Re: [PATCH v4 2/6] rust: pci: add sriov_get_totalvfs() helper

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.