From nobody Mon Feb 9 09:09:33 2026 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (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 655301F585E for ; Thu, 27 Feb 2025 02:19:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740622775; cv=none; b=TnYr7mqkFPk2Mtw6xus5Wanq0kot8wORlJmMgH+azF4nrOCNUxM86nuFkqok1df2lq9GBT1eDUn/BNDw1LnjbQkbvKlCwyKKUv6X3j5TTQ2QuxxXy3tA8WajJQdVhwUnr5MvC8PnzXwm59OjFJglKPP27pvBl5j4fskOP5Js64U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740622775; c=relaxed/simple; bh=P0O5mmkSnDe0SpsR7bTvnzJu0+xYte77F3QT24wbpm0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=C7JnJARFt6qq57BN5Wb4m0qJDeYogJeoJpWpzQ9e4+/FLUqy+GV2NPhyDo4Fb0XqtV9ewmngVDH7K7tniS8ZMQne1B3AdOcQk5yGuf1Iu8hzR6FBX0kskZ1Z6SAcUZZOisnPM5rQusZxqpzKuUtqjPPkMH8QMQMOsy8LdYzlB0k= 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=u0Xr9RMN; arc=none smtp.client-ip=209.85.214.202 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="u0Xr9RMN" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-220caea15ccso12391725ad.2 for ; Wed, 26 Feb 2025 18:19:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1740622773; x=1741227573; 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=iUPGjlm6EABKAwlimnT9Yj0uy9Y0kc3vikfZk6zMyUM=; b=u0Xr9RMNsxVJE42Vyec4L7wv5hwQgKsHPCI3qt4/2eAdpgqeuhscM35oaMtq/TN3P2 0OL5Txkr+v59vkD/mQGlG90xMPNHr40hnGkbTwftTkLVtbOsVSgmfMBTB2/okKnbuO6U I08xs79VLD3mMj0ZX2U1dFjUshA+JEDeSWuZjbvha2ZGCyzE1VmYZVwWkUxNTfFlmEwW +CXuxQD+e14M/diL8RKMkb93imPLoOwAJz/t5B8BqysLfCdpBRmyYfe8JsKHa2ayQ0NZ oCSyKNzdol48LlKRhGIhJrUhnIssbmQX/do7B4kVJDZqguvFRCbsK1mAWt8mim4PFa3z P1mQ== 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=vVOlYx+vXw7dzEU3wuRBqbEiQWHntgQ+MupivLTl7ZimTLFU/mJqv25pgD1V29QJZb DhCZmMSu8gWtdS+Dr4KSHeJmvFa2GnhH4VLJFKcdPpnNP3EHjXdihwQtTGZDUHlKrCZW ZVrmcTBNAtyEGcG3E5YhCSCBxv1PUuCqwJrdUjSIICDuPl775t1Kd7V0PWv44z/iPErO UKk/D0DdZ9IfD+/or+6LXvYpUBEHjGhj21sU5ktgArB7LnMEvvF0HyfEFraZNnM0cwET NL1amcFzqxBoRYO10clbZdwGe9odIeE2w6Wr061kD4/tGhoa3eN1dCd2k7OXaR7kgnh1 yiYQ== X-Gm-Message-State: AOJu0YynPVG1L2Nz4CQ/vzb/HPTGFM2FxstsbqH5/CQ66vrSAJHhbGFI 6+qODtSNzfQSp7khMBvzhU1Iryi/4HU6WPVU/0m12WQnqrZKQV2ZjDIlBgYO8GlAbosXKpmwa3f fVA== 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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; =20 void tsc_save_sched_clock_state(void) { - if (!sched_clock_stable()) + if (!sched_clock_stable() || WARN_ON_ONCE(!using_native_sched_clock())) return; =20 cyc2ns_suspend =3D sched_clock(); @@ -1010,7 +1010,7 @@ void tsc_restore_sched_clock_state(void) unsigned long flags; int cpu; =20 - if (!sched_clock_stable()) + if (!sched_clock_stable() || WARN_ON_ONCE(!using_native_sched_clock())) return; =20 local_irq_save(flags); --=20 2.48.1.711.g2feabab25a-goog