Hi, I tend to change the qualified path to run other emulator binary, which is besides libvirt supporting but based on qemu, so I set the tag as "<emulator>/usr/bin/emulator<emulator>".(I have set the emulator binary to env.). As a result, the messages shown as below: ....(ignoring much xml contents) </devices></domain>, flags=011:00:27.110: 2263: debug : remoteIO:5824 : Do proc=10 serial=3 length=2144 wait=(nil)11:00:27.110: 2263: debug : remoteIO:5896 : We have the buck 10 0x993b9e0 0x993b9e011:00:27.110: 2263: debug : virEventPollUpdateHandle:144 : Update handle w=2 e=011:00:27.111: 2263: debug : virEventPollInterruptLocked:686 : Skip interrupt, 0 011:00:27.136: 2263: debug : remoteIODecodeMessageLength:5214 : Got length, now need 416 total (412 more)11:00:27.136: 2263: debug : remoteIOEventLoop:5750 : Giving up the buck 10 0x993b9e0 (nil)11:00:27.136: 2263: debug : virEventPollUpdateHandle:144 : Update handle w=2 e=111:00:27.136: 2263: debug : virEventPollInterruptLocked:686 : Skip interrupt, 0 011:00:27.136: 2263: debug : remoteIO:5924 : All done with our call 10 (nil) 0x993b9e0 error: Failed to create domain from fedora-qemu.xmlerror: internal error Child process (LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin /usr/bin/emulator -help) status unexpected: exit status 1 11:00:27.137: 2263: debug : virConnectClose:1354 : conn=0x99374a811:00:27.137: 2263: debug : virUnrefConnect:145 : unref connection 0x99374a8 111:00:27.137: 2263: debug : virReleaseConnect:94 : release connection 0x99374a811:00:27.137: 2263: debug : virEventPollRemoveTimeout:278 : Remove timer 111:00:27.137: 2263: debug : virEventPollInterruptLocked:686 : Skip interrupt, 0 011:00:27.137: 2263: debug : virEventPollRemoveHandle:171 : Remove handle w=211:00:27.137: 2263: debug : virEventPollRemoveHandle:184 : mark delete 1 511:00:27.137: 2263: debug : virEventPollInterruptLocked:686 : Skip interrupt, 0 011:00:27.137: 2263: debug : remoteIO:5824 : Do proc=2 serial=4 length=28 wait=(nil)11:00:27.137: 2263: debug : remoteIO:5896 : We have the buck 2 0x993ba78 0x993ba7811:00:27.138: 2263: debug : remoteIODecodeMessageLength:5214 : Got length, now need 56 total (52 more)11:00:27.138: 2263: debug : remoteIOEventLoop:5750 : Giving up the buck 2 0x993ba78 (nil)11:00:27.138: 2263: debug : remoteIO:5924 : All done with our call 2 (nil) 0x993ba78 Could you please tell me what's wrong in the source code? If so, where should I modify? Thanks a lot! Regard,Corey