Re: [Qemu-devel] pvpanic device should not be automatically included as an internal device

[Marcel Apfelbaum]

On Thu, 2013-08-01 at 16:32 +0300, Michael S. Tsirkin wrote:
> On Thu, Aug 01, 2013 at 04:08:57PM +0300, Marcel Apfelbaum wrote:
> > Hi,
> > 
> > The problem with pvpanic being an internal device is that VMs running
> > operating systems without a driver for this device will have problems
> > when qemu will be upgraded (from qemu without this pvpanic).
> > 
> > The outcome may be, for example: in Windows(let's say XP) the Device manager
> > will open a "new device" wizard and the device will appear as an 
> > unrecognized device.
> > Now what will happen on a cluster with hundreds of such VMs? If that 
> > cluster has a health
> > monitoring service it may show all the VMs in a "not healthy" state.
> > 
> > My point is that a device that requires a driver that is not "inbox", 
> > should not
> > be present by default.
> > One possible solution is to add it manually with -device from command line.
> > 
> > Any thoughts?
> > Marcel
> 
> Interesting. You are basically saying we should have a rule
> that no new builtin devices should be added
> without an explicit request from management interface?

Basically, yes.
The only builtin devices shall be devices that the operating systems
know how to handle with the default drivers.
Marcel

> 
>