Hi Marc, Marc Zyngier <marc.zyngier@xxxxxxx> writes: > +Mark > > On 10/01/17 11:38, Punit Agrawal wrote: >> Both AArch32 and AArch64 mode of the ARMv8 architecture support trapping >> certain VM operations, e.g, TLB and cache maintenance >> operations. Selective trapping of these operations for specific VMs can >> be used to track the frequency with which these occur during execution. >> >> Add a software PMU on the host that can support tracking VM >> operations (in the form of PMU events). Supporting new events requires >> providing callbacks to configure the VM to enable/disable the trapping >> and read a count of the frequency. >> >> The host PMU events can be controlled by tools like perf that use >> standard kernel perf interfaces. >> >> Signed-off-by: Punit Agrawal <punit.agrawal@xxxxxxx> >> Cc: Christoffer Dall <christoffer.dall@xxxxxxxxxx> >> Cc: Marc Zyngier <marc.zyngier@xxxxxxx> >> Cc: Will Deacon <will.deacon@xxxxxxx> >> --- >> arch/arm/include/asm/kvm_host.h | 8 ++ >> arch/arm/kvm/arm.c | 2 + >> arch/arm64/include/asm/kvm_host.h | 8 ++ >> virt/kvm/arm/host_pmu.c | 272 ++++++++++++++++++++++++++++++++++++++ >> 4 files changed, 290 insertions(+) >> create mode 100644 virt/kvm/arm/host_pmu.c >> [...] >> > > This patch really makes me think that there is nothing arm-specific in > here at all. Why can't it be a generic feature through which > architectures can expose events in a generic way (or as close as > possible to being generic)? I wasn't sure if other architectures are interested in the functionality - that's the only reason. Having said that, it can be turned off in the config so there shouldn't be any complaints. I'll move this to virt/kvm in the next incarnation. Thanks for taking a look. > > Thanks, > > M. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
