On Tue, Sep 08, 2020 at 08:58:28AM +0100, Marc Zyngier wrote: > It can be desirable to expose a PMU to a guest, and yet not want the > guest to be able to count some of the implemented events (because this > would give information on shared resources, for example. > > For this, let's extend the PMUv3 device API, and offer a way to setup a > bitmap of the allowed events (the default being no bitmap, and thus no > filtering). > > Userspace can thus allow/deny ranges of event. The default policy > depends on the "polarity" of the first filter setup (default deny if the > filter allows events, and default allow if the filter denies events). > This allows to setup exactly what is allowed for a given guest. > > Note that although the ioctl is per-vcpu, the map of allowed events is > global to the VM (it can be setup from any vcpu until the vcpu PMU is > initialized). > > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> > --- > arch/arm64/include/asm/kvm_host.h | 5 +++ > arch/arm64/include/uapi/asm/kvm.h | 16 +++++++ > arch/arm64/kvm/arm.c | 2 + > arch/arm64/kvm/pmu-emul.c | 70 ++++++++++++++++++++++++++++--- > 4 files changed, 87 insertions(+), 6 deletions(-) > Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx> _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
