Re: [Xen-devel] Re: [Xen-changelog] [xen-3.1-testing] xend: fix server/netif.py so that it respects type=None.

["Daniel P. Berrange" <berrange@xxxxxxxxxx>]

On Fri, Oct 05, 2007 at 06:36:22PM +0100, David Edmondson wrote:
> On Fri, Oct 05, 2007 at 06:30:48PM +0100, Daniel P. Berrange wrote:
> > > The whole "PV and IOEMU" at the same time makes me uncomfortable,
> > > though it looks to be more problematic with disks than network
> > > devices.
> > 
> > The key is that the Dom0 configuration of the guest should allow the
> > guest kernel to choose the drivers.
> 
> Understood.
> 
> > Obviously you don't want both drivers active at once, so one idea is
> > for the PV drivers to 'grab' the PCI resources associated with the
> > emulated NIC.
> 
> That seems so wrong.
> 
> In Solaris drivers are loaded as a result of a mapping from the PCI ID
> of the device to a driver name (I've no idea if it's the same in
> Linux). What happens if the RTL8139 driver gets in first?

If the PV driver is unable to grab the PCI resources of the RTL NIC
because RTL8139 is already loaded, then it wouldn't try to initialize 
the PV nic. So this basically provides the safety net against both
being active (accidentally or by delibrate admuin actions). Then you 
need to figure out a way to prioritization the driver you really want.

Dan.
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