[libvirt] [PATCH 2/3] New 'permissive' attribute for hostdev

[Daniel P. Berrange]

On Tue, Dec 22, 2009 at 10:51:15AM +0100, Daniel Veillard wrote:
> On Mon, Dec 21, 2009 at 07:09:08PM +0000, Daniel P. Berrange wrote:
> > On Mon, Dec 21, 2009 at 02:27:18PM +0100, Jiri Denemark wrote:
> > > When it is set to 'yes', some check whether a device is safe to be
> > > assigned to a guest will be weakened.
> > 
> > I think this is a rather ill-defined concept to be adding the guest XML,
> > since there are many checks done for assignment, and this is only impacting
> > one of them. Whether to allow a device beind a non-ACS enable switch to be
> > used in a VM has implications beyond just the one VM it is assigned to. Thus
> > is strikes me that the decision as to whether to allow use of devices behind
> > non-ACS switches should be a host level attribute. eg a config item in the
> > /etc/qemu/qemu.conf file
> 
>   Agreed, it's a Host PCI implementation issue, and this should be
> delt with in a host wide manner I think, a daemon setting, with the
> defaulting being on the safe side sounds the best to me.

I'm having second thoughts about even a host daemon setting. I really
think we ought to be doing full checking ourselves, even with whitelists
if needed. 

Daniel
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