1 //! Driver for VirtIO GPU devices.
2 
3 use crate::hal::{BufferDirection, Dma, Hal};
4 use crate::queue::VirtQueue;
5 use crate::transport::Transport;
6 use crate::volatile::{volread, ReadOnly, Volatile, WriteOnly};
7 use crate::{pages, Error, Result, PAGE_SIZE};
8 use alloc::boxed::Box;
9 use bitflags::bitflags;
10 use log::info;
11 use zerocopy::{AsBytes, FromBytes, FromZeroes};
12 
13 const QUEUE_SIZE: u16 = 2;
14 const SUPPORTED_FEATURES: Features = Features::RING_EVENT_IDX.union(Features::RING_INDIRECT_DESC);
15 
16 /// A virtio based graphics adapter.
17 ///
18 /// It can operate in 2D mode and in 3D (virgl) mode.
19 /// 3D mode will offload rendering ops to the host gpu and therefore requires
20 /// a gpu with 3D support on the host machine.
21 /// In 2D mode the virtio-gpu device provides support for ARGB Hardware cursors
22 /// and multiple scanouts (aka heads).
23 pub struct VirtIOGpu<H: Hal, T: Transport> {
24     transport: T,
25     rect: Option<Rect>,
26     /// DMA area of frame buffer.
27     frame_buffer_dma: Option<Dma<H>>,
28     /// DMA area of cursor image buffer.
29     cursor_buffer_dma: Option<Dma<H>>,
30     /// Queue for sending control commands.
31     control_queue: VirtQueue<H, { QUEUE_SIZE as usize }>,
32     /// Queue for sending cursor commands.
33     cursor_queue: VirtQueue<H, { QUEUE_SIZE as usize }>,
34     /// Send buffer for queue.
35     queue_buf_send: Box<[u8]>,
36     /// Recv buffer for queue.
37     queue_buf_recv: Box<[u8]>,
38 }
39 
40 impl<H: Hal, T: Transport> VirtIOGpu<H, T> {
41     /// Create a new VirtIO-Gpu driver.
new(mut transport: T) -> Result<Self>42     pub fn new(mut transport: T) -> Result<Self> {
43         let negotiated_features = transport.begin_init(SUPPORTED_FEATURES);
44 
45         // read configuration space
46         let config_space = transport.config_space::<Config>()?;
47         unsafe {
48             let events_read = volread!(config_space, events_read);
49             let num_scanouts = volread!(config_space, num_scanouts);
50             info!(
51                 "events_read: {:#x}, num_scanouts: {:#x}",
52                 events_read, num_scanouts
53             );
54         }
55 
56         let control_queue = VirtQueue::new(
57             &mut transport,
58             QUEUE_TRANSMIT,
59             negotiated_features.contains(Features::RING_INDIRECT_DESC),
60             negotiated_features.contains(Features::RING_EVENT_IDX),
61         )?;
62         let cursor_queue = VirtQueue::new(
63             &mut transport,
64             QUEUE_CURSOR,
65             negotiated_features.contains(Features::RING_INDIRECT_DESC),
66             negotiated_features.contains(Features::RING_EVENT_IDX),
67         )?;
68 
69         let queue_buf_send = FromZeroes::new_box_slice_zeroed(PAGE_SIZE);
70         let queue_buf_recv = FromZeroes::new_box_slice_zeroed(PAGE_SIZE);
71 
72         transport.finish_init();
73 
74         Ok(VirtIOGpu {
75             transport,
76             frame_buffer_dma: None,
77             cursor_buffer_dma: None,
78             rect: None,
79             control_queue,
80             cursor_queue,
81             queue_buf_send,
82             queue_buf_recv,
83         })
84     }
85 
86     /// Acknowledge interrupt.
ack_interrupt(&mut self) -> bool87     pub fn ack_interrupt(&mut self) -> bool {
88         self.transport.ack_interrupt()
89     }
90 
91     /// Get the resolution (width, height).
