Re: [PATCH v9 3/8] KVM: arm/arm64: Introduce helpers to manipulate page table entries

[Suzuki K Poulose]

Hi Anshuman,

On 03/12/2018 13:50, Anshuman Khandual wrote:
> On 10/31/2018 11:27 PM, Punit Agrawal wrote:
> > Introduce helpers to abstract architectural handling of the conversion
> > of pfn to page table entries and marking a PMD page table entry as a
> > block entry.
>
> Why is this necessary ? we would still need to access PMD, PUD as is
> without any conversion. IOW KVM knows the breakdown of the page table
> at various levels. Is this something required from generic KVM code ?

The KVM MMU code is shared for arm32 and arm64. Hence we need arch specific
helpers to hide how we deal with the levels. e.g, PUD never exists for
arm32.

>    
> > The helpers are introduced in preparation for supporting PUD hugepages
> > at stage 2 - which are supported on arm64 but do not exist on arm.
>
> Some of these patches (including the earlier two) are good on it's
> own. Do we have still mention in commit message about the incoming PUD
> enablement as the reason for these cleanup patches ?

Cheers
Suzuki