From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38966) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fXLv1-0000TF-J9 for qemu-devel@nongnu.org; Mon, 25 Jun 2018 03:28:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fXLuy-00049C-Ft for qemu-devel@nongnu.org; Mon, 25 Jun 2018 03:28:11 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:49710 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fXLuy-00048t-AA for qemu-devel@nongnu.org; Mon, 25 Jun 2018 03:28:08 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w5P7Oiup068892 for ; Mon, 25 Jun 2018 03:28:07 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0b-001b2d01.pphosted.com with ESMTP id 2jtsvddd3x-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 25 Jun 2018 03:28:07 -0400 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 25 Jun 2018 08:28:04 +0100 From: Christian Borntraeger References: <20180622194736.GA5794@roeck-us.net> <126ac556-0602-b927-58f5-cb5f65a5e0ec@de.ibm.com> Date: Mon, 25 Jun 2018 09:27:59 +0200 MIME-Version: 1.0 In-Reply-To: <126ac556-0602-b927-58f5-cb5f65a5e0ec@de.ibm.com> Content-Language: en-US Message-Id: <88d9afed-f91d-c320-13c8-9a93fc52b700@de.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] s390 qemu boot failure in -next List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Guenter Roeck , Martin Schwidefsky Cc: Vasily Gorbik , Heiko Carstens , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, qemu-s390x , qemu-devel , Cornelia Huck , Thomas Huth Also adding QEMU. On 06/25/2018 09:10 AM, Christian Borntraeger wrote: > > > On 06/22/2018 09:47 PM, Guenter Roeck wrote: >> Hi, >> >> starting with commit 's390/boot: make head.S and als.c be part of the >> decompressor only' in -next, s390 immages no longer boot in qemu. >> As far as I can see, the reason is that the command line is no longer >> passed from qemu to the kernel, which results in a panic because the >> root file system can not be mounted. >> >> Was this change made on purpose ? If so, is there a way to get qemu >> back to working ? > > Certainly not on purpose. > > Vasily, I can reproduce this with KVM and an external kernel boot of the vmlinux file (the elf file) > > e.g. > > qemu-system-s390 -enable-kvm -nographic -kernel vmlinux -append "this string no longer is command line" > > The compressed image (bzImage) seems to work fine though. > > This seems to be an unfortunate side effect of QEMUs ways to "guess" its Linux (checking for start > address 0x10000, which is no longer true for the vmlinux file). With the pure vmlinux elf file > the load address is 0x100000 as there is no unpacker. > > Guenter, can you check if arch/s390/boot/bzImage works for you as a workaround? Something like this in QEMU diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c index f278036fa7..14153ce880 100644 --- a/hw/s390x/ipl.c +++ b/hw/s390x/ipl.c @@ -187,11 +187,13 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp) */ if (pentry == KERN_IMAGE_START || pentry == 0x800) { ipl->start_addr = KERN_IMAGE_START; - /* Overwrite parameters in the kernel image, which are "rom" */ - strcpy(rom_ptr(KERN_PARM_AREA), ipl->cmdline); } else { ipl->start_addr = pentry; } + if (ipl->cmdline) { + /* If there is a command line, put it in the right place */ + strcpy(rom_ptr(KERN_PARM_AREA), ipl->cmdline); + } if (ipl->initrd) { ram_addr_t initrd_offset; would put the command line in no matter what the start address is.