Re: [PATCH RFC 0/4] 5-level EPT

From: Kirill A. Shutemov
Date: Thu Jan 05 2017 - 08:35:20 EST


On Thu, Dec 29, 2016 at 05:25:59PM +0800, Liang Li wrote:
> x86-64 is currently limited physical address width to 46 bits, which
> can support 64 TiB of memory. Some vendors require to support more for
> some use case. Intel plans to extend the physical address width to
> 52 bits in some of the future products.
>
> The current EPT implementation only supports 4 level page table, which
> can support maximum 48 bits physical address width, so it's needed to
> extend the EPT to 5 level to support 52 bits physical address width.
>
> This patchset has been tested in the SIMICS environment for 5 level
> paging guest, which was patched with Kirill's patchset for enabling
> 5 level page table, with both the EPT and shadow page support. I just
> covered the booting process, the guest can boot successfully.
>
> Some parts of this patchset can be improved. Any comments on the design
> or the patches would be appreciated.

This looks reasonable, assuming my very limited knowledge of the subject.

The first patch is actually in my patchset, split across two patches.

--
Kirill A. Shutemov