diff mbox series

[RFC,v5,03/29] KVM: selftests: Store initial stack address in struct kvm_vcpu

Message ID 20231212204647.2170650-4-sagis@google.com
State New
Headers
Series TDX KVM selftests |

Commit Message

Sagi Shahar Dec. 12, 2023, 8:46 p.m. UTC 
  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.

We 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: Ryan Afranji <afranji@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/include/kvm_util_base.h | 1 +
 tools/testing/selftests/kvm/lib/x86_64/processor.c  | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

Comments

Binbin Wu Feb. 21, 2024, 2:29 a.m. UTC | #1 
On 12/13/2023 4:46 AM, Sagi Shahar wrote:
> 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.
>
> We 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: Ryan Afranji <afranji@google.com>
> Signed-off-by: Sagi Shahar <sagis@google.com>
> ---
>   tools/testing/selftests/kvm/include/kvm_util_base.h | 1 +
>   tools/testing/selftests/kvm/lib/x86_64/processor.c  | 4 +++-
>   2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
> index c2e5c5f25dfc..b353617fcdd1 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util_base.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
> @@ -68,6 +68,7 @@ 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_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> index f130f78a4974..b6b9438e0a33 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> @@ -621,10 +621,12 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
>   	vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid());
>   	vcpu_setup(vm, vcpu);
>   
> +	vcpu->initial_stack_addr = stack_vaddr;
> +
>   	/* Setup guest general purpose registers */
>   	vcpu_regs_get(vcpu, &regs);
>   	regs.rflags = regs.rflags | 0x2;
> -	regs.rsp = stack_vaddr;
> +	regs.rsp = vcpu->initial_stack_addr;

Nit: No need to do this change.

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

>   	regs.rip = (unsigned long) guest_code;
>   	vcpu_regs_set(vcpu, &regs);
>
diff mbox series

Patch

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index c2e5c5f25dfc..b353617fcdd1 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -68,6 +68,7 @@  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_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index f130f78a4974..b6b9438e0a33 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -621,10 +621,12 @@  struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
 	vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid());
 	vcpu_setup(vm, vcpu);
 
+	vcpu->initial_stack_addr = stack_vaddr;
+
 	/* Setup guest general purpose registers */
 	vcpu_regs_get(vcpu, &regs);
 	regs.rflags = regs.rflags | 0x2;
-	regs.rsp = stack_vaddr;
+	regs.rsp = vcpu->initial_stack_addr;
 	regs.rip = (unsigned long) guest_code;
 	vcpu_regs_set(vcpu, &regs);