resolution(&mut self) -> Result<(u32, u32)>92     pub fn resolution(&mut self) -> Result<(u32, u32)> {
93         let display_info = self.get_display_info()?;
94         Ok((display_info.rect.width, display_info.rect.height))
95     }
96 
97     /// Setup framebuffer
setup_framebuffer(&mut self) -> Result<&mut [u8]>98     pub fn setup_framebuffer(&mut self) -> Result<&mut [u8]> {
99         // get display info
100         let display_info = self.get_display_info()?;
101         info!("=> {:?}", display_info);
102         self.rect = Some(display_info.rect);
103 
104         // create resource 2d
105         self.resource_create_2d(
106             RESOURCE_ID_FB,
107             display_info.rect.width,
108             display_info.rect.height,
109         )?;
110 
111         // alloc continuous pages for the frame buffer
112         let size = display_info.rect.width * display_info.rect.height * 4;
113         let frame_buffer_dma = Dma::new(pages(size as usize), BufferDirection::DriverToDevice)?;
114 
115         // resource_attach_backing
116         self.resource_attach_backing(RESOURCE_ID_FB, frame_buffer_dma.paddr() as u64, size)?;
117 
118         // map frame buffer to screen
119         self.set_scanout(display_info.rect, SCANOUT_ID, RESOURCE_ID_FB)?;
120 
121         let buf = unsafe { frame_buffer_dma.raw_slice().as_mut() };
122         self.frame_buffer_dma = Some(frame_buffer_dma);
123         Ok(buf)
124     }
125 
126     /// Flush framebuffer to screen.
flush(&mut self) -> Result127     pub fn flush(&mut self) -> Result {
128         let rect = self.rect.ok_or(Error::NotReady)?;
129         // copy data from guest to host
130         self.transfer_to_host_2d(rect, 0, RESOURCE_ID_FB)?;
131         // flush data to screen
132         self.resource_flush(rect, RESOURCE_ID_FB)?;
133         Ok(())
134     }
135 
136     /// Set the pointer shape and position.
setup_cursor( &mut self, cursor_image: &[u8], pos_x: u32, pos_y: u32, hot_x: u32, hot_y: u32, ) -> Result137     pub fn setup_cursor(
138         &mut self,
139         cursor_image: &[u8],
140         pos_x: u32,
141         pos_y: u32,
142         hot_x: u32,
143         hot_y: u32,
144     ) -> Result {
145         let size = CURSOR_RECT.width * CURSOR_RECT.height * 4;
146         if cursor_image.len() != size as usize {
147             return Err(Error::InvalidParam);
148         }
149         let cursor_buffer_dma = Dma::new(pages(size as usize), BufferDirection::DriverToDevice)?;
150         let buf = unsafe { cursor_buffer_dma.raw_slice().as_mut() };
151         buf.copy_from_slice(cursor_image);
152 
153         self.resource_create_2d(RESOURCE_ID_CURSOR, CURSOR_RECT.width, CURSOR_RECT.height)?;
154         self.resource_attach_backing(RESOURCE_ID_CURSOR, cursor_buffer_dma.paddr() as u64, size)?;
155         self.transfer_to_host_2d(CURSOR_RECT, 0, RESOURCE_ID_CURSOR)?;
156         self.update_cursor(
157             RESOURCE_ID_CURSOR,
158             SCANOUT_ID,
159             pos_x,
160             pos_y,
161             hot_x,
162             hot_y,
163             false,
164         )?;
165         self.cursor_buffer_dma = Some(cursor_buffer_dma);
166         Ok(())
167     }
168 
169     /// Move the pointer without updating the shape.
move_cursor(&mut self, pos_x: u32, pos_y: u32) -> Result170     pub fn move_cursor(&mut self, pos_x: u32, pos_y: u32) -> Result {
171         self.update_cursor(RESOURCE_ID_CURSOR, SCANOUT_ID, pos_x, pos_y, 0, 0, true)?;
172         Ok(())
173     }
174 
175     /// Send a request to the device and block for a response.
request<Req: AsBytes, Rsp: FromBytes>(&mut self, req: Req) -> Result<Rsp>176     fn request<Req: AsBytes, Rsp: FromBytes>(&mut self, req: Req) -> Result<Rsp> {
177         req.write_to_prefix(&mut self.queue_buf_send).unwrap();
178         self.control_queue.add_notify_wait_pop(
179             &[&self.queue_buf_send],
180             &mut [&mut self.queue_buf_recv],
181             &mut self.transport,
182         )?;
183         Ok(Rsp::read_from_prefix(&self.queue_buf_recv).unwrap())
184     }
185 
186     /// Send a mouse cursor operation request to the device and block for a response.
