Re: [RFC V1 0/4] iommufd live update

[Jason Gunthorpe <jgg@nvidia.com>]

On Sat, Jul 20, 2024 at 11:56:40AM -0700, Steve Sistare wrote:
> Live update is a technique wherein an application saves its state, launches
> an updated version of itself, and restores its state.  Clients of the
> application experience a brief suspension of service, on the order of
> 100's of milliseconds, but are otherwise unaffected.
> 
> Define the IOMMU_IOAS_CHANGE_PROCESS ioctl to allow management and use
> of an iommufd device to be transferred from one process to another.  The
> application is responsible for transferring the device descriptor to the new
> process, eg either by preservation across fork and exec or via SCM_RIGHTS.

It seems Ok to me, I'm glad it worked out for you

But have you considered using something like the new
memfd_pin_folios() system so that iommufd is bound to the FDs backing
the memory instead of VMAs?

https://lore.kernel.org/all/20240624063952.1572359-1-vivek.kasireddy@intel.com/

I've been expecting to add support for that, but does it help this scenario?

Jason