[PATCH v14 15/22] KVM: selftests: Call KVM_TDX_INIT_VCPU when creating a new TDX vcpu

Lisa Wang <[email protected]> Wed, 22 Jul 2026 23:13:20 +0000
Newsgroups dev.linux.lists.linux-coco,org.kernel.vger.kvm,org.kernel.vger.linux-kernel,org.kernel.vger.linux-kselftest
Message-ID <[email protected]>
From: Sagi Shahar <[email protected]>

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 <[email protected]>
Signed-off-by: Lisa Wang <[email protected]>
---
 .../selftests/kvm/include/x86/tdx/tdx_util.h       | 21 ++++++++++++++
 tools/testing/selftests/kvm/lib/x86/processor.c    | 33 ++++++++++++++++------
 2 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
index f5003cbaa106..07e7f5c90329 100644
--- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
+++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
@@ -44,6 +44,27 @@ static inline bool is_tdx_vm(struct kvm_vm *vm)
 	}								\
 })
 
+#define __tdx_vcpu_ioctl(vcpu, cmd, _flags, arg)			\
+({									\
+	union {								\
+		struct kvm_tdx_cmd c;					\
+		unsigned long raw;					\
+	} tdx_cmd = { .c = {						\
+		.id = (cmd),						\
+		.flags = (u32)(_flags),					\
+		.data = (u64)(arg),					\
+	} };								\
+									\
+	__vcpu_ioctl(vcpu, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd.raw);	\
+})
+
+#define tdx_vcpu_ioctl(vcpu, cmd, flags, arg)				\
+({									\
+	int ret = __tdx_vcpu_ioctl(vcpu, cmd, flags, arg);		\
+	TEST_ASSERT(!ret, "%s failed, errno: %d (%s)",			\
+		     #cmd, errno, strerror(errno));			\
+})
+
 void tdx_init_vm(struct kvm_vm *vm, u64 attributes);
 void tdx_vm_setup_boot_code_region(struct kvm_vm *vm);
 void tdx_vm_setup_boot_parameters_region(struct kvm_vm *vm, u32 nr_runnable_vcpus);
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 8f8bb90fec35..f6a2aa6b86a4 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -838,6 +838,17 @@ gva_t kvm_allocate_vcpu_stack(struct kvm_vm *vm)
 	return stack_gva;
 }
 
+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);
+	vcpu_init_cpuid(vcpu, cpuid);
+	free(cpuid);
+	tdx_vcpu_ioctl(vcpu, KVM_TDX_INIT_VCPU, 0, NULL);
+}
+
 struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, u32 vcpu_id)
 {
 	struct kvm_mp_state mp_state;
@@ -845,15 +856,21 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, u32 vcpu_id)
 	struct kvm_regs regs;
 
 	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)) {
+		tdx_vcpu_init(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;

-- 
2.55.0.229.g6434b31f56-goog