Re: [Qemu-devel] [PATCH v1 0/2] intel-iommu: Extend address width to 48 bits

[Peter Xu <peterx@redhat.com>]

On Tue, Nov 14, 2017 at 06:13:48PM -0500, prasad.singamsetty@oracle.com wrote:
> From: Prasad Singamsetty <prasad.singamsetty@oracle.com>
> 
> This pair of patches extends the intel-iommu to support address
> width to 48 bits. This is required to support qemu guest with large
> memory (>=1TB). 
> 
> Patch1 implements changes to redefine macros and usage to
> allow further changes to add support for 48 bit address width.
> This patch doesn't change the existing functionality or behavior.
> 
> Patch2 adds support for 48 bit address width but keeping the
> default to 39 bits.
> 
> NOTE: Peter Xu had originaly started on this enhancement
> but it was not completed or integrated.
> 
> Unit testing done:
> 
> patch-1:
>    * Boot vm with and without intel-iommu enabled
>    * Boot vm with #cpus below and above 255 cpus
> patch-2:
>    * boot vm without "x-aw-bits" or "x-aw-bits=39": guest boots with 39
>    * boot vm with "x-aw-bits=48": guest boots with 48 bits
>    * boot vm with invalid value for x-aw-bits: guest fails to boot
>    * boot vm with >=1TB memory and "x-aw-bits=48": guest boots
> 
> Prasad Singamsetty (2):
>   intel-iommu: Redefine macros to enable supporting 48 bit address width
>   intel-iommu: Extend address width to 48 bits

Looks quite good to me!

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu