On 5/11/21 3:37 PM, Klaus Jensen wrote: > On May 11 15:12, Hannes Reinecke wrote: >> On 5/11/21 2:22 PM, Klaus Jensen wrote: [ .. ] >>> The hotplug fix looks good - I'll post a series that tries to integrate >>> both. >>> >> Ta. >> >> The more I think about it, the more I think we should be looking into >> reparenting the namespaces to the subsystem. >> That would have the _immediate_ benefit that 'device_del' and >> 'device_add' becomes symmetric (ie one doesn't have to do a separate >> 'device_add nvme-ns'), as the nvme namespace is not affected by the >> hotplug event. >> > > I have that working, but I'm struggling with a QEMU API technicality in > that I apparently cannot simply move the NvmeBus creation to the > nvme-subsys device. For some reason the bus is not available for the > nvme-ns devices. That is, if one does something like this: > > -device nvme-subsys,... > -device nvme-ns,... > > Then I get an error that "no 'nvme-bus' bus found for device 'nvme'ns". > This is probably just me not grok'ing the qdev well enough, so I'll keep > trying to fix that. What works now is to have the regular setup: > _Normally_ the 'id' of the parent device spans a bus, so the syntax should be
-device nvme-subsys,id=subsys1,... -device nvme-ns,bus=subsys1,... As for the nvme device I would initially expose any namespace from the subsystem to the controller; the nvme spec has some concept of 'active' or 'inactive' namespaces which would allow us to blank out individual namespaces on a per-controller basis, but I fear that's not easy to model with qdev and the structure above. > -device nvme-subsys,... > -device nvme,... > -device nvme-ns,... > > And the nvme-ns device will then reparent to the NvmeBus on nvme-subsys > (which magically now IS available when nvme-ns is realized). This has > the same end result, but I really would like that the namespaces could > be specified as children of the subsys directly. > Shudder. Automatic reparenting. To my understanding from qdev that shouldn't even be possible. Please don't. Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect h...@suse.de +49 911 74053 688 SUSE Software Solutions Germany GmbH, 90409 Nürnberg GF: F. Imendörffer, HRB 36809 (AG Nürnberg)
