linux-kernel - Re: [PATCH 0/2] rust: pci: expose is_virtfn() and reject VFs in nova-core

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <0859ec68-6db7-4884-829a-c1e06a6b481e@nvidia.com>
Date: Thu, 2 Oct 2025 07:41:21 +0000
From: Zhi Wang <zhiw@...dia.com>
To: Alexandre Courbot <acourbot@...dia.com>, John Hubbard
	<jhubbard@...dia.com>, Danilo Krummrich <dakr@...nel.org>
CC: Joel Fernandes <joelagnelf@...dia.com>, Timur Tabi <ttabi@...dia.com>,
	Alistair Popple <apopple@...dia.com>, Surath Mitra <smitra@...dia.com>, David
 Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, Bjorn Helgaas
	<bhelgaas@...gle.com>, Krzysztof Wilczyński
	<kwilczynski@...nel.org>, Miguel Ojeda <ojeda@...nel.org>, Alex Gaynor
	<alex.gaynor@...il.com>, Boqun Feng <boqun.feng@...il.com>, Gary Guo
	<gary@...yguo.net>, Björn Roy Baron
	<bjorn3_gh@...tonmail.com>, Benno Lossin <lossin@...nel.org>, Andreas
 Hindborg <a.hindborg@...nel.org>, Alice Ryhl <aliceryhl@...gle.com>, Trevor
 Gross <tmgross@...ch.edu>, "nouveau@...ts.freedesktop.org"
	<nouveau@...ts.freedesktop.org>, "linux-pci@...r.kernel.org"
	<linux-pci@...r.kernel.org>, "rust-for-linux@...r.kernel.org"
	<rust-for-linux@...r.kernel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/2] rust: pci: expose is_virtfn() and reject VFs in
 nova-core

On 1.10.2025 3.26, Alexandre Courbot wrote:
> On Wed Oct 1, 2025 at 7:07 AM JST, John Hubbard wrote:
>> Post-Kangrejos, the approach for NovaCore + VFIO has changed a bit: the
>> idea now is that VFIO drivers, for NVIDIA GPUs that are supported by
>> NovaCore, should bind directly to the GPU's VFs. (An earlier idea was to
>> let NovaCore bind to the VFs, and then have NovaCore call into the upper
>> (VFIO) module via Aux Bus, but this turns out to be awkward and is no
>> longer in favor.) So, in order to support that:
>>
>> Nova-core must only bind to Physical Functions (PFs) and regular PCI
>> devices, not to Virtual Functions (VFs) created through SR-IOV.
> 
> Naive question: will guests also see the passed-through VF as a VF? If
> so, wouldn't this change also prevents guests from using Nova?

In the entire software stack (firmware and interface, host/guest 
driver,and management stack), the entire design assumes that a VF is
tied to a VM.

NVIDIA GPU already provides good enough mechanisms to enforce
those between containers on PF. Moreover, VF on baremetal is not the
only way to support *container* environments. Surely, there are also
other approaches, for example, PF driver with DRM cgroup.

Like what I mentioned, it is really device/use-case specific. The device
vendor chooses the best approaches based on their device characteristic
and schedule/resource isolation capabilities for supporting containers
on bare metal.

Z.