Re: [PATCH 23/62] x86/idt: Move IDT to data segment

[Joerg Roedel]

On Tue, Feb 11, 2020 at 02:41:25PM -0800, Andy Lutomirski wrote:
> On Tue, Feb 11, 2020 at 5:53 AM Joerg Roedel <joro@xxxxxxxxxx> wrote:
> >
> > From: Joerg Roedel <jroedel@xxxxxxx>
> >
> > With SEV-ES, exception handling is needed very early, even before the
> > kernel has cleared the bss segment. In order to prevent clearing the
> > currently used IDT, move the IDT to the data segment.
> 
> Ugh.  At the very least this needs a comment in the code.

Yes, right, added a comment for that.

> I had a patch to fix the kernel ELF loader to clear BSS, which would
> fix this problem once and for all, but it didn't work due to the messy
> way that the decompressor handles memory.  I never got around to
> fixing this, sadly.

Aren't there other ways of booting (Xen-PV?) which don't use the kernel
ELF loader?

Regards,

	Joerg