Re: [PATCH A] KVM: Simplify kvm->tlbs_dirty handling

[Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>]

(2014/02/18 18:43), Xiao Guangrong wrote:
> On 02/18/2014 04:22 PM, Takuya Yoshikawa wrote:
>> When this was introduced, kvm_flush_remote_tlbs() could be called
>> without holding mmu_lock.  It is now acknowledged that the function
>> must be called before releasing mmu_lock, and all callers have already
>> been changed to do so.
>>
>
> I have already posted the patch to moving flush tlb out of mmu-lock
> when do dirty tracking:
> KVM: MMU: flush tlb out of mmu lock when write-protect the sptes

Yes, I had your patch in mind, so made patch B.

>
> Actually some patches (patch 1 - patch 4) in that patchset can be
> pickup-ed separately and i should apologize for the patchset was
> not updated for a long time since i was busy on other development.

Looking forward to seeing that work again!

>
> And moving tlb flush out of mmu-lock should be going on in the
> future, so i think the B patch is more acceptable.
>

Maybe.

Some time ago, someone working on non-x86 stuff asked us why
smp_mb() and cmpxchg() were used there.  So a brief comment
which points them to the note on sync_page() will be helpful.

	Takuya