From nobody Thu Apr 25 20:22:20 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=linux.ibm.com ARC-Seal: i=1; a=rsa-sha256; t=1605888301; cv=none; d=zohomail.com; s=zohoarc; b=nsUp1X3+iV6VGSBzLp1tHyJ3mL9SAv7qHQa6APL9OimjJHBGIos+UtcwhMAt2brJCpYko3lhPPVy1Cb6/B3PomLHVUDS02sCzZoOXerPOYgLTRyJHEZ55d/JRxVTswjOBA3NmL181TMvZ2BDFdWY0qQ96LHVUU04J0zMvaY0dOI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1605888301; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=TQs43wIs6NMavh4ThjfDX/A1OhJxhE0jP8G9tWlb2hA=; b=B8KNoNoIR2zIO4mgTkIERU4pnK9YlDyLPhVFYPn01RCemGEnblYqrmGaEGrF97QlD5A0r/7DEU5bdy1eAWrTfJF/Ci3n4Qnl5W9l3CPu9GlLSzsc/xOLetBz1PMFsgIS0beLADnNtTccNMANGfAdhYnd7uoDG4QXcwpgob72LFQ= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1605888301069717.010348449244; Fri, 20 Nov 2020 08:05:01 -0800 (PST) Received: from localhost ([::1]:60760 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kg8uB-0000NM-H5 for importer@patchew.org; Fri, 20 Nov 2020 11:04:59 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56242) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kg8qo-0005cN-2r; Fri, 20 Nov 2020 11:01:30 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:5299) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kg8qk-0000VI-S9; Fri, 20 Nov 2020 11:01:29 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0AKFWEoL174026; Fri, 20 Nov 2020 11:01:24 -0500 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 34xghf14jn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 20 Nov 2020 11:01:24 -0500 Received: from m0098417.ppops.net (m0098417.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 0AKFWJ8n174257; Fri, 20 Nov 2020 11:01:23 -0500 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 34xghf14h6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 20 Nov 2020 11:01:23 -0500 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 0AKFvxu4022672; Fri, 20 Nov 2020 16:01:21 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma04ams.nl.ibm.com with ESMTP id 34t6v8e4nw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 20 Nov 2020 16:01:21 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0AKG1Isf54002050 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 20 Nov 2020 16:01:18 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 37BDA4C058; Fri, 20 Nov 2020 16:01:18 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 25C8D4C052; Fri, 20 Nov 2020 16:01:18 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Fri, 20 Nov 2020 16:01:18 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 4958) id D5831E23B2; Fri, 20 Nov 2020 17:01:17 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=pp1; bh=TQs43wIs6NMavh4ThjfDX/A1OhJxhE0jP8G9tWlb2hA=; b=aaBfNDRQrI6X6KNmUOWSZj/tjygC6k6WIE5Gqy8eogNBq5CkRX46287TyGuLoxUt4+mz WayeSj6VChs2fRlixtHTtReVxqa54GBHLV4GXaYJKwF0U30G11nLt2SSO8/+2gjkTSBN p/zUm3k6jN1a6DNZ+zq7Daz6uDwM4W9swoAwkmWP5nMrKi8khigjNbOXGi23ruc1EnMS qcjRObKttSs0/iW0oaILovD4qThZq78dGOp2BFMP0pDC0BVOeHchZ+A/N40dkbqc4E1t JYo/bow8BWafE9VID/mbKpiFfqefgw5j1CpAYIBeNSl6IXWKKTsLfsdPz/8ogWQD+B0H lw== From: Eric Farman To: Thomas Huth , Cornelia Huck Subject: [PATCH v2 1/2] pc-bios: s390x: Ensure Read IPL memory is clean Date: Fri, 20 Nov 2020 17:01:16 +0100 Message-Id: <20201120160117.59366-2-farman@linux.ibm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201120160117.59366-1-farman@linux.ibm.com> References: <20201120160117.59366-1-farman@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312, 18.0.737 definitions=2020-11-20_07:2020-11-20, 2020-11-20 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 mlxlogscore=898 spamscore=0 impostorscore=0 lowpriorityscore=0 clxscore=1015 bulkscore=0 malwarescore=0 adultscore=0 mlxscore=0 priorityscore=1501 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011200104 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=148.163.158.5; envelope-from=farman@linux.ibm.com; helo=mx0b-001b2d01.pphosted.com X-Spam_score_int: -19 X-Spam_score: -2.0 X-Spam_bar: -- X-Spam_report: (-2.0 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jason