1/** @file 2 3 This driver produces Block I/O Protocol instances for virtio-blk devices. 4 5 The implementation is basic: 6 7 - No attach/detach (ie. removable media). 8 9 - Although the non-blocking interfaces of EFI_BLOCK_IO2_PROTOCOL could be a 10 good match for multiple in-flight virtio-blk requests, we stick to 11 synchronous requests and EFI_BLOCK_IO_PROTOCOL for now. 12 13 Copyright (C) 2012, Red Hat, Inc. 14 Copyright (c) 2012 - 2014, Intel Corporation. All rights reserved.<BR> 15 16 This program and the accompanying materials are licensed and made available 17 under the terms and conditions of the BSD License which accompanies this 18 distribution. The full text of the license may be found at 19 http://opensource.org/licenses/bsd-license.php 20 21 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT 22 WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 23 24**/ 25 26#include <IndustryStandard/VirtioBlk.h> 27#include <Library/BaseMemoryLib.h> 28#include <Library/DebugLib.h> 29#include <Library/MemoryAllocationLib.h> 30#include <Library/UefiBootServicesTableLib.h> 31#include <Library/UefiLib.h> 32#include <Library/VirtioLib.h> 33 34#include "VirtioBlk.h" 35 36/** 37 38 Convenience macros to read and write region 0 IO space elements of the 39 virtio-blk device, for configuration purposes. 40 41 The following macros make it possible to specify only the "core parameters" 42 for such accesses and to derive the rest. By the time VIRTIO_CFG_WRITE() 43 returns, the transaction will have been completed. 44 45 @param[in] Dev Pointer to the VBLK_DEV structure whose VirtIo space 46 we're accessing. Dev->VirtIo must be valid. 47 48 @param[in] Field A field name from VBLK_HDR, identifying the virtio-blk 49 configuration item to access. 50 51 @param[in] Value (VIRTIO_CFG_WRITE() only.) The value to write to the 52 selected configuration item. 53 54 @param[out] Pointer (VIRTIO_CFG_READ() only.) The object to receive the 55 value read from the configuration item. Its type must be 56 one of UINT8, UINT16, UINT32, UINT64. 57 58 59 @return Status code returned by Virtio->WriteDevice() / 60 Virtio->ReadDevice(). 61 62**/ 63 64#define VIRTIO_CFG_WRITE(Dev, Field, Value) ((Dev)->VirtIo->WriteDevice ( \ 65 (Dev)->VirtIo, \ 66 OFFSET_OF_VBLK (Field), \ 67 SIZE_OF_VBLK (Field), \ 68 (Value) \ 69 )) 70 71#define VIRTIO_CFG_READ(Dev, Field, Pointer) ((Dev)->VirtIo->ReadDevice ( \ 72 (Dev)->VirtIo, \ 73 OFFSET_OF_VBLK (Field), \ 74 SIZE_OF_VBLK (Field), \ 75 sizeof *(Pointer), \ 76 (Pointer) \ 77 )) 78 79 80// 81// UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol 82// Driver Writer's Guide for UEFI 2.3.1 v1.01, 83// 24.2 Block I/O Protocol Implementations 84// 85EFI_STATUS 86EFIAPI 87VirtioBlkReset ( 88 IN EFI_BLOCK_IO_PROTOCOL *This, 89 IN BOOLEAN ExtendedVerification 90 ) 91{ 92 // 93 // If we managed to initialize and install the driver, then the device is 94 // working correctly. 95 // 96 return EFI_SUCCESS; 97} 98 99/** 100 101 Verify correctness of the read/write (not flush) request submitted to the 102 EFI_BLOCK_IO_PROTOCOL instance. 103 104 This function provides most verification steps described in: 105 106 UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol, 12.8 EFI Block I/O 107 Protocol, 108 - EFI_BLOCK_IO_PROTOCOL.ReadBlocks() 109 - EFI_BLOCK_IO_PROTOCOL.WriteBlocks() 110 111 Driver Writer's Guide for UEFI 2.3.1 v1.01, 112 - 24.2.2. ReadBlocks() and ReadBlocksEx() Implementation 113 - 24.2.3 WriteBlocks() and WriteBlockEx() Implementation 114 115 Request sizes are limited to 1 GB (checked). This is not a practical 116 limitation, just conformance to virtio-0.9.5, 2.3.2 Descriptor Table: "no 117 descriptor chain may be more than 2^32 bytes long in total". 118 119 Some Media characteristics are hardcoded in VirtioBlkInit() below (like 120 non-removable media, no restriction on buffer alignment etc); we rely on 121 those here without explicit mention. 