From mboxrd@z Thu Jan  1 00:00:00 1970
From: Izik Eidus <ieidus@redhat.com>
Subject: Re: [PATCH 2/2] kvm: change the dirty page tracking to work with
 dirty bity
Date: Thu, 11 Jun 2009 02:59:59 +0300
Message-ID: <4A3048FF.2030303@redhat.com>
References: <1244651005-18322-1-git-send-email-ieidus@redhat.com> <1244651005-18322-2-git-send-email-ieidus@redhat.com> <1244651005-18322-3-git-send-email-ieidus@redhat.com> <20090610204227.GA12682@amt.cnet> <4A30484E.1040708@redhat.com>
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Cc: kvm@vger.kernel.org, avi@redhat.com
To: Marcelo Tosatti <mtosatti@redhat.com>
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Izik Eidus wrote:
> Marcelo Tosatti wrote:
>
>>>
>>>  
>>>      /* Free page dirty bitmap if unneeded */
>>> -    if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
>>> +    if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES)) {
>>>          new.dirty_bitmap = NULL;
>>> +        if (old.flags & KVM_MEM_LOG_DIRTY_PAGES)
>>> +            kvm_arch_flush_shadow(kvm);
>>> +    }
>>>     
>>
>> Whats this for?
>>   
>
> We have added all this SPTE_DONT_DIRTY..., when we stop dirty bit 
> tracking, we want to continue setting the dirty bit for the spte 
> inside set_spte(), so writing to the page would be faster....

Another way would be doing something like kvm_arch_clean_dont_dirty(), 
might be better than flushing the whole shadow page tables.