From patchwork Mon Jan 26 07:32:22 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nadav Amit X-Patchwork-Id: 5706941 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 8E93F9F1D6 for ; Mon, 26 Jan 2015 07:33:02 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 997F220121 for ; Mon, 26 Jan 2015 07:33:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA5CC20131 for ; Mon, 26 Jan 2015 07:33:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753110AbbAZHc4 (ORCPT ); Mon, 26 Jan 2015 02:32:56 -0500 Received: from mailgw10.technion.ac.il ([132.68.225.10]:24836 "EHLO mailgw10.technion.ac.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752657AbbAZHcu (ORCPT ); Mon, 26 Jan 2015 02:32:50 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AnMFAFHsxVSERCAB/2dsb2JhbABagwaBK8wtAoERQwEBAQEBAXyEDQEFeRBRVxmILM1WhEkBAQEHAgEfj3gHFoQTBapLIoNwbYJCAQEB X-IPAS-Result: AnMFAFHsxVSERCAB/2dsb2JhbABagwaBK8wtAoERQwEBAQEBAXyEDQEFeRBRVxmILM1WhEkBAQEHAgEfj3gHFoQTBapLIoNwbYJCAQEB X-IronPort-AV: E=Sophos;i="5.09,467,1418076000"; d="scan'208";a="7864482" Received: from csa.cs.technion.ac.il ([132.68.32.1]) by mailgw10.technion.ac.il with ESMTP; 26 Jan 2015 09:32:45 +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 235D114003D; Mon, 26 Jan 2015 09:32:44 +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 1E22BA1C54; Mon, 26 Jan 2015 09:32:44 +0200 (IST) From: Nadav Amit To: pbonzini@redhat.com Cc: kvm@vger.kernel.org, Nadav Amit Subject: [PATCH 2/7] KVM: x86: Wrong operand size for far ret Date: Mon, 26 Jan 2015 09:32:22 +0200 Message-Id: <1422257547-4557-3-git-send-email-namit@cs.technion.ac.il> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1422257547-4557-1-git-send-email-namit@cs.technion.ac.il> References: <1422257547-4557-1-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=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham 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 Indeed, Intel SDM specifically states that for the RET instruction "In 64-bit mode, the default operation size of this instruction is the stack-address size, i.e. 64 bits." However, experiments show this is not the case. Here is for example objdump of small 64-bit asm: 4004f1: ca 14 00 lret $0x14 4004f4: 48 cb lretq 4004f6: 48 ca 14 00 lretq $0x14 Therefore, remove the Stack flag from far-ret instructions. Signed-off-by: Nadav Amit --- arch/x86/kvm/emulate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index aa27254..dd71004 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -4062,8 +4062,8 @@ static const struct opcode opcode_table[256] = { G(ByteOp, group11), G(0, group11), /* 0xC8 - 0xCF */ I(Stack | SrcImmU16 | Src2ImmByte, em_enter), I(Stack, em_leave), - I(ImplicitOps | Stack | SrcImmU16, em_ret_far_imm), - I(ImplicitOps | Stack, em_ret_far), + I(ImplicitOps | SrcImmU16, em_ret_far_imm), + I(ImplicitOps, em_ret_far), D(ImplicitOps), DI(SrcImmByte, intn), D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret), /* 0xD0 - 0xD7 */