Re: [PATCH V4 4/4] kvm: add a check if pfn is from NVDIMM pmem.

[Yi Zhang]

On 2018-08-30 at 12:07:11 -0700, Dave Hansen wrote:
> On 08/22/2018 03:58 AM, Zhang Yi wrote:
> >  bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
> >  {
> > -	if (pfn_valid(pfn))
> > -		return PageReserved(pfn_to_page(pfn));
> > +	struct page *page;
> > +
> > +	if (pfn_valid(pfn)) {
> > +		page = pfn_to_page(pfn);
> > +		return PageReserved(page) && !is_dax_page(page);
> > +	}
> 
> This is in desperate need of commenting about what it is doing and why.
> 
> The changelog alone doesn't cut it.
Thanks, Dave, Will add some comments