Re: [libvirt] [Qemu-devel] [PATCH v4 4/4] migration: Expose 'cancelling' status to user

On 03/13/2015 04:49 AM, Paolo Bonzini wrote: > > > On 09/03/2015 07:45, zhanghailiang wrote: >> 'cancelling' status was introduced by commit 51cf4c1a, mainly to avoid a >> possible start of a new migration process while the previous one still exists. >> But we didn't expose this status to user, instead we returned the 'active' state. >> >> Here, we expose it to the user (such as libvirt), 'cancelling' status only >> occurs for a short window before the migration aborts, so for users, >> if they cancel a migration process, it will observe 'cancelling' status >> occasionally. >> >> Testing revealed that with older libvirt (anything 1.2.13 or less) will >> print an odd error message if the state is seen, but that the migration >> is still properly cancelled. Newer libvirt will be patched to recognize >> the new state without the odd error message. >> >> Signed-off-by: zhanghailiang <zhang.zhanghailiang(a)huawei.com&gt; >> Reviewed-by: Eric Blake <eblake(a)redhat.com&gt; >> Cc: libvir-list(a)redhat.com > > Why is this necessary? It simplifies qemu's job of reporting migration status information (qemu is no longer maintaining one set of states internally and a different set of states externally), and I already have the libvirt counterpart patch ready to go to gracefully accept the new state name.

-- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org