From patchwork Tue Jun 23 23:01:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 279640 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=DKIM_INVALID,DKIM_SIGNED, 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 D4004C433DF for ; Tue, 23 Jun 2020 23:02:49 +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 9B7CC20874 for ; Tue, 23 Jun 2020 23:02:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="T9jsu/6/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9B7CC20874 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]:56808 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jnrwG-0002yp-Su for qemu-devel@archiver.kernel.org; Tue, 23 Jun 2020 19:02:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48176) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jnruv-0001jg-8T for qemu-devel@nongnu.org; Tue, 23 Jun 2020 19:01:26 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:36120 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jnrus-00020F-1Z for qemu-devel@nongnu.org; Tue, 23 Jun 2020 19:01:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592953280; 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: content-transfer-encoding:content-transfer-encoding; bh=dSxfIsiKAOAuOkcH6/6KkAm1SJMN+fb41ElIwudmlpc=; b=T9jsu/6/vmW7ko9hCgfcWleTjt8YjgY7PI3Oc1+P+MI5M0qIyWOfxR7YtYDoFfbRVsreI9 u/ZKe5oFFmo7+DaGTAgGcNetRt/Tc4/4KsT0oQj/uIZBLxZdyi93OWWdEz60UNILkWzC25 xasSrFgavufaY9femhDmj7s+cn6SAFs= 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-258-TlDUT0zNOF2W3H6FnjZElg-1; Tue, 23 Jun 2020 19:01:18 -0400 X-MC-Unique: TlDUT0zNOF2W3H6FnjZElg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 503B7107ACF2; Tue, 23 Jun 2020 23:01:17 +0000 (UTC) Received: from localhost (ovpn-113-247.phx2.redhat.com [10.3.113.247]) by smtp.corp.redhat.com (Postfix) with ESMTP id 111725C1D4; Tue, 23 Jun 2020 23:01:16 +0000 (UTC) From: Eduardo Habkost To: qemu-devel@nongnu.org Subject: [PATCH] i386: Mask SVM features if nested SVM is disabled Date: Tue, 23 Jun 2020 19:01:16 -0400 Message-Id: <20200623230116.277409-1-ehabkost@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.120; envelope-from=ehabkost@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/23 01:53:54 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN 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: Yanan Fu , Eduardo Habkost , "Dr. David Alan Gilbert" , Babu Moger , Paolo Bonzini , Igor Mammedov , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" QEMU incorrectly validates FEAT_SVM feature flags against GET_SUPPORTED_CPUID even if SVM features are being masked out by cpu_x86_cpuid(). This can make QEMU print warnings on most AMD CPU models, even when SVM nesting is disabled (which is the default). This bug was never detected before because of a Linux KVM bug: until Linux v5.6, KVM was not filtering out SVM features in GET_SUPPORTED_CPUID when nested was disabled. This KVM bug was fixed in Linux v5.7-rc1, on Linux commit a50718cc3f43 ("KVM: nSVM: Expose SVM features to L1 iff nested is enabled"). Fix the problem by adding a CPUID_EXT3_SVM dependency to all FEAT_SVM feature flags in the feature_dependencies table. Reported-by: Yanan Fu Signed-off-by: Eduardo Habkost --- target/i386/cpu.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index b1b311baa2..a9edcaf531 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1404,6 +1404,10 @@ static FeatureDep feature_dependencies[] = { .from = { FEAT_VMX_SECONDARY_CTLS, VMX_SECONDARY_EXEC_ENABLE_VMFUNC }, .to = { FEAT_VMX_VMFUNC, ~0ull }, }, + { + .from = { FEAT_8000_0001_ECX, CPUID_EXT3_SVM }, + .to = { FEAT_SVM, ~0ull }, + }, }; typedef struct X86RegisterInfo32 {