From patchwork Sun Jan 8 17:13:30 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 9503535 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CDCEC60212 for ; Sun, 8 Jan 2017 17:14:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BD39228391 for ; Sun, 8 Jan 2017 17:14:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B22EC283F6; Sun, 8 Jan 2017 17:14:07 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7359828391 for ; Sun, 8 Jan 2017 17:14:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756729AbdAHRNx (ORCPT ); Sun, 8 Jan 2017 12:13:53 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46676 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756563AbdAHRNv (ORCPT ); Sun, 8 Jan 2017 12:13:51 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A1FFF4E4CB; Sun, 8 Jan 2017 17:13:39 +0000 (UTC) Received: from localhost (ovpn-116-32.gru2.redhat.com [10.97.116.32]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v08HDciv025124; Sun, 8 Jan 2017 12:13:39 -0500 From: Eduardo Habkost To: qemu-devel@nongnu.org Cc: Marcelo Tosatti , Paolo Bonzini , kvm@vger.kernel.org, Haozhong Zhang Subject: [PATCH v2 2/2] kvm: Allow invtsc migration if tsc-khz is set explicitly Date: Sun, 8 Jan 2017 15:13:30 -0200 Message-Id: <20170108171330.11129-3-ehabkost@redhat.com> In-Reply-To: <20170108171330.11129-1-ehabkost@redhat.com> References: <20170108171330.11129-1-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Sun, 08 Jan 2017 17:13:39 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We can safely allow a VM to be migrated with invtsc enabled if tsc-khz is set explicitly, because: * QEMU already refuses to start if it can't set the TSC frequency to the configured value. * Management software is already required to keep device configuration (including CPU configuration) the same on migration source and destination. Signed-off-by: Eduardo Habkost --- Changes v1 -> v2: * Reworded commit message --- target/i386/kvm.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index a26290fdc1..6a51399945 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -962,15 +962,16 @@ int kvm_arch_init_vcpu(CPUState *cs) has_msr_mcg_ext_ctl = has_msr_feature_control = true; } - if ((env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC) && - invtsc_mig_blocker == NULL) { - /* for migration */ - error_setg(&invtsc_mig_blocker, - "State blocked by non-migratable CPU device" - " (invtsc flag)"); - migrate_add_blocker(invtsc_mig_blocker); - /* for savevm */ - vmstate_x86_cpu.unmigratable = 1; + if (!env->user_tsc_khz) { + if ((env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC) && + invtsc_mig_blocker == NULL) { + /* for migration */ + error_setg(&invtsc_mig_blocker, + "State blocked by non-migratable CPU device" + " (invtsc flag)"); + migrate_add_blocker(invtsc_mig_blocker); + /* for savevm */ + vmstate_x86_cpu.unmigratable = 1; } cpuid_data.cpuid.padding = 0;