122 123 @param[in] Media The EFI_BLOCK_IO_MEDIA characteristics for 124 this driver instance, extracted from the 125 underlying virtio-blk device at initialization 126 time. We validate the request against this set 127 of attributes. 128 129 130 @param[in] Lba Logical Block Address: number of logical 131 blocks to skip from the beginning of the 132 device. 133 134 @param[in] PositiveBufferSize Size of buffer to transfer, in bytes. The 135 caller is responsible to ensure this parameter 136 is positive. 137 138 @param[in] RequestIsWrite TRUE iff data transfer goes from guest to 139 device. 140 141 142 @@return Validation result to be forwarded outwards by 143 ReadBlocks() and WriteBlocks, as required by 144 the specs above. 145 146**/ 147STATIC 148EFI_STATUS 149EFIAPI 150VerifyReadWriteRequest ( 151 IN EFI_BLOCK_IO_MEDIA *Media, 152 IN EFI_LBA Lba, 153 IN UINTN PositiveBufferSize, 154 IN BOOLEAN RequestIsWrite 155 ) 156{ 157 UINTN BlockCount; 158 159 ASSERT (PositiveBufferSize > 0); 160 161 if (PositiveBufferSize > SIZE_1GB || 162 PositiveBufferSize % Media->BlockSize > 0) { 163 return EFI_BAD_BUFFER_SIZE; 164 } 165 BlockCount = PositiveBufferSize / Media->BlockSize; 166 167 // 168 // Avoid unsigned wraparound on either side in the second comparison. 169 // 170 if (Lba > Media->LastBlock || BlockCount - 1 > Media->LastBlock - Lba) { 171 return EFI_INVALID_PARAMETER; 172 } 173 174 if (RequestIsWrite && Media->ReadOnly) { 175 return EFI_WRITE_PROTECTED; 176 } 177 178 return EFI_SUCCESS; 179} 180 181 182 183 184/** 185 186 Format a read / write / flush request as three consecutive virtio 187 descriptors, push them to the host, and poll for the response. 188 189 This is the main workhorse function. Two use cases are supported, read/write 190 and flush. The function may only be called after the request parameters have 191 been verified by 192 - specific checks in ReadBlocks() / WriteBlocks() / FlushBlocks(), and 193 - VerifyReadWriteRequest() (for read/write only). 194 195 Parameters handled commonly: 196 197 @param[in] Dev The virtio-blk device the request is targeted 198 at. 199 200 Flush request: 201 202 @param[in] Lba Must be zero. 203 204 @param[in] BufferSize Must be zero. 205 206 @param[in out] Buffer Ignored by the function. 207 208 @param[in] RequestIsWrite Must be TRUE. 209 210 Read/Write request: 211 212 @param[in] Lba Logical Block Address: number of logical blocks 213 to skip from the beginning of the device. 214 215 @param[in] BufferSize Size of buffer to transfer, in bytes. The caller 216 is responsible to ensure this parameter is 217 positive. 218 219 @param[in out] Buffer The guest side area to read data from the device 220 into, or write data to the device from. 221 222 @param[in] RequestIsWrite TRUE iff data transfer goes from guest to 223 device. 224 225 Return values are common to both use cases, and are appropriate to be 226 forwarded by the EFI_BLOCK_IO_PROTOCOL functions (ReadBlocks(), 227 WriteBlocks(), FlushBlocks()). 228 229 230 @retval EFI_SUCCESS Transfer complete. 231 232 @retval EFI_DEVICE_ERROR Failed to notify host side via VirtIo write, or 233 unable to parse host response, or host response 234 is not VIRTIO_BLK_S_OK. 235 236**/ 237 238STATIC 239EFI_STATUS 240EFIAPI 241SynchronousRequest ( 242 IN VBLK_DEV *Dev, 243 IN EFI_LBA Lba, 244 IN UINTN BufferSize, 245 IN OUT volatile VOID *Buffer, 246 IN BOOLEAN RequestIsWrite 247 ) 248{ 249 UINT32 BlockSize; 250 volatile VIRTIO_BLK_REQ Request; 251 volatile UINT8 HostStatus; 252 DESC_INDICES Indices; 253 254 BlockSize = Dev->BlockIoMedia.BlockSize; 255 256 // 257 // ensured by VirtioBlkInit() 258 // 259 ASSERT (BlockSize > 0); 260 ASSERT (BlockSize % 512 == 0); 261 262 // 263 // ensured by contract above, plus VerifyReadWriteRequest() 264 // 265 ASSERT (BufferSize % BlockSize == 0); 266 267 // 268 // Prepare virtio-blk request header, setting zero size for flush. 269 // IO Priority is homogeneously 0. 270 // 271 Request.Type = RequestIsWrite ? 