Re: [RFC PATCH 0/11] KVM: PPC: Update Book3S HV memory handling

Paul Mackerras
2011-11-18T21:54:24Z

On Fri, Nov 18, 2011 at 02:57:11PM +0100, Alexander Graf wrote:
>
> This touches areas that I'm sure non-PPC people would want to see as
> well. Could you please CC kvm@vger too next time?
>
> Avi, Marcelo, mind to review some of the bits in this patch set? :)

I did cc the last patch (the one that adds barriers in the MMU
notifier sequence/count logic) to kvm@vger. Do you mean I should cc
the whole series? The only other thing touching generic code is the
addition of the KVM_MEMSLOT_IO flag in the first patch.

I'm hoping the extra barriers will be OK since they are no-ops on
x86. In fact I now think that the smp_wmbs I added to
kvm_mmu_notifier_invalidate_page and kvm_mmu_notifier_change_pte
aren't in fact necessary, since it's only necessary to ensure that the
sequence number increase is visible before the point where
kvm_unmap_hva or kvm_set_spte_hva unlock the bitlock on the first rmap
chain they look at, which will be ensured anyway by the barrier before
the unlock.

Paul.