From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46374) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YQzaz-0002k4-H2 for qemu-devel@nongnu.org; Thu, 26 Feb 2015 09:39:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YQzav-0002ae-GQ for qemu-devel@nongnu.org; Thu, 26 Feb 2015 09:39:21 -0500 Received: from cantor2.suse.de ([195.135.220.15]:43254 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YQzav-0002aX-Aa for qemu-devel@nongnu.org; Thu, 26 Feb 2015 09:39:17 -0500 Message-ID: <54EF3013.8020608@suse.de> Date: Thu, 26 Feb 2015 15:39:15 +0100 From: Alexander Graf MIME-Version: 1.0 References: <1424951988-40477-1-git-send-email-blaschka@linux.vnet.ibm.com> <1424951988-40477-2-git-send-email-blaschka@linux.vnet.ibm.com> In-Reply-To: <1424951988-40477-2-git-send-email-blaschka@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit 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: Frank Blaschka , qemu-devel@nongnu.org, cornelia.huck@de.ibm.com, borntraeger@de.ibm.com 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? Alex