Re: [PATCH v3 00/10] rust: pci: add abstractions for SR-IOV capability

Danilo Krummrich
2026-03-04T14:58:06Z

On Wed Mar 4, 2026 at 3:26 PM CET, Leon Romanovsky wrote:
> On Wed, Mar 04, 2026 at 10:18:52AM -0400, Jason Gunthorpe wrote:
>> On Wed, Mar 04, 2026 at 10:47:50AM +0200, Leon Romanovsky wrote:
>> > On Tue, Mar 03, 2026 at 04:15:20PM -0500, Peter Colberg wrote:
>> > > Add Rust abstractions for the Single Root I/O Virtualization (SR-IOV)
>> > > capability of a PCI device. Provide a minimal set of wrappers for the
>> > > SR-IOV C API to enable and disable SR-IOV for a device, and query if
>> > > a PCI device is a Physical Function (PF) or Virtual Function (VF).
>> >
>> > <...>
>> >
>> > > For PF drivers written in C, disabling SR-IOV on remove() may be opted
>> > > into by setting the flag managed_sriov in the pci_driver structure. For
>> > > PF drivers written in Rust, disabling SR-IOV on unbind() is mandatory.
>> >
>> > Why? Could you explain the rationale behind this difference between C and
>> > Rust? Let me remind you that SR‑IOV devices which do not disable VFs do so
>> > for a practical and well‑established reason: maximizing hardware
>> > utilization.
>>
>> Personally I think drivers doing this are wrong. That such a driver
>> bug was allowed to become UAPI is pretty bad. The rust approach is
>> better.
>
> We already had this discussion. I see this as a perfectly valid
> use-case.

Can you remind about a specific use-case for this please? (Ideally, one that
can't be solved otherwise.)