Hi Alex, On Mon, Apr 25, 2022 at 03:55:30PM +0100, Alexandru Elisei wrote: [...] > The root cause remains the same: kvm->arch.pmuver was never set to > something sensible because the VCPU feature itself was never set. > > The odroid-c4 is somewhat of a special case, because Linux doesn't probe > the PMU. But the above errors can easily be reproduced on any hardware, > with or without a PMU driver, as long as userspace doesn't set the PMU > feature. This note has me wondering if we could do more negative testing with kvm-unit-tests just by selectively turning on/off features, with the expectation that tests either skip or pass. > Work around the fact that KVM advertises a PMU even when the VCPU feature > is not set by gating all PMU emulation on the feature. The guest can still > access the registers without KVM injecting an undefined exception. We're going to need something similar even after KVM conditionally advertises the PMU. WDYT about wiring up sys_reg_desc::visibility for the AArch32 PMU registers? For now just treat them as REG_RAZ (probably extend this to imply WI too) then promote to REG_HIDDEN in a later patch. -- Thanks, Oliver _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
