Hi Jonathan, On Tue, Jan 3, 2023 at 4:47 AM Marc Zyngier <maz@xxxxxxxxxx> wrote: > > On Tue, 03 Jan 2023 12:40:34 +0000, > Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> wrote: > > > > On Thu, 29 Dec 2022 19:59:21 -0800 > > Reiji Watanabe <reijiw@xxxxxxxxxx> wrote: > > > > > The goal of this series is to allow userspace to limit the number > > > of PMU event counters on the vCPU. > > > > Hi Rieji, > > > > Why do you want to do this? > > > > I can conjecture a bunch of possible reasons, but they may not > > match up with your use case. It would be useful to have that information > > in the cover letter. > > The most obvious use case is to support migration across systems that > implement different numbers of counters. Similar reasoning could also > apply to the debug infrastructure (watchpoints, breakpoints). Exactly, this is to unblock migration support between systems that implement different numbers of counters. I will include this information in the cover letter when I update the series for the v2. Thanks, Reiji > > In any case, being able to decouple the VM from the underlying HW > within the extent that the architecture permits it seems like a > valuable goal. > > Thanks, > > M. > > -- > Without deviation from the norm, progress is not possible.
