libvirt users - Jul 2019 - Installing QEMU from source causing error

Hi,

I am trying to run Qemu-4.0 installed from source code.

When I run virt-manager to create a VM, I get the following error:

```
Unable to complete install: 'internal error: process exited while
connecting to monitor: 2019-07-19T17:06:35.954242Z qemu-system-x86_64:
-enable-kvm: unsupported machine type
Use -machine help to list supported machines'

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 89, in
cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/create.py", line 2553, in
_do_async_install
    guest.start_install(meter=meter)
  File "/usr/share/virt-manager/virtinst/guest.py", line 498, in
start_install
    doboot, transient)
  File "/usr/share/virt-manager/virtinst/guest.py", line 434, in
_create_guest
    domain = self.conn.createXML(install_xml or final_xml, 0)
  File "/usr/lib/python2.7/dist-packages/libvirt.py", line 3603, in
createXML
    if ret is None:raise libvirtError('virDomainCreateXML() failed',
conn=self)
libvirtError: internal error: process exited while connecting to monitor:
2019-07-19T17:06:35.954242Z qemu-system-x86_64: -enable-kvm: unsupported
machine type
Use -machine help to list supported machines

```

I configured the Qemu with following command:
```
./../configure --prefix=/usr --enable-spice --target-list=x86_64-softmmu
--enable-kvm --enable-debug --enable-libssh2
```

Is it that I missed enabling any configuration while installing Qemu? What
is the expected QEMU configuration to run with libvirt?

-
Probir

On Fri, Jul 19, 2019 at 12:16:25PM -0500, Probir Roy
wrote:
> Hi,
> 
> I am trying to run Qemu-4.0 installed from source code.
> 
> When I run virt-manager to create a VM, I get the following error:
> 
> ```
> Unable to complete install: 'internal error: process exited while
> connecting to monitor: 2019-07-19T17:06:35.954242Z qemu-system-x86_64:
> -enable-kvm: unsupported machine type
> Use -machine help to list supported machines'
You don't mention what your OS is ?  Some OS vendors patch QEMU
to have different machine types than upstream QEMU provides, and
I guess that's what you've hit.

If you look in your libvirt XML 'virsh dumpxml $GUESTNAME' you'll
see a machine type listed - probably "pc-$SOMETHING" or
"q35-$SOMETHING".

If you simply delete the "-$SOMETHING" part to leave just
"pc" or
just "q35", then libvirt will expand the machine type into the
latest one available with your self-built QEMU

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|

It is true that the machine contains 'pc-i440fx-4.0'. I am using
Ubuntu18.04 and libvirt-4.0.0

This is probably a separate issue, but while updating the machine name
neither "virsh define" or "virsh edit" updates the name to
"pc".

I was reading the FAQ of libvirt on updating the configuration at :
https://wiki.libvirt.org/page/FAQ#What_is_the_.27virsh_edit.27_command_and_how_do_I_use_it.3F

"... A common problem seen when people edit the on-disk XML is a VM that
simply vanishes the next time libvirtd is restarted after the edit. The VM
disappears from libvirt because the XML has become invalid, after which
libvirt can't do anything with it. "

Is it also true for virsh?

I also tried creating a new VM by "virsh dumpxml" and editing the xml
with
new "name" and "pc" and removed the "uuid" field
and then "virsh define".
virsh creates a new domain with UUID, but with machine='pc-i440fx-4.0'.
Is
it possible the virsh is using some configuration that resetting to
predefined machine name?




On Fri, Jul 19, 2019 at 12:36 PM Daniel P. Berrangé <berrange@redhat.com>
wrote:
> On Fri, Jul 19, 2019 at 12:16:25PM -0500, Probir Roy wrote:
> > Hi,
> >
> > I am trying to run Qemu-4.0 installed from source code.
> >
> > When I run virt-manager to create a VM, I get the following error:
> >
> > ```
> > Unable to complete install: 'internal error: process exited while
> > connecting to monitor: 2019-07-19T17:06:35.954242Z qemu-system-x86_64:
> > -enable-kvm: unsupported machine type
> > Use -machine help to list supported machines'
>
> You don't mention what your OS is ?  Some OS vendors patch QEMU
> to have different machine types than upstream QEMU provides, and
> I guess that's what you've hit.
>
> If you look in your libvirt XML 'virsh dumpxml $GUESTNAME'
you'll
> see a machine type listed - probably "pc-$SOMETHING" or
"q35-$SOMETHING".
>
> If you simply delete the "-$SOMETHING" part to leave just
"pc" or
> just "q35", then libvirt will expand the machine type into the
> latest one available with your self-built QEMU
>
> Regards,
> Daniel
> --
> |: https://berrange.com      -o-
> https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org         -o-
> https://fstop138.berrange.com :|
> |: https://entangle-photo.org    -o-
> https://www.instagram.com/dberrange :|
>

-- 
Probir Roy
College of William and Mary
Phone: 7577531428
Web: www.probir.info