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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 22E9EC2D0CE for ; Fri, 24 Jan 2020 23:07:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E421B2075D for ; Fri, 24 Jan 2020 23:07:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729375AbgAXXHZ (ORCPT ); Fri, 24 Jan 2020 18:07:25 -0500 Received: from mga05.intel.com ([192.55.52.43]:25112 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729182AbgAXXHZ (ORCPT ); Fri, 24 Jan 2020 18:07:25 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Jan 2020 15:07:24 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,359,1574150400"; d="scan'208";a="221171775" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga008.jf.intel.com with ESMTP; 24 Jan 2020 15:07:23 -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, Krish Sadhukhan , Randy Dunlap Subject: [PATCH] KVM: x86: Take a u64 when checking for a valid dr7 value Date: Fri, 24 Jan 2020 15:07:22 -0800 Message-Id: <20200124230722.8964-1-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 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 Take a u64 instead of an unsigned long in kvm_dr7_valid() to fix a build warning on i386 due to right-shifting a 32-bit value by 32 when checking for bits being set in dr7[63:32]. Alternatively, the warning could be resolved by rewriting the check to use an i386-friendly method, but taking a u64 fixes another oddity on 32-bit KVM. Beause KVM implements natural width VMCS fields as u64s to avoid layout issues between 32-bit and 64-bit, a devious guest can stuff vmcs12->guest_dr7 with a 64-bit value even when both the guest and host are 32-bit kernels. KVM eventually drops vmcs12->guest_dr7[63:32] when propagating vmcs12->guest_dr7 to vmcs02, but ideally KVM would not rely on that behavior for correctness. Cc: Jim Mattson Cc: Krish Sadhukhan Fixes: ecb697d10f70 ("KVM: nVMX: Check GUEST_DR7 on vmentry of nested guests") Reported-by: Randy Dunlap Signed-off-by: Sean Christopherson --- arch/x86/kvm/x86.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 2d2ff855773b..3624665acee4 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -357,7 +357,7 @@ static inline bool kvm_pat_valid(u64 data) return (data | ((data & 0x0202020202020202ull) << 1)) == data; } -static inline bool kvm_dr7_valid(unsigned long data) +static inline bool kvm_dr7_valid(u64 data) { /* Bits [63:32] are reserved */ return !(data >> 32); -- 2.24.1