Paolo Bonzini wrote: > Currently, the QEMU driver tries to migrate paused VMs, but the > effect is that the migrated virtual machine will always run on the > destination. > > Furthermore, the state is erroneously stored as paused, so that the > driver is left confused and it is not possible to re-pause the VM > without doing a (useless except to make the libvirtd state consistent) > "virsh resume" first. > > While pausing is not very used, this feature is still nice-to-have > in case for example you're migrating all VMs in emergency, or (when > QEMU will have asynchronous notifications) if you want to run QEMU > with the werror=stop option (*). > > This set of patches is structured as follows: > > 1) patches 1 and 2 fix two bugs that were introduced by the recent > reorganization. > > 2) patch 3 fixes a bug that happens to be in the paths touched later on; > > 3) patch 4 adds the possibility to migrate a VM and leave it suspended > on the destination VM. I added the feature for debugging and thought I > might as well submit it for inclusion. Especially if the last two > patches turn out to be a no-go (at least in their current form), this > patch at least provides the infrastructure and a way to test it. > > 4) patches 5 and 6 actually fix the bug. Unfortunately, this requires > a change to the RPC protocol. I'm not sure whether it is required the > libvirtd's on both sides of the migration to have the same version, > or rather if this is a deal breaker. > > The change to the protocol is in patch 5; the bug fix is in patch 6. > > Please review and ack (or, for the last two, nack). > > Paolo > > (*) While the state of the migrated VM is currently fetched at the > beginning of migration, the communication happens at the end of it > (from Perform to Finish), so this is ready for being improved in > the future once QEMU provides asynchronous notifications. I haven't reviewed the actual code yet, but I like the idea. Unfortunately this patch series is going to clash horribly with the tunnelled migration code that I'm going to commit today, so I'd suggest waiting until I commit, rebasing, and then reposting. -- Chris Lalancette -- Libvir-list mailing list Libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list