CentOS virt - May 2019 - CentOS 7 Xen 4.12 libvirt/virt-manager wrong path for qemu-system-i386

Hello,

While testing Virt-SIG Xen 4.12 rpms on CentOS7 I noticed the following problem
with libvirt/virt-manager when manually installing a new HVM guest from
virt-manager GUI.. basicly the VM installation won't start, because
libvirt/virt-manager is not able to start the VM, due to "missing"
qemu-system-i386 binary:

Unable to complete install: 'unsupported configuration: emulator
'/usr/lib/xen/bin/qemu-system-i386' not found'

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/lib64/python2.7/site-packages/libvirt.py", line 3725, in
createXML
    if ret is None:raise libvirtError('virDomainCreateXML() failed',
conn=self)
libvirtError: unsupported configuration: emulator
'/usr/lib/xen/bin/qemu-system-i386' not found


Quick'n'dirty fix is to create a symlink:

	ln -s /usr/lib64/xen/bin/qemu-system-i386 /usr/lib/xen/bin/qemu-system-i386

.. after creating that symlink the VM can be started just fine and works OK.

We need to fix that default directory path for qemu-system-i386 to be correct
out-of-the-box..


Thanks,

-- Pasi

On Sun, May 05, 2019 at 02:23:22PM +0300, Pasi K?rkk?inen
wrote:
> Hello,
> 
> While testing Virt-SIG Xen 4.12 rpms on CentOS7 I noticed the following
problem with libvirt/virt-manager when manually installing a new HVM guest from
virt-manager GUI.. basicly the VM installation won't start, because
libvirt/virt-manager is not able to start the VM, due to "missing"
qemu-system-i386 binary:
> 
> Unable to complete install: 'unsupported configuration: emulator
'/usr/lib/xen/bin/qemu-system-i386' not found'
> 
> 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/lib64/python2.7/site-packages/libvirt.py", line
3725, in createXML
>     if ret is None:raise libvirtError('virDomainCreateXML()
failed', conn=self)
> libvirtError: unsupported configuration: emulator
'/usr/lib/xen/bin/qemu-system-i386' not found
> 
> 
> Quick'n'dirty fix is to create a symlink:
> 
> 	ln -s /usr/lib64/xen/bin/qemu-system-i386
/usr/lib/xen/bin/qemu-system-i386
> 
> .. after creating that symlink the VM can be started just fine and works
OK.
> 
> We need to fix that default directory path for qemu-system-i386 to be
correct out-of-the-box..
> 
Oh, I forgot to paste the rpm versions I have:

libvirt-daemon-config-network-4.10.0-3.xen412.el7.x86_64
libvirt-libs-4.10.0-3.xen412.el7.x86_64
libvirt-python-4.5.0-1.el7.x86_64
libvirt-daemon-4.10.0-3.xen412.el7.x86_64
libvirt-daemon-driver-network-4.10.0-3.xen412.el7.x86_64
libvirt-daemon-driver-libxl-4.10.0-3.xen412.el7.x86_64
libvirt-bash-completion-4.10.0-3.xen412.el7.x86_64
libvirt-client-4.10.0-3.xen412.el7.x86_64
libvirt-glib-1.0.0-1.el7.x86_64

virt-manager-common-1.5.0-1.el7.noarch
virt-manager-1.5.0-1.el7.noarch
virt-viewer-5.0-11.el7.x86_64

xen-runtime-4.12.0-1.el7.x86_64
xen-libs-4.12.0-1.el7.x86_64
xen-ovmf-20180825-1.gitef529e6ab.el7.x86_64
centos-release-xen-common-8-7.el7.centos.x86_64
centos-release-xen-412-8-7.el7.centos.x86_64
qemu-xen-4.12.0-1.el7.x86_64
xen-4.12.0-1.el7.x86_64
xen-hypervisor-4.12.0-1.el7.x86_64
xen-livepatch-build-tools-4.12.0-1.el7.x86_64
xen-licenses-4.12.0-1.el7.x86_64


