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[v3,0/2] KVM: arm64: PMU event filtering fixes

Message ID 20231019185618.3442949-1-oliver.upton@linux.dev (mailing list archive)
Headers show
Series KVM: arm64: PMU event filtering fixes | expand

Message

Oliver Upton Oct. 19, 2023, 6:56 p.m. UTC 
PMU event exception level filtering fixes

Fixes to KVM's handling of the PMUv3 exception level filtering bits:

 - NSH (count at EL2) and M (count at EL3) should be stateful when the
   respective EL is advertised in the ID registers but have no effect on
   event counting.

 - NSU and NSK modify the event filtering of EL0 and EL1, respectively.
   Though the kernel may not use these bits, other KVM guests might.
   Implement these bits exactly as written in the pseudocode if EL3 is
   advertised.

v2: https://lore.kernel.org/kvmarm/20231013052901.170138-1-oliver.upton@linux.dev/

v2 -> v3:
 - Make the bits conditional on the ID register values
 - Allow the guest to set the M and NSH bits without effect (Marc)

Oliver Upton (2):
  KVM: arm64: Make PMEVTYPER<n>_EL0.NSH RES0 if EL2 isn't advertised
  KVM: arm64: Add PMU event filter bits required if EL3 is implemented

 arch/arm64/kvm/pmu-emul.c      | 36 +++++++++++++++++++++++++---------
 arch/arm64/kvm/sys_regs.c      |  8 ++++++--
 include/kvm/arm_pmu.h          |  5 +++++
 include/linux/perf/arm_pmuv3.h |  9 ++++++---
 4 files changed, 44 insertions(+), 14 deletions(-)


base-commit: 6465e260f48790807eef06b583b38ca9789b6072

Comments

Oliver Upton Oct. 24, 2023, 7:33 p.m. UTC | #1 
On Thu, 19 Oct 2023 18:56:16 +0000, Oliver Upton wrote:
> PMU event exception level filtering fixes
> 
> Fixes to KVM's handling of the PMUv3 exception level filtering bits:
> 
>  - NSH (count at EL2) and M (count at EL3) should be stateful when the
>    respective EL is advertised in the ID registers but have no effect on
>    event counting.
> 
> [...]

Applied to kvmarm/next, thanks!

[1/2] KVM: arm64: Make PMEVTYPER<n>_EL0.NSH RES0 if EL2 isn't advertised
      https://git.kernel.org/kvmarm/kvmarm/c/bc512d6a9b92
[2/2] KVM: arm64: Add PMU event filter bits required if EL3 is implemented
      https://git.kernel.org/kvmarm/kvmarm/c/ae8d3522e5b7

--
Best,
Oliver