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Date: Tue, 04 Nov 2008 15:01:21 +0000
From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
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Subject: Re: [Qemu-devel] vga optmization
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To: qemu-devel@nongnu.org
Cc: Glauber Costa <glommer@redhat.com>, aliguori@us.ibm.com

Avi Kivity wrote:

> Stefano Stabellini wrote:
>> Why don't you make qemu_physical_sync_dirty_bitmap take also and end
>> address, and you merge the two bitmaps in this address range in this
>> function, so you don't have to change cpu_physical_memory_get_dirty at
>> all?
>>
>> I am saying to do something like:
>>
>> void qemu_physical_sync_dirty_bitmap(ram_addr_t start_addr, ram_addr_t
>> end_addr)
>> {
>>     /* sync and merge the two bitmaps between start_addr and end_addr */
>> }
>>
>> then leave cpu_physical_memory_get_dirty untouched.
>> I would prefer this approch, it also leaves more space to other
>> optimizations.
>>   
> 
> That's how current kvm userspace works.  It's also more correct, since
> the kvm bitmap feeds both the vga dirty bits and the live migration
> dirty bits.
> 


That's also how currently qemu-xen works.
I am glad that we agree :)