From patchwork Tue Feb 21 19:14:10 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andy Lutomirski X-Patchwork-Id: 9585387 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 EDB626042F for ; Tue, 21 Feb 2017 19:16:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E7E312852D for ; Tue, 21 Feb 2017 19:16:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DB153285F3; Tue, 21 Feb 2017 19:16:01 +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=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9C3382852D for ; Tue, 21 Feb 2017 19:16:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932306AbdBUTO0 (ORCPT ); Tue, 21 Feb 2017 14:14:26 -0500 Received: from mail.kernel.org ([198.145.29.136]:52066 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932294AbdBUTOX (ORCPT ); Tue, 21 Feb 2017 14:14:23 -0500 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 05CB32025A; Tue, 21 Feb 2017 19:14:21 +0000 (UTC) Received: from localhost (c-71-202-137-17.hsd1.ca.comcast.net [71.202.137.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F28B92024F; Tue, 21 Feb 2017 19:14:19 +0000 (UTC) From: Andy Lutomirski To: Paolo Bonzini , X86 ML Cc: kvm list , "linux-kernel@vger.kernel.org" , Borislav Petkov , Thomas Garnier , Jim Mattson , Andy Lutomirski , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= Subject: [PATCH v2 3/7] x86/kvm/vmx: Get rid of segment_base() on 64-bit kernels Date: Tue, 21 Feb 2017 11:14:10 -0800 Message-Id: X-Mailer: git-send-email 2.9.3 In-Reply-To: References: In-Reply-To: References: MIME-Version: 1.0 X-Virus-Scanned: ClamAV using ClamSMTP Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP It was a bit buggy (it didn't list all segment types that needed 64-bit fixups), but the bug was irrelevant because it wasn't called in any interesting context on 64-bit kernels and was only used for code and data segments on 32-bit kernels. To avoid confusion, make it explicitly 32-bit only. Cc: Thomas Garnier Cc: Jim Mattson Cc: Radim Krčmář Cc: Paolo Bonzini Signed-off-by: Andy Lutomirski --- arch/x86/kvm/vmx.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 46420aaf1684..b1810a0edec3 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2059,6 +2059,12 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset) } } +#ifdef CONFIG_X86_32 +/* + * On 32-bit kernels, VM exits still load the FS and GS bases from the + * VMCS rather than the segment table. KVM uses this helper to figure + * out the current bases to poke them into the VMCS before entry. + */ static unsigned long segment_base(u16 selector) { struct desc_ptr *gdt = this_cpu_ptr(&host_gdt); @@ -2081,12 +2087,9 @@ static unsigned long segment_base(u16 selector) } d = (struct desc_struct *)(table_base + (selector & ~7)); v = get_desc_base(d); -#ifdef CONFIG_X86_64 - if (d->s == 0 && (d->type == 2 || d->type == 9 || d->type == 11)) - v |= ((unsigned long)((struct ldttss_desc64 *)d)->base3) << 32; -#endif return v; } +#endif static void vmx_save_host_state(struct kvm_vcpu *vcpu) {