[PATCH v7 4/4] KVM: arm64/mmu: count KVM s2 mmu usage in secondary pagetable stats

[Ryan Roberts]

> Count the pages used by KVM in arm64 for stage2 mmu in memory stats
> under secondary pagetable stats (e.g. "SecPageTables" in /proc/meminfo)
> to give better visibility into the memory consumption of KVM mmu in a
> similar way to how normal user page tables are accounted.
> 
> Signed-off-by: Yosry Ahmed <yosryahmed at google.com>
> Reviewed-by: Oliver Upton <oliver.upton at linux.dev>
> Reviewed-by: Marc Zyngier <maz at kernel.org>
> ---

I see that you are not including the memory reserved for the host stage2 
table when using protected KVM. Is this something worth adding? (See 
arch/arm64/kvm/pkvm.c:kvm_hyp_reserve()).

This reservation is done pretty early on in bootmem_init() so not sure 
if this could cause some init ordering issues that might be tricky to 
solve though.

Thanks,
Ryan