From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B80D9C433C1 for ; Tue, 30 Mar 2021 15:58:36 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0D60961924 for ; Tue, 30 Mar 2021 15:58:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D60961924 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:38158 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lRGlG-0007lq-ID for qemu-devel@archiver.kernel.org; Tue, 30 Mar 2021 11:58:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44348) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lRGkC-00079D-Ep for qemu-devel@nongnu.org; Tue, 30 Mar 2021 11:57:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:42112) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lRGk2-0002zR-8w for qemu-devel@nongnu.org; Tue, 30 Mar 2021 11:57:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617119834; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=R+pSf73bcchnYr98D5uePLn+RAaE7LYKNCbBF7Or7+Q=; b=fAl4wYbMJE08qfZ4HAjkQBd3BoBzLUtJAG+igW53briNNA4/FfFw4Tmul6FfBpB7cuZnyJ DcEB4NZgN3aW4QwtgYeWVhf4LI/iIs2r3hESUALFZ4EZSf8LEdrFL5/nxb9gZ9+L4nY6yt K2+Rhr8b3sEp8ETsmxBbdu/p4PO0Kq4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-120-kp-50RbKPdq_8O5TQ18FkA-1; Tue, 30 Mar 2021 11:57:12 -0400 X-MC-Unique: kp-50RbKPdq_8O5TQ18FkA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 56F5187A83E; Tue, 30 Mar 2021 15:57:11 +0000 (UTC) Received: from work-vm (ovpn-114-243.ams2.redhat.com [10.36.114.243]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CCC19505AE; Tue, 30 Mar 2021 15:57:05 +0000 (UTC) Date: Tue, 30 Mar 2021 16:57:02 +0100 From: "Dr. David Alan Gilbert" To: Vitaly Kuznetsov Subject: Re: [PATCH] i386: Make 'hv-reenlightenment' require explicit 'tsc-frequency' setting Message-ID: References: <20210330123603.284354-1-vkuznets@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210330123603.284354-1-vkuznets@redhat.com> User-Agent: Mutt/2.0.6 (2021-03-06) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: Eduardo Habkost , "Michael S. Tsirkin" , Richard Henderson , qemu-devel@nongnu.org, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Vitaly Kuznetsov (vkuznets@redhat.com) wrote: > Commit 561dbb41b1d7 "i386: Make migration fail when Hyper-V reenlightenment > was enabled but 'user_tsc_khz' is unset" forbade migrations with when guest > has opted for reenlightenment notifications but 'tsc-frequency' wasn't set > explicitly on the command line. This works but the migration fail late and > this may come as an unpleasant surprise. To make things more explicit, > require 'tsc-frequency=' on the command line when 'hv-reenlightenment' was > enabled. Make the change affect 6.0+ machine types only to preserve > previously-valid configurations valid. > > Signed-off-by: Vitaly Kuznetsov That looks better for me from a migration point of view: Acked-by: Dr. David Alan Gilbert > --- > docs/hyperv.txt | 1 + > hw/i386/pc.c | 1 + > target/i386/cpu.c | 23 +++++++++++++++++++++-- > target/i386/cpu.h | 1 + > 4 files changed, 24 insertions(+), 2 deletions(-) > > diff --git a/docs/hyperv.txt b/docs/hyperv.txt > index e53c581f4586..5b02d341ab25 100644 > --- a/docs/hyperv.txt > +++ b/docs/hyperv.txt > @@ -165,6 +165,7 @@ emulate TSC accesses after migration so 'tsc-frequency=' CPU option also has to > be specified to make migration succeed. The destination host has to either have > the same TSC frequency or support TSC scaling CPU feature. > > +Requires: tsc-frequency > Recommended: hv-frequencies > > 3.16. hv-evmcs > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > index 8a84b25a031e..47b79e949ad7 100644 > --- a/hw/i386/pc.c > +++ b/hw/i386/pc.c > @@ -98,6 +98,7 @@ > > GlobalProperty pc_compat_5_2[] = { > { "ICH9-LPC", "x-smi-cpu-hotunplug", "off" }, > + { TYPE_X86_CPU, "x-hv-reenlightenment-requires-tscfreq", "off"}, > }; > const size_t pc_compat_5_2_len = G_N_ELEMENTS(pc_compat_5_2); > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > index 6b3e9467f177..751636bafac5 100644 > --- a/target/i386/cpu.c > +++ b/target/i386/cpu.c > @@ -6647,10 +6647,23 @@ static void x86_cpu_filter_features(X86CPU *cpu, bool verbose) > } > } > > -static void x86_cpu_hyperv_realize(X86CPU *cpu) > +static void x86_cpu_hyperv_realize(X86CPU *cpu, Error **errp) > { > + CPUX86State *env = &cpu->env; > size_t len; > > + /* > + * Reenlightenment requires explicit 'tsc-frequency' setting for successful > + * migration (see hyperv_reenlightenment_post_load(). As 'hv-passthrough' > + * mode is not migratable, we can loosen the restriction. > + */ > + if (hyperv_feat_enabled(cpu, HYPERV_FEAT_REENLIGHTENMENT) && > + !cpu->hyperv_passthrough && !env->user_tsc_khz && > + cpu->hyperv_reenlightenment_requires_tscfreq) { > + error_setg(errp, "'hv-reenlightenment' requires 'tsc-frequency=' to be set"); > + return; > + } > + > /* Hyper-V vendor id */ > if (!cpu->hyperv_vendor) { > memcpy(cpu->hyperv_vendor_id, "Microsoft Hv", 12); > @@ -6846,7 +6859,11 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) > } > > /* Process Hyper-V enlightenments */ > - x86_cpu_hyperv_realize(cpu); > + x86_cpu_hyperv_realize(cpu, &local_err); > + if (local_err != NULL) { > + error_propagate(errp, local_err); > + return; > + } > > cpu_exec_realizefn(cs, &local_err); > if (local_err != NULL) { > @@ -7374,6 +7391,8 @@ static Property x86_cpu_properties[] = { > DEFINE_PROP_INT32("x-hv-max-vps", X86CPU, hv_max_vps, -1), > DEFINE_PROP_BOOL("x-hv-synic-kvm-only", X86CPU, hyperv_synic_kvm_only, > false), > + DEFINE_PROP_BOOL("x-hv-reenlightenment-requires-tscfreq", X86CPU, > + hyperv_reenlightenment_requires_tscfreq, true), > DEFINE_PROP_BOOL("x-intel-pt-auto-level", X86CPU, intel_pt_auto_level, > true), > DEFINE_PROP_END_OF_LIST() > diff --git a/target/i386/cpu.h b/target/i386/cpu.h > index 570f916878f9..0196a300f018 100644 > --- a/target/i386/cpu.h > +++ b/target/i386/cpu.h > @@ -1677,6 +1677,7 @@ struct X86CPU { > uint32_t hyperv_spinlock_attempts; > char *hyperv_vendor; > bool hyperv_synic_kvm_only; > + bool hyperv_reenlightenment_requires_tscfreq; > uint64_t hyperv_features; > bool hyperv_passthrough; > OnOffAuto hyperv_no_nonarch_cs; > -- > 2.30.2 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK