Could you please tell us if the VMs that won't boot are SMP VMs? I know it's the SMP kernel but what I mean is, is KVM giving the VM more than one CPU? If they are SMP VMs, could you please try to make them single-CPU and try to boot them, then let us know what happens? I am seeing a bug with Linux SMP guests under KVM which causes boot failures and random hangs, and I wonder if it's related.
Could you please tell us if the VMs that won't boot are SMP VMs? I know it's the SMP kernel but what I mean is, is KVM giving the VM more than one CPU? If they are SMP VMs, could you please try to make them single-CPU and try to boot them, then let us know what happens? I am seeing a bug with Linux SMP guests under KVM which causes boot failures and random hangs, and I wonder if it's related.