[Libguestfs] [PATCH 0/2] Don't use snapshot=on

QEMU upstream has broken snapshot=on ... again. These two patches stop using it entirely. Instead we run 'qemu-img create' to create overlay disks as required. Note that the libvirt and UML backends were already doing this: The libvirt backend because <transient/> has never worked, and the UML backend was running uml_mkcow because the UML-equivalent syntax of snapshot=on was broken for years. So this is a factoring out of that logic into a central place. Tested by: make -j1 check check-valgrind check-direct check-valgrind-direct I have not tested the UML backend yet. Rich.