On 05/01/2015 23:48, Marcelo Tosatti wrote: >>> > > But there is no guarantee that vCPU-N has updated its pvti when >>> > > vCPU-M resumes guest instruction execution. >> > >> > Still confused. So we can freeze all vCPUs in the host, then update >> > pvti 1, then resume vCPU 1, then update pvti 0? In that case, we have >> > a problem, because vCPU 1 can observe pvti 0 mid-update, and KVM >> > doesn't increment the version pre-update, and we can return completely >> > bogus results. > Yes.
But then the getcpu test would fail (1->0). Even if you have an ABA situation (1->0->1), it's okay because the pvti that is fetched is the one returned by the first getcpu. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
