From patchwork Mon Dec 27 14:58:23 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kiszka X-Patchwork-Id: 76791 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id F4087B70D5 for ; Tue, 28 Dec 2010 02:02:54 +1100 (EST) Received: from localhost ([127.0.0.1]:40618 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PXEb5-0001Ps-8v for incoming@patchwork.ozlabs.org; Mon, 27 Dec 2010 10:02:51 -0500 Received: from [140.186.70.92] (port=38431 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PXEY7-00005H-MO for qemu-devel@nongnu.org; Mon, 27 Dec 2010 09:59:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PXEY6-0005PC-AS for qemu-devel@nongnu.org; Mon, 27 Dec 2010 09:59:47 -0500 Received: from fmmailgate02.web.de ([217.72.192.227]:35697) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PXEY5-0005On-TV for qemu-devel@nongnu.org; Mon, 27 Dec 2010 09:59:46 -0500 Received: from smtp04.web.de ( [172.20.0.225]) by fmmailgate02.web.de (Postfix) with ESMTP id 67BAA1926A766; Mon, 27 Dec 2010 15:58:24 +0100 (CET) Received: from [178.3.214.57] (helo=mchn199C.mchp.siemens.de) by smtp04.web.de with asmtp (TLSv1:AES256-SHA:256) (WEB.DE 4.110 #2) id 1PXEWm-0004eN-00; Mon, 27 Dec 2010 15:58:24 +0100 Message-ID: <4D18A98F.3070303@web.de> Date: Mon, 27 Dec 2010 15:58:23 +0100 From: Jan Kiszka User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 To: Avi Kivity , Marcelo Tosatti X-Enigmail-Version: 1.1.2 X-Sender: jan.kiszka@web.de X-Provags-ID: V01U2FsdGVkX1/v1SWKycEX788146kQJfwxxQAqxO7jIOnElgY5 BbFOk5qoMyB+cfYUwZJOrbKUkRHd3MTcPGvgDdN4qkO38SAk9l /3AV4xDII= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4-2.6 Cc: qemu-devel , kvm Subject: [Qemu-devel] [PATCH] kvm: x86: Prevent sign extension of DR7 in guest debugging mode X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Jan Kiszka This unbreaks guest debugging when the 4th hardware breakpoint used for guest debugging is a watchpoint of 4 or 8 byte lenght. The 31st bit of DR7 is set in that case and used to cause a sign extension to the high word which was breaking the guest state (vm entry failure). Signed-off-by: Jan Kiszka --- target-i386/kvm.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 9a4bf98..218812a 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -1693,7 +1693,7 @@ void kvm_arch_update_guest_debug(CPUState *env, struct kvm_guest_debug *dbg) dbg->arch.debugreg[n] = hw_breakpoint[n].addr; dbg->arch.debugreg[7] |= (2 << (n * 2)) | (type_code[hw_breakpoint[n].type] << (16 + n*4)) | - (len_code[hw_breakpoint[n].len] << (18 + n*4)); + ((uint32_t)len_code[hw_breakpoint[n].len] << (18 + n*4)); } } /* Legal xcr0 for loading */