On 02.01.2014, at 23:08, Alexey Kardashevskiy <a...@ozlabs.ru> wrote:
> On 01/03/2014 08:04 AM, Alexander Graf wrote: >> >> On 11.12.2013, at 07:47, Alexey Kardashevskiy <a...@ozlabs.ru> wrote: >> >>> On 12/10/2013 06:47 PM, Greg Kurz wrote: >>>> On Tue, 10 Dec 2013 13:43:05 +1100 >>>> Alexey Kardashevskiy <a...@ozlabs.ru> 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 <a...@ozlabs.ru> >>>>> >>>>> >>>>> 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 <a...@ozlabs.ru> >> >> 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. Oops, I thought your comment meant this was fixed. I took it off the queue again :). Alex
