On Wed, 2010-06-16 at 10:23 +0200, Markus Armbruster wrote: > Alex Williamson <alex.williamson@xxxxxxxxxx> writes: > > > On Tue, 2010-06-15 at 12:28 +0100, Paul Brook wrote: > >> > > Alex proposed to disambiguate by adding "identified properties of the > >> > > immediate parent bus and device" to the path component. For PCI, these > >> > > are dev.fn. Likewise for any other bus where devices have unambigous > >> > > bus address. The driver name carries no information! > >> > > >> > From user POV, driver names are very handly to address a device > >> > intuitively - except for the case you have tones of devices on the same > >> > bus that are handled by the same driver. For that case we need to > >> > augment the device name with a useful per-bus ID, derived from the bus > >> > address where available, otherwise based on instance numbers. > >> > >> This is where I think you're missing a trick. We don't need to augment the > >> name, we just need to allow the bus id to be used instead. > > > > For the case of a hot remove, I agree. If the user specifies "pci_del > > pci.0/03.0", that's completely sufficient because we don't care what's > > in that slot, just remove it. However, I still see some use cases for > > device names in the path. Take for example: > > > > (A): /i440FX-pcihost/pci.0/e1000.05.0 > > > > vs > > > > (B): /pci.0/05.0 > > > > (removing both the root bridge driver name and the device driver name) > > / is the main system bus. System bus defines no bus address at the > moment. Therefore, you have to use the driver name i440FX-pcihost. So is the general rule "If a device's parent bus does not provide an address, print device name"? > /i440FX-pcihost/pci.0 is the PCI bus. PCI bus defines a bus address: > dev.fn. Therefore, you can either use the bus address @05.0, or the > driver name e1000. > > We have "/i440FX-pcihost/pci.0/e1000" vs. "/i440FX-pcihost/pci.0/@05.0". I object to being able to use anything but an address under a bus that supports hotplug, but that aside, I think the paths for my example system look like below. Note that anything behind and including the $ is not the canonical path, that begins the free form, usage specific string, here filled by missing device names (open to suggestions other than $ here). Note that were isa devices do not have a bus identifier, I'm using the device name, which I think follows the same rule as i440FX-pcihost. Can we agree this is the goal? Thanks, Alex /i440FX-pcihost/pci.0/@00.0$i440FX /i440FX-pcihost/pci.0/@01.0$PIIX3 /i440FX-pcihost/pci.0/@02.0$cirrus-vga /i440FX-pcihost/pci.0/@01.0/isa.0/mc146818rtc /i440FX-pcihost/pci.0/@01.0/isa.0/@0x3f8$isa-serial /i440FX-pcihost/pci.0/@01.0/isa.0/@0x378$isa-parallel /i440FX-pcihost/pci.0/@01.0/isa.0/i8042 /i440FX-pcihost/pci.0/@01.0/isa.0/isa-fdc /i440FX-pcihost/pci.0/@03.0$i82551 /i440FX-pcihost/pci.0/@04.0$virtio-net-pci /i440FX-pcihost/pci.0/@05.0$e1000 /i440FX-pcihost/pci.0/@06.0$rtl8139 /i440FX-pcihost/pci.0/@07.0$pcnet /i440FX-pcihost/pci.0/@01.0/isa.0/@0x300$ne2k_isa /i440FX-pcihost/pci.0/@01.1$piix3-ide /i440FX-pcihost/pci.0/@01.1/ide.0/@0$ide-drive /i440FX-pcihost/pci.0/@01.1/ide.1/@0$ide-drive /i440FX-pcihost/pci.0/@01.2$piix3-usb-uhci /i440FX-pcihost/pci.0/@01.3$PIIX4_PM /i440FX-pcihost/pci.0/@01.3/i2c/@80$smbus-eeprom /i440FX-pcihost/pci.0/@01.3/i2c/@81$smbus-eeprom /i440FX-pcihost/pci.0/@01.3/i2c/@82$smbus-eeprom /i440FX-pcihost/pci.0/@01.3/i2c/@83$smbus-eeprom /i440FX-pcihost/pci.0/@01.3/i2c/@84$smbus-eeprom /i440FX-pcihost/pci.0/@01.3/i2c/@85$smbus-eeprom /i440FX-pcihost/pci.0/@01.3/i2c/@86$smbus-eeprom /i440FX-pcihost/pci.0/@01.3/i2c/@87$smbus-eeprom /i440FX-pcihost/pci.0/@08.0/scsi.0/@0$scsi-disk /i440FX-pcihost/pci.0/@08.0/scsi.0/@3$scsi-disk /i440FX-pcihost/pci.0/@08.0$lsi53c895a /i440FX-pcihost/pci.0/@01.2/usb.0/@usb0/scsi.0/@0$scsi-disk /i440FX-pcihost/pci.0/@01.2/usb.0/@usb0$usb-storage /i440FX-pcihost/pci.0/@09.0$virtio-blk-pci -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
