Re: [PATCH v3 03/11] x86/iommu: convert VT-d code to use new page table allocator

[Jan Beulich <jbeulich@xxxxxxxx>]

On 03.08.2020 14:29, Paul Durrant wrote:
> From: Paul Durrant <pdurrant@xxxxxxxxxx>
> 
> This patch converts the VT-d code to use the new IOMMU page table allocator
> function. This allows all the free-ing code to be removed (since it is now
> handled by the general x86 code) which reduces TLB and cache thrashing as well
> as shortening the code.
> 
> The scope of the mapping_lock in intel_iommu_quarantine_init() has also been
> increased slightly; it should have always covered accesses to
> 'arch.vtd.pgd_maddr'.

I think I disagree here (this is __init code and hence there's no
risk of races), but anyway (as it doesn't hurt) ...

> NOTE: The common IOMMU needs a slight modification to avoid scheduling the
>       cleanup tasklet if the free_page_table() method is not present (since
>       the tasklet will unconditionally call it).
> 
> Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>