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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 6F631C3F2D1 for ; Thu, 5 Mar 2020 01:35:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5021C20870 for ; Thu, 5 Mar 2020 01:35:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726981AbgCEBfR (ORCPT ); Wed, 4 Mar 2020 20:35:17 -0500 Received: from mga06.intel.com ([134.134.136.31]:44313 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725948AbgCEBel (ORCPT ); Wed, 4 Mar 2020 20:34:41 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Mar 2020 17:34:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,516,1574150400"; d="scan'208";a="234301760" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by fmsmga008.fm.intel.com with ESMTP; 04 Mar 2020 17:34:40 -0800 From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Pu Wen Subject: [PATCH v2 6/7] KVM: x86: Refactor out-of-range logic to contain the madness Date: Wed, 4 Mar 2020 17:34:36 -0800 Message-Id: <20200305013437.8578-7-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200305013437.8578-1-sean.j.christopherson@intel.com> References: <20200305013437.8578-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Move all of the out-of-range logic into a single helper, get_out_of_range_cpuid_entry(), to avoid an extra lookup of CPUID.0.0 and to provide a single location for documenting the out-of-range behavior. No functional change intended. Cc: Jim Mattson Signed-off-by: Sean Christopherson --- arch/x86/kvm/cpuid.c | 47 +++++++++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 18 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index dd3c91ffae11..e4f104c7ace8 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -1020,13 +1020,19 @@ EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); * - Extended: 0x80000000 - 0xbfffffff, 0xd0000000 - 0xffffffff * - Centaur: 0xc0000000 - 0xcfffffff */ -static bool cpuid_function_in_range(struct kvm_vcpu *vcpu, u32 function) +static struct kvm_cpuid_entry2 * +get_out_of_range_cpuid_entry(struct kvm_vcpu *vcpu, u32 *fn_ptr, u32 index) { struct kvm_cpuid_entry2 *basic, *class; + u32 function = *fn_ptr; basic = kvm_find_cpuid_entry(vcpu, 0, 0); if (!basic) - return true; + return NULL; + + if (is_guest_vendor_amd(basic->ebx, basic->ecx, basic->edx) || + is_guest_vendor_hygon(basic->ebx, basic->ecx, basic->edx)) + return NULL; if (function >= 0x40000000 && function <= 0x4fffffff) class = kvm_find_cpuid_entry(vcpu, function & 0xffffff00, 0); @@ -1036,7 +1042,23 @@ static bool cpuid_function_in_range(struct kvm_vcpu *vcpu, u32 function) else class = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); - return class && function <= class->eax; + if (class && function <= class->eax) + return NULL; + + /* + * Leaf specific adjustments are also applied when redirecting to the + * max basic entry, e.g. if the max basic leaf is 0xb but there is no + * entry for CPUID.0xb.index (see below), then the output value for EDX + * needs to be pulled from CPUID.0xb.1. + */ + *fn_ptr = basic->eax; + + /* + * The class does not exist or the requested function is out of range; + * the effective CPUID entry is the max basic leaf. Note, the index of + * the original requested leaf is observed! + */ + return kvm_find_cpuid_entry(vcpu, basic->eax, index); } bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, @@ -1044,25 +1066,14 @@ bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, { u32 orig_function = *eax, function = *eax, index = *ecx; struct kvm_cpuid_entry2 *entry; - struct kvm_cpuid_entry2 *max; bool found; entry = kvm_find_cpuid_entry(vcpu, function, index); found = entry; - /* - * Intel CPUID semantics treats any query for an out-of-range - * leaf as if the highest basic leaf (i.e. CPUID.0H:EAX) were - * requested. AMD CPUID semantics returns all zeroes for any - * undefined leaf, whether or not the leaf is in range. - */ - if (!entry && check_limit && !guest_cpuid_is_amd_or_hygon(vcpu) && - !cpuid_function_in_range(vcpu, function)) { - max = kvm_find_cpuid_entry(vcpu, 0, 0); - if (max) { - function = max->eax; - entry = kvm_find_cpuid_entry(vcpu, function, index); - } - } + + if (!entry && check_limit) + entry = get_out_of_range_cpuid_entry(vcpu, &function, index); + if (entry) { *eax = entry->eax; *ebx = entry->ebx; -- 2.24.1