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[00/13] Extend the vPMU selftest

Message ID 20230213180234.2885032-1-rananta@google.com (mailing list archive)
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Series Extend the vPMU selftest | expand

Message

Raghavendra Rao Ananta Feb. 13, 2023, 6:02 p.m. UTC
Hello,

This vPMU KVM selftest series is an extension to the selftests
introduced by Reiji Watanabe in his series aims to limit the number
of PMCs on vCPU from userspace [1].

The idea behind this series is to expand the test coverage to include
the tests that validates actions from userspace, such as allowing or
denying certain events via KVM_ARM_VCPU_PMU_V3_FILTER attribute, KVM's
guarding of the PMU attributes to count EL2/EL3 events, and formal KVM
behavior that enables PMU emulation. The last part validates the guest
expectations of the vPMU by setting up a stress test that force-migrates
multiple vCPUs frequently across random pCPUs in the system, thus
ensuring KVM's management of vCPU PMU contexts correctly.

Patch-1 renames the test file to be more generic.

Patch-2 refactors the existing tests for plugging-in the upcoming tests
easily.

Patch-3 and 4 add helper macros and functions respectively to interact
with the cycle counter.

Patch-5 extends create_vpmu_vm() to accept an array of event filters
as an argument that are to be applied to the VM.

Patch-6 tests the KVM_ARM_VCPU_PMU_V3_FILTER attribute by scripting
various combinations of events that are to be allowed or denied to
the guest and verifying guest's behavior.

Patch-7 adds test to validate KVM's handling of guest requests to count
events in EL2/EL3.

Patch-8 introduces the vCPU migration stress testing by validating cycle
counter and general purpose counter's behavior across vCPU migrations.

Patch-9, 10, and 11 expands the tests in patch-8 to validate
overflow/IRQ functionality, chained events, and occupancy of all the PMU
counters, respectively.

Patch-12 extends create_vpmu_vm() to create multiple vCPUs for the VM.

Patch-13 expands the stress tests for multiple vCPUs.

The series has been tested on hardwares with PMUv8p1 and PMUvp5.

Thank you.
Raghavendra

[1]: https://lore.kernel.org/all/20230203040242.1792453-1-reijiw@google.com/


Raghavendra Rao Ananta (13):
  selftests: KVM: aarch64: Rename vpmu_counter_access.c to vpmu_test.c
  selftests: KVM: aarch64: Refactor the vPMU counter access tests
  tools: arm64: perf_event: Define Cycle counter enable/overflow bits
  selftests: KVM: aarch64: Add PMU cycle counter helpers
  selftests: KVM: aarch64: Consider PMU event filters for VM creation
  selftests: KVM: aarch64: Add KVM PMU event filter test
  selftests: KVM: aarch64: Add KVM EVTYPE filter PMU test
  selftests: KVM: aarch64: Add vCPU migration test for PMU
  selftests: KVM: aarch64: Test PMU overflow/IRQ functionality
  selftests: KVM: aarch64: Test chained events for PMU
  selftests: KVM: aarch64: Add PMU test to chain all the counters
  selftests: KVM: aarch64: Add multi-vCPU support for vPMU VM creation
  selftests: KVM: aarch64: Extend the vCPU migration test to multi-vCPUs

 tools/arch/arm64/include/asm/perf_event.h     |    7 +
 tools/testing/selftests/kvm/Makefile          |    2 +-
 .../kvm/aarch64/vpmu_counter_access.c         |  642 -------
 .../testing/selftests/kvm/aarch64/vpmu_test.c | 1710 +++++++++++++++++
 4 files changed, 1718 insertions(+), 643 deletions(-)
 delete mode 100644 tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c
 create mode 100644 tools/testing/selftests/kvm/aarch64/vpmu_test.c

Comments

Raghavendra Rao Ananta Feb. 13, 2023, 11:39 p.m. UTC | #1
On Mon, Feb 13, 2023 at 10:02 AM Raghavendra Rao Ananta
<rananta@google.com> wrote:
>
> Hello,
>
> This vPMU KVM selftest series is an extension to the selftests
> introduced by Reiji Watanabe in his series aims to limit the number
> of PMCs on vCPU from userspace [1].
>
> The idea behind this series is to expand the test coverage to include
> the tests that validates actions from userspace, such as allowing or
> denying certain events via KVM_ARM_VCPU_PMU_V3_FILTER attribute, KVM's
> guarding of the PMU attributes to count EL2/EL3 events, and formal KVM
> behavior that enables PMU emulation. The last part validates the guest
> expectations of the vPMU by setting up a stress test that force-migrates
> multiple vCPUs frequently across random pCPUs in the system, thus
> ensuring KVM's management of vCPU PMU contexts correctly.
>
> Patch-1 renames the test file to be more generic.
>
> Patch-2 refactors the existing tests for plugging-in the upcoming tests
> easily.
>
> Patch-3 and 4 add helper macros and functions respectively to interact
> with the cycle counter.
>
> Patch-5 extends create_vpmu_vm() to accept an array of event filters
> as an argument that are to be applied to the VM.
>
> Patch-6 tests the KVM_ARM_VCPU_PMU_V3_FILTER attribute by scripting
> various combinations of events that are to be allowed or denied to
> the guest and verifying guest's behavior.
>
> Patch-7 adds test to validate KVM's handling of guest requests to count
> events in EL2/EL3.
>
> Patch-8 introduces the vCPU migration stress testing by validating cycle
> counter and general purpose counter's behavior across vCPU migrations.
>
> Patch-9, 10, and 11 expands the tests in patch-8 to validate
> overflow/IRQ functionality, chained events, and occupancy of all the PMU
> counters, respectively.
>
> Patch-12 extends create_vpmu_vm() to create multiple vCPUs for the VM.
>
> Patch-13 expands the stress tests for multiple vCPUs.
>
> The series has been tested on hardwares with PMUv8p1 and PMUvp5.
>
Sorry for the typo (thanks Reiji for pointing it out!). It should be
"PMUv3p1 and
PMUv3p5". And the testing was done on v6.2-rc6 + [1].

