From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44564) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1clwum-0005RU-RI for qemu-devel@nongnu.org; Thu, 09 Mar 2017 07:11:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1clwul-0008Rg-JJ for qemu-devel@nongnu.org; Thu, 09 Mar 2017 07:11:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51098) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1clwul-0008Rb-Cs for qemu-devel@nongnu.org; Thu, 09 Mar 2017 07:11:27 -0500 References: <1489017212-2990-1-git-send-email-mst@redhat.com> <1a475607-b876-d79a-5e0b-e1a4a006c65d@redhat.com> From: Marcel Apfelbaum Message-ID: Date: Thu, 9 Mar 2017 14:11:08 +0200 MIME-Version: 1.0 In-Reply-To: <1a475607-b876-d79a-5e0b-e1a4a006c65d@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH RFC] qdev: add init order filter List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , "Michael S. Tsirkin" , qemu-devel@nongnu.org Cc: Marcel Apfelbaum , Peter Maydell , Alex Williamson , Peter Xu , Jason Wang On 03/09/2017 01:13 PM, Paolo Bonzini wrote: > > > On 09/03/2017 00:59, Michael S. Tsirkin wrote: >> Allow forcing a specific order of initialization on >> devices created with -device. >> Helpful e.g. for built-in devices such as IOMMUs which must >> exist before all other devices. >> >> Signed-off-by: Michael S. Tsirkin >> --- >> >> Looks like we have a ton of problems because devices >> are initialized in a random order, while we >> really want e.g. iommu to be initialized >> earlier than devices. >> >> This will be helpful for other things, e.g. >> real hardware often is initialized in a specific order, >> creating built-in devices for the board often >> has to happen in a specific order, etc. > > In the specific case of PCI bus_master_as there is a simple workaround > by placing a dummy container (which lets us build the AddressSpace) and > then adding the alias region at machine_done time. > > This is exactly how MemoryListener is supposed to work, so I would start > from there. > Hi Paolo, This will certainly solve virtio-pci ordering issue, but I am not sure it solves the vfio-pci problem. Here is a link to Alex's explanation: http://www.mail-archive.com/qemu-devel@nongnu.org/msg432365.html Thanks, Marcel > Paolo >