Re: [PATCH v3 1/5] x86/boot/compressed/64: Introduce sev_status

[Arvind Sankar]

On Wed, Oct 28, 2020 at 09:23:52AM +0100, Joerg Roedel wrote:
> On Mon, Oct 26, 2020 at 07:27:06PM +0100, Borislav Petkov wrote:
> > A couple of lines above you call get_sev_encryption_bit() which already
> > reads MSR_AMD64_SEV. Why not set sev_status there too instead of reading
> > that MSR again here?
> > 
> > It can read that MSR once and use sev_status(%rip) from then on to avoid
> > reading that MSR multiple times...
> 
> Right, makes sense. I updated the patch.

Hang on, get_sev_encryption_bit() is also called from startup_32(),
so it can't contain any 64-bit instructions to set sev_status.