Re: [RFC PATCH 04/21] KVM: TDX: Enforce 4KB mapping level during TD build Time

[Kirill A. Shutemov]

On Thu, Apr 24, 2025 at 11:05:00AM +0800, Yan Zhao wrote:
> During the TD build phase (i.e., before the TD becomes RUNNABLE), enforce a
> 4KB mapping level both in the S-EPT managed by the TDX module and the
> mirror page table managed by KVM.
> 
> During this phase, TD's memory is added via tdh_mem_page_add(), which only
> accepts 4KB granularity. Therefore, return PG_LEVEL_4K in TDX's
> .private_max_mapping_level hook to ensure KVM maps at the 4KB level in the
> mirror page table. Meanwhile, iterate over each 4KB page of a large gmem
> backend page in tdx_gmem_post_populate() and invoke tdh_mem_page_add() to
> map at the 4KB level in the S-EPT.
> 
> Still allow huge pages in gmem backend during TD build time. Based on [1],
> which gmem series allows 2MB TPH and non-in-place conversion, pass in

s/TPH/THP/

-- 
  Kiryl Shutsemau / Kirill A. Shutemov