1 // Copyright 2017 The Chromium OS Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE-BSD-3-Clause file. 4 5 use std::sync::{Arc, Barrier}; 6 use vm_device::BusDevice; 7 use vmm_sys_util::eventfd::EventFd; 8 9 /// A i8042 PS/2 controller that emulates just enough to shutdown the machine. 10 pub struct I8042Device { 11 reset_evt: EventFd, 12 } 13 14 impl I8042Device { 15 /// Constructs a i8042 device that will signal the given event when the guest requests it. 16 pub fn new(reset_evt: EventFd) -> I8042Device { 17 I8042Device { reset_evt } 18 } 19 } 20 21 // i8042 device is located at I/O port 0x61. We partially implement two 8-bit 22 // registers: port 0x61 (I8042_PORT_B_REG, offset 0 from base of 0x61), and 23 // port 0x64 (I8042_COMMAND_REG, offset 3 from base of 0x61). 24 impl BusDevice for I8042Device { 25 fn read(&mut self, _base: u64, offset: u64, data: &mut [u8]) { 26 if data.len() == 1 && offset == 3 { 27 data[0] = 0x0; 28 } else if data.len() == 1 && offset == 0 { 29 // Like kvmtool, we return bit 5 set in I8042_PORT_B_REG to 30 // avoid hang in pit_calibrate_tsc() in Linux kernel. 31 data[0] = 0x20; 32 } 33 } 34 35 fn write(&mut self, _base: u64, offset: u64, data: &[u8]) -> Option<Arc<Barrier>> { 36 if data.len() == 1 && data[0] == 0xfe && offset == 3 { 37 info!("i8042 reset signalled"); 38 if let Err(e) = self.reset_evt.write(1) { 39 error!("Error triggering i8042 reset event: {}", e); 40 } 41 } 42 43 None 44 } 45 } 46