Re: [Qemu-devel] [PATCHv3 03/13] qemu: add routines to manage PCI capabilities

[Michael S. Tsirkin]

On Wed, Jun 10, 2009 at 04:24:28PM +0100, Paul Brook wrote:
> > > caps can be anywhere, but we don't expect it to change during machine
> > > execution lifetime.
> > >
> > > Or I am just confused by the name "pci_device_load" ?
> >
> > Right. So I want to load an image and it has capability X at offset Y.
> > wmask has to match. I don't want to assume that we never change Y
> > for the device without breaking old images, so I clear wmask here
> > and set it up again after looking up capabilities that I loaded.
> 
> We should not be loading state into a different device (or a similar device 
> with a different set of capabilities).
> 
> If you want to provide backwards compatibility then you should do that by 
> creating a device that is the same as the original.  As I mentioned in my 
> earlier mail, loading a snapshot should never do anything that can not be 
> achieved through normal operation.
> 
> Paul

Why shouldn't it? You don't load a snapshot while guest is running.

-- 
MST