Re: [PATCH v2 0/4] hw/nvme: fix controller hotplugging

[Klaus Jensen <its@irrelevant.dk>]

[-- Attachment #1: Type: text/plain, Size: 2389 bytes --]

On Jul  7 17:49, Klaus Jensen wrote:
>From: Klaus Jensen <k.jensen@samsung.com>
>
>Back in May, Hannes posted a fix[1] to re-enable NVMe PCI hotplug. We
>discussed a bit back and fourth and I mentioned that the core issue was
>an artifact of the parent/child relationship stemming from the qdev
>setup we have with namespaces attaching to controller through a qdev
>bus.
>
>The gist of this series is the fourth patch "hw/nvme: fix controller hot
>unplugging" which basically causes namespaces to be reassigned to a bus
>owned by the subsystem if the parent controller is linked to one. This
>fixes `device_del/add nvme` in such settings.
>
>Note, that in the case that there is no subsystem involved, nvme devices
>can be removed from the system with `device_del`, but this *will* cause
>the namespaces to be removed as well since there is no place (i.e. no
>subsystem) for them to "linger". And since this series does not add
>support for hotplugging nvme-ns devices, while an nvme device can be
>readded, no namespaces can. Support for hotplugging nvme-ns devices is
>present in [1], but I'd rather not add that since I think '-device
>nvme-ns' is already a bad design choice.
>
>Now, I do realize that it is not "pretty" to explicitly change the
>parent bus, so I do have a an RFC patch in queue that replaces the
>subsystem and namespace devices with objects, but keeps -device shims
>available for backwards compatibility. This approach will solve the
>problems properly and should be a better model. However, I don't believe
>it will make it for 6.1 and I'd really like to at least fix the
>unplugging for 6.1 and this gets the job done.
>
>  [1]: 20210511073511.32511-1-hare@suse.de
>
>v2:
>- added R-b's by Hannes for patches 1 through 3
>- simplified "hw/nvme: fix controller hot unplugging"
>
>Klaus Jensen (4):
>  hw/nvme: remove NvmeCtrl parameter from ns setup/check functions
>  hw/nvme: mark nvme-subsys non-hotpluggable
>  hw/nvme: unregister controller with subsystem at exit
>  hw/nvme: fix controller hot unplugging
>
> hw/nvme/nvme.h   | 18 +++++++++-------
> hw/nvme/ctrl.c   | 14 ++++++------
> hw/nvme/ns.c     | 55 +++++++++++++++++++++++++++++++-----------------
> hw/nvme/subsys.c |  9 ++++++++
> 4 files changed, 63 insertions(+), 33 deletions(-)
>
>-- 
>2.32.0
>

Applied patches 1 through 3 to nvme-next.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]