b0e760659c
- fallback.rs: config reads at offset >= 256 (PCIe extended space) now return the PCI-standard 0xFFFFFFFF 'absent' value and writes are dropped, instead of panicking the PCI daemon. This is the exact behavior of real hardware and Linux's CF8 path on MCFG-less machines, and it lets MSI-X feature discovery degrade to INTx cleanly. Found by the first driver-manager QEMU gate (i440fx): pcid panicked at fallback.rs:65 and the boot hung. - driver_handler.rs: drop vestigial func param from read_full_device_id. - driver_interface/mod.rs: use Option::insert's return value directly (must_use) instead of discarding and re-reading as_ref.