cursor_request<Req: AsBytes>(&mut self, req: Req) -> Result187     fn cursor_request<Req: AsBytes>(&mut self, req: Req) -> Result {
188         req.write_to_prefix(&mut self.queue_buf_send).unwrap();
189         self.cursor_queue.add_notify_wait_pop(
190             &[&self.queue_buf_send],
191             &mut [],
192             &mut self.transport,
193         )?;
194         Ok(())
195     }
196 
get_display_info(&mut self) -> Result<RespDisplayInfo>197     fn get_display_info(&mut self) -> Result<RespDisplayInfo> {
198         let info: RespDisplayInfo =
199             self.request(CtrlHeader::with_type(Command::GET_DISPLAY_INFO))?;
200         info.header.check_type(Command::OK_DISPLAY_INFO)?;
201         Ok(info)
202     }
203 
resource_create_2d(&mut self, resource_id: u32, width: u32, height: u32) -> Result204     fn resource_create_2d(&mut self, resource_id: u32, width: u32, height: u32) -> Result {
205         let rsp: CtrlHeader = self.request(ResourceCreate2D {
206             header: CtrlHeader::with_type(Command::RESOURCE_CREATE_2D),
207             resource_id,
208             format: Format::B8G8R8A8UNORM,
209             width,
210             height,
211         })?;
212         rsp.check_type(Command::OK_NODATA)
213     }
214 
set_scanout(&mut self, rect: Rect, scanout_id: u32, resource_id: u32) -> Result215     fn set_scanout(&mut self, rect: Rect, scanout_id: u32, resource_id: u32) -> Result {
216         let rsp: CtrlHeader = self.request(SetScanout {
217             header: CtrlHeader::with_type(Command::SET_SCANOUT),
218             rect,
219             scanout_id,
220             resource_id,
221         })?;
222         rsp.check_type(Command::OK_NODATA)
223     }
224 
resource_flush(&mut self, rect: Rect, resource_id: u32) -> Result225     fn resource_flush(&mut self, rect: Rect, resource_id: u32) -> Result {
226         let rsp: CtrlHeader = self.request(ResourceFlush {
227             header: CtrlHeader::with_type(Command::RESOURCE_FLUSH),
228             rect,
229             resource_id,
230             _padding: 0,
231         })?;
232         rsp.check_type(Command::OK_NODATA)
233     }
234 
transfer_to_host_2d(&mut self, rect: Rect, offset: u64, resource_id: u32) -> Result235     fn transfer_to_host_2d(&mut self, rect: Rect, offset: u64, resource_id: u32) -> Result {
236         let rsp: CtrlHeader = self.request(TransferToHost2D {
237             header: CtrlHeader::with_type(Command::TRANSFER_TO_HOST_2D),
238             rect,
239             offset,
240             resource_id,
241             _padding: 0,
242         })?;
243         rsp.check_type(Command::OK_NODATA)
244     }
245 
resource_attach_backing(&mut self, resource_id: u32, paddr: u64, length: u32) -> Result246     fn resource_attach_backing(&mut self, resource_id: u32, paddr: u64, length: u32) -> Result {
247         let rsp: CtrlHeader = self.request(ResourceAttachBacking {
248             header: CtrlHeader::with_type(Command::RESOURCE_ATTACH_BACKING),
249             resource_id,
250             nr_entries: 1,
251             addr: paddr,
252             length,
253             _padding: 0,
254         })?;
255         rsp.check_type(Command::OK_NODATA)
256     }
257 
update_cursor( &mut self, resource_id: u32, scanout_id: u32, pos_x: u32, pos_y: u32, hot_x: u32, hot_y: u32, is_move: bool, ) -> Result258     fn update_cursor(
259         &mut self,
260         resource_id: u32,
261         scanout_id: u32,
262         pos_x: u32,
263         pos_y: u32,
264         hot_x: u32,
265         hot_y: u32,
266         is_move: bool,
267     ) -> Result {
268         self.cursor_request(UpdateCursor {
269             header: if is_move {
270                 CtrlHeader::with_type(Command::MOVE_CURSOR)
271             } else {
272                 CtrlHeader::with_type(Command::UPDATE_CURSOR)
273             },
274             pos: CursorPos {
275                 scanout_id,
276                 x: pos_x,
277                 y: pos_y,
278                 _padding: 0,
279             },
280             resource_id,
281             hot_x,
282             hot_y,
283             _padding: 0,
284         })
285     }
286 }
287 
288 impl<H: Hal, T: Transport> Drop for VirtIOGpu<H, T> {
drop(&mut self)289     fn drop(&mut self) {
290         // Clear any pointers pointing to DMA regions, so the device doesn't try to access them
291         // after they have been freed.
