From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 84DC23C1081 for ; Fri, 26 Jun 2026 21:35:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782509744; cv=none; b=SQcRazCE+cxxbTfEZEq+Btru93+iGirf01AW4q3Y31n+qfOmsPYtUGemNQQ4VuRXa4W8fJzjdPBKBtj9MzVy2ozllFR2ZTomWbXIJrev1q+B9jrZLa0S0bDfMzHHfD6eWXr7lZnczhTHE2u9Fm3YXw1FK41mxCVgNYNAW30MAo0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782509744; c=relaxed/simple; bh=kuU5LM3fvlkSR21au3e2Xd4AVeUOwm5tX2qycnU7BXQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=d0Veg2fSlh1brxx+jfTESjwTfLhb91rMb2X6speMEDXtucZAsViAfN+3aUZ80LCIvnXRmM4tUdbYE43dcXbnnG3dza76Xr2RgPT+YH+onCCSdQ5bBy4r3+05bYZ+UP+pvD9xYY6fN7Q1pbX5cN0qj8LRp0W20rnql/3uiAIpQqY= 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=Dea/MSPt; arc=none smtp.client-ip=209.85.216.74 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="Dea/MSPt" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-37e00ef16d9so1262824a91.2 for ; Fri, 26 Jun 2026 14:35:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782509742; x=1783114542; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=ht+2H0jf5K8WYzsVOZrAc6DiqyjXLSwmmI/Hl439zCU=; b=Dea/MSPtA5+Vq/HJ0wv0jOGBw3pKs63BLaajvS3BTLGWYes6nb48aqyDr+p/pzvZsL CAb3FZrMjSQduzlBa0y/mi6oDM1wjbZDeqpQm/LoRbCgwaiWjkyfxx8MFW2Q9YmGnHdo kH4XzMvur9YplR+VN3NPt7z3UhJ70atPM1vO/++gDkexuHh+c4oZR2R98qnJP/VHq7K2 KU8C3C/DjUIzBri5DjZ+RyjQtPbHh6kJ3QtgWEl5XxBxItxDKMQQnOdfclo9cxpybSMA Em4ahyhuFmyGNF9cRIyKRinZYolS5nULIrM7XyeMSAPimnN+WdhSUMq6vDoB0smJHIdr VFHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782509742; x=1783114542; h=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; bh=ht+2H0jf5K8WYzsVOZrAc6DiqyjXLSwmmI/Hl439zCU=; b=BZVbzB/4PqK7oQGKMvAtFXIugh/7C6qhz93GDMnACpxRUggtXs8ion4ycNqSoYXw98 nO8BYuVuZHXgJs4LQwlZfRrl6bKshrwJZc4NwGOa23QXeEsfwYqjMU3J7Tchg7mB4eFl NymV3Ym3pVOUp50yRxai/bLkmoMrvROEOBlwnkhp1/D1/3jSIE6fD659G+c43aZ6iyOl 4+brbXlZQRYwD2B4V8QoUS79c/IWHRJMpJADZi+szzfF207nK/3TiLkwLdhe4GHyBfaj cvxx2b1TW4Axj6INtbFd4ZLQZe4MKBcN4VaAMN2JWutVAB/fN2MsZX124NVaAjq3s8PF lE0w== X-Forwarded-Encrypted: i=1; AHgh+RrAQpyWdQsQ4L5nwQZxqsspOQ/6fsqAjy+DHtGYmOkixNh3jhPlntaEEOXVFRK8wQ03lgG8Ndd9/Zo1/Is=@vger.kernel.org X-Gm-Message-State: AOJu0YwhwFrkntdIJrYG4SbayGNh5gM3werZqzZnCWjr7xT/N6VHKaE0 OMPsFg/vQTNJSKrTydZwUq02v7XTZ4i+nYEeixZ317g0VHVEMGCTrr51zLIysmNGV73rTHslrL6 JwuG8CA== X-Received: from pjzp14.prod.google.com ([2002:a17:90b:10e:b0:37d:a52a:ff00]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:4acd:b0:36b:93f7:a903 with SMTP id 98e67ed59e1d1-37dfa25a0d4mr8609950a91.18.1782509741562; Fri, 26 Jun 2026 14:35:41 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 26 Jun 2026 14:35:17 -0700 In-Reply-To: <20260626213534.3866178-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260626213534.3866178-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.rc0.799.gd6f94ed593-goog Message-ID: <20260626213534.3866178-5-seanjc@google.com> Subject: [PATCH v8 04/20] KVM: selftests: Initialize the default/global pRNG during kvm_selftest_init() From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Oliver Upton , Sean Christopherson Cc: Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, David Matlack , Josh Hilke Content-Type: text/plain; charset="UTF-8" Initialize the default kvm_rng during selftest initialization so that the pRNG can be used by tests before creating a VM. As pointed out by Sashiko, failure to actually initialize the generate makes it decidedly not random. Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/lib/kvm_util.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 875030c22d07..1016865d3f7a 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -24,6 +24,13 @@ u32 kvm_random_seed; struct kvm_random_state kvm_rng; static u32 last_kvm_seed; +static void kvm_seed_rng(u32 seed) +{ + kvm_random_seed = last_kvm_seed = seed; + pr_info("Random seed: 0x%x\n", kvm_random_seed); + kvm_rng = new_kvm_random_state(kvm_random_seed); +} + static size_t vcpu_mmap_sz(void); int __open_path_or_exit(const char *path, int flags, const char *enoent_help) @@ -515,11 +522,9 @@ struct kvm_vm *__vm_create(struct vm_shape shape, u32 nr_runnable_vcpus, slot0 = memslot2region(vm, 0); ucall_init(vm, slot0->region.guest_phys_addr + slot0->region.memory_size); - if (kvm_random_seed != last_kvm_seed) { - pr_info("Random seed: 0x%x\n", kvm_random_seed); - last_kvm_seed = kvm_random_seed; - } - kvm_rng = new_kvm_random_state(kvm_random_seed); + if (kvm_random_seed != last_kvm_seed) + kvm_seed_rng(kvm_random_seed); + sync_global_to_guest(vm, kvm_rng); kvm_arch_vm_post_create(vm, nr_runnable_vcpus); @@ -2279,8 +2284,7 @@ void __attribute((constructor)) kvm_selftest_init(void) sigaction(SIGILL, &sig_sa, NULL); sigaction(SIGFPE, &sig_sa, NULL); - kvm_random_seed = last_kvm_seed = random(); - pr_info("Random seed: 0x%x\n", kvm_random_seed); + kvm_seed_rng(random()); kvm_selftest_arch_init(); } -- 2.55.0.rc0.799.gd6f94ed593-goog