From patchwork Thu Feb 27 02:18:33 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 13993621 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9CDF7C19776 for ; Thu, 27 Feb 2025 02:26:52 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.897612.1306345 (Exim 4.92) (envelope-from ) id 1tnTbn-0007XD-VM; Thu, 27 Feb 2025 02:26:43 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 897612.1306345; Thu, 27 Feb 2025 02:26:43 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1tnTbn-0007WI-Rh; Thu, 27 Feb 2025 02:26:43 +0000 Received: by outflank-mailman (input) for mailman id 897612; Thu, 27 Feb 2025 02:26:42 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1tnTUt-00063X-PE for xen-devel@lists.xenproject.org; Thu, 27 Feb 2025 02:19:35 +0000 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [2607:f8b0:4864:20::649]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 4875acc8-f4b1-11ef-9898-31a8f345e629; Thu, 27 Feb 2025 03:19:34 +0100 (CET) Received: by mail-pl1-x649.google.com with SMTP id d9443c01a7336-2210305535bso12713345ad.1 for ; Wed, 26 Feb 2025 18:19:34 -0800 (PST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 4875acc8-f4b1-11ef-9898-31a8f345e629 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1740622773; x=1741227573; darn=lists.xenproject.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=iUPGjlm6EABKAwlimnT9Yj0uy9Y0kc3vikfZk6zMyUM=; b=wGmFhVUxZ15qHzYCAZmewBLmyp/Eu581w701AgHZPUQ9+Ww1W8Z9G5ML8wo102ZXt4 jY6UeZtB9By2V0udvxnTJhLohBxBLUhFZdcxagixbd8Jd9/0jw+1BZvZEFnyYf5AbeXq 80Lu5n0NyQzRv5eMKejbaiAFY2mP1zCD2COhtnWXxPA67bBSQlMNtvqsPVatp/vARKZ6 PjJ50bDM1FlEsQSjdQ4t+/ZWzUPFjzg7g/wGHHF6WheIRK67G+xq04qkiYaxOVe7cxn/ tYz1Embx8Vp0XSd5DOeLkGHu+EWCT7LCBU3ctZ6+Gb2FRqqvZWXLLOLaKlWFI799Ocfn 8TSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740622773; x=1741227573; 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=iUPGjlm6EABKAwlimnT9Yj0uy9Y0kc3vikfZk6zMyUM=; b=Q7cCoO7F6WTb00wuAf2jGkIC9BAceERHmXMzprKSgwE4c60sBxP0S5GxGbYo91Rh3f 1/a1jRWWxS7YVe3r6L0WVy/PpC0ouO89Ck9YFLJk4PvRIviQJiH1n7mEFL6/E9J6AZFo 6GqUHm2h0h8rgAiz3hK3zexD6bR5YSeLEwNz4bpRGuj9bKTLKs6XZ5eUxJU8XXF3IsOZ 5DjID9oZObsm5Ngqn43qeWcuhc4ngxOfSirStSLyh10OYaavz9MbISphZp0iPpfI+8CA pYj5DJV0VsRvOf569JaPWRwf/x5VhkqTI0ZxhvKAI3xgVpkDBHGO1S0vB/+KwKC1TScI DE5w== X-Forwarded-Encrypted: i=1; AJvYcCVGzvlAiuvkUUxyqY3HXwMVfpWIcs0ClEnE0m25PQddAETeseaIm9N7S+wopFMH6NOcdhqv0pksSj0=@lists.xenproject.org X-Gm-Message-State: AOJu0Yyor9GNoGTolafLCs/DYYq/iFOAbOZ+um7A96khEvaPgoO/cae3 XT1gM8dR7ZLQmDUBvqDXcnRZWXbd3rs0AFLhyXO+0HDq4LNpOa2WEkHKsvMarReywBmRLY1s2OG 85A== X-Google-Smtp-Source: AGHT+IESbVD77xvo7C+ciGzHtrGqGL0Rj+DzLIK2/TaODo5QawXajXsWSJTUc7OSugj7U0H5GgKBaGLNEhI= X-Received: from pfld12.prod.google.com ([2002:a05:6a00:198c:b0:732:7e28:8f7d]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:1813:b0:732:6221:7180 with SMTP id d2e1a72fcca58-73426c943c4mr38161657b3a.5.1740622772828; Wed, 26 Feb 2025 18:19:32 -0800 (PST) Reply-To: Sean Christopherson Date: Wed, 26 Feb 2025 18:18:33 -0800 In-Reply-To: <20250227021855.3257188-1-seanjc@google.com> Mime-Version: 1.0 References: <20250227021855.3257188-1-seanjc@google.com> X-Mailer: git-send-email 2.48.1.711.g2feabab25a-goog Message-ID: <20250227021855.3257188-18-seanjc@google.com> Subject: [PATCH v2 17/38] x86/tsc: WARN if TSC sched_clock save/restore used with PV sched_clock From: Sean Christopherson To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "Kirill A. Shutemov" , Paolo Bonzini , Sean Christopherson , Juergen Gross , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Ajay Kaher , Jan Kiszka , Andy Lutomirski , Peter Zijlstra , Daniel Lezcano , John Stultz Cc: linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org, virtualization@lists.linux.dev, linux-hyperv@vger.kernel.org, xen-devel@lists.xenproject.org, Tom Lendacky , Nikunj A Dadhania Now that all PV clocksources override the sched_clock save/restore hooks when overriding sched_clock, WARN if the "default" TSC hooks are invoked when using a PV sched_clock, e.g. to guard against regressions. Signed-off-by: Sean Christopherson --- arch/x86/kernel/tsc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 472d6c71d3a5..5501d76243c8 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -990,7 +990,7 @@ static unsigned long long cyc2ns_suspend; void tsc_save_sched_clock_state(void) { - if (!sched_clock_stable()) + if (!sched_clock_stable() || WARN_ON_ONCE(!using_native_sched_clock())) return; cyc2ns_suspend = sched_clock(); @@ -1010,7 +1010,7 @@ void tsc_restore_sched_clock_state(void) unsigned long flags; int cpu; - if (!sched_clock_stable()) + if (!sched_clock_stable() || WARN_ON_ONCE(!using_native_sched_clock())) return; local_irq_save(flags);