Re: [PATCH v3 0/2] x86: enforce and cleanup RIP-relative accesses in early boot code

[Kevin Loughlin]

On Wed, Jan 31, 2024 at 10:30 AM Borislav Petkov <bp@xxxxxxxxx> wrote:
>
> On Wed, Jan 31, 2024 at 10:16:55AM -0800, Jacob Xu wrote:
> > We're interested in fixing SEV-SNP guest boots which are currently
> > broken when using a guest kernel compiled with clang. It seems like
> > every other user of SEV/SNP linux kernel code uses GCC to compile the
> > kernel so they've avoided this issue.
>
> Lemme give that a try here.
>
> > E.g. Google COS uses clang to compile the kernel and we've made do
> > with an internal fix for a while.
>
> Which means that, theoretically, you could forward-port this internal
> fix until the issue is fixed for real, I'd say.

True. I just think it would be better to have an upstream fix for
clang builds of SEV-SNP guests; I believe the first such SEV-SNP code
was merged in 5.19 if I'm not mistaken.