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 for Android: free password hash cracker in your pocket

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

Message-Id: <DD7GERKWFHB0.3919YYC6AJA2P@nvidia.com>
Date: Thu, 02 Oct 2025 10:43:44 +0900
From: "Alexandre Courbot" <acourbot@...dia.com>
To: "Zhi Wang" <zhiw@...dia.com>, "Jason Gunthorpe" <jgg@...dia.com>
Cc: "John Hubbard" <jhubbard@...dia.com>, "Alexandre Courbot"
 <acourbot@...dia.com>, "Danilo Krummrich" <dakr@...nel.org>, "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>, "Alex Williamson"
 <alex.williamson@...hat.com>
Subject: Re: [PATCH 0/2] rust: pci: expose is_virtfn() and reject VFs in
 nova-core

On Thu Oct 2, 2025 at 6:13 AM JST, Zhi Wang wrote:
> On 1.10.2025 17.48, Jason Gunthorpe wrote:
>> On Wed, Oct 01, 2025 at 08:09:37AM +0000, Zhi Wang wrote:
>>>>> 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)?
>>>>
>>>
>>> The guest driver will read PMC_BOOT_1 and check PMC_BOOT_1_VGPU_VF flag
>>> to tell if it is running on a VF or a PF.
>> 
>> Yes exactly, and then novacore should modify its behavior and operate
>> the device in the different mode.
>> 
>> It doesn't matter if a VM is involved or not, a VF driver running side
>> by side wit the PF driver should still work.
>> 
>> There are use cases where people do this, eg they can stick the VF
>> into a linux container and use the SRIOV mechanism as a QOS control.
>> 'This container only gets 1/4 of a GPU'
>> 
>
> Right, I also mentioned the same use cases of NIC/GPU in another reply
> to Danilo. But what I get is NVIDIA doesn't use bare metal VF to support
> linux container, it seems there have been other solutions. IMHO, it is
> not mandatory that we have to support VF driver on bare metal so far
> yet.

For my education, what gets in the way of supporting a VF on the bare
metal if we already support it from inside a VM?