From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37372) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ej00t-0006iW-JH for qemu-devel@nongnu.org; Tue, 06 Feb 2018 04:58:08 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ej00p-0007ny-8G for qemu-devel@nongnu.org; Tue, 06 Feb 2018 04:58:07 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:50688) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ej00o-0007nU-VH for qemu-devel@nongnu.org; Tue, 06 Feb 2018 04:58:03 -0500 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w169tVFB118738 for ; Tue, 6 Feb 2018 04:58:01 -0500 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0a-001b2d01.pphosted.com with ESMTP id 2fy96mas3a-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 06 Feb 2018 04:58:01 -0500 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 6 Feb 2018 09:57:59 -0000 References: <1517864246-11101-1-git-send-email-walling@linux.vnet.ibm.com> <1517864246-11101-6-git-send-email-walling@linux.vnet.ibm.com> <3389032a-caf2-8d9a-ccf0-f7ce36b389d6@de.ibm.com> From: Viktor Mihajlovski Date: Tue, 6 Feb 2018 10:57:50 +0100 MIME-Version: 1.0 In-Reply-To: <3389032a-caf2-8d9a-ccf0-f7ce36b389d6@de.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Message-Id: <8c7d5b99-bc38-1ed2-ca7c-e6a8fac65b32@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH v5 05/12] s390-ccw: move auxiliary IPL data to separate location List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christian Borntraeger , "Collin L. Walling" , qemu-s390x@nongnu.org, qemu-devel@nongnu.org Cc: frankja@linux.vnet.ibm.com, cohuck@redhat.com, thuth@redhat.com, david@redhat.com, alifm@linux.vnet.ibm.com, eblake@redhat.com On 06.02.2018 10:45, Christian Borntraeger wrote: > On 02/05/2018 09:57 PM, Collin L. Walling wrote: >> The s390-ccw firmware needs some information in support of the >> boot process which is not available on the native machine. >> Examples are the netboot firmware load address and now the >> boot menu parameters. >> >> While storing that data in unused fields of the IPL parameter block >> works, that approach could create problems if the parameter block >> definition should change in the future. Because then a guest could >> overwrite these fields using the set IPLB diagnose. >> >> In fact the data in question is of more global nature and not really >> tied to an IPL device, so separating it is rather logical. >> >> This commit introduces a new structure to hold firmware relevant >> IPL parameters set by QEMU. The data is stored at location 204 (dec) >> and can contain up to 7 32-bit words. This area is available to >> programming in the z/Architecture Principles of Operation and >> can thus safely be used by the firmware until the IPL has completed. > > This content is set by QEMU/the ccw bios on every IPL, so we do not > have to change anything for migration. Correct? > Hm ... this is true for the netboot start address, but I am not sure about the boot menu parameters added in a follow on patch. I'll comment there... [...] -- Regards, Viktor Mihajlovski