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: <DD6LORTLMF02.6M7ZD36XOLJP@nvidia.com>
Date: Wed, 01 Oct 2025 10:39:14 +0900
From: "Alexandre Courbot" <acourbot@...dia.com>
To: "John Hubbard" <jhubbard@...dia.com>, "Alexandre Courbot"
 <acourbot@...dia.com>, "Danilo Krummrich" <dakr@...nel.org>
Cc: "Joel Fernandes" <joelagnelf@...dia.com>, "Timur Tabi"
 <ttabi@...dia.com>, "Alistair Popple" <apopple@...dia.com>, "Zhi Wang"
 <zhiw@...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>,
 <linux-pci@...r.kernel.org>, <rust-for-linux@...r.kernel.org>, "LKML"
 <linux-kernel@...r.kernel.org>, "Jason Gunthorpe" <jgg@...dia.com>, "Alex
 Williamson" <alex.williamson@...hat.com>
Subject: Re: [PATCH 0/2] rust: pci: expose is_virtfn() and reject VFs in
 nova-core

On Wed Oct 1, 2025 at 10:26 AM JST, John Hubbard wrote:
> On 9/30/25 5:26 PM, 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?
>
> I'm also new to this area. I would expect that guests *must* see
> these as PFs, otherwise...nothing makes any sense.

But if the guest sees the passed-through VF as a PF, won't it try to
do things it is not supposed to do like loading the GSP firmware (which
is managed by the host)?