Re: [PATCH v3 01/10] rust: pci: add internal SR-IOV enable and disable helpers

[Danilo Krummrich]

On Wed Sep 30, 2026 at 12:18 PM CEST, Zhi Wang wrote:
> +impl Device<device::CoreInternal<'_>> {
> +    /// Enable the Single Root I/O Virtualization (SR-IOV) capability for this device,
> +    /// where `nr_virtfn` is number of Virtual Functions (VF) to enable.
> +    #[expect(dead_code)]
> +    pub(crate) fn enable_sriov(&self, nr_virtfn: c_int) -> Result {

This can just be a u16; there are no implicit type conversions in Rust and the
PCIe SR-IOV spec defines this as 16bit register.

The conversion should be infallible, so you can just pass nr_virtfn.into().

> +        // SAFETY:
> +        // `self.as_raw` returns a valid pointer to a `struct pci_dev`.
> +        //
> +        // `pci_enable_sriov()` checks that the enable operation is valid:
> +        // - the device is a Physical Function (PF),
> +        // - SR-IOV is currently disabled, and
> +        // - `nr_virtfn` does not exceed the total number of supported VFs.
> +        //
> +        // The CoreInternal device context inherits from the Bound device context,
> +        // which guarantees that the PF device is bound to a driver.

	// - `self.as_raw` returns a valid pointer to a `struct pci_dev`.
	//
	// - `pci_enable_sriov()` checks that the enable operation is valid:
	//   - the device is a Physical Function (PF),
	//   - SR-IOV is currently disabled, and
	//   - `nr_virtfn` does not exceed the total number of supported VFs.
	//
	// - The [`CoreInternal`] device context inherits from the [`Bound`] device context,
	//   which guarantees that the PF device is bound to a driver.

> +        to_result(unsafe { bindings::pci_enable_sriov(self.as_raw(), nr_virtfn) })
> +    }