From patchwork Sat Feb 1 18:51:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 11361271 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9AB1B112B for ; Sat, 1 Feb 2020 18:54:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 78798206E6 for ; Sat, 1 Feb 2020 18:54:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727260AbgBASwd (ORCPT ); Sat, 1 Feb 2020 13:52:33 -0500 Received: from mga02.intel.com ([134.134.136.20]:11286 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727152AbgBASwa (ORCPT ); Sat, 1 Feb 2020 13:52:30 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Feb 2020 10:52:27 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,390,1574150400"; d="scan'208";a="248075498" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga002.jf.intel.com with ESMTP; 01 Feb 2020 10:52:25 -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 Subject: [PATCH 23/61] KVM: x86: Clear output regs for CPUID 0x14 if PT isn't exposed to guest Date: Sat, 1 Feb 2020 10:51:40 -0800 Message-Id: <20200201185218.24473-24-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200201185218.24473-1-sean.j.christopherson@intel.com> References: <20200201185218.24473-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Clear the output regs for the main CPUID 0x14 leaf (index=0) if Intel PT isn't exposed to the guest. Leaf 0x14 enumerates Intel PT capabilities and should return zeroes if PT is not supported. Incorrectly reporting PT capabilities is essentially a cosmetic error, i.e. doesn't negatively affect any known userspace/kernel, as the existence of PT itself is correctly enumerated via CPUID 0x7. Signed-off-by: Sean Christopherson Reviewed-by: Vitaly Kuznetsov --- arch/x86/kvm/cpuid.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index d3c93b94abc3..056faf27b14b 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -663,8 +663,10 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) break; /* Intel PT */ case 0x14: - if (!f_intel_pt) + if (!f_intel_pt) { + entry->eax = entry->ebx = entry->ecx = entry->edx = 0; break; + } for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) { if (!do_host_cpuid(array, function, i))