From nobody Wed Dec 17 09:44:27 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F756C00A98 for ; Fri, 20 Oct 2023 15:13:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377670AbjJTPNM (ORCPT ); Fri, 20 Oct 2023 11:13:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377653AbjJTPNC (ORCPT ); Fri, 20 Oct 2023 11:13:02 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75FE9D6B for ; Fri, 20 Oct 2023 08:12:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697814780; x=1729350780; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=MPIjCtbNsICrtwqXzYBNDwDeX3sLS3gFAi6SoZOpAO8=; b=M3wr1ALKLBSje8Ikwl/9PKg8FPHyHjLUkUIp+ZmoLiszw/O/SRRBChfL h15XxMovWnD04y2yg/laqcGtYe9Zb1jLuIR2LAl6aIYNsw6MdyrdA50G6 R2dqBQIHmAd5Z5Rj4etimVSYHVwLcwR9/Jo4oK3A1/n7uKtZjBlqBQKwT b8JAJwDUZ3GVa0VUi3L3nZbHvIWPog/fvzcz906FvyCQ8K5hUPNsulk7n EyyrWxVr3mHZxx7wNDr6mZY6gYJpJ/n6AaQjLfbovPHsBaC2BF4e4/hxB CuZqNDoVdFCpypQVLh3qdiHJkWoHjdMHWCYzALwNuPkjsFLvKhzlcyij4 A==; X-IronPort-AV: E=McAfee;i="6600,9927,10869"; a="376893621" X-IronPort-AV: E=Sophos;i="6.03,239,1694761200"; d="scan'208";a="376893621" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2023 08:12:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10869"; a="761080250" X-IronPort-AV: E=Sophos;i="6.03,239,1694761200"; d="scan'208";a="761080250" Received: from dgutows1-mobl.ger.corp.intel.com (HELO box.shutemov.name) ([10.249.39.237]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2023 08:12:48 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id 10D5D10A296; Fri, 20 Oct 2023 18:12:45 +0300 (+03) From: "Kirill A. Shutemov" To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "Rafael J. Wysocki" , Peter Zijlstra , Adrian Hunter , Kuppuswamy Sathyanarayanan , Elena Reshetova , Jun Nakajima , Rick Edgecombe , Tom Lendacky , "Kalra, Ashish" , Sean Christopherson , "Huang, Kai" , Baoquan He , kexec@lists.infradead.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov Subject: [PATCHv2 04/13] x86/kvm: Do not try to disable kvmclock if it was not enabled Date: Fri, 20 Oct 2023 18:12:33 +0300 Message-ID: <20231020151242.1814-5-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231020151242.1814-1-kirill.shutemov@linux.intel.com> References: <20231020151242.1814-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" kvm_guest_cpu_offline() tries to disable kvmclock regardless if it is present in the VM. It leads to write to a MSR that doesn't exist on some configurations, namely in TDX guest: unchecked MSR access error: WRMSR to 0x12 (tried to write 0x00000000000000= 00) at rIP: 0xffffffff8110687c (kvmclock_disable+0x1c/0x30) kvmclock enabling is gated by CLOCKSOURCE and CLOCKSOURCE2 KVM paravirt features. Do not disable kvmclock if it was not enabled. Signed-off-by: Kirill A. Shutemov Fixes: c02027b5742b ("x86/kvm: Disable kvmclock on all CPUs on shutdown") Cc: Paolo Bonzini Cc: Wanpeng Li Cc: Vitaly Kuznetsov Cc: Sean Christopherson Reviewed-by: Sean Christopherson Reviewed-by: Vitaly Kuznetsov --- arch/x86/kernel/kvmclock.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index fb8f52149be9..f2fff625576d 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -24,8 +24,8 @@ =20 static int kvmclock __initdata =3D 1; static int kvmclock_vsyscall __initdata =3D 1; -static int msr_kvm_system_time __ro_after_init =3D MSR_KVM_SYSTEM_TIME; -static int msr_kvm_wall_clock __ro_after_init =3D MSR_KVM_WALL_CLOCK; +static int msr_kvm_system_time __ro_after_init; +static int msr_kvm_wall_clock __ro_after_init; static u64 kvm_sched_clock_offset __ro_after_init; =20 static int __init parse_no_kvmclock(char *arg) @@ -195,7 +195,8 @@ static void kvm_setup_secondary_clock(void) =20 void kvmclock_disable(void) { - native_write_msr(msr_kvm_system_time, 0, 0); + if (msr_kvm_system_time) + native_write_msr(msr_kvm_system_time, 0, 0); } =20 static void __init kvmclock_init_mem(void) @@ -294,7 +295,10 @@ void __init kvmclock_init(void) if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE2)) { msr_kvm_system_time =3D MSR_KVM_SYSTEM_TIME_NEW; msr_kvm_wall_clock =3D MSR_KVM_WALL_CLOCK_NEW; - } else if (!kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)) { + } else if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)) { + msr_kvm_system_time =3D MSR_KVM_SYSTEM_TIME; + msr_kvm_wall_clock =3D MSR_KVM_WALL_CLOCK; + } else { return; } =20 --=20 2.41.0