From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E194043CE5A for ; Tue, 4 Aug 2026 21:00:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785877252; cv=none; b=OmVBXEiDrXg5Qk3067acHwcyLudtDomYwckJDvGMQBhjnM64DUwd6KOMsIH60CkdlI1pXAN/ndnOWfrgPOXiW0GcPckwDSonsoFTxaMhIS3LwqlXQ9aMQAsj3E17FwQGD3NFV9MMN2bQfqNHsl0y2tXxWYbg10NTKiqhnomHoqo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785877252; c=relaxed/simple; bh=cxsYu/SAZXKKH+qzPWN68EM5LaGATeu0vffi9KXr19s=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=PVaFbB83BbecV6zPUL0afLHjiMuU4WXzctxYFVgDcGSFHJXYz2YQgjYAlSBFxd0FOjPhPvKgL455embi2yvl4jLqfSKlNqm+YUnm4i7jRBJCCYDxEtgE74Xo4ID5QV+i4emdkc9aPJRJNvDL2EMTOUn5WmccvwXtPDyi/SivHhU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=IYUweXdH; arc=none smtp.client-ip=209.85.210.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="IYUweXdH" Received: by mail-pf1-f199.google.com with SMTP id d2e1a72fcca58-84a67b16217so343178b3a.3 for ; Tue, 04 Aug 2026 14:00:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1785877250; x=1786482050; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:reply-to:from:to:cc:subject:date:message-id :reply-to:content-type; bh=UeyWwtdawyJZ7yaU5xxuUItmJbT+/6l6O65XfniG79w=; b=IYUweXdHYWSPRtxGr6juyRxIGuRlR49fgbWbYEwBPGxmUmcqBaxHJ77v9m/j8eFEr2 pQDlBF/PKa0nu/0KOJT4ySqrgPiDh4L+fBQ3RHEbIYa0msUoUCNhUMq5SzIu+t9ddLCH 2EgYZkTbdmDSvgK22X/AVRppTU1b6gQv45uJ8pxke0CAVwrohY+tZ2R0L0am6owB8v7D 2uXEN5Lq9jPyxz2sSc/bwEb2hVyhP6ksDMv7QPlWJ6y0HBKKjJKJhi7rUoGt7AOmdBEz ppEgE+xfxwbho722dD9n2f60JfG1q/NOM3IAgXW8/pxaGu1/pRnJaQ+y9hDrUpfFDERU i2lA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785877250; x=1786482050; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:reply-to:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to:content-type; bh=UeyWwtdawyJZ7yaU5xxuUItmJbT+/6l6O65XfniG79w=; b=l3lSDAZ82ocIK4N/+g00GMxoN6oYtc+L33HgczFlHaCARHn4QTW102VesYW5CxHMee KpVoaW9Zqjni/u4izDD0pQJUSyTViJF31kWgiJMe5Skfnoo4tMCT5eUSPKBuORsxMe5M XbtT038W9L0LNX8vcMvj0ir5z752O8oldc8/mhsGH+AQLSCRFQuXnIML4Rsrpp+aLAaV adwZ+nJympxIgWiai4EnBMPjJ4RbQ2yeQyiVg0CSXFiHQaVrr60dSDhT6DAGNHV8u3Yu mHXVgg263MBQX2emt1b+1cGljQdWa5sk7YiU6W/9CaiWQrt/714RcBEXB3OruQEFE25S dMzw== X-Forwarded-Encrypted: i=1; AHgh+RpYNfoeaU8mh/vdh4lnBjhOXFWrQj57BXca3pJb82wkJg7DzWDG2Cqev8mkAA+JBVwjNd8R/ll9p4HfXys=@vger.kernel.org X-Gm-Message-State: AOJu0YxJnT2I8Lk/g6BaGQxZSDj0exPNOX8uETFHzbPB0SLu+6aEh0aX QdFNImX3LecVxixViR5lOmWQo0jppE4pkjgsUgpGbxOKTpwRDbdQcOILKlGIq+hyCGe+p/8/cnF KNnM6rg== X-Received: from pfx48.prod.google.com ([2002:a05:6a00:a470:b0:848:81e8:f2d9]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:3d54:b0:847:8b1d:230d with SMTP id d2e1a72fcca58-84f2e014151mr1449461b3a.3.1785877250032; Tue, 04 Aug 2026 14:00:50 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 4 Aug 2026 14:00:45 -0700 In-Reply-To: <20260804210046.3413149-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260804210046.3413149-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.571.g244d577d93-goog Message-ID: <20260804210046.3413149-2-seanjc@google.com> Subject: [PATCH v3 1/2] KVM: selftests: Test one random GP counter in PMU arch events testcase From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" To significantly reduce the PMU counter test's runtime, without sacrificing test coverage in the aggregate, test a random GP counter in the arch events testcase instead of testing every possible GP counter. Testing every PMC in every run of the test significantly increases the runtime of the test, without providing an equivalent increase in