Re: [RFC Patch 0/2] KVM: SVM: Cgroup support for SVM SEV ASIDs

[Sean Christopherson]

On Tue, Nov 24, 2020, Vipin Sharma wrote:
> On Tue, Nov 24, 2020 at 09:27:25PM +0000, Sean Christopherson wrote:
> > Is a root level stat file needed?  Can't the infrastructure do .max - .current
> > on the root cgroup to calculate the number of available ids in the system?
> 
> For an efficient scheduling of workloads in the cloud infrastructure, a
> scheduler needs to know the total capacity supported and the current
> usage of the host to get the overall picture. There are some issues with
> .max -.current approach:
> 
> 1. Cgroup v2 convention is to not put resource control files in the
>    root. This will mean we need to sum (.max -.current) in all of the
>    immediate children of the root.

Ah, that's annoying.  Now that you mention it, I do vaguely recall this behavior.
 
> 2. .max can have any limit unless we add a check to not allow a user to
>    set any value more than the supported one. 

Duh, didn't think that one through.

Thanks!