292         self.transport.queue_unset(QUEUE_TRANSMIT);
293         self.transport.queue_unset(QUEUE_CURSOR);
294     }
295 }
296 
297 #[repr(C)]
298 struct Config {
299     /// Signals pending events to the driver。
300     events_read: ReadOnly<u32>,
301 
302     /// Clears pending events in the device.
303     events_clear: WriteOnly<u32>,
304 
305     /// Specifies the maximum number of scanouts supported by the device.
306     ///
307     /// Minimum value is 1, maximum value is 16.
308     num_scanouts: Volatile<u32>,
309 }
310 
311 /// Display configuration has changed.
312 const EVENT_DISPLAY: u32 = 1 << 0;
313 
314 bitflags! {
315     #[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
316     struct Features: u64 {
317         /// virgl 3D mode is supported.
318         const VIRGL                 = 1 << 0;
319         /// EDID is supported.
320         const EDID                  = 1 << 1;
321 
322         // device independent
323         const NOTIFY_ON_EMPTY       = 1 << 24; // legacy
324         const ANY_LAYOUT            = 1 << 27; // legacy
325         const RING_INDIRECT_DESC    = 1 << 28;
326         const RING_EVENT_IDX        = 1 << 29;
327         const UNUSED                = 1 << 30; // legacy
328         const VERSION_1             = 1 << 32; // detect legacy
329 
330         // since virtio v1.1
331         const ACCESS_PLATFORM       = 1 << 33;
332         const RING_PACKED           = 1 << 34;
333         const IN_ORDER              = 1 << 35;
334         const ORDER_PLATFORM        = 1 << 36;
335         const SR_IOV                = 1 << 37;
336         const NOTIFICATION_DATA     = 1 << 38;
337     }
338 }
339 
340 #[repr(transparent)]
341 #[derive(AsBytes, Clone, Copy, Debug, Eq, PartialEq, FromBytes, FromZeroes)]
342 struct Command(u32);
343 
344 impl Command {
345     const GET_DISPLAY_INFO: Command = Command(0x100);
346     const RESOURCE_CREATE_2D: Command = Command(0x101);
347     const RESOURCE_UNREF: Command = Command(0x102);
348     const SET_SCANOUT: Command = Command(0x103);
349     const RESOURCE_FLUSH: Command = Command(0x104);
350     const TRANSFER_TO_HOST_2D: Command = Command(0x105);
351     const RESOURCE_ATTACH_BACKING: Command = Command(0x106);
352     const RESOURCE_DETACH_BACKING: Command = Command(0x107);
353     const GET_CAPSET_INFO: Command = Command(0x108);
354     const GET_CAPSET: Command = Command(0x109);
355     const GET_EDID: Command = Command(0x10a);
356 
357     const UPDATE_CURSOR: Command = Command(0x300);
358     const MOVE_CURSOR: Command = Command(0x301);
359 
360     const OK_NODATA: Command = Command(0x1100);
361     const OK_DISPLAY_INFO: Command = Command(0x1101);
362     const OK_CAPSET_INFO: Command = Command(0x1102);
363     const OK_CAPSET: Command = Command(0x1103);
364     const OK_EDID: Command = Command(0x1104);
365 
366     const ERR_UNSPEC: Command = Command(0x1200);
367     const ERR_OUT_OF_MEMORY: Command = Command(0x1201);
368     const ERR_INVALID_SCANOUT_ID: Command = Command(0x1202);
369 }
370 
371 const GPU_FLAG_FENCE: u32 = 1 << 0;
372 
373 #[repr(C)]
374 #[derive(AsBytes, Debug, Clone, Copy, FromBytes, FromZeroes)]
375 struct CtrlHeader {
376     hdr_type: Command,
377     flags: u32,
378     fence_id: u64,
379     ctx_id: u32,
380     _padding: u32,
381 }
382 
383 impl CtrlHeader {
with_type(hdr_type: Command) -> CtrlHeader384     fn with_type(hdr_type: Command) -> CtrlHeader {
385         CtrlHeader {
386             hdr_type,
387             flags: 0,
388             fence_id: 0,
389             ctx_id: 0,
390             _padding: 0,
391         }
392     }
393 
394     /// Return error if the type is not same as expected.
