Re: [PATCH v12 11/23] KVM: selftests: Set up TDX boot parameters region

On 10/29/2025 5:20 AM, Sagi Shahar wrote:

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+void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm) +{

• struct td_boot_parameters *params =

• addr_gpa2hva(vm, TD_BOOT_PARAMETERS_GPA);
  

• uint32_t cr4;
• TEST_ASSERT_EQ(vm->mode, VM_MODE_PXXV48_4K);
• cr4 = kvm_get_default_cr4();
• /* TDX spec 11.6.2: CR4 bit MCE is fixed to 1 */
• cr4 |= X86_CR4_MCE;
• /* TDX spec 11.6.2: CR4 bit VMXE and SMXE are fixed to 0 */
• cr4 &= ~(X86_CR4_VMXE | X86_CR4_SMXE);
• /* Set parameters! */
• params->cr0 = kvm_get_default_cr0();
• params->cr3 = vm->pgd;

Since TDX guest code starts from 32-bit, is it better to check that vm->pgd is not beyond 32-bit?

• params->cr4 = cr4;
• params->idtr.base = vm->arch.idt;
• params->idtr.limit = kvm_get_default_idt_limit();
• params->gdtr.base = vm->arch.gdt;
• params->gdtr.limit = kvm_get_default_gdt_limit();
• TEST_ASSERT(params->cr0 != 0, "cr0 should not be 0");
• TEST_ASSERT(params->cr3 != 0, "cr3 should not be 0");
• TEST_ASSERT(params->cr4 != 0, "cr4 should not be 0");
• TEST_ASSERT(params->gdtr.base != 0, "gdt base address should not be 0");
• TEST_ASSERT(params->idtr.base != 0, "idt base address should not be 0");

+}

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