From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50484) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dZar9-0005jZ-Hy for qemu-devel@nongnu.org; Mon, 24 Jul 2017 06:44:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dZar6-0008IF-GF for qemu-devel@nongnu.org; Mon, 24 Jul 2017 06:44:55 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36416 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 1dZar6-0008Gu-Aq for qemu-devel@nongnu.org; Mon, 24 Jul 2017 06:44:52 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6OAhrfZ081559 for ; Mon, 24 Jul 2017 06:44:50 -0400 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0a-001b2d01.pphosted.com with ESMTP id 2bwegfa9yr-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 24 Jul 2017 06:44:50 -0400 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 24 Jul 2017 04:44:49 -0600 References: <20170718142455.32676-1-cohuck@redhat.com> <20170719150313.6acdb087@gondolin> From: Christian Borntraeger Date: Mon, 24 Jul 2017 12:44:43 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-IE Content-Transfer-Encoding: 7bit Message-Id: <870ba6c0-e285-d75a-098e-0a2d1e02e02b@de.ibm.com> Subject: Re: [Qemu-devel] [PATCH RFC v2 0/9] s390x: zPCI detangling List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth , Cornelia Huck , qemu-devel@nongnu.org Cc: agraf@suse.de, pmorel@linux.vnet.ibm.com, zyimin@linux.vnet.ibm.com On 07/19/2017 03:31 PM, Thomas Huth wrote: > On 19.07.2017 15:03, Cornelia Huck wrote: >> On Tue, 18 Jul 2017 16:24:46 +0200 >> Cornelia Huck wrote: >> >>> Next try of the zPCI detangling, taking cpu models into account. >>> >>> The goal of this is twofold: >>> - Being able to disable PCI support in a build completely, as for v1. >>> - Properly fencing off PCI if the relevant facility bit is not provided. >>> >>> The second one leads to an interesting usability problem: -device help >>> still shows the various pci devices, but you cannot add them if the >>> cpu model does not include zpci, due to the phb not being instantiated. >>> The user is presented with >>> >>> qemu-system-s390x: -device virtio-rng-pci: No 'PCI' bus found for device 'virtio-rng-pci' >>> >>> ...which is not very helpful, as it does not point to the root cause (no >>> zpci in the cpu model, and therefore no pci at all). Not sure how one can >>> communicate this root cause, ideas welcome. >> >> An idea on how to improve this would still be welcome :) > > IMHO it's ok to keep that error message ... but we should add a section > to http://wiki.qemu.org/Documentation/Platforms/S390X about PCI devices, > including a sample error message as above and a note what has to be done > to get a machine with PCI support, so that people can find that page via > Google in case they run into this problem. I agree, the message is actually not that bad for an error message. With an wiki entry we should be fine.