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

[Dave Hansen]

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.