From d7eec2360e389cc877a76c2b098f7b745007d2b2 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 12 Feb 2020 11:31:02 +0000 Subject: KVM: arm64: Add PMU event filtering infrastructure 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). Reviewed-by: Andrew Jones Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/arm64/include/asm/kvm_host.h') diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 33e0f0a64c42..0384defc2a01 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -111,6 +111,11 @@ struct kvm_arch { */ bool return_nisv_io_abort_to_user; + /* + * VM-wide PMU filter, implemented as a bitmap and big enough for + * up to 2^10 events (ARMv8.0) or 2^16 events (ARMv8.1+). + */ + unsigned long *pmu_filter; unsigned int pmuver; }; -- cgit v1.2.3