Re: [Qemu-devel] [RFC v4 23/58] vga: convert vga and its derivatives to the memory API

[Jan Kiszka]

On 2011-07-20 16:48, Avi Kivity wrote:
> On 07/20/2011 05:45 PM, Jan Kiszka wrote:
>>>
>>>  (that's the whole point - it can be made invisible by something outside
>>>  the cirrus card's knowledge).
>>>
>>>  Note - with kvm, there is still a race between syncing the bitmap and
>>>  removing the region.  However that is a bug in the kvm API; it is not
>>>  possible to work around it in qemu.
>>>
>>
>> Dirty log off, reconfigure, dirty log on?
> 
> What happens if there's a write after the first comma (assuming 
> "reconfigure" == "remove slot")?
> 
> Granted, the guest shouldn't be doing that.
> 
> Hmm, I guess you could just mark the entire range dirty after removing it.

Maybe.

So the problem is that the dirty bitmap is lost when we unregister a
region with the KVM kernel?

Jan

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