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: 712400 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3txPzr4jwPz9sR9 for ; Mon, 9 Jan 2017 04:15:04 +1100 (AEDT) Received: from localhost ([::1]:34119 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cQH3c-00050r-27 for incoming@patchwork.ozlabs.org; Sun, 08 Jan 2017 12:15:00 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60838) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cQH2K-0004BV-Nj for qemu-devel@nongnu.org; Sun, 08 Jan 2017 12:13:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cQH2J-0006Hr-Im for qemu-devel@nongnu.org; Sun, 08 Jan 2017 12:13:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42092) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cQH2J-0006Gt-DS for qemu-devel@nongnu.org; Sun, 08 Jan 2017 12:13:39 -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 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) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 2/2] kvm: Allow invtsc migration if tsc-khz is set explicitly X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Marcelo Tosatti , kvm@vger.kernel.org, Haozhong Zhang Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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;