Re: [PATCH 10/14] iommufd-lu: Implement ioctl to let userspace mark an HWPT to be preserved

Samiullah Khawaja
2026-03-23T16:24:36Z

On Fri, Mar 20, 2026 at 04:34:41PM -0700, Vipin Sharma wrote:
>On Fri, Mar 20, 2026 at 12:40:44AM +0000, Samiullah Khawaja wrote:
>> On Thu, Mar 19, 2026 at 04:35:32PM -0700, Vipin Sharma wrote:
>> > On Tue, Feb 03, 2026 at 10:09:44PM +0000, Samiullah Khawaja wrote:
>> > > From: YiFei Zhu <zhuyifei@google.com>
>> > > @@ -374,6 +374,10 @@ struct iommufd_hwpt_paging {
>> > > bool auto_domain : 1;
>> > > bool enforce_cache_coherency : 1;
>> > > bool nest_parent : 1;
>> > > +#ifdef CONFIG_IOMMU_LIVEUPDATE
>> > > + bool lu_preserve : 1;
>> > > + u32 lu_token;
>> >
>> > Should we use full name i.e. liveupdate here and other places in this
>> > series?
>>
>> I think using full name liveupdate would be too long in other places in
>> this series. And also there are other examples of "luo" being used as a
>> short form. Please see:
>>
>> https://lore.kernel.org/all/20251125165850.3389713-15-pasha.tatashin@soleen.com/
>
>That patch is using "luo" short, which I think is also wrong in saying
>memfd_luo, as there is nothing related to orchestrator (O of LUO) in
>that patch. It is saving memfd state for liveupdate. But that ship has
>sailed.

Yes, I think that makes sense.
>
>In the current patch, I don't think it will be too long, and it also
>easier to read code without someone to know what "lu" is. We have worked
>on it so we know what "lu" stands for and kind of accepted it but I
>agree what Greg k-h was also suggesting.

Agreed, in this patch it won't be too long. I think for the public API
being used in other subsystems we can use "liveupdate", but internally
we can use lu. I will rework this.
>
>https://lore.kernel.org/all/2025093023-frantic-sediment-9849@gregkh/
> - "You have more letters, please use them. "lu" is too short."
>
>Not a hard no from me, just a suggestion.

Thanks,
Sami