Re: [libvirt] [PATCH v2 1/2] conf: add xml element devices/pvpanic

On Thu, Dec 05, 2013 at 10:41:13AM +0800, Hu Tao wrote: > On Wed, Dec 04, 2013 at 03:53:17PM +0000, Daniel P. Berrange wrote: > > On Wed, Dec 04, 2013 at 08:46:53AM -0700, Eric Blake wrote: > > > On 12/04/2013 08:42 AM, Daniel P. Berrange wrote: > > > >> Dan, do you have any thoughts on the best representation to use? Or is > > > >> Hu's original proposal of: > > > >> > > > >> <pvpanic ioport='0x505'/> > > > > > > > > I'm not a fan of doing a special case attribute for 'ioport' - this is > > > > something something that should be part of an <address> element, since > > > > ioport numbers are a generic addressing concept for many devices. > > > > eg ISA serial / parallel ports have IRQ / IO ports IIUC. > > > > > > So something more like: > > > > > > <pvpanic> > > > <address type='ioport' slot='0x505'/> > > > </pvpanic> > > > > > > and introducing a new type='ioport' namespace into the <address> XML > > > since it is yet another numbering system for guest-visible addressing? > > > > Yes, I'm not sure I'd call the type 'ioport' - the address type reflects > > the bus/controller type that the device is associated with. What is the > > "bus" type that a pvpanic device is attached to ? Is it a ISA bus device, > > or is it a "platform" device or something else ? eg it might be appropriate > > to use > > > > <address type='platform' ioport='0x666'/> > > It's an ISA device. So the address should be: > > <address type='isa' ioport='0x505'/> Ok. It looks like it does not require an IRQ line though IIUC. For the general ISA address type though, we want to represent both ioport and IRQ values. So I guess we need the IRQ attribute to be optional in some manner.