Herne , Eric Farman , Janosch Frank , Matthew Rosato , qemu-devel@nongnu.org, Christian Borntraeger , qemu-s390x@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" If, for example, we boot off a virtio device and chreipl to a vfio-ccw device, the space at lowcore will be non-zero. We build a Read IPL CCW at address zero, but it will have leftover PSW data that will conflict with the Format-0 CCW being generated: 0x0: 00080000 80010000 ------ Ccw0.cda -- Ccw0.chainData -- Reserved bits The data address will be overwritten with the correct value (0x0), but the apparent data chain bit will cause subsequent memory to be used as the target of the data store, which may not be where we expect (0x0). Clear out this space when we boot from DASD, so that we know it exists exactly as we expect. Signed-off-by: Eric Farman Reviewed-by: Jason J. Herne Acked-by: Christian Borntraeger Reviewed-by: Janosch Frank Acked-by: Cornelia Huck --- pc-bios/s390-ccw/dasd-ipl.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/pc-bios/s390-ccw/dasd-ipl.c b/pc-bios/s390-ccw/dasd-ipl.c index 0fc879bb8e..71cbae2f16 100644 --- a/pc-bios/s390-ccw/dasd-ipl.c +++ b/pc-bios/s390-ccw/dasd-ipl.c @@ -100,6 +100,9 @@ static void make_readipl(void) { Ccw0 *ccwIplRead =3D (Ccw0 *)0x00; =20 + /* Clear out any existing data */ + memset(ccwIplRead, 0, sizeof(Ccw0)); + /* Create Read IPL ccw at address 0 */ ccwIplRead->cmd_code =3D CCW_CMD_READ_IPL; ccwIplRead->cda =3D 0x00; /* Read into address 0x00 in main memory */ --=20 2.17.1 From nobody Thu Apr 25 20:22:20 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=linux.ibm.com ARC-Seal: i=1; a=rsa-sha256; t=1605888397; cv=none; d=zohomail.com; s=zohoarc; b=L1P0vssmXrfUUGrZYLJqDl9Sdb5hCaMdTGqvYMk+qSQ0HriTJL7vSmHRppFwZJfp92zPp1F5uvXU3ACP4V9X4bBLHLYt3yBcUtwGsWtjq6ijAQM/aN9jdTQC3YNfBMigjSjLr0nSEY6fhyqoBaSVLhth2qT3jo2H88ex+Js9sH0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1605888397; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=L7Ao0tdT8nnEVKmYBfCWf3TYpBBOl5ef5qtaVpwtDKg=; b=li9qDhVnNMqvwxKdDN0j0prSABYS+PjoWIed8AD/ovKYvfWNFKGuHbsMKdEzWyJHbTw5PAwf+Imd5fw7xa4Cf2/xHGrJRo8uJbFoneCMdBHJJN1bpjEtPvfncYjt4ry+Gwfjg5ZPo1p1CKWGTOnOfwTC3VVpifGhhErmio3t+RI= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1605888397305242.3377864256064; Fri, 20 Nov 2020 08:06:37 -0800 (PST) Received: from localhost ([::1]:36476 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kg8vk-0002Zc-0y for importer@patchew.org; Fri, 20 Nov 2020 11:06:36 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56696) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kg8rx-0006qv-Nw; Fri, 20 Nov 2020 11:02:41 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:46422) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kg8rw-0000y7-0l; Fri, 20 Nov 2020 11:02:41 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0AKG2MUA142148; Fri, 20 Nov 2020 11:02:38 -0500 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 34xghf15vn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 20 Nov 2020 11:02:38 -0500 Received: from m0098417.ppops.net (m0098417.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 0AKG2N71142266; Fri, 20 Nov 2020 11:02:38 -0500 Received: from ppma02fra.de.ibm.com (47.49.7a9f.ip4.static.sl-reverse.com [159.122.73.71]) by mx0a-001b2d01.pphosted.com with ESMTP id 34xghf15u2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 20 Nov 2020 11:02:37 -0500 Received: from pps.filterd (ppma02fra.de.ibm.com [127.0.0.1]) by ppma02fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 0AKG2CH3000482; Fri, 20 Nov 2020 16:02:36 GMT Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by ppma02fra.de.ibm.com with ESMTP id 34t6v8cuwq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 20 Nov 2020 16:02:36 +0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0AKG1I3k59310578 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 20 Nov 2020 16:01:18 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 390D2A4053; Fri, 20 Nov 2020 16:01:18 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 