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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 33936C4360C for ; Thu, 26 Sep 2019 21:31:14 +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 0398B20872 for ; Thu, 26 Sep 2019 21:31:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0398B20872 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]:44658 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iDbM0-00057h-Vb for qemu-devel@archiver.kernel.org; Thu, 26 Sep 2019 17:31:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50388) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iDbKS-0004b6-Fe for qemu-devel@nongnu.org; Thu, 26 Sep 2019 17:29:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iDbKP-0004nO-Th for qemu-devel@nongnu.org; Thu, 26 Sep 2019 17:29:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51218) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iDbKP-0004kx-Jx for qemu-devel@nongnu.org; Thu, 26 Sep 2019 17:29:33 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A5E1B10DCC8F; Thu, 26 Sep 2019 21:29:27 +0000 (UTC) Received: from localhost (ovpn-116-45.gru2.redhat.com [10.97.116.45]) by smtp.corp.redhat.com (Postfix) with ESMTP id 15F365D6B0; Thu, 26 Sep 2019 21:29:26 +0000 (UTC) Date: Thu, 26 Sep 2019 18:29:25 -0300 From: Eduardo Habkost To: qemu-devel@nongnu.org Subject: Re: [PATCH] i386: Re-add "pconfig" CPUID flag name Message-ID: <20190926212925.GU8144@habkost.net> References: <20190926212326.4092-1-ehabkost@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190926212326.4092-1-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.64]); Thu, 26 Sep 2019 21:29:27 +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 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: thomas.lendacky@amd.com, luwei.kang@intel.com, berrange@redhat.com, Robert Hoo , kai.huang@intel.com, robert.hu@intel.com, Paolo Bonzini , Jiri Denemark , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Sep 26, 2019 at 06:23:26PM -0300, Eduardo Habkost wrote: > QEMU 3.1.0 was shipped with the "pconfig" CPU property available, > added by commit 5131dc433df5 ("i386: Add CPUID bit for PCONFIG"). > > Then the feature was removed in QEMU 4.0.0 (and 3.1.1), by commit > 712f807e1965 ("Revert 'i386: Add CPUID bit for PCONFIG'"). > > In theory this would be OK, but we do have a problem: existing > software (like libvirt) was already using "pconfig=off" since > QEMU 3.1.0 on some cases. This means software that worked with > QEMU 3.1.0 doesn't work with QEMU 3.1.1 and newer. > > One symptom is the following error being generated by > virt-install while trying to use the 'host-model' CPU model, on a > host that's identified as Icelake-Server: > > ERROR internal error: qemu unexpectedly closed the monitor: \ > 2019-09-24T22:57:42.550032Z qemu-kvm: \ > can't apply global Icelake-Server-x86_64-cpu.pconfig=off: Property '.pconfig' not found > > Re-add "pconfig" to feature_word_info[FEAT_7_0_EDX].feat_names so > "pconfig=off" will work again. > > This change still won't let users set "monitor=on" because all Sorry, I meant "pconfig=on" above. > accelerators currently report the feature as unsupported. But to > make sure PCONFIG won't be enabled by accident in the future > before we implement the necessary migration code, also add the > feature to .unmigratable_flags. > > Fixes: 712f807e1965 ("Revert 'i386: Add CPUID bit for PCONFIG'") > Signed-off-by: Eduardo Habkost > --- > target/i386/cpu.h | 2 ++ > target/i386/cpu.c | 8 +++++++- > 2 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/target/i386/cpu.h b/target/i386/cpu.h > index 8e090acd74..b728bd22f1 100644 > --- a/target/i386/cpu.h > +++ b/target/i386/cpu.h > @@ -731,6 +731,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS]; > #define CPUID_7_0_EDX_AVX512_4VNNIW (1U << 2) > /* AVX512 Multiply Accumulation Single Precision */ > #define CPUID_7_0_EDX_AVX512_4FMAPS (1U << 3) > +/* PCONFIG Instruction */ > +#define CPUID_7_0_EDX_PCONFIG (1U << 18) > /* Speculation Control */ > #define CPUID_7_0_EDX_SPEC_CTRL (1U << 26) > /* Arch Capabilities */ > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > index 71034aeb5a..3e25505bd3 100644 > --- a/target/i386/cpu.c > +++ b/target/i386/cpu.c > @@ -1084,7 +1084,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { > NULL, NULL, NULL, NULL, > NULL, NULL, "md-clear", NULL, > NULL, NULL, NULL, NULL, > - NULL, NULL, NULL /* pconfig */, NULL, > + NULL, NULL, "pconfig", NULL, > NULL, NULL, NULL, NULL, > NULL, NULL, "spec-ctrl", "stibp", > NULL, "arch-capabilities", "core-capability", "ssbd", > @@ -1095,6 +1095,12 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { > .reg = R_EDX, > }, > .tcg_features = TCG_7_0_EDX_FEATURES, > + /* > + * CPU state altered by the PCONFIG instruction (e.g. MKTME key table) > + * is not migrated by QEMU yet, so PCONFIG is unmigratable until > + * this is implemented. > + */ > + .unmigratable_flags = CPUID_7_0_EDX_PCONFIG, > }, > [FEAT_7_1_EAX] = { > .type = CPUID_FEATURE_WORD, > -- > 2.21.0 > -- Eduardo