[PATCH 1/8] rust: pci: add is_virtfn(), to check for VFs

[Peter Colberg]

From: John Hubbard <jhubbard@xxxxxxxxxx>

Add a method to check if a PCI device is a Virtual Function (VF) created
through Single Root I/O Virtualization (SR-IOV).

Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
Reviewed-by: Alistair Popple <apopple@xxxxxxxxxx>
Signed-off-by: Peter Colberg <pcolberg@xxxxxxxxxx>
---
This patch was originally part of the series "rust: pci: expose
is_virtfn() and reject VFs in nova-core" and modified as follows:
- Replace true -> `true` in doc comment.
- Shorten description and omit justification specific to nova-core.

Link: https://lore.kernel.org/rust-for-linux/20250930220759.288528-2-jhubbard@xxxxxxxxxx/
---
 rust/kernel/pci.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 82e128431f080fde78a06dc5c284ab12739e747e..c20b8daeb7aadbef9f6ecfc48c972436efac9a08 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -409,6 +409,12 @@ pub fn resource_start(&self, bar: u32) -> Result<bindings::resource_size_t> {
         Ok(unsafe { bindings::pci_resource_start(self.as_raw(), bar.try_into()?) })
     }
 
+    /// Returns `true` if this device is a Virtual Function (VF).
+    pub fn is_virtfn(&self) -> bool {
+        // SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.
+        unsafe { (*self.as_raw()).is_virtfn() != 0 }
+    }
+
     /// Returns the size of the given PCI BAR resource.
     pub fn resource_len(&self, bar: u32) -> Result<bindings::resource_size_t> {
         if !Bar::index_is_valid(bar) {

-- 
2.51.1