdx_vcpu_init(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
>> +{
>> + struct kvm_cpuid2 *cpuid;
>> +
>> + cpuid = allocate_kvm_cpuid2(MAX_NR_CPUID_ENTRIES);
>> + tdx_vcpu_ioctl(vcpu, KVM_TDX_GET_CPUID, 0, cpuid);
>
> If I remember correctly, though KVM_TDX_GET_CPUID is a vcpu ioctl, the data returned by KVM is retrived from TDX module and TDX module only maintains the TD scope CPUID.
KVM_TDX_GET_CPUID does return TD-scoped CPUID metadata only.
> So the CPUID returned here is TD scope, for per-vcpu CPUIDs, e.g., x2apicid, we need to update them accordingly.
>
> This seems not a functional gap. I'm OK to leave it to the future, but please leave a TODO comment for it.
>
The handling for legacy VMs is similar, i.e. kvm_get_supported_cpuid()also has
no per-vcpu CPUID info like APIC ID. It seems that KVM selftests doesn't test
CPUID topology enumeration.
A comment could be helpful, although it may not be a TODO comment.