272 (BufferSize == 0 ? VIRTIO_BLK_T_FLUSH : VIRTIO_BLK_T_OUT) : 273 VIRTIO_BLK_T_IN; 274 Request.IoPrio = 0; 275 Request.Sector = MultU64x32(Lba, BlockSize / 512); 276 277 VirtioPrepare (&Dev->Ring, &Indices); 278 279 // 280 // preset a host status for ourselves that we do not accept as success 281 // 282 HostStatus = VIRTIO_BLK_S_IOERR; 283 284 // 285 // ensured by VirtioBlkInit() -- this predicate, in combination with the 286 // lock-step progress, ensures we don't have to track free descriptors. 287 // 288 ASSERT (Dev->Ring.QueueSize >= 3); 289 290 // 291 // virtio-blk header in first desc 292 // 293 VirtioAppendDesc (&Dev->Ring, (UINTN) &Request, sizeof Request, 294 VRING_DESC_F_NEXT, &Indices); 295 296 // 297 // data buffer for read/write in second desc 298 // 299 if (BufferSize > 0) { 300 // 301 // From virtio-0.9.5, 2.3.2 Descriptor Table: 302 // "no descriptor chain may be more than 2^32 bytes long in total". 303 // 304 // The predicate is ensured by the call contract above (for flush), or 305 // VerifyReadWriteRequest() (for read/write). It also implies that 306 // converting BufferSize to UINT32 will not truncate it. 307 // 308 ASSERT (BufferSize <= SIZE_1GB); 309 310 // 311 // VRING_DESC_F_WRITE is interpreted from the host's point of view. 312 // 313 VirtioAppendDesc (&Dev->Ring, (UINTN) Buffer, (UINT32) BufferSize, 314 VRING_DESC_F_NEXT | (RequestIsWrite ? 0 : VRING_DESC_F_WRITE), 315 &Indices); 316 } 317 318 // 319 // host status in last (second or third) desc 320 // 321 VirtioAppendDesc (&Dev->Ring, (UINTN) &HostStatus, sizeof HostStatus, 322 VRING_DESC_F_WRITE, &Indices); 323 324 // 325 // virtio-blk's only virtqueue is #0, called "requestq" (see Appendix D). 326 // 327 if (VirtioFlush (Dev->VirtIo, 0, &Dev->Ring, &Indices) == EFI_SUCCESS && 328 HostStatus == VIRTIO_BLK_S_OK) { 329 return EFI_SUCCESS; 330 } 331 332 return EFI_DEVICE_ERROR; 333} 334 335 336/** 337 338 ReadBlocks() operation for virtio-blk. 339 340 See 341 - UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol, 12.8 EFI Block I/O 342 Protocol, EFI_BLOCK_IO_PROTOCOL.ReadBlocks(). 343 - Driver Writer's Guide for UEFI 2.3.1 v1.01, 24.2.2. ReadBlocks() and 344 ReadBlocksEx() Implementation. 345 346 Parameter checks and conformant return values are implemented in 347 VerifyReadWriteRequest() and SynchronousRequest(). 348 349 A zero BufferSize doesn't seem to be prohibited, so do nothing in that case, 350 successfully. 351 352**/ 353 354EFI_STATUS 355EFIAPI 356VirtioBlkReadBlocks ( 357 IN EFI_BLOCK_IO_PROTOCOL *This, 358 IN UINT32 MediaId, 359 IN EFI_LBA Lba, 360 IN UINTN BufferSize, 361 OUT VOID *Buffer 362 ) 363{ 364 VBLK_DEV *Dev; 365 EFI_STATUS Status; 366 367 if (BufferSize == 0) { 368 return EFI_SUCCESS; 369 } 370 371 Dev = VIRTIO_BLK_FROM_BLOCK_IO (This); 372 Status = VerifyReadWriteRequest ( 373 &Dev->BlockIoMedia, 374 Lba, 375 BufferSize, 376 FALSE // RequestIsWrite 377 ); 378 if (EFI_ERROR (Status)) { 379 return Status; 380 } 381 382 return SynchronousRequest ( 383 Dev, 384 Lba, 385 BufferSize, 386 Buffer, 387 FALSE // RequestIsWrite 388 ); 389} 390 391/** 392 393 WriteBlocks() operation for virtio-blk. 394 395 See 396 - UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol, 12.8 EFI Block I/O 397 Protocol, EFI_BLOCK_IO_PROTOCOL.WriteBlocks(). 398 - Driver Writer's Guide for UEFI 2.3.1 v1.01, 24.2.3 WriteBlocks() and 399 WriteBlockEx() Implementation. 400 401 Parameter checks and conformant return values are implemented in 402 VerifyReadWriteRequest() and SynchronousRequest(). 403 404 A zero BufferSize doesn't seem to be prohibited, so do nothing in that case, 405 successfully. 406 407**/ 408 409EFI_STATUS 410EFIAPI 411VirtioBlkWriteBlocks ( 412 IN EFI_BLOCK_IO_PROTOCOL *This, 413 IN UINT32 MediaId, 414 IN EFI_LBA Lba, 415 IN UINTN BufferSize, 416 IN VOID *Buffer 417 ) 418{ 419 VBLK_DEV *Dev; 420 EFI_STATUS Status; 421 422 if (BufferSize == 0) { 423 return EFI_SUCCESS; 424 } 425 426 Dev = VIRTIO_BLK_FROM_BLOCK_IO (This); 427 Status = VerifyReadWriteRequest ( 428 &Dev->BlockIoMedia, 429 Lba, 430 BufferSize, 431 TRUE // RequestIsWrite 432 ); 433 if (EFI_ERROR (Status)) { 434 return Status; 435 } 436 437 return SynchronousRequest ( 438 Dev, 439 Lba, 440 BufferSize, 441 Buffer, 442 TRUE // RequestIsWrite 443 ); 444} 445 446 447/** 448 449 FlushBlocks() operation for virtio-blk. 450 451 See 452 - UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol, 12.8 EFI Block I/O 453 Protocol, EFI_BLOCK_IO_PROTOCOL.FlushBlocks(). 454 - Driver Writer's Guide for UEFI 2.3.1 v1.01, 24.2.4 FlushBlocks() and 455 FlushBlocksEx() Implementation. 456 457 If the underlying virtio-blk device doesn't support flushing (ie. 458 write-caching), then this function should not be called by higher layers, 459 according to EFI_BLOCK_IO_MEDIA characteristics set in VirtioBlkInit(). 460 Should they do nonetheless, we do nothing, successfully. 461 462**/ 463 464EFI_STATUS 465EFIAPI 466VirtioBlkFlushBlocks ( 467 IN EFI_BLOCK_IO_PROTOCOL *This 468 ) 469{ 470 VBLK_DEV *Dev; 471 472 Dev = VIRTIO_BLK_FROM_BLOCK_IO (This); 473 return Dev->BlockIoMedia.WriteCaching ? 474 SynchronousRequest ( 475 Dev, 476 0, // Lba 477 0, // BufferSize 478 NULL, // Buffer 479 TRUE // RequestIsWrite 480 ) : 481 EFI_SUCCESS; 482} 483 484 485/** 486 487 Device probe function for this driver. 488 489 The DXE core calls this function for any given device in order to see if the 490 driver can drive the device. 491 492 Specs relevant in the general sense: 493 494 - UEFI Spec 2.3.1 + Errata C: 495 - 6.3 Protocol Handler Services -- for accessing the underlying device 496 - 10.1 EFI Driver Binding Protocol -- for exporting ourselves 497 498 - Driver Writer's Guide for UEFI 2.3.1 v1.01: 499 - 5.1.3.4 OpenProtocol() and CloseProtocol() -- for accessing the 500 underlying device 501 - 9 Driver Binding Protocol -- for exporting ourselves 502 503 @param[in] This The EFI_DRIVER_BINDING_PROTOCOL object 504 incorporating this driver (independently of 505 any device). 506 507 @param[in] DeviceHandle The device to probe. 508 509 @param[in] RemainingDevicePath Relevant only for bus drivers, ignored. 510 511 512 @retval EFI_SUCCESS The driver supports the device being probed. 513 514 @retval EFI_UNSUPPORTED Based on virtio-blk discovery, we do not support 515 the device. 516 517 @return Error codes from the OpenProtocol() boot service or 518 the VirtIo protocol. 519 520**/ 521 522EFI_STATUS 523EFIAPI 524VirtioBlkDriverBindingSupported ( 525 IN EFI_DRIVER_BINDING_PROTOCOL *This, 526 IN EFI_HANDLE DeviceHandle, 527 IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath 528 ) 529{ 530 EFI_STATUS Status; 531 VIRTIO_DEVICE_PROTOCOL *VirtIo; 532 533 // 534 // Attempt to open the device with the VirtIo set of interfaces. On success, 535 // the protocol is "instantiated" for the VirtIo device. Covers duplicate 536 // open attempts (EFI_ALREADY_STARTED). 537 // 538 Status = gBS->OpenProtocol ( 539 DeviceHandle, // candidate device 540 &gVirtioDeviceProtocolGuid, // for generic VirtIo access 541 (VOID **)&VirtIo, // handle to instantiate 542 This->DriverBindingHandle, // requestor driver identity 543 DeviceHandle, // ControllerHandle, according to 544 // the UEFI Driver Model 545 EFI_OPEN_PROTOCOL_BY_DRIVER // get exclusive VirtIo access to 546 // the device; to be released 547 ); 548 if (EFI_ERROR (Status)) { 549 return Status; 550 } 551 552 if (VirtIo->SubSystemDeviceId != VIRTIO_SUBSYSTEM_BLOCK_DEVICE) { 553 Status = EFI_UNSUPPORTED; 554 } 555 556 // 557 // We needed VirtIo access only transitorily, to see whether we support the 558 // device or not. 559 // 560 gBS->CloseProtocol (DeviceHandle, &gVirtioDeviceProtocolGuid, 561 This->DriverBindingHandle, DeviceHandle); 562 return Status; 563} 564 565 566/** 567 568 Set up all BlockIo and virtio-blk aspects of this driver for the specified 569 device. 570 571 @param[in out] Dev The driver instance to configure. The caller is 572 responsible for Dev->VirtIo's validity (ie. working IO 573 access to the underlying virtio-blk device). 574 575 @retval EFI_SUCCESS Setup complete. 576 577 @retval EFI_UNSUPPORTED The driver is unable to work with the virtio ring or 578 virtio-blk attributes the host provides. 579 580 @return Error codes from VirtioRingInit() or 581 VIRTIO_CFG_READ() / VIRTIO_CFG_WRITE(). 582 583**/ 584 585STATIC 586EFI_STATUS 587EFIAPI 588VirtioBlkInit ( 589 IN OUT VBLK_DEV *Dev 590 ) 591{ 592 UINT8 NextDevStat; 593 EFI_STATUS Status; 594 595 UINT32 Features; 596 UINT64 NumSectors; 597 UINT32 BlockSize; 598 UINT8 PhysicalBlockExp; 599 UINT8 AlignmentOffset; 600 UINT32 OptIoSize; 601 UINT16 QueueSize; 602 603 PhysicalBlockExp = 0; 604 AlignmentOffset = 0; 605 OptIoSize = 0; 606 607 // 608 // Execute virtio-0.9.5, 2.2.1 Device Initialization Sequence. 609 // 610 NextDevStat = 0; // step 1 -- reset device 611 Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); 612 if (EFI_ERROR (Status)) { 613 goto Failed; 614 } 615 616 NextDevStat |= VSTAT_ACK; // step 2 -- acknowledge device presence 617 Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); 618 if (EFI_ERROR (Status)) { 619 goto Failed; 620 } 621 622 NextDevStat |= VSTAT_DRIVER; // step 3 -- we know how to drive it 623 Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); 624 if (EFI_ERROR (Status)) { 625 goto Failed; 626 } 627 628 // 629 // Set Page Size - MMIO VirtIo Specific 630 // 631 Status = Dev->VirtIo->SetPageSize (Dev->VirtIo, EFI_PAGE_SIZE); 632 if (EFI_ERROR (Status)) { 633 goto Failed; 634 } 635 636 // 637 // step 4a -- retrieve and validate features 638 // 639 Status = Dev->VirtIo->GetDeviceFeatures (Dev->VirtIo, &Features); 640 if (EFI_ERROR (Status)) { 641 goto Failed; 642 } 643 644 Status = VIRTIO_CFG_READ (Dev, Capacity, &NumSectors); 645 if (EFI_ERROR (Status)) { 646 goto Failed; 647 } 648 if (NumSectors == 0) { 649 Status = EFI_UNSUPPORTED; 650 goto Failed; 651 } 652 653 if (Features & VIRTIO_BLK_F_BLK_SIZE) { 654 Status = VIRTIO_CFG_READ (Dev, BlkSize, &BlockSize); 655 if (EFI_ERROR (Status)) { 656 goto Failed; 657 } 658 if (BlockSize == 0 || BlockSize % 512 != 0 || 659 ModU64x32 (NumSectors, BlockSize / 512) != 0) { 660 // 661 // We can only handle a logical block consisting of whole sectors, 662 // and only a disk composed of whole logical blocks. 663 // 664 Status = EFI_UNSUPPORTED; 665 goto Failed; 666 } 667 } 668 else { 669 BlockSize = 512; 670 } 671 672 if (Features & VIRTIO_BLK_F_TOPOLOGY) { 673 Status = VIRTIO_CFG_READ (Dev, Topology.PhysicalBlockExp, 674 &PhysicalBlockExp); 675 if (EFI_ERROR (Status)) { 676 goto Failed; 677 } 678 if (PhysicalBlockExp >= 32) { 679 Status = EFI_UNSUPPORTED; 680 goto Failed; 681 } 682 683 Status = VIRTIO_CFG_READ (Dev, Topology.AlignmentOffset, &AlignmentOffset); 684 if (EFI_ERROR (Status)) { 685 goto Failed; 686 } 687 688 Status = VIRTIO_CFG_READ (Dev, Topology.OptIoSize, &OptIoSize); 689 if (EFI_ERROR (Status)) { 690 goto Failed; 691 } 692 } 693 694 // 695 // step 4b -- allocate virtqueue 696 // 697 Status = Dev->VirtIo->SetQueueSel (Dev->VirtIo, 0); 698 if (EFI_ERROR (Status)) { 699 goto Failed; 700 } 701 Status = Dev->VirtIo->GetQueueNumMax (Dev->VirtIo, &QueueSize); 702 if (EFI_ERROR (Status)) { 703 goto Failed; 704 } 705 if (QueueSize < 3) { // SynchronousRequest() uses at most three descriptors 706 Status = EFI_UNSUPPORTED; 707 goto Failed; 708 } 709 710 Status = VirtioRingInit (QueueSize, &Dev->Ring); 711 if (EFI_ERROR (Status)) { 712 goto Failed; 713 } 714 715 // 716 // Additional steps for MMIO: align the queue appropriately, and set the 717 // size. If anything fails from here on, we must release the ring resources. 718 // 719 Status = Dev->VirtIo->SetQueueNum (Dev->VirtIo, QueueSize); 720 if (EFI_ERROR (Status)) { 721 goto ReleaseQueue; 722 } 723 724 Status = Dev->VirtIo->SetQueueAlign (Dev->VirtIo, EFI_PAGE_SIZE); 725 if (EFI_ERROR (Status)) { 726 goto ReleaseQueue; 727 } 728 729 // 730 // step 4c -- Report GPFN (guest-physical frame number) of queue. 