Linux PCI subsystem development
 help / color / mirror / Atom feed
From: "Danilo Krummrich" <dakr@kernel.org>
To: "Zhi Wang" <zhiw@nvidia.com>
Cc: <acourbot@nvidia.com>, <airlied@gmail.com>, <simona@ffwll.ch>,
	<ojeda@kernel.org>, <alex.gaynor@gmail.com>,
	<boqun.feng@gmail.com>, <gary@garyguo.net>,
	<bjorn3_gh@protonmail.com>, <lossin@kernel.org>,
	<a.hindborg@kernel.org>, <aliceryhl@google.com>,
	<tmgross@umich.edu>, <jhubbard@nvidia.com>,
	<ecourtney@nvidia.com>, <joelagnelf@nvidia.com>,
	<apopple@nvidia.com>, <cjia@nvidia.com>, <smitra@nvidia.com>,
	<kjaju@nvidia.com>, <alkumar@nvidia.com>, <ankita@nvidia.com>,
	<aniketa@nvidia.com>, <kwankhede@nvidia.com>,
	<targupta@nvidia.com>, <nova-gpu@lists.linux.dev>,
	<linux-kernel@vger.kernel.org>, <zhiwang@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"David Laight" <david.laight.linux@gmail.com>,
	<linux-pci@vger.kernel.org>
Subject: Re: [PATCH v4 2/6] rust: pci: add sriov_get_totalvfs() helper
Date: Fri, 10 Jul 2026 01:00:09 +0200	[thread overview]
Message-ID: <DJUEWLO5YJFE.3BKHFV0J9K3TA@kernel.org> (raw)
In-Reply-To: <20260709150206.1046839-3-zhiw@nvidia.com>

On Thu Jul 9, 2026 at 5:02 PM CEST, Zhi Wang wrote:
> +    /// Returns the total number of VFs, or [`None`] if SR-IOV is not available.
> +    #[inline]
> +    pub fn sriov_get_totalvfs(&self) -> Option<NonZero<u16>> {
> +        // SAFETY: `self.as_raw()` is a valid pointer to a `struct pci_dev`.
> +        let total_vfs = unsafe { bindings::pci_sriov_get_totalvfs(self.as_raw()) };
> +
> +        // CAST: The C function returns `unsigned int`, but the value originates
> +        // from TotalVFs/driver_max_VFs (which are defined as `u16`), so this cast
> +        // cannot truncate.
> +        NonZero::new(total_vfs as u16)
> +    }
>  }
>  
>  impl<'a> Device<device::Core<'a>> {

It is not a problem yet, but sriov_get_totalvfs() should go into the
Device<Core> impl above.

Once we also have sriov_set_totalvfs() this would otherwise be a potential data
race.

      reply	other threads:[~2026-07-09 23:00 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20260709150206.1046839-1-zhiw@nvidia.com>
2026-07-09 15:02 ` [PATCH v4 1/6] PCI/IOV: Return unsigned int from pci_sriov_get_totalvfs() Zhi Wang
2026-07-09 22:46   ` Bjorn Helgaas
2026-07-09 22:58     ` Danilo Krummrich
2026-07-09 15:02 ` [PATCH v4 2/6] rust: pci: add sriov_get_totalvfs() helper Zhi Wang
2026-07-09 23:00   ` Danilo Krummrich [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=DJUEWLO5YJFE.3BKHFV0J9K3TA@kernel.org \
    --to=dakr@kernel.org \
    --cc=a.hindborg@kernel.org \
    --cc=acourbot@nvidia.com \
    --cc=airlied@gmail.com \
    --cc=alex.gaynor@gmail.com \
    --cc=aliceryhl@google.com \
    --cc=alkumar@nvidia.com \
    --cc=aniketa@nvidia.com \
    --cc=ankita@nvidia.com \
    --cc=apopple@nvidia.com \
    --cc=bhelgaas@google.com \
    --cc=bjorn3_gh@protonmail.com \
    --cc=boqun.feng@gmail.com \
    --cc=cjia@nvidia.com \
    --cc=david.laight.linux@gmail.com \
    --cc=ecourtney@nvidia.com \
    --cc=gary@garyguo.net \
    --cc=jhubbard@nvidia.com \
    --cc=joelagnelf@nvidia.com \
    --cc=kjaju@nvidia.com \
    --cc=kwankhede@nvidia.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=lossin@kernel.org \
    --cc=nova-gpu@lists.linux.dev \
    --cc=ojeda@kernel.org \
    --cc=simona@ffwll.ch \
    --cc=smitra@nvidia.com \
    --cc=targupta@nvidia.com \
    --cc=tmgross@umich.edu \
    --cc=zhiw@nvidia.com \
    --cc=zhiwang@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox