Re: [PATCH] KVM: nSVM: Gate CET state copy in svm_copy_vmrun_state() on guest SHSTK

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [High] KVM: nSVM: undeclared vcpu in svm_copy_vmrun_state() breaks
  build
--

commit 11b89023661c173dccf1cc07088879a6b4ff0bef
Author: Jim Mattson <jmattson@google.com>

KVM: nSVM: Gate CET state copy in svm_copy_vmrun_state() on guest SHSTK

This commit changes svm_copy_vmrun_state() to check
guest_cpu_cap_has(vcpu, X86_FEATURE_SHSTK) instead of
kvm_cpu_cap_has(X86_FEATURE_SHSTK) before copying CET shadow stack fields.

> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index f9090b601efaa..2a1c279bd54a1 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -1218,7 +1218,7 @@ void svm_copy_vmrun_state(struct vmcb_save_area *to_save,
>  	to_save->rip = from_save->rip;
>  	to_save->cpl = 0;
>  
> -	if (kvm_cpu_cap_has(X86_FEATURE_SHSTK)) {
> +	if (guest_cpu_cap_has(vcpu, X86_FEATURE_SHSTK)) {
>  		to_save->s_cet  = from_save->s_cet;
>  		to_save->isst_addr = from_save->isst_addr;
>  		to_save->ssp = from_save->ssp;

[Severity: High]
Does this fail to build because vcpu is undeclared in
svm_copy_vmrun_state()?  The function only takes to_save and from_save, so
its signature and callers in svm_set_nested_state(), svm_enter_smm(), and
svm_leave_smm() need to pass vcpu as well.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261112212628.265262-1-jmattson@google.com?part=1