On Wed, Aug 20, 2025 at 4:18 PM Sagi Shahar <sagis@google.com> wrote:
>
> On Wed, Aug 13, 2025 at 8:34 AM Chenyi Qiang <chenyi.qiang@intel.com> wrote:
> >
> >
> >
> > On 8/8/2025 4:16 AM, Sagi Shahar wrote:
> > > From: Ackerley Tng <ackerleytng@google.com>
> > >
> > > This also exercises the KVM_TDX_CAPABILITIES ioctl.
> > >
> > > Suggested-by: Isaku Yamahata <isaku.yamahata@intel.com>
> > > Co-developed-by: Isaku Yamahata <isaku.yamahata@intel.com>
> > > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> > > Signed-off-by: Ackerley Tng <ackerleytng@google.com>
> > > Signed-off-by: Sagi Shahar <sagis@google.com>
> > > ---
> > > .../selftests/kvm/lib/x86/tdx/tdx_util.c | 17 +++++++++++++++++
> > > 1 file changed, 17 insertions(+)
> > >
> > > diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> > > index 392d6272d17e..bb074af4a476 100644
> > > --- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> > > +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> > > @@ -140,6 +140,21 @@ static void tdx_apply_cpuid_restrictions(struct kvm_cpuid2 *cpuid_data)
> > > }
> > > }
> > >
> > > +static void tdx_check_attributes(struct kvm_vm *vm, uint64_t attributes)
> > > +{
> > > + struct kvm_tdx_capabilities *tdx_cap;
> > > +
> > > + tdx_cap = tdx_read_capabilities(vm);
> > > +
> > > + /* TDX spec: any bits 0 in supported_attrs must be 0 in attributes */
> > > + TEST_ASSERT_EQ(attributes & ~tdx_cap->supported_attrs, 0);
> > > +
> > > + /* TDX spec: any bits 1 in attributes must be 1 in supported_attrs */
> > > + TEST_ASSERT_EQ(attributes & tdx_cap->supported_attrs, attributes);
> > > +
> > > + free(tdx_cap);
> > > +}
> > > +
> > > #define KVM_MAX_CPUID_ENTRIES 256
> > >
> > > #define CPUID_EXT_VMX BIT(5)
> > > @@ -256,6 +271,8 @@ static void tdx_td_init(struct kvm_vm *vm, uint64_t attributes)
> > > memcpy(&init_vm->cpuid, cpuid, kvm_cpuid2_size(cpuid->nent));
> > > free(cpuid);
> > >
> > > + tdx_check_attributes(vm, attributes);
> > > +
> > > init_vm->attributes = attributes;
> > >
> > > tdx_apply_cpuid_restrictions(&init_vm->cpuid);
> >
> > Do we need to set the init_vm->xfam based on cpuid.0xd and validate it with tdx_cap->supported_xfam?
> >
> I don't think it's necessary. And according to the TDX spec (TDX
> Module Base Spec - 11.8.3. Extended Features Execution Control) the
> mapping from CPUID to XFAM is not trivial. Checking attributes makes
> sense since some tests use non-default attributes but right now we
> don't have any test which uses XFAM features. We can add XFAM support
> in the future if it's needed and do the check then.
I just saw the comment on "KVM: selftests: TDX: Add basic TDX CPUID
test" which suggests adding xfam support. I can add a check for xfam
when I rework that patch but I still think that the values for xfam
should come from the test and validated here instead of being
calculated based on cpuid.