Re: [PATCH 3/3] KVM: VMX: Extend VMX's #AC interceptor to handle split lock #AC in guest

From: Jim Mattson
Date: Thu Apr 02 2020 - 19:18:17 EST


On Thu, Apr 2, 2020 at 4:16 PM Kenneth R. Crudup <kenny@xxxxxxxxx> wrote:
>
>
> On Thu, 2 Apr 2020, Steven Rostedt wrote:
>
> > If we go the approach of not letting VM modules load if it doesn't have the
> > sld_safe flag set, how is this different than a VM module not loading due
> > to kabi breakage?
>
> Why not a compromise: if such a module is attempted to be loaded, print up
> a message saying something akin to "turn the parameter 'split_lock_detect'
> off" as we reject loading it- and if we see that we've booted with it off
> just splat a WARN_ON() if someone tries to load such modules?

What modules are we talking about? I thought we were discussing L1
hypervisors, which are just binary blobs. The only modules at the L0
level are kvm and kvm_intel.