From patchwork Tue May 9 11:20:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 9717675 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 A756560236 for ; Tue, 9 May 2017 11:22:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9AC7E2097A for ; Tue, 9 May 2017 11:22:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8F18B26E78; Tue, 9 May 2017 11:22:20 +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 lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 3EC0F2097A for ; Tue, 9 May 2017 11:22:20 +0000 (UTC) Received: from localhost ([::1]:36497 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d83Df-00053r-DZ for patchwork-qemu-devel@patchwork.kernel.org; Tue, 09 May 2017 07:22:19 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56674) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d83C8-0004jn-9s for qemu-devel@nongnu.org; Tue, 09 May 2017 07:20:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d83C7-00058s-25 for qemu-devel@nongnu.org; Tue, 09 May 2017 07:20:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57392) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d83C6-00058j-Ro for qemu-devel@nongnu.org; Tue, 09 May 2017 07:20:42 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CF450461EA; Tue, 9 May 2017 11:20:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com CF450461EA Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=berrange@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com CF450461EA Received: from t460.redhat.com (ovpn-117-114.ams2.redhat.com [10.36.117.114]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9907C7839D; Tue, 9 May 2017 11:20:38 +0000 (UTC) From: "Daniel P. Berrange" To: qemu-devel@nongnu.org Date: Tue, 9 May 2017 12:20:33 +0100 Message-Id: <20170509112034.23351-2-berrange@redhat.com> In-Reply-To: <20170509112034.23351-1-berrange@redhat.com> References: <20170509112034.23351-1-berrange@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 09 May 2017 11:20:42 +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 v3 1/2] i386: rewrite way CPUID index is validated 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 , Eduardo Habkost , Richard Henderson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Change the nested if statements into a flat format, to make it clearer what validation / capping is being performed on different CPUID index values. Signed-off-by: Daniel P. Berrange Reviewed-by: Eduardo Habkost --- target/i386/cpu.c | 35 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 20 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 13c0985..8cb4af4 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -2626,28 +2626,23 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, X86CPU *cpu = x86_env_get_cpu(env); CPUState *cs = CPU(cpu); uint32_t pkg_offset; + uint32_t limit; - /* test if maximum index reached */ - if (index & 0x80000000) { - if (index > env->cpuid_xlevel) { - if (env->cpuid_xlevel2 > 0) { - /* Handle the Centaur's CPUID instruction. */ - if (index > env->cpuid_xlevel2) { - index = env->cpuid_xlevel2; - } else if (index < 0xC0000000) { - index = env->cpuid_xlevel; - } - } else { - /* Intel documentation states that invalid EAX input will - * return the same information as EAX=cpuid_level - * (Intel SDM Vol. 2A - Instruction Set Reference - CPUID) - */ - index = env->cpuid_level; - } - } + /* Calculate & apply limits for different index ranges */ + if (index >= 0xC0000000) { + limit = env->cpuid_xlevel2; + } else if (index >= 0x80000000) { + limit = env->cpuid_xlevel; } else { - if (index > env->cpuid_level) - index = env->cpuid_level; + limit = env->cpuid_level; + } + + if (index > limit) { + /* Intel documentation states that invalid EAX input will + * return the same information as EAX=cpuid_level + * (Intel SDM Vol. 2A - Instruction Set Reference - CPUID) + */ + index = env->cpuid_level; } switch(index) {