-- Pasi

On Sun, May 05, 2019 at 02:23:22PM +0300, Pasi K?rkk?inen
wrote:
> Hello,
Thanks for the bug report.
> While testing Virt-SIG Xen 4.12 rpms on CentOS7 I noticed the following
problem with libvirt/virt-manager when manually installing a new HVM guest from
virt-manager GUI.. basicly the VM installation won't start, because
libvirt/virt-manager is not able to start the VM, due to "missing"
qemu-system-i386 binary:
> 
> Unable to complete install: 'unsupported configuration: emulator
'/usr/lib/xen/bin/qemu-system-i386' not found'
> 
> 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/lib64/python2.7/site-packages/libvirt.py", line
3725, in createXML
>     if ret is None:raise libvirtError('virDomainCreateXML()
failed', conn=self)
> libvirtError: unsupported configuration: emulator
'/usr/lib/xen/bin/qemu-system-i386' not found
Starting a guest with libvirt works fine, libvirt is able to find the
qemu binary. (Well, libxl can...)

Here is an osstest flight starting an HVM guest with libvirt:
http://logs.test-lab.xenproject.org/osstest/logs/136701/test-amd64-amd64-libvirt-qemuu-debianhvm-amd64/info.html

Maybe the issue is that I need to rebuild `libvirt-python' and
`virt-manager' packages?
> Quick'n'dirty fix is to create a symlink:
> 
> 	ln -s /usr/lib64/xen/bin/qemu-system-i386
/usr/lib/xen/bin/qemu-system-i386
> 
> .. after creating that symlink the VM can be started just fine and works
OK.
> 
> We need to fix that default directory path for qemu-system-i386 to be
correct out-of-the-box..
I can certainly move the binary from "/usr/lib64" to
"/usr/lib", and
hope it doesn't break anything, with Xen 4.10 packages the qemu binary
is in /usr/lib64. But to be honest I don't know which is best for CentOS
between "lib64" and "lib".

Thanks,

-- 
Anthony PERARD

Hi,

On Wed, May 22, 2019 at 10:46:25AM +0100, Anthony PERARD
wrote:
> On Sun, May 05, 2019 at 02:23:22PM +0300, Pasi K?rkk?inen wrote:
> > Hello,
> 
> Thanks for the bug report.
> 
> > While testing Virt-SIG Xen 4.12 rpms on CentOS7 I noticed the
following problem with libvirt/virt-manager when manually installing a new HVM
guest from virt-manager GUI.. basicly the VM installation won't start,
because libvirt/virt-manager is not able to start the VM, due to
"missing" qemu-system-i386 binary:
> > 
> > Unable to complete install: 'unsupported configuration: emulator
'/usr/lib/xen/bin/qemu-system-i386' not found'
> > 
> > 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/lib64/python2.7/site-packages/libvirt.py", line
3725, in createXML
> >     if ret is None:raise libvirtError('virDomainCreateXML()
failed', conn=self)
> > libvirtError: unsupported configuration: emulator
'/usr/lib/xen/bin/qemu-system-i386' not found
> 
> Starting a guest with libvirt works fine, libvirt is able to find the
> qemu binary. (Well, libxl can...)
> 
> Here is an osstest flight starting an HVM guest with libvirt:
>
http://logs.test-lab.xenproject.org/osstest/logs/136701/test-amd64-amd64-libvirt-qemuu-debianhvm-amd64/info.html
> 
> Maybe the issue is that I need to rebuild `libvirt-python' and
> `virt-manager' packages?
> 
Hmm.. maybe. I guess we need to investigate a bit more where the directory path
is actually coming from..

> > Quick'n'dirty fix is to create a symlink:
> > 
> > 	ln -s /usr/lib64/xen/bin/qemu-system-i386
/usr/lib/xen/bin/qemu-system-i386
> > 
> > .. after creating that symlink the VM can be started just fine and
works OK.
> > 
> > We need to fix that default directory path for qemu-system-i386 to be
correct out-of-the-box..
> 
> I can certainly move the binary from "/usr/lib64" to
"/usr/lib", and
> hope it doesn't break anything, with Xen 4.10 packages the qemu binary
> is in /usr/lib64. But to be honest I don't know which is best for
CentOS
> between "lib64" and "lib".
> 
I think /usr/lib64/ is the correct location, as the qemu-system-i386 binary is
64bit:

# file /usr/lib64/xen/bin/qemu-system-i386
/usr/lib64/xen/bin/qemu-system-i386: ELF 64-bit LSB shared object, x86-64,
version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32,
BuildID[sha1]=12576991824bc1611d8630aaa30df9b00f175980, stripped


> -- 
> Anthony PERARD

Thanks,

-- Pasi