On Wed, 08 Dec 2021 16:11:13 +0000, Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote: > > > On the contrary, I am *very* happy to limit a VM to a single PMU (and > > thus CPU) type on these systems. Really. > > Ok, so any kind of asymmetry is unacceptable. > > Accepted behaviour: > > 1. If userspace sets PMU for one VCPU, then *all* other VCPUs must > have a PMU set, and furthermore, it must be the same PMU as the > first VCPU, > > or > > 2. If userspace has initialized a PMU (via > KVM_ARM_VCPU_PMU_V3_CTRL(KVM_ARM_VCPU_PMU_V3_INIT)) without setting > a PMU, then it is forbidden for userspace to set a PMU for the other > VCPUs. > > Is that what you had in mind? Exactly. This sidesteps any sort of odd behaviour by forcing userspace to pick a side. Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
