On 1/31/22 11:01, Peter Krempa wrote: > On Mon, Jan 31, 2022 at 10:42:28 +0100, Michal Privoznik wrote: >> There is plenty of places where a domain XML is parsed using >> VIR_DOMAIN_DEF_PARSE_SKIP_VALIDATE flag, but not all are >> warranted. The flag usage is okay when parsing an XML produced by >> us (e.g. when copying virDomainDef). In the rest of places >> (especially when the XML might come from user) we need to >> validate the XML, otherwise we may start QEMU assuming it has >> certain capabilities while in fact it doesn't. For instance, in >> this specific case when migrating a guest with virtio-mem to a >> QEMU that has virtio-mem disabled, loading migration fails with: >> >> qemu-kvm: ... 'virtio-mem-pci' is not a valid device model name >> >> This bug is more visible the more we transfer validation from >> qemu_command.c into qemu_validate.c. > > This is weird, because the validation should be done on the destination > when starting the qemu process with the already parsed definition. I think my patch does exactly that. I mean, the places I'm fixing are run on the destination. And running the validation on the source - well, we are running ABI stability check anyway so why not run validator? > > In case we skipt that for migration for any reason that would be the > place to fix it rather than messing with the parsing step. > > The handling should be equivalent to what happens when you have an > un-validated XML already defined and attempt to start the VM from such > definition. > Fair enough, so in that case we need to remove the check from qemuProcessStartValidate(). Michal
