[PATCHv10 05/18] x86/kexec: Keep CR4.MCE set during kexec for TDX guest

[Borislav Petkov]

On Mon, Apr 29, 2024 at 06:16:54PM +0300, Kirill A. Shutemov wrote:
> Yes, that's what happens in current upstream.

Let's rewrite that commit message then:

"TDX guests run with MCA enabled (CR4.MCE=1b) from the very start. If
that bit is cleared during CR4 register reprogramming during boot or
kexec flows, a #VE exception will be raised which the guest kernel
cannot handle that early.

Therefore, make sure the CR4.MCE setting is preserved over kexec too and
avoid raising any #VEs."

without that bit about TDX guests might be allowed to clear CR4.MCE
which is only confusing and unnecessary.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette