Re: [PATCH v15 14/23] KVM: selftests: Expose function to allocate vCPU stack

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] selftests: replace descriptive X86_EFLAGS_FIXED macro with magic number 0x2
--

commit 450df5680580dea1fd0ac5294cee549f78bbf604
Author: Sagi Shahar <sagis@google.com>

KVM: selftests: Expose function to allocate vCPU stack

This commit introduces kvm_allocate_vcpu_stack to handle vCPU stack
allocation separately. This is done in preparation for TDX, where
the vCPU stack address is a property of the specific boot code rather
than being initialized via the KVM_SET_REGS ioctl.

> diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
> index da430d4e7765f..4a753fb43007f 100644
> --- a/tools/testing/selftests/kvm/lib/x86/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86/processor.c

[ ... ]

> @@ -864,8 +883,8 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, u32 vcpu_id)
>  
>  	/* Setup guest general purpose registers */
>  	vcpu_regs_get(vcpu, &regs);
> -	regs.rflags = regs.rflags | X86_EFLAGS_FIXED;
> -	regs.rsp = vm_alloc_stack(vm, DEFAULT_STACK_PGS);
> +	regs.rflags = regs.rflags | 0x2;

[Severity: Low]
This isn't a bug, but was it intentional to replace the descriptive
X86_EFLAGS_FIXED macro with the magic number 0x2 here?

Using the macro helps document that this sets the mandatory fixed bit in
RFLAGS, maintaining code readability during vCPU register initialization.

> +	regs.rsp = kvm_allocate_vcpu_stack(vm);
>  	vcpu_regs_set(vcpu, &regs);
>  
>  	/* Setup the MP state */

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261001-tdx-selftests-v15-0-7c62a5d8a992@google.com?part=14