KVM vm isn't starting

I have installed webmin/cloudmin and a kvm vm that i have running for over 2 months, i have backups of the vm, but frequently the vm isn't appearing on the cloudmin interfase, now the vm isn't starting and i can't debbug or restore without it appear in there, even on command line, if i run virsh and list it's not there, but the vm is running, i think the problem is that some kernel updates failed inside the vm, but how could i repair/restore?