From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36631) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VyqRU-0001UN-Q7 for qemu-devel@nongnu.org; Thu, 02 Jan 2014 17:08:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VyqRO-0000fn-Jg for qemu-devel@nongnu.org; Thu, 02 Jan 2014 17:08:40 -0500 Received: from mail-pd0-f180.google.com ([209.85.192.180]:54311) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VyqRO-0000fX-Dq for qemu-devel@nongnu.org; Thu, 02 Jan 2014 17:08:34 -0500 Received: by mail-pd0-f180.google.com with SMTP id q10so14576257pdj.25 for ; Thu, 02 Jan 2014 14:08:32 -0800 (PST) Message-ID: <52C5E355.2040006@ozlabs.ru> Date: Fri, 03 Jan 2014 09:08:21 +1100 From: Alexey Kardashevskiy MIME-Version: 1.0 References: <1373951995-9866-1-git-send-email-aik@ozlabs.ru> <20131209163357.14448.60087.stgit@bahia.local> <52A67FB9.60109@ozlabs.ru> <20131210084723.43cb0e74@bahia.local> <52A80A9B.200@ozlabs.ru> <8E202663-C6A5-48A7-BBE3-525EC0DE1D61@suse.de> In-Reply-To: <8E202663-C6A5-48A7-BBE3-525EC0DE1D61@suse.de> Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] spapr-pci: remove io ports workaround List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: QEMU Developers , qemu-ppc , Anthony Liguori , Paolo Bonzini , David Gibson , Paul Mackerras On 01/03/2014 08:04 AM, Alexander Graf wrote: > > On 11.12.2013, at 07:47, Alexey Kardashevskiy wrote: > >> On 12/10/2013 06:47 PM, Greg Kurz wrote: >>> On Tue, 10 Dec 2013 13:43:05 +1100 >>> Alexey Kardashevskiy wrote: >>>> On 12/10/2013 03:33 AM, Greg Kurz wrote: >>>>> In the past, IO space could not be mapped into the memory address space >>>>> so we introduced a workaround for that. Nowadays it does not look >>>>> necessary so we can remove the workaround and make sPAPR PCI >>>>> configuration simplier. >>>>> >>>>> This workaround has also an evil side effect with virtio devices: >>>>> because all PHBs have their .io region at the same address, the devices >>>>> get mapped in the .io-alias region of every PHB (AKA. mapped multiple >>>>> times). This breaks the ioeventfd feature and causes qemu to abort() >>>>> when running with KVM and asking for more than one PHB: >>>>> >>>>> $ qemu-system-ppc64 -machine type=pseries,accel=kvm -smp 1 -m 4G \ >>>>> -hda /local/greg/images/fedora-be.qcow2 \ >>>>> -device >>>>> virtio-9p-pci,fsdev=fsdev0,mount_tag=share,bus=pci,ioeventfd=on \ >>>>> -fsdev local,security_model=none,id=fsdev0,path=$HOME/share1 \ -device >>>>> spapr-pci-host-bridge,index=15 kvm_mem_ioeventfd_add: error adding >>>>> ioeventfd: File exists Aborted >>>>> >>>>> This will prevent to use virtio and VFIO passthrough at the same time, >>>>> since VFIO needs a dedicated PHB to work on ppc. >>>>> >>>>> Signed-off-by: Alexey Kardashevskiy >>>> >>>> >>>> I have not seen this version yet so please remove me from "SOB". The patch >>>> you replied to was eventually reworked and went to upstream as >>>> 66aab867cedd2a2d81b4d64eff7c3e0f6f272bbf >>>> >>> >>> Hi Alex, >>> >>> I agree you have not seen this version yet... The patch I replied to was my >>> primary source of inspiration and contains these bits, hence the SOB. >>> Anyway, the SOB is now removed until you decide to add one yourself. :) >>> >>>> This one might be correct too but I want to try this first :) >>>> >>> >>> Well, I hope it is. Please try it. >> >> >> Yep. Tried. Looks good, did not break a thing as far as I can tell, even >> VGA works :) >> >> >> Signed-off-by: Alexey Kardashevskiy > > Thanks, applied to ppc-next. Please read the rest of this thread. It does not visibly break things but with this patch QEMU starts calling unassigned_mem_accepts() (normally silent) which is not a good sign. -- Alexey