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

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

I also ran "virsh capabilities". It looks like the machine
"pc-i440fx-4.0"
is available there. Does it mean anything to this case? I am guessing
"4.0"
means Qemu version, which is the version I am trying to install from source.

https://gist.github.com/proywm/433de1f410c5e7d68cff5833e03fb5dc

On Sat, Jul 20, 2019 at 2:36 PM Probir Roy <proy@email.wm.edu> wrote:
> 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
>

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

On Sat, 2019-07-20 at 20:45 -0500, Probir Roy wrote:
> I also ran "virsh capabilities". It looks like the machine
"pc-i440fx-4.0" is available there. Does it mean anything to this
case? I am guessing "4.0" means Qemu version, which is the version I
am trying to install from source.
> 
> https://gist.github.com/proywm/433de1f410c5e7d68cff5833e03fb5dc
It's true that the pc-i440fx-4.0 machine type exists, but it's in
the /usr/bin/kvm-spice binary while...

[...]
> > > > 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'
... from the error message it looks like you're using the
/usr/bin/qemu-system-x86_64 binary instead, which does *not* contain
that machine type.

Since the newest machine type for that binary is versioned with 3.0,
are you sure you've compiled and installed QEMU 4.0?

-- 
Andrea Bolognani / Red Hat / Virtualization