validation coverage, as the odds of a KVM having a bug that only affected a subset of counters and only when testing all other counters are extremely low. Opportunistically clean up kvm_random_u64_in_range() to eliminate unnecessary newlines. Signed-off-by: Sean Christopherson --- .../testing/selftests/kvm/include/test_util.h | 4 ++-- tools/testing/selftests/kvm/lib/test_util.c | 22 +++++++++++++++---- .../selftests/kvm/x86/pmu_counters_test.c | 18 +++++++-------- 3 files changed, 28 insertions(+), 16 deletions(-) diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index e8356ee54d7b..a6a3e1657895 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -135,8 +135,8 @@ static inline u64 kvm_random_u64(struct kvm_random_state *state) return ((u64)kvm_random_u32(state) << 32) | kvm_random_u32(state); } -u64 kvm_random_u64_in_range(struct kvm_random_state *state, u64 min, - u64 max); +u32 kvm_random_u32_in_range(struct kvm_random_state *state, u32 min, u32 max); +u64 kvm_random_u64_in_range(struct kvm_random_state *state, u64 min, u64 max); enum vm_mem_backing_src_type { VM_MEM_SRC_ANONYMOUS, diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index 6b00ab11f3c0..4dff72f6bd34 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -43,12 +43,26 @@ u32 kvm_random_u32(struct kvm_random_state *state) return state->seed; } +/* Returns a random u32 in the inclusive range [min, max] */ +u32 kvm_random_u32_in_range(struct kvm_random_state *state, u32 min, u32 max) +{ + u32 value, range; + + TEST_ASSERT(min <= max, "PEBKAC, min = 0x%x, max = 0x%x", min, max); + + value = kvm_random_u32(state); + + range = max - min; + if (range == UINT_MAX) + return value; + + return min + (value % (range + 1)); +} + /* Returns a random u64 in the inclusive range [min, max] */ -u64 kvm_random_u64_in_range(struct kvm_random_state *state, u64 min, - u64 max) +u64 kvm_random_u64_in_range(struct kvm_random_state *state, u64 min, u64 max) { - u64 value; - u64 range; + u64 value, range; TEST_ASSERT(min <= max, "PEBKAC, min = 0x%lx, max = 0x%lx", min, max); diff --git a/tools/testing/selftests/kvm/x86/pmu_counters_test.c b/tools/testing/selftests/kvm/x86/pmu_counters_test.c index dc6afac3aa91..8abf17cc9469 100644 --- a/tools/testing/selftests/kvm/x86/pmu_counters_test.c +++ b/tools/testing/selftests/kvm/x86/pmu_counters_test.c @@ -273,6 +273,7 @@ static void guest_test_arch_event(u8 idx) struct kvm_x86_pmu_feature gp_event, fixed_event; u32 base_pmc_msr; unsigned int i; + u64 eventsel; /* The host side shouldn't invoke this without a guest PMU. */ GUEST_ASSERT(pmu_version); @@ -287,19 +288,16 @@ static void guest_test_arch_event(u8 idx) GUEST_ASSERT_EQ(idx, gp_event.f.bit); GUEST_ASSERT(nr_gp_counters); + i = kvm_random_u32_in_range(&kvm_rng, 0, nr_gp_counters - 1); - for (i = 0; i < nr_gp_counters; i++) { - u64 eventsel = ARCH_PERFMON_EVENTSEL_OS | - ARCH_PERFMON_EVENTSEL_ENABLE | - intel_pmu_arch_events[idx]; + eventsel = ARCH_PERFMON_EVENTSEL_OS | ARCH_PERFMON_EVENTSEL_ENABLE | + intel_pmu_arch_events[idx]; - wrmsr(MSR_P6_EVNTSEL0 + i, 0); - if (guest_has_perf_global_ctrl) - wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, BIT_ULL(i)); + wrmsr(MSR_P6_EVNTSEL0 + i, 0); + if (guest_has_perf_global_ctrl) + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, BIT_ULL(i)); - __guest_test_arch_event(idx, i, base_pmc_msr + i, - MSR_P6_EVNTSEL0 + i, eventsel); - } + __guest_test_arch_event(idx, i, base_pmc_msr + i, MSR_P6_EVNTSEL0 + i, eventsel); if (!guest_has_perf_global_ctrl) return; -- 2.55.0.571.g244d577d93-goog