[PATCH v12 18/23] KVM: selftests: Set entry point for TDX guest code

Sagi Shahar
2025-10-28T21:21:13Z

Since the rip register is inaccessible for TDX VMs, we need a different
way to set the guest entry point for TDX VMs. This is done by writing
the guest code address to a predefined location in the guest memory and
loading it into rip as part of the TDX boot code.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
tools/testing/selftests/kvm/lib/x86/processor.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 036875fe140f..17f5a381fe43 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -691,9 +691,13 @@ void vcpu_arch_set_entry_point(struct kvm_vcpu *vcpu, void *guest_code)
{
struct kvm_regs regs;

- vcpu_regs_get(vcpu, &regs);
- regs.rip = (unsigned long) guest_code;
- vcpu_regs_set(vcpu, &regs);
+ if (is_tdx_vm(vcpu->vm))
+ vm_tdx_set_vcpu_entry_point(vcpu, guest_code);
+ else {
+ vcpu_regs_get(vcpu, &regs);
+ regs.rip = (unsigned long) guest_code;
+ vcpu_regs_set(vcpu, &regs);
+ }
}

vm_vaddr_t kvm_allocate_vcpu_stack(struct kvm_vm *vm)
--
2.51.1.851.g4ebd6896fd-goog