[PATCH v6 03/30] KVM: selftests: Store initial stack address in struct kvm_vcpu

From: Sagi Shahar
Date: Mon Apr 14 2025 - 17:49:51 EST


From: Ackerley Tng <ackerleytng@xxxxxxxxxx>

TDX guests' registers cannot be initialized directly using
vcpu_regs_set(), hence the stack pointer needs to be initialized by
the guest itself, running boot code beginning at the reset vector.

Store the stack address as part of struct kvm_vcpu so that it can
be accessible later to be passed to the boot code for rsp
initialization.

Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
Signed-off-by: Sagi Shahar <sagis@xxxxxxxxxx>
---
tools/testing/selftests/kvm/include/kvm_util.h | 1 +
tools/testing/selftests/kvm/lib/x86/processor.c | 2 ++
2 files changed, 3 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 1bc0b44e78de..74ecfd8d7ae0 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -58,6 +58,7 @@ struct kvm_vcpu {
int fd;
struct kvm_vm *vm;
struct kvm_run *run;
+ vm_vaddr_t initial_stack_addr;
#ifdef __x86_64__
struct kvm_cpuid2 *cpuid;
#endif
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 1d6ae28aa398..7c0fe3b138a1 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -695,6 +695,8 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
vcpu_init_sregs(vm, vcpu);
vcpu_init_xcrs(vm, vcpu);

+ vcpu->initial_stack_addr = stack_vaddr;
+
/* Setup guest general purpose registers */
vcpu_regs_get(vcpu, &regs);
regs.rflags = regs.rflags | 0x2;
--
2.49.0.504.g3bcea36a83-goog