Re: [Qemu-devel] [PATCH 0/3] VFIO-based PCI device assignment for QEMU 1.2

[Andreas Hartmann <andihartmann@01019freenet.de>]

Alex Williamson wrote:
> On Mon, 2012-08-13 at 08:27 -0500, Anthony Liguori wrote:
>> Alex Williamson <alex.williamson@redhat.com> writes:
>>
>>> VFIO kernel support was just merged into Linux, so I'd like to
>>> formally propose inclusion of the QEMU vfio-pci driver for
>>> QEMU 1.2.  Included here is support for x86 PCI device assignment.
>>> PCI INTx is not yet enabled, but devices making use of either MSI
>>> or MSI-X work.  The level irqfd and eoifd support I've proposed
>>> for KVM enable an accelerated patch for this through KVM.  I'd
>>> like to get this base driver in first and enable the remaining
>>> support in-tree.
>>>
>>> I've split this version up a little from the RFC to make it a bit
>>> easier to review.  Review comments from Blue Swirl and Avi are
>>> already incorporated, including Avi's requests to simplify both
>>> the PCI BAR mapping and unmapping paths.
>>
>> Hi Alex,
>>
>> Thanks for pushing this forward!  Hopefully this will finally kill
>> off qemu-kvm.git for good.
>>
>> I think this series is going to have to wait for 1.3 to open up.  We
>> have a very short release window for this release and I'd feel a lot
>> more comfortable having such a significant feature spend some time in
>> the development cycle getting testing/review.
>>
>> I'd like to see a few Reviewed-by's too for this series before it
>> goes in.  I expect they won't be hard to get but I also expect it
>> will take a few more revisions of this series to get there.
> 
> That's disappointing, but I can understand your reluctance.  Blue
> Swirl reviewed the RFC and could perhaps add a Reviewed-by.  Alexey
> has been working on the POWER port and I'm sure could provide a
> Reviewed-by.  We also have a few early adopters that are already
> making use of this code.

I'm running qemu with vfio patch since Jun 05, 2012
(awilliam-qemu-vfio-v0.14.0-rc0-6402-g323cf9f.tar.gz). I didn't
encounter any problem so far.

If you like, I could compile a more actual version, too (if there have
been any changes).

To see more about my use case:
http://permalink.gmane.org/gmane.linux.drivers.rt2x00.user/1051

You may add a Tested-by Andreas Hartmann <andihartmann@01019freenet.de>
if you like.

Unfortunately, I'm only running the vfio VM (kvm) with this version of
qemu, but I'm running parallel 4 other VM's with the unchanged version
of qemu (kvm-0.15.0-123.2.x86_64), too.
One of these 4 VM's uses PCIe passthrough.

I now tried to run all VMs with the new version of qemu. At this point,
I unfortunately run into a problem with the VM which passes through a
PCIe device. The error message is (during start of VM):

virsh start VM
error: Failed to start domain VM
error: internal error process exited while connecting to monitor: qemu-system-x86_64: -device pci-assign,host=04:00.0,id=hostdev0,bus=pci.0,addr=0x6: Parameter 'driver' expects device type

The xml file for libvirt looks like this: 

<domain type='kvm'>
  <name>VM</name>
  <uuid>44444444-4444-2222-7777-111111111111</uuid>
  <memory>1048576</memory>
  <currentMemory>262144</currentMemory>
  <vcpu>1</vcpu>
  <os>
    <type arch='x86_64' machine='pc-0.14'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <pae/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <devices>
    <emulator>/usr/local/bin/qemu-system-x86_64</emulator>

    <hostdev mode='subsystem' type='pci' managed='yes'>
      <source>
        <address domain='0x0000' bus='0x04' slot='0x00' function='0x0'/>
      </source>
    </hostdev>

    <disk type='file' device='disk'>
      <source file='/hds/vm.qed' type='aio'/>
      <target dev='vda' bus='virtio'/>
      <driver name='qemu' type='qed' cache='none'/>
    </disk>

    <input type='mouse' bus='ps2'/>
    <graphics type='vnc' autoport='yes'/>
    <video>
      <model type='cirrus' vram='9216' heads='1'/>
    </video>
  </devices>
</domain>


Maybe, this is fixed in a newer version of qemu for vfio?


Thanks,
kind regards,
Andreas Hartmann