On Thu, Mar 27, 2025 at 11:39:31AM -0300, Fabiano Rosas wrote: > It has always been possible to enable arbitrary migration capabilities > and attempt to take a snapshot of the VM with the savevm/loadvm > commands as well as their QMP counterparts > snapshot-save/snapshot-load. > > Most migration capabilities are not meant to be used with snapshots > and there's a risk of crashing QEMU or producing incorrect > behavior. Ideally, every migration capability would either be > implemented for savevm or explicitly rejected.
IMHO, this a prime example of why migration config shouldn't be held as global state, and instead passed as parameters to the commands that need them. The snapshot-save/load commands would then only be able to accept what few settings are actually relevant, instead of inheriting any/all global migration state. > Add a compatibility check routine and reject the snapshot command if > an incompatible capability is enabled. For now only act on the the two > that actually cause a crash: multifd and mapped-ram. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2818 Issue is 2881 not 2818 ^^^^^^^ > Signed-off-by: Fabiano Rosas <faro...@suse.de> > --- > migration/options.c | 26 ++++++++++++++++++++++++++ > migration/options.h | 1 + > migration/savevm.c | 8 ++++++++ > 3 files changed, 35 insertions(+) With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
