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

From: Paul Mackerras
Date: Thu Feb 14 2013 - 22:55:00 EST


On Mon, Feb 11, 2013 at 11:12:42PM +1100, aik@xxxxxxxxx wrote:
> From: Alexey Kardashevskiy <aik@xxxxxxxxx>
>
> 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@xxxxxxxxx>
> Cc: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
> ---

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@xxxxxxxxx>

Paul.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/