Comment 33 for bug 795717

Sorry after installing Serge's test kernel I did not have the time to test the proposed version but his did fix the issue.

Unfortunately it appears that the Ubuntu kernel in 11.04 also has this issue.

                if (tsc_delta < 0)
                        mark_tsc_unstable("KVM discovered backwards TSC");
                if (check_tsc_unstable()) {
                        kvm_x86_ops->adjust_tsc_offset(vcpu, -tsc_delta);
                        vcpu->arch.tsc_catchup = 1;
                }
                kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
                if (vcpu->cpu != cpu)
                        kvm_migrate_timers(vcpu);
                vcpu->cpu = cpu;
        }
}

I have made the same diff change I added above and the issue goes away.