Re: [PATCH v7 5/8] KVM: x86/mmu: Don't pass FOLL_GET to __kvm_follow_pfn

[Yu Zhang]

> > @@ -883,7 +884,7 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
> >   */
> >  static int FNAME(sync_spte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int i)
> >  {
> > -	bool host_writable;
> > +	bool host_writable, is_refcounted;
> >  	gpa_t first_pte_gpa;
> >  	u64 *sptep, spte;
> >  	struct kvm_memory_slot *slot;
> > @@ -940,10 +941,12 @@ static int FNAME(sync_spte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int
> >  	sptep = &sp->spt[i];
> >  	spte = *sptep;
> >  	host_writable = spte & shadow_host_writable_mask;
> > +	// TODO: is this correct?
> > +	is_refcounted = spte & SPTE_MMU_PAGE_REFCOUNTED;
> >  	slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
> >  	make_spte(vcpu, sp, slot, pte_access, gfn,
> >  		  spte_to_pfn(spte), spte, true, false,
> > -		  host_writable, &spte);
> > +		  host_writable, is_refcounted, &spte);
> 
> Could we restrict that a non-refcounted page shall not be used as shadow page?

Oh, sorry. It's not about shadow page. It's about guest page being
mapped as not refcounted. Silly me...

B.R.
Yu