Re: [RFC,05/10] x86/speculation: Add basic IBRS support infrastructure

From: Eduardo Habkost
Date: Mon Jan 29 2018 - 20:13:05 EST


On Mon, Jan 29, 2018 at 05:10:11PM -0500, Konrad Rzeszutek Wilk wrote:
[...]
> The migration code could be 'tickled' (when arrived at the destination)
> to recheck the CPUID and do the alternative logic to turn the
> proper bits on.
>
> And this tickling could be as simple as an ACPI DSDT/AML code
> specific to KVM PnP devices (say the CPUs?) to tell the guest to
> resample its environment?

This would be nice to have for other CPU features, but if I
understood a previous message from Andi on this thread correctly,
it wouldn't be useful for the Spectre mitigations.

--
Eduardo