1 // Copyright 2022, The Android Open Source Project
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 //! Functions to scan the PCI bus for VirtIO device.
16
17 use aarch64_paging::paging::MemoryRegion;
18 use alloc::alloc::{alloc_zeroed, dealloc, handle_alloc_error, Layout};
19 use core::{mem::size_of, ptr::NonNull};
20 use fdtpci::PciInfo;
21 use log::{debug, info};
22 use virtio_drivers::{
23 device::console::VirtIOConsole,
24 transport::{
25 pci::{bus::PciRoot, PciTransport},
26 DeviceType, Transport,
27 },
28 BufferDirection, Error, Hal, PhysAddr, PAGE_SIZE,
29 };
30 use vmbase::virtio::pci::{self, PciTransportIterator};
31
32 /// The standard sector size of a VirtIO block device, in bytes.
33 const SECTOR_SIZE_BYTES: usize = 512;
34
35 /// The size in sectors of the test block device we expect.
36 const EXPECTED_SECTOR_COUNT: usize = 4;
37
check_pci(pci_root: &mut PciRoot)38 pub fn check_pci(pci_root: &mut PciRoot) {
39 let mut checked_virtio_device_count = 0;
40 let mut block_device_count = 0;
41 let mut socket_device_count = 0;
42 for mut transport in PciTransportIterator::<HalImpl>::new(pci_root) {
43 info!(
44 "Detected virtio PCI device with device type {:?}, features {:#018x}",
45 transport.device_type(),
46 transport.read_device_features(),
47 );
48 match transport.device_type() {
49 DeviceType::Block => {
50 check_virtio_block_device(transport, block_device_count);
51 block_device_count += 1;
52 checked_virtio_device_count += 1;
53 }
54 DeviceType::Console => {
55 check_virtio_console_device(transport);
56 checked_virtio_device_count += 1;
57 }
58 DeviceType::Socket => {
59 check_virtio_socket_device(transport);
60 socket_device_count += 1;
61 checked_virtio_device_count += 1;
62 }
63 _ => {}
64 }
65 }
66
67 assert_eq!(checked_virtio_device_count, 6);
68 assert_eq!(block_device_count, 2);
69 assert_eq!(socket_device_count, 1);
70 }
71
72 /// Checks the given VirtIO block device.
check_virtio_block_device(transport: PciTransport, index: usize)73 fn check_virtio_block_device(transport: PciTransport, index: usize) {
74 let mut blk = pci::VirtIOBlk::<HalImpl>::new(transport).expect("failed to create blk driver");
75 info!("Found {} KiB block device.", blk.capacity() * SECTOR_SIZE_BYTES as u64 / 1024);
76 match index {
77 0 => {
78 assert_eq!(blk.capacity(), EXPECTED_SECTOR_COUNT as u64);
79 let mut data = [0; SECTOR_SIZE_BYTES * EXPECTED_SECTOR_COUNT];
80 for i in 0..EXPECTED_SECTOR_COUNT {
81 blk.read_blocks(i, &mut data[i * SECTOR_SIZE_BYTES..(i + 1) * SECTOR_SIZE_BYTES])
82 .expect("Failed to read block device.");
83 }
84 for (i, chunk) in data.chunks(size_of::<u32>()).enumerate() {
85 assert_eq!(chunk, &(i as u32).to_le_bytes());
86 }
87 info!("Read expected data from block device.");
88 }
89 1 => {
90 assert_eq!(blk.capacity(), 0);
91 let mut data = [0; SECTOR_SIZE_BYTES];
92 assert_eq!(blk.read_blocks(0, &mut data), Err(Error::IoError));
93 }
94 _ => panic!("Unexpected VirtIO block device index {}.", index),
95 }
96 }
97
98 /// Checks the given VirtIO socket device.
check_virtio_socket_device(transport: PciTransport)99 fn check_virtio_socket_device(transport: PciTransport) {
100 let socket = pci::VirtIOSocket::<HalImpl>::new(transport)
101 .expect("Failed to create VirtIO socket driver");
102 info!("Found socket device: guest_cid={}", socket.guest_cid());
103 }
104
105 /// Checks the given VirtIO console device.
