Re: [PATCH 1/2] x86/virt/tdx: Use PFN directly for mapping guest private memory

Edgecombe, Rick P
2026-04-02T23:54:04Z

On Thu, 2026-04-02 at 16:46 -0700, Sean Christopherson wrote:
> > Can you remind me, with the new API we were going to do an in-place add
> > right?
> > Then I'd wonder if we could maybe change tdh_mem_page_add() to only have a
> > single pfn arg.
>
> No.  In-place ADD will be supported, but it won't be mandatory.  Practically
> speaking, we can't make it mandatory unless we're willing to completely rip
> out support for per-VM attributes (or at least, per-VM PRIVATE tracking).  I
> suppose we could require in-place ADD when using per-gmem attributes, but I
> don't see the point given that TDH_MEM_PAGE_ADD itself takes a source and
> dest.

Thanks. It might still be cleaner to copy clear text from the GUPed page to the
destination page and let the tdh_mem_page_add() call in the map path do it in-
place? Especially if we want to support in-place add as an option, it would make
the code more uniform.

But it sounds like we don't need to decide now.