Re: [RFC PATCH 02/12] KVM: x86/mmu: Add dedicated API to map guest_memfd pfn into TDP MMU

[Yan Zhao]

On Thu, Aug 28, 2025 at 08:54:48AM +0800, Edgecombe, Rick P wrote:
> On Wed, 2025-08-27 at 16:25 +0800, Yan Zhao wrote:
> > > +{
> > > +	struct kvm_page_fault fault = {
> > > +		.addr = gfn_to_gpa(gfn),
> > > +		.error_code = PFERR_GUEST_FINAL_MASK |
> > > PFERR_PRIVATE_ACCESS,
> > > +		.prefetch = true,
> > > +		.is_tdp = true,
> > > +		.nx_huge_page_workaround_enabled =
> > > is_nx_huge_page_enabled(vcpu->kvm),
> > > +
> > > +		.max_level = KVM_MAX_HUGEPAGE_LEVEL,
> > Looks the kvm_tdp_mmu_map_private_pfn() is only for initial memory mapping,
> > given that ".prefetch = true" and RET_PF_SPURIOUS is not a valid return value.
> 
> Hmm, what are you referring to regarding RET_PF_SPURIOUS?
If kvm_tdp_mmu_map_private_pfn() can also be invoked after initial memory
mapping stage, RET_PF_SPURIOUS is a valid return case.

But in this patch, only RET_PF_RETRY and RET_PF_FIXED are valid.
So, I think it's expected to be invoked only by initial memory mapping stage :)