From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38481) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fXT7T-0001fJ-AZ for qemu-devel@nongnu.org; Mon, 25 Jun 2018 11:09:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fXT7P-0001UT-9m for qemu-devel@nongnu.org; Mon, 25 Jun 2018 11:09:31 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:35538 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 1fXT7P-0001UM-4L for qemu-devel@nongnu.org; Mon, 25 Jun 2018 11:09:27 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w5PF4HHB057917 for ; Mon, 25 Jun 2018 11:09:26 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ju2q6g74s-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 25 Jun 2018 11:09:26 -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 16:09:24 +0100 Date: Mon, 25 Jun 2018 17:09:17 +0200 From: Vasily Gorbik References: <64bcba64-b88f-3594-da6e-7c2118482c20@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <64bcba64-b88f-3594-da6e-7c2118482c20@roeck-us.net> Message-Id: Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] s390 qemu boot failure in -next List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christian Borntraeger , Martin Schwidefsky Cc: Heiko Carstens , Cornelia Huck , Guenter Roeck , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, qemu-s390x , qemu-devel , Thomas Huth On Mon, Jun 25, 2018 at 06:35:30AM -0700, Guenter Roeck wrote: > On 06/25/2018 05:26 AM, Christian Borntraeger wrote: > >=20 > >=20 > > On 06/25/2018 10:49 AM, Cornelia Huck wrote: > > > On Mon, 25 Jun 2018 10:36:33 +0200 > > > Vasily Gorbik wrote: > > >=20 > > > > This change has been done on purpose. Uncompressed image is not g= oing > > > > to be bootable any more. In future the decompressor phase would g= et > > > > more function (early memory detection as an example) and there is= no > > > > chance to duplicate that code in uncompressed image as well (to k= eep it > > > > bootable on its own). The patch series commit messages contain mo= re > > > > technical details. > > > >=20 > > > > For qemu either bzImage or arch/s390/boot/compressed/vmlinux shou= ld be > > > > used, which are bootable images. > > > >=20 > > > > But that's really confusing that uncompressed vmlinux is still ki= nd > > > > of booting. May be we should discuss how to avoid this confusion > > > > (may be change uncompressed image enty point to a function doing > > > > disabled wait with badb007 or smth) and how to encourage people t= o use > > > > arch/s390/boot/compressed/vmlinux instead. > > >=20 >=20 > If an image is not expected to be bootable, a message such as "This ima= ge does > not boot. Please use " would be nice. Unfortunately, whi= ch image > to boot under qemu is pretty much undocumented, and it is guesswork for= each > architecture/platform. >=20 > Guenter >=20 > > I talked to Vasily and the vmlinux file in the linux source path is j= ust an > > intermediate file. Future changes will happen that will make that ELF= file > > unsuitable for direct boot anyway (e.g. think about potential ASLR or= Kasan > > changes). > >=20 > > If yes, it would make sense to explicitly fence it. But I'm > > > worried that it would break previously working setups (did we docum= ent > > > the purpose of the images anywhere? > > >=20 To avoid confusion with trying to boot uncompressed vmlinux under qemu we could detect it and print "nice" message in the kernel. Please consider the following patch. Vasily Gorbik (1): s390/boot: block uncompressed vmlinux booting attempts arch/s390/boot/head.S | 4 ++-- arch/s390/include/asm/setup.h | 3 ++- arch/s390/kernel/early.c | 12 ++++++++++++ 3 files changed, 16 insertions(+), 3 deletions(-) --=20 =E2=A3=94=E2=A2=BB=E2=A3=9F=E2=A2=A2 2.18.0.rc2.13.g4da9a5d =E2=A3=BF=E2=A2=BF=E2=A1=BF=E2=A3=BF pacman edition