On 2024-08-29 13:18:27, Sean Christopherson wrote:
> On Thu, Aug 29, 2024, Vipin Sharma wrote:
> > @@ -871,8 +871,17 @@ void track_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp)
> > return;
> >
> > ++kvm->stat.nx_lpage_splits;
> > - list_add_tail(&sp->possible_nx_huge_page_link,
> > - &kvm->arch.possible_nx_huge_pages);
> > + if (is_tdp_mmu_page(sp)) {
> > +#ifdef CONFIG_X86_64
> > + ++kvm->arch.tdp_mmu_possible_nx_huge_pages_count;
> > + list_add_tail(&sp->possible_nx_huge_page_link,
> > + &kvm->arch.tdp_mmu_possible_nx_huge_pages);
> > +#endif
>
> Pass in the count+list, that way there's no #ifdef and no weird questions for
> what happens if the impossible happens (is_tdp_mmu_page() on 32-bit KVM).
>
> void track_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp,
> u64 *nr_pages, struct list_head *pages)
> {
> /*
> * If it's possible to replace the shadow page with an NX huge page,
> * i.e. if the shadow page is the only thing currently preventing KVM
> * from using a huge page, add the shadow page to the list of "to be
> * zapped for NX recovery" pages. Note, the shadow page can already be
> * on the list if KVM is reusing an existing shadow page, i.e. if KVM
> * links a shadow page at multiple points.
> */
> if (!list_empty(&sp->possible_nx_huge_page_link))
> return;
>
> ++kvm->stat.nx_lpage_splits;
> ++(*nr_pages);
> list_add_tail(&sp->possible_nx_huge_page_link, pages);
> }
>
Sounds good, I was not sure if passing pointers and incrementing count
via pointer will be accepted.
