Re: [PATCH v2 3/3] x86/boot: Implement early memory acceptance for SEV-SNP

[Kirill A. Shutemov]

On Mon, Apr 07, 2025 at 07:21:17PM +0200, Ard Biesheuvel wrote:
> On Mon, 7 Apr 2025 at 18:44, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> >
> >
> > * Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> wrote:
> >
> > > On Fri, Apr 04, 2025 at 08:07:03AM -0700, Dionna Amalie Glaze wrote:
> > > > If the GHCB is available, we should always prefer it.
> > >
> > > I believe we should consider the cost of code duplication in this
> > > situation.
> > >
> > > If the non-early version is only used in the kexec path, it will not be
> > > tested as frequently and could be more easily broken. I think it would be
> > > acceptable for kexec to be slightly slower if it results in more
> > > maintainable code.
> >
> > Absolutely so.
> >
> 
> It would be nice if someone could quantify 'slightly slower' - I am
> leaning to the same conclusion but I have no clue what the actual
> performance impact is.

If we can survive the performance of the initial boot, we can live with it
for kexec.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov