Re: [PATCH v2 2/2] net: move backend cleanup to NIC cleanup

[Jason Wang]

On Fri, Sep 13, 2024 at 12:54 AM Eugenio Pérez <eperezma@redhat.com> wrote:
>
> Commit a0d7215e33 ("vhost-vdpa: do not cleanup the vdpa/vhost-net
> structures if peer nic is present") effectively delayed the backend
> cleanup, allowing the frontend or the guest to access it resources as
> long as the frontend is still visible to the guest.
>
> However it does not clean up the resources until the qemu process is
> over.  This causes an effective leak if the device is deleted with
> device_del, as there is no way to close the vdpa device.  This makes
> impossible to re-add that device to this or other QEMU instances until
> the first instance of QEMU is finished.
>
> Move the cleanup from qemu_cleanup to the NIC deletion and to
> net_cleanup.
>
> Fixes: a0d7215e33 ("vhost-vdpa: do not cleanup the vdpa/vhost-net structures 
> if peer nic is present")
> Reported-by: Lei Yang <leiyang@redhat.com>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
> v2: Remove NIC peer also at net_cleanup. vhost-user trust all the
> backends are clean before qemu removes char devices.
>
> This is not a requisite introduced by this commit as
> system/runstate.c:qemu_cleanup shows.
> ---

Unfortunately, this fails the build:

https://gitlab.com/jasowang/qemu/-/jobs/8138832559

Thanks