Re: [PATCH v13 6/7] arm: KVM: dirty log read write protect support

Paolo Bonzini <[email protected]> Sat, 08 Nov 2014 07:28:50 +0000
Newsgroups org.kernel.vger.kvm-ia64,org.infradead.lists.linux-arm-kernel,org.kernel.vger.kvm,org.kernel.vger.kvm-ppc
Message-ID <[email protected]>

On 07/11/2014 20:47, Mario Smarduch wrote:
>> That can happen if the error occurred in the final
>> copy to userspace, after page tables have been modified.
>
> Upon error return userspace should terminate logging, error out whether
> used for migration or other use cases, with some stale spte TLBs cached
> read/write, which doesn't appear to be harmful.

Fair enough; for x86 I elected to always do the TLB flush, but you can
do it differently.  Perhaps add a comment with the above paragraph, thouhg.

> But you mention 'final copy' which makes me think I'm missing something?

I meant final copy before leaving the function.

Paolo