>>> On 08.01.19 at 17:37, <rcojoc...@bitdefender.com> wrote: > On 1/8/19 6:27 PM, Jan Beulich wrote: >>>>> On 19.12.18 at 19:52, <ppircal...@bitdefender.com> wrote: >>> Signed-off-by: Petre Pircalabu <ppircal...@bitdefender.com> >> >> An empty description is not helpful. The immediate question is: Why? >> We don't do this for other interface versions. I'm unconvinced a >> special purpose piece of information like this one belongs into the >> rather generic version hypercall. > > For an introspection application meant to be deployed on several Xen > versions without recompiling, it is important to be able to decide at > runtime what size and layout the vm_event struct has. > > Currently this can somewhat be done by associating the current version > with the vm_event version, but that is not ideal for obvious reasons. > Reading the vm_event version from an actual vm_event is also out of the > question, because in order to be able to receive the first vm_event we > have to set the ring buffer up, and that requires knowledge of the size > of the vm_event. So a run-time mechanism for querying the vm_event > version is needed. > > We just thought that this was the most flexible place to add it.
How about a new XEN_DOMCTL_VM_EVENT_GET_VERSION? Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
