Red Hat Bugzilla – Bug 1273686
libvirt do not check the if the serial type is changed during migrate/save
Last modified: 2016-11-03 14:28:25 EDT
Description of problem: libvirt do not check the if the serial type is changed during migrate/save, if we change them will cause migrate or save/restore failed, and as we know libvirt have function like *CheckABIStability to avoid this Version-Release number of selected component (if applicable): libvirt-1.2.17-13.el7.x86_64 How reproducible: 100% Steps to Reproduce: 1. prepare a running guest use isa-serial # virsh dumpxml rhel7.0-rhel <serial type='pty'> <source path='/dev/pts/1'/> <target type='isa-serial' port='1'/> <alias name='serial0'/> </serial> <console type='pty'> <source path='/dev/pts/1'/> <target type='serial' port='1'/> <alias name='serial0'/> </console> 2. save this guest to a file: # virsh save rhel7.0-rhel r7.save Domain rhel7.0-rhel saved to r7.save 3. edit the save file: <serial type='pty'> <target type='isa-serial' port='1'/> </serial> change to: <serial type='pty'> <target type='pci-serial' port='1'/> </serial> # virsh save-image-edit r7.save State file r7.save edited. # virsh save-image-dumpxml r7.save |grep serial <controller type='virtio-serial' index='0'> <serial type='pty'> <target type='pci-serial' port='1'/> </serial> <target type='serial' port='1'/> <address type='virtio-serial' controller='0' bus='0' port='2'/> 4. restore the guest: # virsh restore r7.save error: Failed to restore domain from r7.save error: internal error: early end of file from monitor: possible problem: 2015-10-21T02:33:18.134054Z qemu-kvm: Unknown savevm section or instance 'serial' 0 2015-10-21T02:33:18.134166Z qemu-kvm: load of migration failed: Invalid argument Actual results: libvirt not check if he serial type is changed during migrate/save Expected results: this will cause qemu cannot restore with new save file Additional info: test with other chr device: change <console type='pty'> <target type='serial' port='1'/> </console> to <console type='pty'> <target type='virtio' port='1'/> </console> # virsh save-image-edit r7.save error: unsupported configuration: Target console type virtio does not match source serial Failed. Try again? [y,n,f,?]:
Send a patch to upstream: https://www.redhat.com/archives/libvir-list/2015-October/msg00667.html
commit a98145e7c9f023b0253e91dd41d3484b95e51bc4 Author: Luyao Huang <lhuang@redhat.com> Date: Wed Oct 21 15:14:03 2015 +0800 conf: Add serial target type to ABI stability check https://bugzilla.redhat.com/show_bug.cgi?id=1273686 There is no ABI check for serial target type attribute, just add it. v1.2.20-140-ga98145e
Verify this bug with libvirt-1.3.1-1.el7, steps as following 1.prepare a running guest use isa-serial # virsh dumpxml rhel74 <serial type='pty'> <source path='/dev/pts/1'/> <target type='isa-serial' port='1'/> <alias name='serial0'/> </serial> <console type='pty'> <source path='/dev/pts/1'/> <target type='serial' port='1'/> <alias name='serial0'/> </console> 2.Dumpxml the guest's xml to local file #virsh dumpxml rhel74 >rhel74.xml 3.Save the guest to a save file #virsh save rhel74 7r.save 4.edit the save file: <serial type='pty'> <target type='isa-serial' port='1'/> </serial> change to: <serial type='pty'> <target type='pci-serial' port='1'/> </serial> will get the expect error # virsh save-image-edit 7r.save error: unsupported configuration：Target serial type pci-serial does not match source isa-serial Failed. Try again? [y,n,f,?]: 5.edit the guest's xml <serial type='pty'> <target type='isa-serial' port='1'/> </serial> change to: <serial type='pty'> <target type='pci-serial' port='1'/> </serial> 6.Restore guest with the modified xml, will get the expect error # virsh restore 7r.save --xml rhel74.xml error: Failed to restore domain from 7r.save error: unsupported configuration：Target serial type pci-serial does not match source isa-serial 7.Prepare a migration env, then migrate the guest with specify the upper modified xml, will get the following error # virsh migrate --live rhel74 qemu+ssh://$dest_ip/system --verbose --xml rhel74.xml --unsafe root@$dest_ip's password: error: unsupported configuration: Target serial type pci-serial does not match source isa-serial
Per comment 4 , move to verified.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHSA-2016-2577.html