Re: [RFC PATCH 0/6] ARM64: KVM: PMU infrastructure support

[Christoffer Dall <christoffer.dall@linaro.org>]

Hi Anup,

[This time to the new email]

What are your plans in terms of follow-up on this one?

Should we review these patches and reply to anup _at_ brainfaul.org or
are you looking for someone else to pick them up?

Thanks,
-Christoffer

On Tue, Aug 05, 2014 at 02:54:09PM +0530, Anup Patel wrote:
> This patchset enables PMU virtualization in KVM ARM64. The
> Guest can now directly use PMU available on the host HW.
> 
> The virtual PMU IRQ injection for Guest VCPUs is managed by
> small piece of code shared between KVM ARM and KVM ARM64. The
> virtual PMU IRQ number will be based on Guest machine model and
> user space will provide it using set device address vm ioctl.
> 
> The second last patch of this series implements full context
> switch of PMU registers which will context switch all PMU
> registers on every KVM world-switch.
> 
> The last patch implements a lazy context switch of PMU registers
> which is very similar to lazy debug context switch.
> (Refer, http://lists.infradead.org/pipermail/linux-arm-kernel/2014-July/271040.html)
> 
> Also, we reserve last PMU event counter for EL2 mode which
> will not be accessible from Host and Guest EL1 mode. This
> reserved EL2 mode PMU event counter can be used for profiling
> KVM world-switch and other EL2 mode functions.
> 
> All testing have been done using KVMTOOL on X-Gene Mustang and
> Foundation v8 Model for both Aarch32 and Aarch64 guest.
> 
> Anup Patel (6):
>   ARM64: Move PMU register related defines to asm/pmu.h
>   ARM64: perf: Re-enable overflow interrupt from interrupt handler
>   ARM: perf: Re-enable overflow interrupt from interrupt handler
>   ARM/ARM64: KVM: Add common code PMU IRQ routing
>   ARM64: KVM: Implement full context switch of PMU registers
>   ARM64: KVM: Upgrade to lazy context switch of PMU registers
> 
>  arch/arm/include/asm/kvm_host.h   |    9 +
>  arch/arm/include/uapi/asm/kvm.h   |    1 +
>  arch/arm/kernel/perf_event_v7.c   |    8 +
>  arch/arm/kvm/arm.c                |    6 +
>  arch/arm/kvm/reset.c              |    4 +
>  arch/arm64/include/asm/kvm_asm.h  |   39 +++-
>  arch/arm64/include/asm/kvm_host.h |   12 ++
>  arch/arm64/include/asm/pmu.h      |   44 +++++
>  arch/arm64/include/uapi/asm/kvm.h |    1 +
>  arch/arm64/kernel/asm-offsets.c   |    2 +
>  arch/arm64/kernel/perf_event.c    |   40 +---
>  arch/arm64/kvm/Kconfig            |    7 +
>  arch/arm64/kvm/Makefile           |    1 +
>  arch/arm64/kvm/hyp-init.S         |   15 ++
>  arch/arm64/kvm/hyp.S              |  209 +++++++++++++++++++-
>  arch/arm64/kvm/reset.c            |    4 +
>  arch/arm64/kvm/sys_regs.c         |  385 +++++++++++++++++++++++++++++++++----
>  include/kvm/arm_pmu.h             |   52 +++++
>  virt/kvm/arm/pmu.c                |  105 ++++++++++
>  19 files changed, 870 insertions(+), 74 deletions(-)
>  create mode 100644 include/kvm/arm_pmu.h
>  create mode 100644 virt/kvm/arm/pmu.c
> 
> -- 
> 1.7.9.5
>