[Qemu-discuss] confused about PCIe Passthrough

[Andreas Hergesell]

Dear all,

I'm running a debian home server virtualized with kvm/qemu. Until last
week, I ran debian wheezy and passed my DVB card to a VM running mythTV.
This setup was running fine.
Then I updated the host to debian jessie.
When I try to start the mythTV VM now, I get:
----------------------------
2016-06-21T20:25:55.865229Z qemu-system-x86_64: -device
vfio-pci,host=02:00.0,id=hostdev0,bus=pci.0,addr=0x6: vfio: error, group
6 is not viable, please ensure all devices within the iommu_group are
bound to their vfio bus driver.
2016-06-21T20:25:55.865279Z qemu-system-x86_64: -device
vfio-pci,host=02:00.0,id=hostdev0,bus=pci.0,addr=0x6: vfio: failed to
get group 6
2016-06-21T20:25:55.865304Z qemu-system-x86_64: -device
vfio-pci,host=02:00.0,id=hostdev0,bus=pci.0,addr=0x6: Device
initialization failed.
2016-06-21T20:25:55.865330Z qemu-system-x86_64: -device
vfio-pci,host=02:00.0,id=hostdev0,bus=pci.0,addr=0x6: Device 'vfio-pci'
could not be initialized
-----------------------------

OK vfio was not used before. After asking google I found:

-------------------------------
find /sys/kernel/iommu_groups/ -type l
[...]
/sys/kernel/iommu_groups/6/devices/0000:00:15.0
/sys/kernel/iommu_groups/6/devices/0000:00:15.1
/sys/kernel/iommu_groups/6/devices/0000:02:00.0
/sys/kernel/iommu_groups/6/devices/0000:03:00.0
[...]
-------------------------------

Device 0000:02:00.0 is my DVB card, I try to passthrough.

---------------------------
lspci -nnk
[...]
00:15.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Hudson PCI
to PCI bridge (PCIE port 0) [1022:43a0]
        Kernel driver in use: pcieport
00:15.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Hudson PCI
to PCI bridge (PCIE port 1) [1022:43a1]
        Kernel driver in use: pcieport
02:00.0 Multimedia controller [0480]: Digital Devices GmbH Octopus DVB
Adapter [dd01:0003]
        Subsystem: Digital Devices GmbH Cine S2 V6 DVB adapter [dd01:0020]
03:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd.
RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168]
(rev 09)
        Subsystem: ASUSTeK Computer Inc. P8 series motherboard [1043:8505]
        Kernel driver in use: r8169
[...]
----------------------------

03:00.0 is my only network card on the host which I cannot passthrough.

I'm confused about the results of google right now. I only found
solutions to move to a different pcie slot - but I only have one - and
people telling that this is not possible due to hardware reasons. Since
the setup was running fine with wheezy, I cannot believe this.


I really appreciate any hint. I'm sure, I overlooked a solution or
misunderstood something.


Best regards

Andreas