On 6/17/19 12:38 AM, Alexander Graf wrote: >> Yes I know, but as a benefit we could get rid of all the GSBASE >> horrors in >> the entry code as we could just put the percpu space into the local PGD. > > Would that mean that with Meltdown affected CPUs we open speculation > attacks against the mmlocal memory from KVM user space? Not necessarily. There would likely be a _set_ of local PGDs. We could still have pair of PTI PGDs just like we do know, they'd just be a local PGD pair.