Re: [RFC 14/33] KVM: x86: Add VTL to the MMU role

[Sean Christopherson]

On Wed, Nov 08, 2023, Nicolas Saenz Julienne wrote:
> With the upcoming introduction of per-VTL memory protections, make MMU
> roles VTL aware. This will avoid sharing PTEs between vCPUs that belong
> to different VTLs, and that have distinct memory access restrictions.
> 
> Four bits are allocated to store the VTL number in the MMU role, since
> the TLFS states there is a maximum of 16 levels.

How many does KVM actually allow/support?  Multiplying the number of possible
roots by 16x is a *major* change.