Subject: Re: [PATCH 3/4] powerpc: preparing to support real mode optimization

From: Paul Mackerras <[email-masked]>
Date: Fri, 15 Feb 2013 14:37:40 +1100

On Mon, Feb 11, 2013 at 11:12:42PM +1100, [email-masked] wrote:
> From: Alexey Kardashevskiy <[email-masked]>
> 
> he current VFIO-on-POWER implementation supports only user mode
> driven mapping, i.e. QEMU is sending requests to map/unmap pages.
> However this approach is really slow in really fast hardware so
> it is better to be moved to the real mode.
> 
> The patch adds an API to increment/decrement page counter as
> get_user_pages API used for user mode mapping does not work
> in the real mode.
> 
> CONFIG_SPARSEMEM_VMEMMAP and CONFIG_FLATMEN are supported.
> 
> Signed-off-by: Alexey Kardashevskiy <[email-masked]>
> Cc: David Gibson <[email-masked]>
> ---

The names are slightly odd, in that they include "vmemmap_" but exist
and work in the flatmem case as well.  Apart from that...

Reviewed-by: Paul Mackerras <[email-masked]>

Paul.