From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33547) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fG5mS-0008J7-P3 for qemu-devel@nongnu.org; Tue, 08 May 2018 12:48:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fG5mO-00013Z-ST for qemu-devel@nongnu.org; Tue, 08 May 2018 12:48:00 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:53778 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 1fG5mO-00013V-N6 for qemu-devel@nongnu.org; Tue, 08 May 2018 12:47:56 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w48GiSPG064809 for ; Tue, 8 May 2018 12:47:56 -0400 Received: from e06smtp12.uk.ibm.com (e06smtp12.uk.ibm.com [195.75.94.108]) by mx0b-001b2d01.pphosted.com with ESMTP id 2hufjjgew0-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 08 May 2018 12:47:55 -0400 Received: from localhost by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 8 May 2018 17:47:54 +0100 References: <20180508141506.56480-1-borntraeger@de.ibm.com> From: Christian Borntraeger Date: Tue, 8 May 2018 18:47:48 +0200 MIME-Version: 1.0 In-Reply-To: <20180508141506.56480-1-borntraeger@de.ibm.com> Content-Language: en-US Message-Id: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH] s390x/ipl: Try to detect Linux vs non Linux for initial IPL PSW List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: qemu-devel , qemu-s390x , Cornelia Huck , Thomas Huth , David Hildenbrand , Halil Pasic , Janosch Frank , Alexander Graf , Richard Henderson On 05/08/2018 04:15 PM, Christian Borntraeger wrote: > Right now the IPL device always starts from address 0x10000 (the usual > Linux entry point). To run other guests (e.g. test programs) it is > useful to use the IPL PSW from address 0. We can use the Linux magic > at 0x10008 to decide. > > Signed-off-by: Christian Borntraeger > Acked-by: Jason J. Herne > --- > hw/s390x/ipl.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c > index 150f6c0582..c0fed26f03 100644 > --- a/hw/s390x/ipl.c > +++ b/hw/s390x/ipl.c > @@ -104,7 +104,9 @@ static uint64_t bios_translate_addr(void *opaque, uint64_t srcaddr) > static void s390_ipl_realize(DeviceState *dev, Error **errp) > { > S390IPLState *ipl = S390_IPL(dev); > - uint64_t pentry = KERN_IMAGE_START; > + uint64_t *iplpsw; > + uint64_t pentry; > + char *magic; > int kernel_size; > Error *err = NULL; > > @@ -156,6 +158,17 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp) > NULL, 1, EM_S390, 0, 0); > if (kernel_size < 0) { > kernel_size = load_image_targphys(ipl->kernel, 0, ram_size); > + /* if this is Linux use KERN_IMAGE_START */ > + magic = rom_ptr(0x10008); > + if (magic && !memcmp(magic, "S390EP", 6)) { > + pentry = KERN_IMAGE_START; > + } else { > + /* if not Linux use the IPL PSW */ > + iplpsw = rom_ptr(0); > + if (iplpsw) { > + pentry = *iplpsw & 0x7fffffffUL; I forgot endianess conversion here. > + } > + } > } > if (kernel_size < 0) { > error_setg(&err, "could not load kernel '%s'", ipl->kernel); >