On Wed, Apr 29, 2020 at 07:02:56AM +0000, Ani Sinha wrote: > > > > On Apr 29, 2020, at 12:27 PM, Michael S. Tsirkin <m...@redhat.com> wrote: > > > > On Wed, Apr 29, 2020 at 06:54:52AM +0000, Ani Sinha wrote: > >> > >> > >>> On Apr 29, 2020, at 12:22 PM, Michael S. Tsirkin <m...@redhat.com> wrote: > >>> > >>> On Wed, Apr 29, 2020 at 06:11:20AM +0000, Ani Sinha wrote: > >>>> > >>>> > >>>>> On Apr 29, 2020, at 10:58 AM, Michael S. Tsirkin <m...@redhat.com> > >>>>> wrote: > >>>>> > >>>>> o if there's a need to disable > >>>>> just one of these, commit log needs to do a better job documenting the > >>>>> usecase. > >>>> > >>>> The use case is simple. With this feature admins will be able to do what > >>>> they were forced to do from Windows driver level but now at the bus > >>>> level. Hence, > >>>> (a) They need not have access to the guest VM to change or update > >>>> windows driver registry settings. They can enable the same setting from > >>>> admin management console without any access to VM. > >>>> (b) It is more robust. No need to mess with driver settings. Incorrect > >>>> settings can brick guest OS. Also no guest specific knowhow required. > >>>> (c) It is more scalable since a single cluster wide setting can be used > >>>> for all VM power ons and the management plane can take care of the rest > >>>> automatically. No need to access individual VMs to enforce this. > >>>> (d) I am told that the driver level solution does not persist across a > >>>> reboot. > >>>> > >>>> Ani > >>> > >>> Looks like disabling both plug and unplug would also address these needs. > >> > >> No the driver level solution does not prevent hot plugging of devices but > >> blocks just hot unplugging. The solution I am proposing tries to do the > >> same but from the bus/hypervisor level. > > > > Why does the driver level solution need to prevent just hot unplugging? > > Because it not fair to prevent end users from hot plugging new devices when > it is the (accidental?) hot unplugging of existing devices which causes > issues.
Accidental? So maybe what you need is actually something else then - avoid *removing* the device when it's powered down. > > > > > >> > >>> -- > >>> MST
