From patchwork Mon Jun 17 17:56:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liran Alon X-Patchwork-Id: 10999879 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 895EC924 for ; Mon, 17 Jun 2019 17:58:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7F33C2898D for ; Mon, 17 Jun 2019 17:58:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 734B7289C5; Mon, 17 Jun 2019 17:58:23 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=ham 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 1A2902898D for ; Mon, 17 Jun 2019 17:58:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728651AbfFQR6W (ORCPT ); Mon, 17 Jun 2019 13:58:22 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:47742 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728562AbfFQR6V (ORCPT ); Mon, 17 Jun 2019 13:58:21 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5HHs6kO148245; Mon, 17 Jun 2019 17:57:32 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=corp-2018-07-02; bh=49HRpG9G1+QXdfmmlaxcFNw0+wgkBMXI7yMkggaZdA8=; b=A2okq+D9xdwl+t0WEfkcPWvWMBc7wD0saM5Z/6+jHSbeTBlaw+IR7/o49p03iLVPqElm 2v8B69hzCZ08Ts7Ab+kU86o4GRMi65SWQHWnagBIr3D/mnBmcvp8Sn+sIAmmX6jPcwbw k5wkLx4w7P5V94/Cz2NWG2OIfT7RcIChx09w4ZmlzaaAiNT7gToYFm0qTwMo74mOzMxL DownXIdc9oTM8bN9er+pmvQw5AA9HBkfc9C/TJuAlOGRJRwQzSjVFzH+s1MuDMOcov4F Wn6fE3mcDDt96jNOLxrULRkhPuU1mwpq1Va7raiyMJjo29Zou5/NuDZXK8axfLomvqLb 6Q== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 2t4saq7w43-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 17 Jun 2019 17:57:32 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5HHvWaX130537; Mon, 17 Jun 2019 17:57:32 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3030.oracle.com with ESMTP id 2t59gdc0hq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 17 Jun 2019 17:57:32 +0000 Received: from abhmp0012.oracle.com (abhmp0012.oracle.com [141.146.116.18]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x5HHvUZF029068; Mon, 17 Jun 2019 17:57:30 GMT Received: from spark.ravello.local (/213.57.127.2) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 17 Jun 2019 10:57:29 -0700 From: Liran Alon To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, mtosatti@redhat.com, rth@twiddle.net, ehabkost@redhat.com, kvm@vger.kernel.org, jmattson@google.com, maran.wilson@oracle.com, dgilbert@redhat.com, Liran Alon , Nikita Leshenko , Krish Sadhukhan Subject: [QEMU PATCH v3 3/9] KVM: i386: Re-inject #DB to guest with updated DR6 Date: Mon, 17 Jun 2019 20:56:52 +0300 Message-Id: <20190617175658.135869-4-liran.alon@oracle.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190617175658.135869-1-liran.alon@oracle.com> References: <20190617175658.135869-1-liran.alon@oracle.com> MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9291 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906170160 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9291 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906170160 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If userspace (QEMU) debug guest, when #DB is raised in guest and intercepted by KVM, KVM forwards information on #DB to userspace instead of injecting #DB to guest. While doing so, KVM don't update vCPU DR6 but instead report the #DB DR6 value to userspace for further handling. See KVM's handle_exception() DB_VECTOR handler. QEMU handler for this case is kvm_handle_debug(). This handler basically checks if #DB is related to one of user set hardware breakpoints and if not, it re-inject #DB into guest. The re-injection is done by setting env->exception_injected to #DB which will later be passed as events.exception.nr to KVM_SET_VCPU_EVENTS ioctl by kvm_put_vcpu_events(). However, in case userspace re-injects #DB, KVM expects userspace to set vCPU DR6 as reported to userspace when #DB was intercepted! Otherwise, KVM_REQ_EVENT handler will inject #DB with wrong DR6 to guest. Fix this issue by updating vCPU DR6 appropriately when re-inject #DB to guest. Reviewed-by: Nikita Leshenko Reviewed-by: Krish Sadhukhan Signed-off-by: Liran Alon --- target/i386/kvm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 738dd91ff3cc..c8fd53055d37 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -3558,6 +3558,9 @@ static int kvm_handle_debug(X86CPU *cpu, /* pass to guest */ env->exception_injected = arch_info->exception; env->has_error_code = 0; + if (arch_info->exception == EXCP01_DB) { + env->dr[6] = arch_info->dr6; + } } return ret;