Re: [PATCHv11 06/19] x86/kexec: Keep CR4.MCE set during kexec for TDX guest

From: Nikolay Borisov
Date: Wed May 29 2024 - 07:39:48 EST




On 28.05.24 г. 12:55 ч., Kirill A. Shutemov wrote:
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 it.

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

The change doesn't affect non-TDX-guest environments.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

Reviewed-by: Nikolay Borisov <nik.borisov@xxxxxxxx>