Re: [PATCH v2 3/7] virt: geniezone: Introduce GenieZone hypervisor support

[Yi-De Wu (吳一德)]

On Fri, 2023-04-28 at 15:48 -0700, Trilok Soni wrote:
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> 
> Hi Marc,
> 
> > 
> > [...]
> > 
> > > +/**
> > > + * gzvm_gfn_to_pfn_memslot() - Translate gfn (guest ipa) to pfn
> > > (host
> > > pa),
> > > + *                   result is in @pfn
> > > + *
> > > + * Leverage KVM's gfn_to_pfn_memslot(). Because
> > > gfn_to_pfn_memslot()
> > > needs
> > > + * kvm_memory_slot as parameter, this function populates
> > > necessary
> > > fileds
> > > + * for calling gfn_to_pfn_memslot().
> > > + *
> > > + * Return:
> > > + * * 0            - Succeed
> > > + * * -EFAULT        - Failed to convert
> > > + */
> > > +static int gzvm_gfn_to_pfn_memslot(struct gzvm_memslot *memslot,
> > > u64
> > > gfn, u64 *pfn)
> > > +{
> > > +    hfn_t __pfn;
> > > +    struct kvm_memory_slot kvm_slot = {0};
> > > +
> > > +    kvm_slot.base_gfn = memslot->base_gfn;
> > > +    kvm_slot.npages = memslot->npages;
> > > +    kvm_slot.dirty_bitmap = NULL;
> > > +    kvm_slot.userspace_addr = memslot->userspace_addr;
> > > +    kvm_slot.flags = memslot->flags;
> > > +    kvm_slot.id = memslot->slot_id;
> > > +    kvm_slot.as_id = 0;
> > > +
> > > +    __pfn = gfn_to_pfn_memslot(&kvm_slot, gfn);
> > 
> > Again, I absolutely oppose this horror. This is internal to KVM,
> > and we want to be able to change this without having to mess
> > with your own code that we cannot test anyway.
> > 
> > What if we start using the extra fields that you don't populate
> > as they mean nothing to you? Or add a backpointer to the kvm
> > structure to do fancy accounting?
> > 
> > You have your own hypervisor, that's well and good. Since your
> > main argument is that it is supposed to be standalone, make it
> > *really* standalone and don't use KVM as a prop.
> 
> 
> Agreed, same comments were made earlier too. I would prefer that
> GenieZone have its own identify rather than sharing the
> APIs/data-structures here.
> 
> ---Trilok Soni

Same with previous discussion, we'd like to copy or rename the related 
part from KVM and keep the maintainance at our own if it's ok.