Re: [PATCH 0/4] Swapping

[Izik Eidus <izike-atKUWr5tajBWk0Htik3J/w@public.gmane.org>]

Anthony Liguori wrote:
> Izik Eidus wrote:
>> Anthony Liguori wrote:
>>> I've been playing around with these patches.  If I do an 
>>> madvise(MADV_DONTNEED) in userspace, when I close the VM, I get the 
>>> following bug.  My knowledge of the mm is limited but since 
>>> madvise(MADV_DONTNEED) effectively does a zap_page_range() I wonder 
>>> if we're lacking the necessary callback to also remove any potential 
>>> GPA covered by that range from shadow page cache.
>>>
>>> Regards,
>>>
>>> Anthony Liguori
>> it probably beacuse the changes of the first patch, ( that make all 
>> present shadow pages rmapped )
>> Anthony can you please check what happn if you run latest kvm with 
>> the patch (of the rmap) and without the patch?
>
> It looks like it's my patch for doing an in kernel mmap() to support 
> older userspaces.  I'll figure out what the problem is.
>
> But at any rate, would madvise() be able to evict the current contents 
> of something in the shadow page cache or will the guest not pick up 
> the new memory until the old gets evicted from the shadow page cache?
if i understand you right, then madvise() wont harm us, beacuse we 
protect all our shadow memory by removing the writable bit from it.
therefor the guest cant change anything without we know it.
>
> Regards,
>
> Anthony Liguori
>


-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/