Re: Meltdown workaround enabled?

On Tue, Mar 13, 2018 at 10:39 PM, Theo de Raadt <deraadt@openbsd.org> wrote:
>> According to some sources, Intel and a handful of others have known about the
>> issue since February 2017(!), so perhaps it has already been patched in the
>> 08Jan2018 BIOS. I too have doubts that to date any processor has been
>> redesigned to avoid the flaws entirely, but then again...
>
> Sure. A BIOS can change the flag bits.
>
> Be nice to know. Did a BIOS change them?

I downgraded the bios to try and figure this out. Going back just one
revision (1/8/2018 to 12/18/2017) causes it to lose the flag and
-current's MELTDOWN workaround to activate.

Previous BIOS revision (12/18/2017):
bcamp@nuc6cayh:~ (OpenBSD 6.3)
$ cpuid 0x7
eax = 0x00000000 0 "????"
ebx = 0x2294e283 580182659 "???""
ecx = 0x00000000 0 "????"
edx = 0x00000000 0 "????"

Newest BIOS revision (1/8/2018):
bcamp@nuc6cayh:~ (OpenBSD 6.3)
$ cpuid 0x7
eax = 0x00000000 0 "????"
ebx = 0x2294e283 580182659 "???""
ecx = 0x00000000 0 "????"
edx = 0x2c000000 738197504 "???,"