From patchwork Sun Nov 2 09:54:49 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nadav Amit X-Patchwork-Id: 5211521 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 6692FC11AD for ; Sun, 2 Nov 2014 09:55:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A4EDD20173 for ; Sun, 2 Nov 2014 09:55:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9F62201BB for ; Sun, 2 Nov 2014 09:55:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752008AbaKBJzy (ORCPT ); Sun, 2 Nov 2014 04:55:54 -0500 Received: from mailgw12.technion.ac.il ([132.68.225.12]:47167 "EHLO mailgw12.technion.ac.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751748AbaKBJzZ (ORCPT ); Sun, 2 Nov 2014 04:55:25 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ArMCAAH/VVSERCABjGdsb2JhbABc2R4CgRAWAQEBAQEBEAEBASdChAMBBSdSEFFXGYhBwyuFaAEBAQcCAR+REAcWhDUFuEtqgksBAQE X-IPAS-Result: ArMCAAH/VVSERCABjGdsb2JhbABc2R4CgRAWAQEBAQEBEAEBASdChAMBBSdSEFFXGYhBwyuFaAEBAQcCAR+REAcWhDUFuEtqgksBAQE X-IronPort-AV: E=Sophos;i="5.07,295,1413234000"; d="scan'208";a="127554972" Received: from csa.cs.technion.ac.il ([132.68.32.1]) by mailgw12.technion.ac.il with ESMTP; 02 Nov 2014 11:55:12 +0200 Received: from csn.cs.technion.ac.il (csn.cs.technion.ac.il [132.68.32.15]) by csa.cs.technion.ac.il (Postfix) with ESMTP id 111BC140045; Sun, 2 Nov 2014 11:55:10 +0200 (IST) Received: from csl-tapuz20.cs.technion.ac.il (csl-tapuz20.cs.technion.ac.il [132.68.206.58]) by csn.cs.technion.ac.il (Postfix) with ESMTPSA id CB27CA1BFF; Sun, 2 Nov 2014 11:55:09 +0200 (IST) From: Nadav Amit To: pbonzini@redhat.com Cc: kvm@vger.kernel.org, nadav.amit@gmail.com, Nadav Amit Subject: [PATCH 09/21] KVM: x86: SYSCALL cannot clear eflags[1] Date: Sun, 2 Nov 2014 11:54:49 +0200 Message-Id: <1414922101-17626-10-git-send-email-namit@cs.technion.ac.il> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1414922101-17626-1-git-send-email-namit@cs.technion.ac.il> References: <1414922101-17626-1-git-send-email-namit@cs.technion.ac.il> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP SYSCALL emulation currently clears in 64-bit mode eflags according to MSR_SYSCALL_MASK. However, on bare-metal eflags[1] which is fixed to one cannot be cleared, even if MSR_SYSCALL_MASK masks the bit. This wrong behavior may result in failed VM-entry, as VT disallows entry with eflags[1] cleared. This patch sets the bit after masking eflags on syscall. Signed-off-by: Nadav Amit --- arch/x86/kvm/emulate.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index e624d62..f1484bb 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2286,6 +2286,7 @@ static int em_syscall(struct x86_emulate_ctxt *ctxt) ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data); ctxt->eflags &= ~msr_data; + ctxt->eflags |= EFLG_RESERVED_ONE_MASK; #endif } else { /* legacy mode */