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.