From patchwork Thu Oct 2 22:10:02 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nadav Amit X-Patchwork-Id: 5020611 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 [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B63389F327 for ; Thu, 2 Oct 2014 22:10:38 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id F0C352010E for ; Thu, 2 Oct 2014 22:10:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1AC7D20114 for ; Thu, 2 Oct 2014 22:10:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752680AbaJBWK2 (ORCPT ); Thu, 2 Oct 2014 18:10:28 -0400 Received: from mailgw12.technion.ac.il ([132.68.225.12]:24923 "EHLO mailgw12.technion.ac.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751778AbaJBWKV (ORCPT ); Thu, 2 Oct 2014 18:10:21 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AssBAJDMLVSERCABjGdsb2JhbABfg2FYynWHTQKBDRYBARABAQEnQIQEAQV5EFFXBxKIPg23YoY6GI9CZAeESwWLVIpaiHSXemkBAQGBA4FEAQEB X-IPAS-Result: AssBAJDMLVSERCABjGdsb2JhbABfg2FYynWHTQKBDRYBARABAQEnQIQEAQV5EFFXBxKIPg23YoY6GI9CZAeESwWLVIpaiHSXemkBAQGBA4FEAQEB X-IronPort-AV: E=Sophos;i="5.04,641,1406581200"; d="scan'208";a="124253433" Received: from csa.cs.technion.ac.il ([132.68.32.1]) by mailgw12.technion.ac.il with ESMTP; 03 Oct 2014 01:10:17 +0300 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 764B714003B; Fri, 3 Oct 2014 01:10:16 +0300 (IDT) 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 6AB9DA0C6D; Fri, 3 Oct 2014 01:10:16 +0300 (IDT) From: Nadav Amit To: pbonzini@redhat.com, joro@8bytes.org Cc: kvm@vger.kernel.org, Nadav Amit Subject: [PATCH 1/5] KVM: x86: Clear DR7.LE during task-switch Date: Fri, 3 Oct 2014 01:10:02 +0300 Message-Id: <1412287806-16016-2-git-send-email-namit@cs.technion.ac.il> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1412287806-16016-1-git-send-email-namit@cs.technion.ac.il> References: <1412287806-16016-1-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=-7.9 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 DR7.LE should be cleared during task-switch. This feature is poorly documented. For reference, see: http://pdos.csail.mit.edu/6.828/2005/readings/i386/s12_02.htm Signed-off-by: Nadav Amit Reviewed-by: Radim Kr?má? --- arch/x86/kvm/vmx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 04fa1b8..4190eb5 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5483,7 +5483,7 @@ static int handle_task_switch(struct kvm_vcpu *vcpu) } /* clear all local breakpoint enable flags */ - vmcs_writel(GUEST_DR7, vmcs_readl(GUEST_DR7) & ~0x55); + vmcs_writel(GUEST_DR7, vmcs_readl(GUEST_DR7) & ~0x155); /* * TODO: What about debug traps on tss switch?