Re: [libvirt] [RFC] kvm: x86: export vCPU halted state to sysfs

On Fri, 2 Feb 2018 15:54:15 +0000 Daniel P. Berrangé <berrange(a)redhat.com&gt; wrote: > > > The most important question I have is: does this solution satisfy the > > > needs of upper management? That is, if we implement the solution suggested > > > by Eduardo than the feature of automatically hotplugging more CPUs > > > will only work for s390. Is this OK? > > > > > > If yes, then I think this is the best solution. And the next question > > > would be: Viktor, can you change this in libvirt while we fix query-cpus > > > in QEMU? > > > > > The latest proposal was to use a flag for query-cpus (like full-state) > > which would control the set of properties queried and reported. If this > > is the way we decide to go, I can make the necessary changes in libvirt. > > Regardless of whether we add that flag to query-cpus or not, we still have > the general problem of solving the cross-architecture semantics to be > more sane. Let's the both then: o Make qemuDomainRefreshVcpuHalted() s390-only in libvirt. This by itself fixes the original performance issue o Deprecate the "halted" field in query-cpus in QEMU. This fixes new instances of this same problem