[libvirt] RFC: add <currentVcpu> element

[Eric Blake]

On 09/27/2010 11:20 AM, Eric Blake wrote:
> No change to existing API semantics, although the implementation can
> wrap old APIs to call the new ones with appropriate flags where
> appropriate to minimize code duplication.

One more API to think about:

virDomainGetInfo returns a virDomainInfoPtr, where that struct includes 
an unsigned short nrVirtCpu member.  I'm assuming that since this is a 
public struct involved in on-the-wire RPC protocol, we can't change it 
to add a new member (and it also implicitly means that we are limited to 
64k vcpus, even though the unsigned int argument of virDomainSetVcpus 
could otherwise go larger).  Given my testing, it looks like this field 
tracks live changes from virsh setvcpus, so this now needs to be 
explicitly documented as the current vcpu rather than the maximum, when 
the two differ.  Which means we have another synonym:

>> - current vcpu on running guests
>
> virDomainGetVcpusFlags(,VIR_DOMAIN_VCPU_ACTIVE)
> virDomainGetVcpus() + parsing pinning info
virDomainGetInfo()

-- 
Eric Blake   eblake at redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org