Re: [Qemu-devel] Re: [RFC PATCH 0/5] Introduce canonical device hierarchy string

Markus Armbruster
2010-06-15T08:53:45Z

Alex Williamson <alex.williamson@redhat.com> writes:

> On Mon, 2010-06-14 at 09:02 +0200, Gerd Hoffmann wrote:
>> Hi,
>>
>> > My premise with this attempt is that we walk the hierarchy and use the
>> > names to create the base of the path. As we get to the device,
>> > particularly to the parent bus of the device, we need to start looking at
>> > properties to ensure uniqueness.
>>
>> You'll need that for every bus along the way down to the device. Create
>> a virtual machine with two lsi scsi host adapters, then attach a disk
>> with scsi id 0 to each. Just the scsi id isn't good enougth to identify
>> the device. You'll need the lsi pci address too.
>
> Yep, see below.
>
>> > For now, the only properties I've tagged as path
>> > properties are PCI bus addresses and MAC addresses.
>>
>> mac address isn't needed here. You need the property which specifies
>> the bus address. For PCI this obviously is the PCI address. For scsi
>> the scsi id. For ISA you can use the I/O port base. virtio-serial the
>> port number, ...
>
> PCI: addr
> SCSI: scsi-id
> ISA: serial/parallel = iobase, others??

If there's no iobase (pathological case), require ID.

> ide-drive: unit

Bus name is IDE, but it's clear enough what you mean :)

> I2C: address
>
> virtio-serial doesn't seem to make a DeviceState per port, so I think it
> can be skipped.

Really?

Anyway, its port number should do as bus address.

> I'm sure I'm still missing some...

s390-virtio
SSI
System
USB …