Re: [libvirt] [RFC PATCH v2 REBASE 00/18] Introduce vGPU mdev framework to libvirt
On 2017年03月16日 22:41, Erik Skultety wrote:
> [2] 2005
> ubuntu@z-nuc-11:~/vgpu-meta/libvirt-stage$
> ***************************************************
> start libvirt-d
> 2017-03-09 19:04:57.211+0000: 2059: info : libvirt version: 3.1.0
> 2017-03-09 19:04:57.211+0000: 2059: info : hostname: z-nuc-11.maas
> 2017-03-09 19:04:57.211+0000: 2059: error : qemuMonitorOpenUnix:367 :
> failed to connect to monitor socket: No such process
> 2017-03-09 19:04:57.213+0000: 2059: error :
> virMediatedDeviceGetIOMMUGroupDev:153 : internal error: IOMMU group file
/sys/bus/mdev/devices/894f3983-1a36-42b3-b52c-1024aca216be/iommu_group
> is not a symlink
When I saw this error message for the first time in the original thread, I got
confused, since this just checks whether the symlink exists, if it
doesn't, the vfio device probably also doesn't exist (but take this with a
grain of salt, I haven't investigated that deep) and libvirt needs it to pass
it onto qemu command line. I hit this issue once by accident in the past and at
that time I didn't understand what caused it, but after a reboot it was gone.
So seeing it here it caught my eye and I investigated it last week. What I
found out was that it's caused by the vfio-mdev module not being loaded
automatically as a dependency. I solved it by autoloading the module on system
boot. So this is not a libvirt issue, but just for a reference, there is a BZ
on this [1].
it's does not show up every time. might be my bad.
> 2017-03-09 19:04:57.213+0000: 2003: info : libvirt version: 3.1.0
> 2017-03-09 19:04:57.213+0000: 2003: info : hostname: z-nuc-11.maas
> 2017-03-09 19:04:57.213+0000: 2003: error : virNetSocketReadWire:1800 :
> End of file while reading data: Input/output error
I suppose this corresponds to the problem above, do you hit this error if you
work around the vfio-mdev module problem described above?
> the screen call trace while start the VM (same for Ubuntu, Win10 etc)
======================================================
>
> ubuntu@z-nuc-11:~/vgpu-meta/libvirt-stage$ myvirsh start vgpu-ubuntu
> 2017-03-09 19:06:50.483+0000: 2232: info : libvirt version: 3.1.0
> 2017-03-09 19:06:50.483+0000: 2232: info : hostname: z-nuc-11.maas
> 2017-03-09 19:06:50.483+0000: 2232: warning : qemuDomainObjTaint:4056 :
> Domain id=1 name='vgpu-ubuntu' uuid=972b5e38-0437-11e7-8f97-d36dba74552d
> is tainted: high-privileges
> 2017-03-09 19:06:50.819+0000: 2204: info : libvirt version: 3.1.0
> 2017-03-09 19:06:50.819+0000: 2232: warning : virDomainAuditHostdev:456
> : Unexpected hostdev type while encoding audit message: 4
This one's interesting, again, are you able to hit the error when you work
around the missing vfio-mdev module? I'll have a look at this if you actually
can hit the error, even if the XML is correct.
the module should be there, the
domain is running and virtual gpu is
working.
ubuntu@z-nuc-11:~/vgpu-meta/libvirt-stage$ sudo lsmod| grep mdev
vfio_mdev 16384 1
mdev 20480 2 kvmgt,vfio_mdev
vfio 28672 6 vfio_iommu_type1,kvmgt,vfio_mdev
on the v3, the trace still there. refer to my "test by" email on mdev-next.
Regards
Yongli He
I posted v3 of the series and also created a new branch 'mdev-next' on my
github [2]. I dropped the attribute 'type' from the source address element, so
follow the example in the updated docs.
Thanks for giving it a try.
Erik
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1420572
[2] https://github.com/eskultety/libvirt/commits/mdev-next