Thank you.
Raghavendra
> Thank you.
> Raghavendra
>
> [1]: https://lore.kernel.org/all/20230203040242.1792453-1-reijiw@google.com/
>
>
> Raghavendra Rao Ananta (13):
>   selftests: KVM: aarch64: Rename vpmu_counter_access.c to vpmu_test.c
>   selftests: KVM: aarch64: Refactor the vPMU counter access tests
>   tools: arm64: perf_event: Define Cycle counter enable/overflow bits
>   selftests: KVM: aarch64: Add PMU cycle counter helpers
>   selftests: KVM: aarch64: Consider PMU event filters for VM creation
>   selftests: KVM: aarch64: Add KVM PMU event filter test
>   selftests: KVM: aarch64: Add KVM EVTYPE filter PMU test
>   selftests: KVM: aarch64: Add vCPU migration test for PMU
>   selftests: KVM: aarch64: Test PMU overflow/IRQ functionality
>   selftests: KVM: aarch64: Test chained events for PMU
>   selftests: KVM: aarch64: Add PMU test to chain all the counters
>   selftests: KVM: aarch64: Add multi-vCPU support for vPMU VM creation
>   selftests: KVM: aarch64: Extend the vCPU migration test to multi-vCPUs
>
>  tools/arch/arm64/include/asm/perf_event.h     |    7 +
>  tools/testing/selftests/kvm/Makefile          |    2 +-
>  .../kvm/aarch64/vpmu_counter_access.c         |  642 -------
>  .../testing/selftests/kvm/aarch64/vpmu_test.c | 1710 +++++++++++++++++
>  4 files changed, 1718 insertions(+), 643 deletions(-)
>  delete mode 100644 tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c
>  create mode 100644 tools/testing/selftests/kvm/aarch64/vpmu_test.c
>
> --
> 2.39.1.581.gbfd45094c4-goog
>
Oliver Upton Feb. 14, 2023, 8:19 a.m. UTC | #2
Hi Raghavendra,

On Mon, Feb 13, 2023 at 06:02:21PM +0000, Raghavendra Rao Ananta wrote:
> Hello,
> 
> This vPMU KVM selftest series is an extension to the selftests
> introduced by Reiji Watanabe in his series aims to limit the number
> of PMCs on vCPU from userspace [1].

Right off the bat, I'd much prefer it if the patches weren't posted this
way. Building on top of an in flight series requires that reviewers page
in the context from Reiji's selftest patch in another thread then read
what you have.

I imagine this happened organically because you two are developing in
parallel (which is great!), but at this point Reiji's kernel changes are
only tangientally related to the selftest. Given that, is it possible to
split the test + KVM changes into two distinct series that each of you
will own? That way it is possible to get the full picture from one email
thread alone.

> The idea behind this series is to expand the test coverage to include
> the tests that validates actions from userspace, such as allowing or
> denying certain events via KVM_ARM_VCPU_PMU_V3_FILTER attribute, KVM's
> guarding of the PMU attributes to count EL2/EL3 events, and formal KVM
> behavior that enables PMU emulation. The last part validates the guest
> expectations of the vPMU by setting up a stress test that force-migrates
> multiple vCPUs frequently across random pCPUs in the system, thus
> ensuring KVM's management of vCPU PMU contexts correctly.
> 
> Patch-1 renames the test file to be more generic.
> 
> Patch-2 refactors the existing tests for plugging-in the upcoming tests
> easily.

sidenote: if you wind up reposting the complete series these can just be
squashed into the original patch.

> Patch-3 and 4 add helper macros and functions respectively to interact
> with the cycle counter.
> 
> Patch-5 extends create_vpmu_vm() to accept an array of event filters
> as an argument that are to be applied to the VM.
> 
> Patch-6 tests the KVM_ARM_VCPU_PMU_V3_FILTER attribute by scripting
> various combinations of events that are to be allowed or denied to
> the guest and verifying guest's behavior.
> 
> Patch-7 adds test to validate KVM's handling of guest requests to count
> events in EL2/EL3.
> 
> Patch-8 introduces the vCPU migration stress testing by validating cycle
> counter and general purpose counter's behavior across vCPU migrations.
> 
> Patch-9, 10, and 11 expands the tests in patch-8 to validate
> overflow/IRQ functionality, chained events, and occupancy of all the PMU
> counters, respectively.
> 
> Patch-12 extends create_vpmu_vm() to create multiple vCPUs for the VM.
> 
> Patch-13 expands the stress tests for multiple vCPUs.
> 
> The series has been tested on hardwares with PMUv8p1 and PMUvp5.