Re: [PATCH v16 10/22] KVM: guest_memfd: Add plumbing to host to map guest_memfd pages

[Sean Christopherson <seanjc@google.com>]

On Wed, Jul 23, 2025, Xiaoyao Li wrote:
> On 7/23/2025 6:47 PM, Fuad Tabba wrote:
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index a1c49bc681c4..e5cd54ba1eaa 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -13518,6 +13518,16 @@ bool kvm_arch_no_poll(struct kvm_vcpu *vcpu)
> >   }
> >   EXPORT_SYMBOL_GPL(kvm_arch_no_poll);
> > +#ifdef CONFIG_KVM_GUEST_MEMFD
> > +/*
> > + * KVM doesn't yet support mmap() on guest_memfd for VMs with private memory
> > + * (the private vs. shared tracking needs to be moved into guest_memfd).
> > + */
> > +bool kvm_arch_supports_gmem_mmap(struct kvm *kvm)
> > +{
> > +	return !kvm_arch_has_private_mem(kvm);
> > +}
> > +
> 
> I think it's better to move the kvm_arch_supports_gmem_mmap() stuff to patch
> 20. Because we don't know how kvm_arch_supports_gmem_mmap() is going to be
> used unitll that patch.

No strong preference on my end.