From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49939) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UwUE1-00029d-FL for qemu-devel@nongnu.org; Tue, 09 Jul 2013 05:28:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UwUDv-0007Qk-NX for qemu-devel@nongnu.org; Tue, 09 Jul 2013 05:28:45 -0400 Received: from cantor2.suse.de ([195.135.220.15]:35687 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UwUDv-0007QS-EX for qemu-devel@nongnu.org; Tue, 09 Jul 2013 05:28:39 -0400 Message-ID: <51DBD7C0.3080504@suse.de> Date: Tue, 09 Jul 2013 11:28:32 +0200 From: =?ISO-8859-1?Q?Andreas_F=E4rber?= MIME-Version: 1.0 References: <1372338255-3934-1-git-send-email-peter.maydell@linaro.org> <39E5AB85-E7DD-4B9F-9F6F-F80CA6FCAC11@suse.de> <83A07262-ED9A-4E5A-BC11-5B357F5B4996@suse.de> <87li5gbyqv.fsf@codemonkey.ws> <39D95139-6E9C-4FD8-A007-C08444C1AA67@suse.de> <87mwpwpxqm.fsf@codemonkey.ws> In-Reply-To: <87mwpwpxqm.fsf@codemonkey.ws> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 0/8] Add virtio-mmio and use it in vexpress List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori , Peter Maydell Cc: patches@linaro.org, qemu-devel@nongnu.org, Alexander Graf , David Gibson , kvmarm@lists.cs.columbia.edu, KONRAD Frederic Am 08.07.2013 23:06, schrieb Anthony Liguori: > Alexander Graf writes: >=20 >> On 08.07.2013, at 22:08, Anthony Liguori wrote: >> >>> I think we're trying to fit a square peg into a round hole. >>> >>> virtio-mmio is a virtio transport where each device has a dedicated s= et >>> of system resources. >>> >>> Alex, it sounds like you want virtio-mmio-bus which would be a single >>> set of system resources that implemented a virtio bus on top of it. >> >> Well, what I really want is a sysbus that behaves like PCI from a >> usability point of view ;). >=20 > Which means you need to have (1) a discovery mechanism with a stable > addressing mechanism (2) a way to communicate this to the guest from th= e > host. FWIW I vaguely remember a Lightning Talk at FOSDEM 2012 about MMIO device discovery through chained in-memory data structures or so: https://archive.fosdem.org/2012/schedule/event/wishbone.html http://www.ohwr.org/projects/fpga-config-space Maybe such metadata could be supplied alongside a virtual device, whether on Wishbone, AMBA or whatever? Just a thought. Regards, Andreas > That's all that PCI is. A host controller is a "sysbus" device that > uses a standardized discovery and addressing mechanism. >=20 > Regards, >=20 > Anthony Liguori --=20 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imend=F6rffer; HRB 16746 AG N=FCrnbe= rg