Re: [EXTERNAL] [PATCH 1/9] x86/kexec: Disable global pages before writing to control page

[Dave Hansen]

On 12/17/24 06:56, David Woodhouse wrote:
>> Anyway, I think we can leave the belt-and-suspenders programming in this
>> case. A comment wouldn't hurt I guess.
> I'm a little lost. In this case I don't see belt-and-suspenders
> programming. We're not loading CR3 after clearing CR4.PGE just to be
> paranoid about making really really sure the TLB is flushed.
> 
> We're loading CR3 because we're switching from the kernel's page tables
> to the new identity mapping set up for the relocate_kernel environment.

Yes, agreed, that's another reason the CR3 write must stay. I hadn't
even considered that part yet honestly.