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

[Sagi Shahar <sagis@google.com>]

From: Ackerley Tng <ackerleytng@google.com>

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@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 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