Re: [RFC 07/19] KVM: x86/mmu: Factor wrprot for nested PML out of make_spte

[Sean Christopherson]

On Wed, Nov 10, 2021, Ben Gardon wrote:
> When running a nested VM, KVM write protects SPTEs in the EPT/NPT02
> instead of using PML for dirty tracking. This avoids expensive
> translation later, when emptying the Page Modification Log. In service
> of removing the vCPU pointer from make_spte, factor the check for nested
> PML out of the function.

Aha!  The dependency on @vcpu can be avoided without having to take a flag from
the caller.  The shadow page has everything we need.  The check is really "is this
a page for L2 EPT".  The kvm_x86_ops.cpu_dirty_log_size gets us the EPT part, and
kvm_mmu_page.guest_mode gets us the L2 part.

Compile tested only...