From patchwork Tue Aug 7 14:52:45 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 1286101 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 6C8163FDD5 for ; Tue, 7 Aug 2012 14:53:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755266Ab2HGOw5 (ORCPT ); Tue, 7 Aug 2012 10:52:57 -0400 Received: from e06smtp10.uk.ibm.com ([195.75.94.106]:46386 "EHLO e06smtp10.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755251Ab2HGOwy (ORCPT ); Tue, 7 Aug 2012 10:52:54 -0400 Received: from /spool/local by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 7 Aug 2012 15:52:52 +0100 Received: from b06cxnps3075.portsmouth.uk.ibm.com (9.149.109.195) by e06smtp10.uk.ibm.com (192.168.101.140) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Tue, 7 Aug 2012 15:52:50 +0100 Received: from d06av01.portsmouth.uk.ibm.com (d06av01.portsmouth.uk.ibm.com [9.149.37.212]) by b06cxnps3075.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q77EqiDK19071144; Tue, 7 Aug 2012 14:52:44 GMT Received: from d06av01.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av01.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q77EqnLH009278; Tue, 7 Aug 2012 08:52:50 -0600 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d06av01.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q77EqmHm009235; Tue, 7 Aug 2012 08:52:48 -0600 From: Cornelia Huck To: KVM , linux-s390 , qemu-devel Cc: Avi Kivity , Marcelo Tosatti , Anthony Liguori , Rusty Russell , Christian Borntraeger , Carsten Otte , Alexander Graf , Heiko Carstens , Martin Schwidefsky , Sebastian Ott Subject: [PATCH 1/4] s390/kvm: Handle hosts not supporting s390-virtio. Date: Tue, 7 Aug 2012 16:52:45 +0200 Message-Id: <1344351168-2568-2-git-send-email-cornelia.huck@de.ibm.com> X-Mailer: git-send-email 1.7.11.4 In-Reply-To: <1344351168-2568-1-git-send-email-cornelia.huck@de.ibm.com> References: <1344351168-2568-1-git-send-email-cornelia.huck@de.ibm.com> x-cbid: 12080714-4966-0000-0000-0000032837CA Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Running under a kvm host does not necessarily imply the presence of a page mapped above the main memory with the virtio information; however, the code includes a hard coded access to that page. Instead, check for the presence of the page and exit gracefully before we hit an addressing exception if it does not exist. Signed-off-by: Cornelia Huck --- drivers/s390/kvm/kvm_virtio.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c index 47cccd5..408447c 100644 --- a/drivers/s390/kvm/kvm_virtio.c +++ b/drivers/s390/kvm/kvm_virtio.c @@ -418,6 +418,21 @@ static void kvm_extint_handler(struct ext_code ext_code, } } +static int __init test_devices_support(void) +{ + int ccode = -EIO; + + asm volatile( + "0: cli 0(%1),0\n" + " ipm %0\n" + " srl %0,28\n" + "1:\n" + EX_TABLE(0b,1b) + : "+d" (ccode) + : "a" (kvm_devices) + : "cc"); + return ccode; +} /* * Init function for virtio * devices are in a single page above top of "normal" mem @@ -443,6 +458,12 @@ static int __init kvm_devices_init(void) } kvm_devices = (void *) real_memory_size; + if (test_devices_support() < 0) { + vmem_remove_mapping(real_memory_size, PAGE_SIZE); + root_device_unregister(kvm_root); + /* No error. */ + return 0; + } INIT_WORK(&hotplug_work, hotplug_devices);