> > Now for some reason, I need to add “ -qmp tcp:127.0.0.1:1235” when > creating a KVM VM using libvirt. You might need to elaborate how exactly you're doing this.

> This command meaning in “qemu-kvm --help” is: -qmp dev like > -monitor but opens in 'control' mode. The above is used if you want to explicitly control a running QEMU instance via QMP, e.g. manually issue them QMP commands via telnet(1) for development/testing/debugging.

> I added command-line equivalent options into the xml file, like below > format: > > <qemu:commandline> <qemu:arg value="-s"/> <qemu:arg value="-qmp"/> > <qemu:arg value="tcp:127.0.0.1:1235"/> </qemu:commandline> In guests created in a regular fashion (e.g. virt-install, virt-manager), this is all handled by libvirt for you via its APIs. > However when I create VM using this xml file, I got the error: > > # virsh create instance-libvirt.xml error: Failed to create domain > from instance-libvirt.xml error: internal error process exited while > connecting to monitor: qemu-kvm: -qmp tcp:127.0.0.1:1235: Duplicate ID > 'monitor' for mon duplicate chardev: monitor > > The VM I created, without “—qmp” option, has below options showing in > “ps aux | grep qemu-kvm”: > > -chardev > socket,id=charmonitor,path=/var/lib/libvirt/qemu/vmifs_test.monitor,server,nowait > -mon chardev=charmonitor,id=monitor,mode=control > > Looks like libvirt automatically adds the monitor options upon VM > creation. As I understand it, libvirt uses its own APIs to handle interactions with QEMU monitor console, e.g. qemuMonitorOpen(), etc. If you're fine delving into code, you might want to libvirt sources, specificially this directory: libvirt/src/qemu.

> Is there a way to disable this and use “—qmp” instead when creating > VM? I doubt libvirt developers will agree with this proposal. But if you're intending to try QEMU monitor console for testing, here's some old notes on different ways to access QEMU monitor via QMP: http://kashyapc.com/2013/03/31/multiple-ways-to-access-qemu-monitor-proto...

> > Now for some reason, I need to add “ -qmp tcp:127.0.0.1:1235” when > creating a KVM VM using libvirt. You might need to elaborate how exactly you're doing this.

> This command meaning in “qemu-kvm --help” is: -qmp dev like > -monitor but opens in 'control' mode. The above is used if you want to explicitly control a running QEMU instance via QMP, e.g. manually issue them QMP commands via telnet(1) for development/testing/debugging.

> I added command-line equivalent options into the xml file, like below > format: > > <qemu:commandline> <qemu:arg value="-s"/> <qemu:arg value="-qmp"/> > <qemu:arg value="tcp:127.0.0.1:1235"/> </qemu:commandline> In guests created in a regular fashion (e.g. virt-install, virt-manager), this is all handled by libvirt for you via its APIs. > However when I create VM using this xml file, I got the error: > > # virsh create instance-libvirt.xml error: Failed to create domain > from instance-libvirt.xml error: internal error process exited while > connecting to monitor: qemu-kvm: -qmp tcp:127.0.0.1:1235: Duplicate ID > 'monitor' for mon duplicate chardev: monitor > > The VM I created, without “—qmp” option, has below options showing in > “ps aux | grep qemu-kvm”: > > -chardev > socket,id=charmonitor,path=/var/lib/libvirt/qemu/vmifs_test.monitor,server,nowait > -mon chardev=charmonitor,id=monitor,mode=control > > Looks like libvirt automatically adds the monitor options upon VM > creation. As I understand it, libvirt uses its own APIs to handle interactions with QEMU monitor console, e.g. qemuMonitorOpen(), etc. If you're fine delving into code, you might want to libvirt sources, specificially this directory: libvirt/src/qemu.

> Is there a way to disable this and use “—qmp” instead when creating > VM? I doubt libvirt developers will agree with this proposal. But if you're intending to try QEMU monitor console for testing, here's some old notes on different ways to access QEMU monitor via QMP: http://kashyapc.com/2013/03/31/multiple-ways-to-access-qemu-monitor-proto...

On Mon, Nov 10, 2014 at 06:54:58PM -0700, Min Du wrote: > Hi Kashyap, > > Thanks for the reply. > >>> >>> Now for some reason, I need to add “ -qmp tcp:127.0.0.1:1235” when >>> creating a KVM VM using libvirt. >> >> You might need to elaborate how exactly you're doing this. > > I wanted to add “-qmp tcp:127.0.0.1:1235” when creating VM because I > was using a multi-level debugger which needs this option to get more > information of the VM kernel debuginfo and the processes running inside > the VM besides gdb attach. That's impossible, because libvirt owns the QMP monitor and cannot delegate use to another process. A core part of the VM startup process requires that libvirt talk to the QMP monitor to accomplish work, as well as to receive ongoing notifications of changes in state. What is the debugger program you are using ? It really needs to be updated to use the libvirt APIs instead of QEMU monitor directly. Libvirt provides an API for issuing monitor commands which it should be able to use. It is just a question of re-writing the debugger to know about this. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|

Hi, Now for some reason, I need to add “ -qmp tcp:127.0.0.1:1235” when creating a KVM VM using libvirt. This command meaning in “qemu-kvm --help” is: -qmp dev like -monitor but opens in 'control' mode. I added command-line equivalent options into the xml file, like below format: <qemu:commandline> <qemu:arg value="-s"/> <qemu:arg value="-qmp"/> <qemu:arg value="tcp:127.0.0.1:1235"/> </qemu:commandline> However when I create VM using this xml file, I got the error: # virsh create instance-libvirt.xml error: Failed to create domain from instance-libvirt.xml error: internal error process exited while connecting to monitor: qemu-kvm: -qmp tcp:127.0.0.1:1235: Duplicate ID 'monitor' for mon duplicate chardev: monitor The VM I created, without “—qmp” option, has below options showing in “ps aux | grep qemu-kvm”: -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/vmifs_test.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control Looks like libvirt automatically adds the monitor options upon VM creation. Is there a way to disable this and use “—qmp” instead when creating VM?