Paolo Bonzini <pbonz...@redhat.com> writes: > On 16/09/20 13:29, Dr. David Alan Gilbert wrote: >>> I have tracked the bug to the fact that `kvmclock` is not exposed and >>> disabled from qemu PoV but is in fact used by `hv-time` (in KVM). >>> >>> I think we should enable the `kvmclock` (qemu device) if `hv-time` is >>> present and add Hyper-V support for the `kvmclock_current_nsec` >>> function. > > Yes, this seems correct. I would have to check but it may even be > better to _always_ send kvmclock data in the live migration stream. >
The question I have is: with 'kvm=off', do we actually restore TSC reading on migration? (and I guess the answer is 'no' or Hyper-V TSC page would 'just work' I guess). So yea, maybe dropping the 'cpu->env.features[FEAT_KVM]' check is the right fix. -- Vitaly
