Method read

vmm/src/cpu.rs:3205–3236

(&mut self, _base: u64, offset: u64, data: &mut [u8])

impl BusDevice for AcpiCpuHotplugController {
    fn read(&mut self, _base: u64, offset: u64, data: &mut [u8]) {
        // The Linux kernel, quite reasonably, doesn't zero the memory it gives us.
        data.fill(0);
        let vcpu_states = self.vcpu_states.lock().unwrap();

        match offset {
            Self::CPU_SELECTION_OFFSET => {
                assert!(data.len() >= core::mem::size_of::<u32>());
                data[0..core::mem::size_of::<u32>()]
                    .copy_from_slice(&self.selected_cpu.to_le_bytes());
            }
            Self::CPU_STATUS_OFFSET => {
                if self.selected_cpu < self.max_vcpus {
                    let state = &vcpu_states[usize::try_from(self.selected_cpu).unwrap()];
                    if state.active() {
                        data[0] |= 1 << Self::CPU_ENABLE_FLAG;
                    }
                    if state.inserting {
                        data[0] |= 1 << Self::CPU_INSERTING_FLAG;
                    }
                    if state.removing {
                        data[0] |= 1 << Self::CPU_REMOVING_FLAG;
                    }
                } else {
                    warn!("Out of range vCPU id: {}", self.selected_cpu);
                }
            }
            _ => {
                warn!("Unexpected offset for accessing CPU manager device: {offset:#}");
            }
        }
    }

    fn write(&mut self, _base: u64, offset: u64, data: &[u8]) -> Option<Arc<Barrier>> {
        match offset {