[PATCH v11 16/21] KVM: selftests: Call KVM_TDX_INIT_VCPU when creating a new TDX vcpu

Sagi Shahar
2025-09-25T17:29:25Z

TDX VMs need to issue the KVM_TDX_INIT_VCPU ioctl for each vcpu after
vcpu creation.

Since the cpuids for TD are managed by the TDX module, read the values
virtualized for the TD using KVM_TDX_GET_CPUID and set them in kvm using
KVM_SET_CPUID2 so that kvm has an accurate view of the VM cpuid values.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
.../testing/selftests/kvm/lib/x86/processor.c | 35 ++++++++++++++-----
1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 63b751253d1b..f7ddea3b2044 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -687,6 +687,19 @@ vm_vaddr_t kvm_allocate_vcpu_stack(struct kvm_vm *vm)
return stack_vaddr;
}

+static void vm_tdx_vcpu_add(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpuid2 *cpuid;
+
+ cpuid = allocate_kvm_cpuid2(MAX_NR_CPUID_ENTRIES);
+ vm_tdx_vcpu_ioctl(vcpu, KVM_TDX_GET_CPUID, 0, cpuid);
+ vcpu_init_cpuid(vcpu, cpuid);
+ free(cpuid);
+ vm_tdx_vcpu_ioctl(vcpu, KVM_TDX_INIT_VCPU, 0, NULL);
+
+ vm_tdx_load_vcpu_boot_parameters(vm, vcpu);
+}
+
struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
{
struct kvm_mp_state mp_state;
@@ -694,15 +707,21 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
struct kvm_vcpu *vcpu;

vcpu = __vm_vcpu_add(vm, vcpu_id);
- vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid());
- vcpu_init_sregs(vm, vcpu);
- vcpu_init_xcrs(vm, vcpu);

- /* Setup guest general purpose registers */
- vcpu_regs_get(vcpu, &regs);
- regs.rflags = regs.rflags | 0x2;
- regs.rsp = kvm_allocate_vcpu_stack(vm);
- vcpu_regs_set(vcpu, &regs);
+ if (is_tdx_vm(vm)) {
+ vm_tdx_vcpu_add(vm, vcpu);
+ } else {
+ vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid());
+
+ vcpu_init_sregs(vm, vcpu);
+ vcpu_init_xcrs(vm, vcpu);
+
+ /* Setup guest general purpose registers */
+ vcpu_regs_get(vcpu, &regs);
+ regs.rflags = regs.rflags | 0x2;
+ regs.rsp = kvm_allocate_vcpu_stack(vm);
+ vcpu_regs_set(vcpu, &regs);
+ }

/* Setup the MP state */
mp_state.mp_state = 0;
--
2.51.0.536.g15c5d4f767-goog