From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Evensky Subject: Re: [PATCH] kvm tools: adds a PCI device that exports a host shared segment as a PCI BAR in the guest Date: Thu, 25 Aug 2011 15:03:53 -0700 Message-ID: <20110825220353.GC27983@dancer.ca.sandia.gov> References: <232C9ABA-F703-4AE5-83BC-774C715D4D8F@suse.de> <20110825044913.GA24996@dancer.ca.sandia.gov> <1314248794.32391.60.camel@jaguar> <1314271548.3692.22.camel@lappy> <30669_1314285268_p7PFESZN013126_20110825150806.GF24996@dancer.ca.sandia.gov> <20110825210018.GA27983@dancer.ca.sandia.gov> <4E56BA67.9000901@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Sasha Levin , Stefan Hajnoczi , Pekka Enberg , Alexander Graf , kvm@vger.kernel.org, cam@cs.ualberta.ca To: Avi Kivity Return-path: Received: from sentry-two.sandia.gov ([132.175.109.14]:54226 "EHLO sentry-two.sandia.gov" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755568Ab1HYWED (ORCPT ); Thu, 25 Aug 2011 18:04:03 -0400 Content-Disposition: inline In-Reply-To: <4E56BA67.9000901@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: I need to specify the physical address because I need to ioremap the memory during boot. The production issue I think is a memory limitation. We certainly do use QEMU a lot; but for this the kvm tool is a better fit. \dae On Fri, Aug 26, 2011 at 12:11:03AM +0300, Avi Kivity wrote: > On 08/26/2011 12:00 AM, David Evensky wrote: > >I've tested ivshmem with the latest git pull (had minor trouble > >building on debian sid, vnc and unused var, but trivial to work > >around). > > > >QEMU's -device ivshmem,size=16,shm=/kvm_shmem > > > >seems to function as my proposed > > > > --shmem pci:0xfd000000:16M:handle=/kvm_shmem > > > >except that I can't specify the BAR. I am able to read what > >I'm given, 0xfd000000, from lspci -vvv; but for our application > >we need to be able to specify the address on the command line. > > > >If folks are open, I would like to request this feature in the > >ivshmem. > > It's not really possible. Qemu does not lay out the BARs, the guest > does (specifically the bios). You might be able to re-arrange the > layout after the guest boots. > > Why do you need the BAR at a specific physical address? > > >It would be cool to test our application with QEMU, > >even if we can't use it in production. > > Why can't you use qemu in production? > > -- > I have a truly marvellous patch that fixes the bug which this > signature is too narrow to contain. > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html