linux-kernel - [PATCH 0/5] KVM: selftests: Fix PMC checks in PMU counters test

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Message-ID: <20250117234204.2600624-1-seanjc@google.com>
Date: Fri, 17 Jan 2025 15:41:58 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	kernel test robot <oliver.sang@...el.com>
Subject: [PATCH 0/5] KVM: selftests: Fix PMC checks in PMU counters test

Fix a flaw in the Intel PMU counters test where it asserts that an event is
counting correctly without actually knowing what the event counts given the
underlying hardware.

The bug manifests as failures with the Top-Down Slots architectural event
when running CPUs that doesn't actually support that arch event (pre-ICX).
The arch event encoding still counts _something_, just not Top-Down Slots
(I haven't bothered to look up what it was counting).  The passed by sheer
dumb luck until an unrelated change caused the count of the unknown event
to drop.

All credit to Dapeng for hunting down the problem.

Sean Christopherson (5):
  KVM: selftests: Make Intel arch events globally available in PMU
    counters test
  KVM: selftests: Only validate counts for hardware-supported arch
    events
  KVM: selftests: Remove dead code in Intel PMU counters test
  KVM: selftests: Drop the "feature event" param from guest test helpers
  KVM: selftests: Print out the actual Top-Down Slots count on failure

 .../selftests/kvm/x86/pmu_counters_test.c     | 143 ++++++++++--------
 1 file changed, 83 insertions(+), 60 deletions(-)

base-commit: eb723766b1030a23c38adf2348b7c3d1409d11f0
-- 
2.48.0.rc2.279.g1de40edade-goog