731 // 732 Status = Dev->VirtIo->SetQueueAddress (Dev->VirtIo, 733 (UINT32) ((UINTN) Dev->Ring.Base >> EFI_PAGE_SHIFT)); 734 if (EFI_ERROR (Status)) { 735 goto ReleaseQueue; 736 } 737 738 739 // 740 // step 5 -- Report understood features. There are no virtio-blk specific 741 // features to negotiate in virtio-0.9.5, plus we do not want any of the 742 // device-independent (known or unknown) VIRTIO_F_* capabilities (see 743 // Appendix B). 744 // 745 Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, 0); 746 if (EFI_ERROR (Status)) { 747 goto ReleaseQueue; 748 } 749 750 // 751 // step 6 -- initialization complete 752 // 753 NextDevStat |= VSTAT_DRIVER_OK; 754 Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); 755 if (EFI_ERROR (Status)) { 756 goto ReleaseQueue; 757 } 758 759 // 760 // Populate the exported interface's attributes; see UEFI spec v2.4, 12.9 EFI 761 // Block I/O Protocol. 762 // 763 Dev->BlockIo.Revision = 0; 764 Dev->BlockIo.Media = &Dev->BlockIoMedia; 765 Dev->BlockIo.Reset = &VirtioBlkReset; 766 Dev->BlockIo.ReadBlocks = &VirtioBlkReadBlocks; 767 Dev->BlockIo.WriteBlocks = &VirtioBlkWriteBlocks; 768 Dev->BlockIo.FlushBlocks = &VirtioBlkFlushBlocks; 769 Dev->BlockIoMedia.MediaId = 0; 770 Dev->BlockIoMedia.RemovableMedia = FALSE; 771 Dev->BlockIoMedia.MediaPresent = TRUE; 772 Dev->BlockIoMedia.LogicalPartition = FALSE; 773 Dev->BlockIoMedia.ReadOnly = (BOOLEAN) ((Features & VIRTIO_BLK_F_RO) != 0); 774 Dev->BlockIoMedia.WriteCaching = (BOOLEAN) ((Features & VIRTIO_BLK_F_FLUSH) != 0); 775 Dev->BlockIoMedia.BlockSize = BlockSize; 776 Dev->BlockIoMedia.IoAlign = 0; 777 Dev->BlockIoMedia.LastBlock = DivU64x32 (NumSectors, 778 BlockSize / 512) - 1; 779 780 DEBUG ((DEBUG_INFO, "%a: LbaSize=0x%x[B] NumBlocks=0x%Lx[Lba]\n", 781 __FUNCTION__, Dev->BlockIoMedia.BlockSize, 782 Dev->BlockIoMedia.LastBlock + 1)); 783 784 if (Features & VIRTIO_BLK_F_TOPOLOGY) { 785 Dev->BlockIo.Revision = EFI_BLOCK_IO_PROTOCOL_REVISION3; 786 787 Dev->BlockIoMedia.LowestAlignedLba = AlignmentOffset; 788 Dev->BlockIoMedia.LogicalBlocksPerPhysicalBlock = 1u << PhysicalBlockExp; 789 Dev->BlockIoMedia.OptimalTransferLengthGranularity = OptIoSize; 790 791 DEBUG ((DEBUG_INFO, "%a: FirstAligned=0x%Lx[Lba] PhysBlkSize=0x%x[Lba]\n", 792 __FUNCTION__, Dev->BlockIoMedia.LowestAlignedLba, 793 Dev->BlockIoMedia.LogicalBlocksPerPhysicalBlock)); 794 DEBUG ((DEBUG_INFO, "%a: OptimalTransferLengthGranularity=0x%x[Lba]\n", 795 __FUNCTION__, Dev->BlockIoMedia.OptimalTransferLengthGranularity)); 796 } 797 return EFI_SUCCESS; 798 799ReleaseQueue: 800 VirtioRingUninit (&Dev->Ring); 801 802Failed: 803 // 804 // Notify the host about our failure to setup: virtio-0.9.5, 2.2.2.1 Device 805 // Status. VirtIo access failure here should not mask the original error. 806 // 807 NextDevStat |= VSTAT_FAILED; 808 Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); 809 810 return Status; // reached only via Failed above 811} 812 813 814/** 815 816 Uninitialize the internals of a virtio-blk device that has been successfully 817 set up with VirtioBlkInit(). 818 819 @param[in out] Dev The device to clean up. 820 821**/ 822 823STATIC 824VOID 825EFIAPI 826VirtioBlkUninit ( 827 IN OUT VBLK_DEV *Dev 828 ) 829{ 830 // 831 // Reset the virtual device -- see virtio-0.9.5, 2.2.2.1 Device Status. When 832 // VIRTIO_CFG_WRITE() returns, the host will have learned to stay away from 833 // the old comms area. 834 // 835 Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0); 836 837 VirtioRingUninit (&Dev->Ring); 838 839 SetMem (&Dev->BlockIo, sizeof Dev->BlockIo, 0x00); 840 SetMem (&Dev->BlockIoMedia, sizeof Dev->BlockIoMedia, 0x00); 841} 842 843 844/** 845 846 Event notification function enqueued by ExitBootServices(). 847 848 @param[in] Event Event whose notification function is being invoked. 849 850 @param[in] Context Pointer to the VBLK_DEV structure. 