check_virtio_console_device(transport: PciTransport)106 fn check_virtio_console_device(transport: PciTransport) {
107 let mut console = VirtIOConsole::<HalImpl, PciTransport>::new(transport)
108 .expect("Failed to create VirtIO console driver");
109 info!("Found console device: {:?}", console.info());
110 for &c in b"Hello VirtIO console\n" {
111 console.send(c).expect("Failed to send character to VirtIO console device");
112 }
113 info!("Wrote to VirtIO console.");
114 }
115
116 /// Gets the memory region in which BARs are allocated.
get_bar_region(pci_info: &PciInfo) -> MemoryRegion117 pub fn get_bar_region(pci_info: &PciInfo) -> MemoryRegion {
118 MemoryRegion::new(pci_info.bar_range.start as usize, pci_info.bar_range.end as usize)
119 }
120
121 struct HalImpl;
122
123 /// SAFETY: See the 'Implementation Safety' comments on methods below for how they fulfill the
124 /// safety requirements of the unsafe `Hal` trait.
125 unsafe impl Hal for HalImpl {
126 /// # Implementation Safety
127 ///
128 /// `dma_alloc` ensures the returned DMA buffer is not aliased with any other allocation or
129 /// reference in the program until it is deallocated by `dma_dealloc` by allocating a unique
130 /// block of memory using `alloc_zeroed`, which is guaranteed to allocate valid, unique and
131 /// zeroed memory. We request an alignment of at least `PAGE_SIZE` from `alloc_zeroed`.
dma_alloc(pages: usize, _direction: BufferDirection) -> (PhysAddr, NonNull<u8>)132 fn dma_alloc(pages: usize, _direction: BufferDirection) -> (PhysAddr, NonNull<u8>) {
133 debug!("dma_alloc: pages={}", pages);
134 let layout =
135 Layout::from_size_align(pages.checked_mul(PAGE_SIZE).unwrap(), PAGE_SIZE).unwrap();
136 assert_ne!(layout.size(), 0);
137 // SAFETY: We just checked that the layout has a non-zero size.
138 let vaddr = unsafe { alloc_zeroed(layout) };
139 let vaddr =
140 if let Some(vaddr) = NonNull::new(vaddr) { vaddr } else { handle_alloc_error(layout) };
141 let paddr = virt_to_phys(vaddr);
142 (paddr, vaddr)
143 }
144
dma_dealloc(paddr: PhysAddr, vaddr: NonNull<u8>, pages: usize) -> i32145 unsafe fn dma_dealloc(paddr: PhysAddr, vaddr: NonNull<u8>, pages: usize) -> i32 {
146 debug!("dma_dealloc: paddr={:#x}, pages={}", paddr, pages);
147 let layout = Layout::from_size_align(pages * PAGE_SIZE, PAGE_SIZE).unwrap();
148 // SAFETY: The memory was allocated by `dma_alloc` above using the same allocator, and the
149 // layout is the same as was used then.
150 unsafe {
151 dealloc(vaddr.as_ptr(), layout);
152 }
153 0
154 }
155
156 /// # Implementation Safety
157 ///
158 /// The returned pointer must be valid because the `paddr` describes a valid MMIO region, and we
159 /// previously mapped the entire PCI MMIO range. It can't alias any other allocations because
160 /// the PCI MMIO range doesn't overlap with any other memory ranges.
mmio_phys_to_virt(paddr: PhysAddr, _size: usize) -> NonNull<u8>161 unsafe fn mmio_phys_to_virt(paddr: PhysAddr, _size: usize) -> NonNull<u8> {
162 NonNull::new(paddr as _).unwrap()
163 }
164
share(buffer: NonNull<[u8]>, _direction: BufferDirection) -> PhysAddr165 unsafe fn share(buffer: NonNull<[u8]>, _direction: BufferDirection) -> PhysAddr {
166 let vaddr = buffer.cast();
167 // Nothing to do, as the host already has access to all memory.
168 virt_to_phys(vaddr)
169 }
170
unshare(_paddr: PhysAddr, _buffer: NonNull<[u8]>, _direction: BufferDirection)171 unsafe fn unshare(_paddr: PhysAddr, _buffer: NonNull<[u8]>, _direction: BufferDirection) {
172 // Nothing to do, as the host already has access to all memory and we didn't copy the buffer
173 // anywhere else.
174 }
175 }
176
virt_to_phys(vaddr: NonNull<u8>) -> PhysAddr177 fn virt_to_phys(vaddr: NonNull<u8>) -> PhysAddr {
178 vaddr.as_ptr() as _
179 }
180