From nobody Mon Feb 9 20:36:24 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=gmail.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1625705916350246.31588295774873; Wed, 7 Jul 2021 17:58:36 -0700 (PDT) Received: from localhost ([::1]:41966 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m1IN9-0005Mx-1i for importer@patchew.org; Wed, 07 Jul 2021 20:58:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37924) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m1IKk-0001mR-8s for qemu-devel@nongnu.org; Wed, 07 Jul 2021 20:56:06 -0400 Received: from mga06.intel.com ([134.134.136.31]:36375) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m1IKe-0007Kq-2D for qemu-devel@nongnu.org; Wed, 07 Jul 2021 20:56:02 -0400 Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jul 2021 17:55:54 -0700 Received: from ls.sc.intel.com (HELO localhost) ([143.183.96.54]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jul 2021 17:55:54 -0700 X-IronPort-AV: E=McAfee;i="6200,9189,10038"; a="270534892" X-IronPort-AV: E=Sophos;i="5.84,222,1620716400"; d="scan'208";a="270534892" X-IronPort-AV: E=Sophos;i="5.84,222,1620716400"; d="scan'208";a="423770018" From: isaku.yamahata@gmail.com To: qemu-devel@nongnu.org, pbonzini@redhat.com, alistair@alistair23.me, ehabkost@redhat.com, marcel.apfelbaum@gmail.com, mst@redhat.com, cohuck@redhat.com, mtosatti@redhat.com, xiaoyao.li@intel.com, seanjc@google.com, erdemaktas@google.com Subject: [RFC PATCH v2 09/44] target/i386: kvm: don't synchronize guest tsc for TD guest Date: Wed, 7 Jul 2021 17:54:39 -0700 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=134.134.136.31; envelope-from=isaku.yamahata@intel.com; helo=mga06.intel.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_ADSP_CUSTOM_MED=0.001, FORGED_GMAIL_RCVD=1, FREEMAIL_FORGED_FROMDOMAIN=0.25, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, NML_ADSP_CUSTOM_MED=0.9, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, kvm@vger.kernel.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZM-MESSAGEID: 1625705917161100002 Content-Type: text/plain; charset="utf-8" From: Isaku Yamahata Make kvm_synchronize_all_tsc() nop for TD-guest. TDX module specification, 9.11.1 TSC Virtualization "Virtual TSC values are consistent among all the TD;s VCPUs at the level suppored by the CPU". There is no need for qemu to synchronize tsc and VMM can't access to guest TSC. Actually do_kvm_synchronize_tsc() hits assert due to failure to write to guest tsc. > qemu/target/i386/kvm.c:235: kvm_get_tsc: Assertion `ret =3D=3D 1' failed. Signed-off-by: Isaku Yamahata Reviewed-by: Connor Kuehl --- target/i386/kvm/kvm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index c29cb420a1..ecb1714920 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -254,7 +254,7 @@ void kvm_synchronize_all_tsc(void) { CPUState *cpu; =20 - if (kvm_enabled()) { + if (kvm_enabled() && vm_type !=3D KVM_X86_TDX_VM) { CPU_FOREACH(cpu) { run_on_cpu(cpu, do_kvm_synchronize_tsc, RUN_ON_CPU_NULL); } --=20 2.25.1