851 852**/ 853 854STATIC 855VOID 856EFIAPI 857VirtioBlkExitBoot ( 858 IN EFI_EVENT Event, 859 IN VOID *Context 860 ) 861{ 862 VBLK_DEV *Dev; 863 864 // 865 // Reset the device. This causes the hypervisor to forget about the virtio 866 // ring. 867 // 868 // We allocated said ring in EfiBootServicesData type memory, and code 869 // executing after ExitBootServices() is permitted to overwrite it. 870 // 871 Dev = Context; 872 Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0); 873} 874 875/** 876 877 After we've pronounced support for a specific device in 878 DriverBindingSupported(), we start managing said device (passed in by the 879 Driver Exeuction Environment) with the following service. 880 881 See DriverBindingSupported() for specification references. 882 883 @param[in] This The EFI_DRIVER_BINDING_PROTOCOL object 884 incorporating this driver (independently of 885 any device). 886 887 @param[in] DeviceHandle The supported device to drive. 888 889 @param[in] RemainingDevicePath Relevant only for bus drivers, ignored. 890 891 892 @retval EFI_SUCCESS Driver instance has been created and 893 initialized for the virtio-blk device, it 894 is now accessibla via EFI_BLOCK_IO_PROTOCOL. 895 896 @retval EFI_OUT_OF_RESOURCES Memory allocation failed. 897 898 @return Error codes from the OpenProtocol() boot 899 service, the VirtIo protocol, VirtioBlkInit(), 900 or the InstallProtocolInterface() boot service. 901 902**/ 903 904EFI_STATUS 905EFIAPI 906VirtioBlkDriverBindingStart ( 907 IN EFI_DRIVER_BINDING_PROTOCOL *This, 908 IN EFI_HANDLE DeviceHandle, 909 IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath 910 ) 911{ 912 VBLK_DEV *Dev; 913 EFI_STATUS Status; 914 915 Dev = (VBLK_DEV *) AllocateZeroPool (sizeof *Dev); 916 if (Dev == NULL) { 917 return EFI_OUT_OF_RESOURCES; 918 } 919 920 Status = gBS->OpenProtocol (DeviceHandle, &gVirtioDeviceProtocolGuid, 921 (VOID **)&Dev->VirtIo, This->DriverBindingHandle, 922 DeviceHandle, EFI_OPEN_PROTOCOL_BY_DRIVER); 923 if (EFI_ERROR (Status)) { 924 goto FreeVirtioBlk; 925 } 926 927 // 928 // VirtIo access granted, configure virtio-blk device. 929 // 930 Status = VirtioBlkInit (Dev); 931 if (EFI_ERROR (Status)) { 932 goto CloseVirtIo; 933 } 934 935 Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK, 936 &VirtioBlkExitBoot, Dev, &Dev->ExitBoot); 937 if (EFI_ERROR (Status)) { 938 goto UninitDev; 939 } 940 941 // 942 // Setup complete, attempt to export the driver instance's BlockIo interface. 943 // 944 Dev->Signature = VBLK_SIG; 945 Status = gBS->InstallProtocolInterface (&DeviceHandle, 946 &gEfiBlockIoProtocolGuid, EFI_NATIVE_INTERFACE, 947 &Dev->BlockIo); 948 if (EFI_ERROR (Status)) { 949 goto CloseExitBoot; 950 } 951 952 return EFI_SUCCESS; 953 954CloseExitBoot: 955 gBS->CloseEvent (Dev->ExitBoot); 956 957UninitDev: 958 VirtioBlkUninit (Dev); 959 960CloseVirtIo: 961 gBS->CloseProtocol (DeviceHandle, &gVirtioDeviceProtocolGuid, 962 This->DriverBindingHandle, DeviceHandle); 963 964FreeVirtioBlk: 965 FreePool (Dev); 966 967 return Status; 968} 969 970 971/** 972 973 Stop driving a virtio-blk device and remove its BlockIo interface. 974 975 This function replays the success path of DriverBindingStart() in reverse. 976 The host side virtio-blk device is reset, so that the OS boot loader or the 977 OS may reinitialize it. 978 979 @param[in] This The EFI_DRIVER_BINDING_PROTOCOL object 980 incorporating this driver (independently of any 981 device). 982 983 @param[in] DeviceHandle Stop driving this device. 984 985 @param[in] NumberOfChildren Since this function belongs to a device driver 986 only (as opposed to a bus driver), the caller 987 environment sets NumberOfChildren to zero, and 988 we ignore it. 989 990 @param[in] ChildHandleBuffer Ignored (corresponding to NumberOfChildren). 