[SeaBIOS] [PATCH] don't expose pvpanic device in the UI

[Michael S. Tsirkin]

On Mon, Aug 05, 2013 at 12:01:57PM -0400, Paolo Bonzini wrote:
> 
> > > > > That's just pushing the problem elsewhere. How management suppose to
> > > > > know
> > > > > if guest support pvpanic device?
> > > > 
> > > > The problem isn't new and management already does that when figuring
> > > > whenever the guest should get ide/ahci/virtio-blk/virtio-scsi storage,
> > > > ac97 or intel-hda sound, rtl8139/e1000/virtio nic, ...
> > > 
> > > Depending on the management, "management" could just be the user.
> > > Most of the time the user simply says to use virtio in the XML.
> > > 
> > > If it had to be specified manually every time, pvpanic would be
> > > just another knob that nobody uses.
> > 
> > Management tools already set XML appropriately depending
> > on the guest. If users are happy to leave the device alone,
> > we are also happy.
> 
> What if the guest is upgraded?  How does the user know they have
> to add a magic device?

Device is useless without a driver anyway.
How does user know there's need to install a driver?
Same thing really.

> This is really against the original purpose
> of pvpanic.

Then the purpose was wrong.

It's useful to be able to have a virtual
machine that looks like a physical machine.  From this point of view,
any PV that can't be disabled is a bug.

It's easy enough to add random stuff to the default
machine but it just does not scale.

So let's add -device pvpanic to QEMU, same as any device, if
you think everyone absolutely wants this device explain this
to libvirt guys and they'll add it by default, they
are much closer to real users and can treat this appropriately.

> > > (Besides, I would not be much worried about Microsoft's choice of
> > > icons.  I doubt a machine would be considered "not healthy" just
> > > because the "missing driver" icon looks worrisome).
> > 
> > I think Marcel commented on events in event manager, not
> > about the icon.
> 
> I didn't see any remark about the event log.  His original message
> went from "The outcome may be, for example: in Windows [...] the device
> will appear as an unrecognized device" straight to "a health
> monitoring service it may show all the VMs in a 'not healthy' state".
> 
> Really, all guests handle the missing driver without asking the user.

Did you really check them all?

> At some point MSFT even issued a hotfix to disable the pesky Found
> New Hardware wizard.  Let's treat it as a guest bug, hide the device
> altogether with _OSI (detecting Vista or 2008 or Linux),
> and declare
> that Windows 2000/XP/2003 lack support for pvpanic.

Sounds like you merely mean all windows guests.

> 
> Paolo

If we go that route, we really must detect 2000/XP/2003.
Blacklist specific bad guests, don't whitelist
guests.


-- 
MST