Re: [PATCH v5] x86: call smp vmxoff in smp stop
From: David Hildenbrand
Date: Thu Apr 20 2017 - 06:01:52 EST
On 19.04.2017 18:18, Paolo Bonzini wrote:
> From: Tiantian Feng <fengtiantian@xxxxxxxxxx>
>
> A CPU in VMX root mode will ignore INIT signals and fail to bring
> up the APs after reboot. Therefore, on a panic we disable VMX on all
> CPUs before rebooting or triggering kdump.
>
> Do this when halting the machine as well, in case a firmware-level reboot
> does not perform a cold reset for all processors. Without doing this,
> rebooting the host may hang.
Guess this make sense, just wonder if something like that is actually
expected to work? Not doing a cold reset feels like leaving a lot of
stuff in an uninitialized state. Shouldn't that specific firmware then
care about performing any necessary resets?
--
Thanks,
David