991 992**/ 993 994EFI_STATUS 995EFIAPI 996VirtioBlkDriverBindingStop ( 997 IN EFI_DRIVER_BINDING_PROTOCOL *This, 998 IN EFI_HANDLE DeviceHandle, 999 IN UINTN NumberOfChildren, 1000 IN EFI_HANDLE *ChildHandleBuffer 1001 ) 1002{ 1003 EFI_STATUS Status; 1004 EFI_BLOCK_IO_PROTOCOL *BlockIo; 1005 VBLK_DEV *Dev; 1006 1007 Status = gBS->OpenProtocol ( 1008 DeviceHandle, // candidate device 1009 &gEfiBlockIoProtocolGuid, // retrieve the BlockIo iface 1010 (VOID **)&BlockIo, // target pointer 1011 This->DriverBindingHandle, // requestor driver identity 1012 DeviceHandle, // requesting lookup for dev. 1013 EFI_OPEN_PROTOCOL_GET_PROTOCOL // lookup only, no ref. added 1014 ); 1015 if (EFI_ERROR (Status)) { 1016 return Status; 1017 } 1018 1019 Dev = VIRTIO_BLK_FROM_BLOCK_IO (BlockIo); 1020 1021 // 1022 // Handle Stop() requests for in-use driver instances gracefully. 1023 // 1024 Status = gBS->UninstallProtocolInterface (DeviceHandle, 1025 &gEfiBlockIoProtocolGuid, &Dev->BlockIo); 1026 if (EFI_ERROR (Status)) { 1027 return Status; 1028 } 1029 1030 gBS->CloseEvent (Dev->ExitBoot); 1031 1032 VirtioBlkUninit (Dev); 1033 1034 gBS->CloseProtocol (DeviceHandle, &gVirtioDeviceProtocolGuid, 1035 This->DriverBindingHandle, DeviceHandle); 1036 1037 FreePool (Dev); 1038 1039 return EFI_SUCCESS; 1040} 1041 1042 1043// 1044// The static object that groups the Supported() (ie. probe), Start() and 1045// Stop() functions of the driver together. Refer to UEFI Spec 2.3.1 + Errata 1046// C, 10.1 EFI Driver Binding Protocol. 1047// 1048STATIC EFI_DRIVER_BINDING_PROTOCOL gDriverBinding = { 1049 &VirtioBlkDriverBindingSupported, 1050 &VirtioBlkDriverBindingStart, 1051 &VirtioBlkDriverBindingStop, 1052 0x10, // Version, must be in [0x10 .. 0xFFFFFFEF] for IHV-developed drivers 1053 NULL, // ImageHandle, to be overwritten by 1054 // EfiLibInstallDriverBindingComponentName2() in VirtioBlkEntryPoint() 1055 NULL // DriverBindingHandle, ditto 1056}; 1057 1058 1059// 1060// The purpose of the following scaffolding (EFI_COMPONENT_NAME_PROTOCOL and 1061// EFI_COMPONENT_NAME2_PROTOCOL implementation) is to format the driver's name 1062// in English, for display on standard console devices. This is recommended for 1063// UEFI drivers that follow the UEFI Driver Model. Refer to the Driver Writer's 1064// Guide for UEFI 2.3.1 v1.01, 11 UEFI Driver and Controller Names. 1065// 1066// Device type names ("Virtio Block Device") are not formatted because the 1067// driver supports only that device type. Therefore the driver name suffices 1068// for unambiguous identification. 1069// 1070 1071STATIC 1072EFI_UNICODE_STRING_TABLE mDriverNameTable[] = { 1073 { "eng;en", L"Virtio Block Driver" }, 1074 { NULL, NULL } 1075}; 1076 1077STATIC 1078EFI_COMPONENT_NAME_PROTOCOL gComponentName; 1079 1080EFI_STATUS 1081EFIAPI 1082VirtioBlkGetDriverName ( 1083 IN EFI_COMPONENT_NAME_PROTOCOL *This, 1084 IN CHAR8 *Language, 1085 OUT CHAR16 **DriverName 1086 ) 1087{ 1088 return LookupUnicodeString2 ( 1089 Language, 1090 This->SupportedLanguages, 1091 mDriverNameTable, 1092 DriverName, 1093 (BOOLEAN)(This == &gComponentName) // Iso639Language 1094 ); 1095} 1096 1097EFI_STATUS 1098EFIAPI 1099VirtioBlkGetDeviceName ( 1100 IN EFI_COMPONENT_NAME_PROTOCOL *This, 1101 IN EFI_HANDLE DeviceHandle, 1102 IN EFI_HANDLE ChildHandle, 1103 IN CHAR8 *Language, 1104 OUT CHAR16 **ControllerName 1105 ) 1106{ 1107 return EFI_UNSUPPORTED; 1108} 1109 1110STATIC 1111EFI_COMPONENT_NAME_PROTOCOL gComponentName = { 1112 &VirtioBlkGetDriverName, 1113 &VirtioBlkGetDeviceName, 1114 "eng" // SupportedLanguages, ISO 639-2 language codes 1115}; 1116 1117STATIC 1118EFI_COMPONENT_NAME2_PROTOCOL gComponentName2 = { 1119 (EFI_COMPONENT_NAME2_GET_DRIVER_NAME) &VirtioBlkGetDriverName, 1120 (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME) &VirtioBlkGetDeviceName, 1121 "en" // SupportedLanguages, RFC 4646 language codes 1122}; 1123 1124 1125// 1126// Entry point of this driver. 1127// 1128EFI_STATUS 1129EFIAPI 1130VirtioBlkEntryPoint ( 1131 IN EFI_HANDLE ImageHandle, 1132 IN EFI_SYSTEM_TABLE *SystemTable 1133 ) 1134{ 1135 return EfiLibInstallDriverBindingComponentName2 ( 1136 ImageHandle, 1137 SystemTable, 1138 &gDriverBinding, 1139 ImageHandle, 1140 &gComponentName, 1141 &gComponentName2 1142 ); 1143} 1144 1145