Re: [PATCH v9 02/29] x86/boot: Relocate definition of the initial state of CR0

From: Andy Lutomirski
Date: Thu Oct 26 2017 - 03:51:53 EST


On Tue, Oct 3, 2017 at 8:54 PM, Ricardo Neri
<ricardo.neri-calderon@xxxxxxxxxxxxxxx> wrote:
> Both head_32.S and head_64.S utilize the same value to initialize the
> control register CR0. Also, other parts of the kernel might want to access
> this initial definition (e.g., emulation code for User-Mode Instruction
> Prevention uses this state to provide a sane dummy value for CR0 when
> emulating the smsw instruction). Thus, relocate this definition to a
> header file from which it can be conveniently accessed.

Reviewed-by: Andy Lutomirski <luto@xxxxxxxxxx>

with the slight caveat that I think it might be a wee bit better if
UMIP emulation used a separate define UMIP_REPORTED_CR0.