Re: [PATCH][HVM] pass-through PCI device hotplug support

["Daniel P. Berrange" <berrange@redhat.com>]

On Wed, Jan 23, 2008 at 11:52:09PM +0800, Zhai, Edwin wrote:
> All,
> 
> This patch enables HVM guest VT-d device hotplug via a simple ACPI hotplug 
> device model. Pls. have a look.
> 
> On VT-d side, it's very useful as you can dynamically assign VT-d device to a 
> guest as long as it support ACPI hotplug(Linux 2.6, 2000, 2003, XP... pass the 
> test).
> 
> * Usage is very simple.
> Three new commands are added:
> "xm dpci-list domid" show the current assigned vtd device, like:
> ID  domain   bus   slot   func
> 0      0x0  0x02   0x00    0x0
> 
> "xm dpci-remove" hot remove the specified vtd device by the ID, like:
> xm dpci-remove EdwinHVMDomainVtd 0
> 
> "xm dpci-insert" hot add a new vtd device, like '03:00.0':
> xm dpci-insert EdwinHVMDomainVtd 3 0 0

IMHO we shouldn't have a 'd' on the front of the command names. VT-d is a 
vendor specific implementation whose nomenculture doesn't need to be exposed
to users. In addition the existing block & network hotplug commands use
'attach' and 'detach' for their command names. So for sake of consistency
I'd recommend command names of:

  pci-list
  pci-attach
  pci-detach

I think it is useful to use the same unique naming & data for both attach and
detach operations. So if we use a (bus,slot,func) triple for attachment, I
think we should use the same (bus,slot,func) triple for detachment too,
rather than having to make apps / users lookup the dynamically-allocated
'ID' value for the device.

Regards,
Dan.
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