Re: [libvirt] [PATCH v2 1/2] Add pcihole64 attribute to root PCI controllers

On Tue, Aug 13, 2013 at 11:53:42AM +0200, Ján Tomko wrote: > On 08/13/2013 10:55 AM, Daniel P. Berrange wrote: >> On Tue, Aug 13, 2013 at 10:51:04AM +0200, Ján Tomko wrote: >>> <controller type='pci' index='0' model='pci-root' pcihole64='1'/> >>> >>> It can be used to adjust (or disable) the size of the 64-bit >>> PCI hole. The size attribute is in gigabytes, since it would >>> get rounded up to nearest GB by QEMU anyway. >> >> Choosing the units based on what one specific hypervisor happens to >> currently do has proven to be a pretty bad idea in the past. I'd say >> we should be using KB here. Or better yet, have this as a separate >> child element, and then support a 'units' attribute at the same time, >> defaulting to KB. >> > > Would it be okay to use the largest usable unit when formatting the XML > to make it more human-friendly? No, because you'd be throwing away data if the user had requested less than a GB. Outputting XML should use the smallest unit for which we want to support, which IMHO should be KB.