277BBA405D; Fri, 20 Nov 2020 16:01:18 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Fri, 20 Nov 2020 16:01:18 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 4958) id D8733E23B4; Fri, 20 Nov 2020 17:01:17 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=pp1; bh=L7Ao0tdT8nnEVKmYBfCWf3TYpBBOl5ef5qtaVpwtDKg=; b=N5388cZpMwzNyWFNNMBjiCUbqiC13dPaqjwbCHzLEgoDpkFlb/7nEdaaxXDcQSaY7qV8 1pdJ9EMCeNApUEb7gFREALU44Lis42hi6xZRWTVGaB1fkyTNC+TPqM0sIsjqFi690pYB sJGVSqIyLJix1YWqCIfQxd3YzuAPya7td3qeQ6UuJ1q7CPPnDLoh06ldqS7uV9Vpn8c7 9pAnwzmc8ykAQRKtGxnJ5rnsWJK8tXHAG5myJK6jF31QXPRwTnwYh6tO6RaIFQCR+P9X Hvpjjp3il3uXx6PbbcbNUuYeYBbZx5ENVIx+8IDts1L8OVNOvsSswG3lEAM0gUTHXzJF vA== From: Eric Farman To: Thomas Huth , Cornelia Huck Subject: [PATCH v2 2/2] pc-bios: s390x: Clear out leftover S390EP string Date: Fri, 20 Nov 2020 17:01:17 +0100 Message-Id: <20201120160117.59366-3-farman@linux.ibm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201120160117.59366-1-farman@linux.ibm.com> References: <20201120160117.59366-1-farman@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312, 18.0.737 definitions=2020-11-20_08:2020-11-20, 2020-11-20 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 mlxlogscore=999 spamscore=0 impostorscore=0 lowpriorityscore=0 clxscore=1015 bulkscore=0 malwarescore=0 adultscore=0 mlxscore=0 priorityscore=1501 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011200106 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=148.163.158.5; envelope-from=farman@linux.ibm.com; helo=mx0b-001b2d01.pphosted.com X-Spam_score_int: -19 X-Spam_score: -2.0 X-Spam_bar: -- X-Spam_report: (-2.0 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jason Herne , Eric Farman , Janosch Frank , Matthew Rosato , qemu-devel@nongnu.org, Christian Borntraeger , qemu-s390x@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" A Linux binary will have the string "S390EP" at address 0x10008, which is important in getting the guest up off the ground. In the case of a reboot (specifically chreipl going to a new device), we should defer to the PSW at address zero for the new config, which will re-write "S390EP" from the new image. Let's clear it out at this point so that a reipl to, say, a DASD passthrough device drives the IPL path from scratch without disrupting disrupting the order of operations for other boots. Rather than hardcoding the address of this magic (again), let's define it somewhere so that the two users are visibly related. Signed-off-by: Eric Farman --- pc-bios/s390-ccw/jump2ipl.c | 2 +- pc-bios/s390-ccw/main.c | 6 ++++++ pc-bios/s390-ccw/s390-arch.h | 3 +++ 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c index fbae45b03c..b9c70d64a5 100644 --- a/pc-bios/s390-ccw/jump2ipl.c +++ b/pc-bios/s390-ccw/jump2ipl.c @@ -78,7 +78,7 @@ void jump_to_low_kernel(void) * kernel start address (when jumping to the PSW-at-zero address inste= ad, * the kernel startup code fails when we booted from a network device). */ - if (!memcmp((char *)0x10008, "S390EP", 6)) { + if (!memcmp((char *)S390EP, "S390EP", 6)) { jump_to_IPL_code(KERN_IMAGE_START); } =20 diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c index fc4bfaa455..5d2b7ba94d 100644 --- a/pc-bios/s390-ccw/main.c +++ b/pc-bios/s390-ccw/main.c @@ -178,6 +178,12 @@ static void boot_setup(void) memcpy(lpmsg + 10, loadparm_str, 8); sclp_print(lpmsg); =20 + /* + * Clear out any potential S390EP magic (see jump_to_low_kernel()), + * so we don't taint our decision-making process during a reboot. + */ + memset((char *)S390EP, 0, 6); + have_iplb =3D store_iplb(&iplb); } =20 diff --git a/pc-bios/s390-ccw/s390-arch.h b/pc-bios/s390-ccw/s390-arch.h index 6da44d4436..a741488aaa 100644 --- a/pc-bios/s390-ccw/s390-arch.h +++ b/pc-bios/s390-ccw/s390-arch.h @@ -95,6 +95,9 @@ typedef struct LowCore { =20 extern LowCore *lowcore; =20 +/* Location of "S390EP" in a Linux binary (see arch/s390/boot/head.S) */ +#define S390EP 0x10008 + static inline void set_prefix(uint32_t address) { asm volatile("spx %0" : : "m" (address) : "memory"); --=20 2.17.1