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

Paul Mackerras
2013-02-15T03:37:40Z

On Mon, Feb 11, 2013 at 11:12:42PM +1100, aik@ozlabs.ru wrote:
> From: Alexey Kardashevskiy <aik@ozlabs.ru>
>
> 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 <aik@ozlabs.ru>
> Cc: David Gibson <david@gibson.dropbear.id.au>
> ---

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 <paulus@samba.org>

Paul.