On Tue, May 14, 2019 at 03:37:26PM +0200, Michal Privoznik wrote: > On 5/13/19 8:48 PM, Daniel Henrique Barboza wrote: > > Tried to reproduce the error using my x86 laptop but got hit by > > https://bugzilla.redhat.com/show_bug.cgi?id=1689216 when trying > > to create the snapshot using upstream code: > > > > $ sudo ./run tools/virsh snapshot-create-as ub1810-cpu-hotplug snap > > error: operation failed: Failed to take snapshot: Error: Nested VMX > > virtualization does not support live migration yet > > > > > > Since this issue is arch independent I tried it out with a Power server. > > Here's the behavior with current upstream: > > > > > > - relevant piece of VM XML: > > > > <domain type='kvm'> > > <name>dhb</name> > > <uuid>d3fe0169-2be6-431c-85a5-cc178601bb69</uuid> > > <memory unit='KiB'>67108864</memory> > > <currentMemory unit='KiB'>67108864</currentMemory> > > <vcpu placement='static' current='4'>16</vcpu> > > > > $ sudo ./run tools/virsh setvcpus dhb 8 --live > > > > $ > > $ sudo ./run tools/virsh snapshot-create-as dhb snap1 > > Domain snapshot snap1 created > > $ > > $ sudo ./run tools/virsh snapshot-revert dhb snap1 > > > > $ > > $ sudo ./run tools/virsh dumpxml --inactive dhb > > <domain type='kvm'> > > <name>dhb</name> > > <uuid>d3fe0169-2be6-431c-85a5-cc178601bb69</uuid> > > <memory unit='KiB'>67108864</memory> > > <currentMemory unit='KiB'>67108864</currentMemory> > > <vcpu placement='static' current='8'>16</vcpu> > > <vcpus> > > > > The inactive XML got overwritten by the vcpu hotplug, which is not > > intended. > > > > > > After the patch, the problem isn't reproduced: the inactive VM XML was > > preserved after the snapshot-revert. > > > > > > Maxiwell, you (or the commiter) can add the following in the commit-msg: > > > > Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1689216 > > > > > > Since the bug you're fixing here also fixes this RH bugzilla. > > > > > > Reviewed-by: Daniel Henrique Barboza <danielhb413@xxxxxxxxx> > > Tested-by: Daniel Henrique Barboza <danielhb413@xxxxxxxxx> > > Actually, I think that this is not the proper fix. The proper fix would be > to store both active AND inactive XMLs when creating a snapshot and then > restore them both on snapshot revert. While this fix may fix one use case, > it's not dealing with the issue properly IMO. But I'm not snapshot expert > really. > > Michal > Hi Michal, My patch only revert the ‘snapshot XML’ in the active domain and do not touch in the inactive XML. A limitation is that many snapshots will have the same inactive XML (the last one). Maybe save both inactive and active XML with ‘snapshot create’ is an answer. -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
