> -----Original Message----- > From: Wido den Hollander [mailto:w...@widodh.nl] > Sent: Tuesday, August 07, 2012 7:35 AM > To: cloudstack-dev@incubator.apache.org > Subject: Detection of available Qemu emulators > > Hi, > > I recently upgraded to libvirt 0.10-rc1 and stumbled upon the problem > that my Instances won't start, somehow the Agent is trying to use > /usr/bin/qemu-system-s390x as the emulator. > > I dove in the code to find out why this is happening: > > LibvirtComputingResource does a libvirt.getCapabilities() which returns > and XML which is thrown in a XML parser. > > I ran "virsh capabilities" on the command line and it returns a big XML, > with the last entry: > > <capabilities> > .. > .. > .. > > <guest> > <os_type>hvm</os_type> > <arch name='s390x'> > <wordsize>64</wordsize> > <emulator>/usr/bin/qemu-system-s390x</emulator> > <machine>s390-virtio</machine> > <machine canonical='s390-virtio'>s390</machine> > <domain type='qemu'> > </domain> > <domain type='kvm'> > <emulator>/usr/bin/qemu-system-s390x</emulator> > </domain> > </arch> > </guest> > > </capabilities> > > All available emulators are thrown in a StringBuffer upon Agent boot > and > whenever deploying a Instance the last emulator is picked from this > StringBuffer (LibvirtCapXMLParser): > > public String getEmulator() { > return _emulator.toString(); > } > > > In LibvirtComputingResource this happends: > > private String getHypervisorPath(Connect conn) { > File f = new File("/usr/bin/cloud-qemu-kvm"); > if (f.exists()) { > return "/usr/bin/cloud-qemu-kvm"; > } else { > f = new File("/usr/libexec/cloud-qemu-kvm"); > if (f.exists()) { > return "/usr/libexec/cloud-qemu-kvm"; > } > > LibvirtCapXMLParser parser = new LibvirtCapXMLParser(); > try { > parser.parseCapabilitiesXML(conn.getCapabilities()); > } catch (LibvirtException e) { > > } > return parser.getEmulator(); > } > } > > Do we also still need these hardcoded hypervisor paths in there? Isn't > that legacy from when CloudStack shipped it's own version of Qemu?
Yah, don't need this hardcoded path anymore for Apache release. > > Anyway, the problem is, I'm getting a wrong emulator returned which > causes my x86_64 instance to be booted with a s390 emulator. > > One of the ideas I had was parsing the XML every time you try to start > a > Instance and match for an emulator with the correct "arch" and > "wordsize"? > > The getCapabilities() call from Libvirt is rather heavy and slow, so > running that should be prevented though. > > Any suggestions? Change LibvirtCapXMLParser, returns the correct hypervisor path, according to arch(x86_64) and domain type is 'kvm' > > Wido
