https://bugzilla.redhat.com/show_bug.cgi?id=982304 The problem is virDomainDeviceDefParse's incompleteness. When doing a hot(un-)plug or update, the passed XML snippet is parsed. However, if virDomainDeviceDefParse doesn't recognize the device (due its implementation incompleteness) an error is returned: error: XML error: unknown device type and the control doesn't even reach the check for supported devices for current operation, where much more correct error message would be printed out: error: Operation not supported: persistent detach of device 'memballoon' is not supported Michar Privoznik (3): conf: Extend virDomainDeviceDefParse handled types conf: Rework virDomainDeviceDefParse qemu: Fix hot (un-)plug error codes and messages src/conf/domain_conf.c | 111 ++++++++++++++++++++++++++++++++++--------------- src/qemu/qemu_driver.c | 42 ++++++++++--------- 2 files changed, 101 insertions(+), 52 deletions(-) -- 1.8.1.5 -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list