From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56352) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YR0LI-0007Ub-Hx for qemu-devel@nongnu.org; Thu, 26 Feb 2015 10:27:13 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YR0LE-0004Iz-7m for qemu-devel@nongnu.org; Thu, 26 Feb 2015 10:27:12 -0500 Received: from e06smtp10.uk.ibm.com ([195.75.94.106]:59823) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YR0LD-0004Ie-VC for qemu-devel@nongnu.org; Thu, 26 Feb 2015 10:27:08 -0500 Received: from /spool/local by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 26 Feb 2015 15:27:06 -0000 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id 4E1AB1B0804B for ; Thu, 26 Feb 2015 15:27:18 +0000 (GMT) Received: from d06av04.portsmouth.uk.ibm.com (d06av04.portsmouth.uk.ibm.com [9.149.37.216]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t1QFR2uv12255674 for ; Thu, 26 Feb 2015 15:27:02 GMT Received: from d06av04.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av04.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t1QFR2CN009926 for ; Thu, 26 Feb 2015 08:27:02 -0700 Date: Thu, 26 Feb 2015 16:27:01 +0100 From: Frank Blaschka Message-ID: <20150226152701.GA31166@tuxmaker.boeblingen.de.ibm.com> References: <1424951988-40477-1-git-send-email-blaschka@linux.vnet.ibm.com> <1424951988-40477-2-git-send-email-blaschka@linux.vnet.ibm.com> <54EF3013.8020608@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54EF3013.8020608@suse.de> Subject: Re: [Qemu-devel] [PATCH RFC 1/1] s390x/pci: Extend pci representation by new zpci device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: cornelia.huck@de.ibm.com, borntraeger@de.ibm.com, qemu-devel@nongnu.org On Thu, Feb 26, 2015 at 03:39:15PM +0100, Alexander Graf wrote: > > > On 26.02.15 12:59, Frank Blaschka wrote: > > This patch extends the current s390 pci implementation to > > provide more flexibility in configuration of s390 specific > > device handling. For this we had to introduce a new facility > > (and bus) to hold devices representing information actually > > provided by s390 firmware and I/O configuration. > > > > On s390 the physical structure of the pci system (bridge, bus, slot) > > in not shown to the OS. For this the pci bridge and bus created > > in qemu can also not be shown to the guest. The new zpci device class > > represents this abstract view on the bare pci function and allows to > > provide s390 specific configuration attributes for it. > > > > Sample qemu configuration: > > -device e1000,id=zpci1 > > -device ne2k_pci,id=zpci2 > > -device zpci,fid=2,uid=1248,pci_id=zpci1 > > -device zpci,fid=17,uid=2244,pci_id=zpci2 > > > > A zpci device references the corresponding PCI device via device id. > > The new design allows to define multiple host bridges and support more > > pci devices. > > Isn't this reverse? Shouldn't it rather be > > -device zpci,...,id=zpci1 > -device e1000,bus=zpci1.0 > > with a limit on each virtual zpci bus to only support one device? Do you mean something like having multiple host bridges (providing a pci bus each) and limit the bus to just one device? -device s390-pcihost,fid=16,uid=1234 -device s390-pcihost,fid=17,uid=5678 -device e1000,bus=pci.0 -device ne2k_pci,bus=pci.1 We also discussed this option but we don't like the idea to put attributes belong to the pci device to the host bridge. > > > Alex >