Re: [Xen-devel] [PATCH v2 01/20] xen: Add Xen specific page definition

[David Vrabel]

On 09/07/15 21:42, Julien Grall wrote:
> The Xen hypercall interface is always using 4K page granularity on ARM
> and x86 architecture.
> 
> With the incoming support of 64K page granularity for ARM64 guest, it
> won't be possible to re-use the Linux page definition in Xen drivers.
> 
> Introduce Xen page definition helpers based on the Linux page
> definition. They have exactly the same name but prefixed with
> XEN_/xen_ prefix.
> 
> Also modify page_to_pfn to use new Xen page definition.
>
> Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
> ---
>     I'm wondering if we should drop page_to_pfn has the macro will likely
>     misuse when Linux is using 64KB page granularity.

I think we want xen_gfn_to_page() and xen_page_to_gfn() and Xen
front/back drivers never deal with PFNs only GFNs.

David

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