check_type(&self, expected: Command) -> Result395     fn check_type(&self, expected: Command) -> Result {
396         if self.hdr_type == expected {
397             Ok(())
398         } else {
399             Err(Error::IoError)
400         }
401     }
402 }
403 
404 #[repr(C)]
405 #[derive(AsBytes, Debug, Copy, Clone, Default, FromBytes, FromZeroes)]
406 struct Rect {
407     x: u32,
408     y: u32,
409     width: u32,
410     height: u32,
411 }
412 
413 #[repr(C)]
414 #[derive(Debug, FromBytes, FromZeroes)]
415 struct RespDisplayInfo {
416     header: CtrlHeader,
417     rect: Rect,
418     enabled: u32,
419     flags: u32,
420 }
421 
422 #[repr(C)]
423 #[derive(AsBytes, Debug)]
424 struct ResourceCreate2D {
425     header: CtrlHeader,
426     resource_id: u32,
427     format: Format,
428     width: u32,
429     height: u32,
430 }
431 
432 #[repr(u32)]
433 #[derive(AsBytes, Debug)]
434 enum Format {
435     B8G8R8A8UNORM = 1,
436 }
437 
438 #[repr(C)]
439 #[derive(AsBytes, Debug)]
440 struct ResourceAttachBacking {
441     header: CtrlHeader,
442     resource_id: u32,
443     nr_entries: u32, // always 1
444     addr: u64,
445     length: u32,
446     _padding: u32,
447 }
448 
449 #[repr(C)]
450 #[derive(AsBytes, Debug)]
451 struct SetScanout {
452     header: CtrlHeader,
453     rect: Rect,
454     scanout_id: u32,
455     resource_id: u32,
456 }
457 
458 #[repr(C)]
459 #[derive(AsBytes, Debug)]
460 struct TransferToHost2D {
461     header: CtrlHeader,
462     rect: Rect,
463     offset: u64,
464     resource_id: u32,
465     _padding: u32,
466 }
467 
468 #[repr(C)]
469 #[derive(AsBytes, Debug)]
470 struct ResourceFlush {
471     header: CtrlHeader,
472     rect: Rect,
473     resource_id: u32,
474     _padding: u32,
475 }
476 
477 #[repr(C)]
478 #[derive(AsBytes, Debug, Clone, Copy)]
479 struct CursorPos {
480     scanout_id: u32,
481     x: u32,
482     y: u32,
483     _padding: u32,
484 }
485 
486 #[repr(C)]
487 #[derive(AsBytes, Debug, Clone, Copy)]
488 struct UpdateCursor {
489     header: CtrlHeader,
490     pos: CursorPos,
491     resource_id: u32,
492     hot_x: u32,
493     hot_y: u32,
494     _padding: u32,
495 }
496 
497 const QUEUE_TRANSMIT: u16 = 0;
498 const QUEUE_CURSOR: u16 = 1;
499 
500 const SCANOUT_ID: u32 = 0;
501 const RESOURCE_ID_FB: u32 = 0xbabe;
502 const RESOURCE_ID_CURSOR: u32 = 0xdade;
503 
504 const CURSOR_RECT: Rect = Rect {
505     x: 0,
506     y: 0,
507     width: 64,
508     height: 64,
509 };
510