Re: [PATCH] vfio/type1: Cleanup remaining vaddr removal/update fragments

[Steven Sistare <steven.sistare@oracle.com>]

On 12/8/2022 11:40 AM, Alex Williamson wrote:
> On Thu, 8 Dec 2022 07:56:30 +0000
> "Tian, Kevin" <kevin.tian@intel.com> wrote:
> 
>>> From: Alex Williamson <alex.williamson@redhat.com>
>>> Sent: Thursday, December 8, 2022 5:45 AM
>>>
>>> Fix several loose ends relative to reverting support for vaddr removal
>>> and update.  Mark feature and ioctl flags as deprecated, restore local
>>> variable scope in pin pages, remove remaining support in the mapping
>>> code.
>>>
>>> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
>>> ---
>>>
>>> This applies on top of Steve's patch[1] to fully remove and deprecate
>>> this feature in the short term, following the same methodology we used
>>> for the v1 migration interface removal.  The intention would be to pick
>>> Steve's patch and this follow-on for v6.2 given that existing support
>>> exposes vulnerabilities and no known upstream userspaces make use of
>>> this feature.
>>>
>>> [1]https://lore.kernel.org/all/1670363753-249738-2-git-send-email-
>>> steven.sistare@oracle.com/
>>>   
>>
>> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
>>
>> btw given the exposure and no known upstream usage should this be
>> also pushed to stable kernels?
> 
> I'll add to both:
> 
> Cc: stable@vger.kernel.org # v5.12+

We maintain and use a version of qemu that contains the live update patches,
and requires these kernel interfaces. Other companies are also experimenting 
with it.  Please do not remove it from stable.

- Steve