From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Amirmohammad Eftekhar <amirmohammad.eftekhar@cispa.de>,
Sashiko Bot <sashiko-bot@kernel.org>
Subject: [PATCH v3 04/21] KVM: selftests: Use KVM's pRNG to randomize L1's TSC ratio in TSC scaling test
Date: Wed, 30 Sep 2026 10:36:18 -0700 [thread overview]
Message-ID: <20260930173635.3362655-5-seanjc@google.com> (raw)
In-Reply-To: <20260930173635.3362655-1-seanjc@google.com>
Use KVM's pRNG to randomize L1's TSC ratio in the nested TSC scaling test,
so that reproducing a failure with a specific seed is slightly easier.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
tools/testing/selftests/kvm/x86/nested_tsc_scaling_test.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/x86/nested_tsc_scaling_test.c b/tools/testing/selftests/kvm/x86/nested_tsc_scaling_test.c
index c763f4cf0f62..65de46f80a3e 100644
--- a/tools/testing/selftests/kvm/x86/nested_tsc_scaling_test.c
+++ b/tools/testing/selftests/kvm/x86/nested_tsc_scaling_test.c
@@ -166,8 +166,7 @@ int main(int argc, char *argv[])
* referenced by both main() and l1_guest_code() and using a global
* variable does not work.
*/
- srand(time(NULL));
- l1_scale_factor = (rand() % 9) + 2;
+ l1_scale_factor = (kvm_random_u32(&kvm_rng) % 9) + 2;
printf("L1's scale down factor is: %"PRIu64"\n", l1_scale_factor);
printf("L2's scale up factor is: %llu\n", L2_SCALE_FACTOR);
--
2.56.0.rc1.315.gc6ed9934b7-goog
next prev parent reply other threads:[~2026-09-30 17:37 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-30 17:36 [PATCH v3 00/21] KVM: x86: Fix nested TSC scaling edge cases Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 01/21] KVM: x86: Saturate L2's TSC frequency if it exceeds hardware supports Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 02/21] KVM: SVM: Fallback to the default TSC ratio if KVM tries to use a bad multiplier Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 03/21] KVM: x86: Allow userspace to set KVM's max supported guest TSC frequency Sean Christopherson
2026-09-30 17:36 ` Sean Christopherson [this message]
2026-09-30 17:36 ` [PATCH v3 05/21] KVM: selftests: Drop redundant VMWRITE of TSC_MULTIPLIER_HIGH Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 06/21] KVM: selftests: Drop unnecessary use of PRIu64 in nested TSC scaling test Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 07/21] KVM: selftests: Randomize L2's scale factor " Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 08/21] KVM: selftests: Rename TSC freq checkers " Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 09/21] KVM: selftests: Extract guts of nested TSC scaling test to helper function Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 10/21] KVM: selftests: Track L2 multiplier, not scale-up factor, in nested TSC test Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 11/21] KVM: selftests: Print out the failing L{0,1,2} level in nested TSC scaling test Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 12/21] KVM: selftests: Allow +/- 1 tolerance if expected TSC frequency is <100 Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 13/21] KVM: selftests: Use KVM's reported TSC KHz as L0's frequency (sanity checked) Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 14/21] KVM: selftests: Explicitly pass TSC frequencies to guts of TSC scaling test Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 15/21] KVM: selftests: Sanity check KVM's default TSC freq in nested " Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 16/21] KVM: selftests: Test L1 "up" and L2 "down" " Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 17/21] KVM: selftests: Verify that KVM saturates L2 TSC freq on {under,over}flow Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 18/21] KVM: selftests: Test non-zero TSC offset on SVM in nested TSC scaling test Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 19/21] KVM: selftests: Randomize L2's TSC offset in the " Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 20/21] KVM: selftests: Use GUEST_SYNC2() in " Sean Christopherson
2026-09-30 17:36 ` [PATCH v3 21/21] KVM: selftests: Spell out UCALL in nested TSC scaling test's enums Sean Christopherson
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