3 This driver produces Block I/O Protocol instances for virtio-blk devices.
5 The implementation is basic:
7 - No attach/detach (ie. removable media).
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.
13 Copyright (C) 2012, Red Hat, Inc.
14 Copyright (c) 2012, Intel Corporation. All rights reserved.<BR>
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
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.
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>
34 #include "VirtioBlk.h"
38 Convenience macros to read and write region 0 IO space elements of the
39 virtio-blk device, for configuration purposes.
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.
45 @param[in] Dev Pointer to the VBLK_DEV structure whose VirtIo space
46 we're accessing. Dev->VirtIo must be valid.
48 @param[in] Field A field name from VBLK_HDR, identifying the virtio-blk
49 configuration item to access.
51 @param[in] Value (VIRTIO_CFG_WRITE() only.) The value to write to the
52 selected configuration item.
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.
59 @return Status code returned by Virtio->WriteDevice() /
64 #define VIRTIO_CFG_WRITE(Dev, Field, Value) ((Dev)->VirtIo->WriteDevice ( \
66 OFFSET_OF_VBLK (Field), \
67 SIZE_OF_VBLK (Field), \
71 #define VIRTIO_CFG_READ(Dev, Field, Pointer) ((Dev)->VirtIo->ReadDevice ( \
73 OFFSET_OF_VBLK (Field), \
74 SIZE_OF_VBLK (Field), \
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
88 IN EFI_BLOCK_IO_PROTOCOL
*This
,
89 IN BOOLEAN ExtendedVerification
93 // If we managed to initialize and install the driver, then the device is
101 Verify correctness of the read/write (not flush) request submitted to the
102 EFI_BLOCK_IO_PROTOCOL instance.
104 This function provides most verification steps described in:
106 UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol, 12.8 EFI Block I/O
108 - EFI_BLOCK_IO_PROTOCOL.ReadBlocks()
109 - EFI_BLOCK_IO_PROTOCOL.WriteBlocks()
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
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".
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.
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
130 @param[in] Lba Logical Block Address: number of logical
131 blocks to skip from the beginning of the
134 @param[in] PositiveBufferSize Size of buffer to transfer, in bytes. The
135 caller is responsible to ensure this parameter
138 @param[in] RequestIsWrite TRUE iff data transfer goes from guest to
142 @@return Validation result to be forwarded outwards by
143 ReadBlocks() and WriteBlocks, as required by
150 VerifyReadWriteRequest (
151 IN EFI_BLOCK_IO_MEDIA
*Media
,
153 IN UINTN PositiveBufferSize
,
154 IN BOOLEAN RequestIsWrite
159 ASSERT (PositiveBufferSize
> 0);
161 if (PositiveBufferSize
> SIZE_1GB
||
162 PositiveBufferSize
% Media
->BlockSize
> 0) {
163 return EFI_BAD_BUFFER_SIZE
;
165 BlockCount
= PositiveBufferSize
/ Media
->BlockSize
;
168 // Avoid unsigned wraparound on either side in the second comparison.
170 if (Lba
> Media
->LastBlock
|| BlockCount
- 1 > Media
->LastBlock
- Lba
) {
171 return EFI_INVALID_PARAMETER
;
174 if (RequestIsWrite
&& Media
->ReadOnly
) {
175 return EFI_WRITE_PROTECTED
;
186 Format a read / write / flush request as three consecutive virtio
187 descriptors, push them to the host, and poll for the response.
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
192 - specific checks in ReadBlocks() / WriteBlocks() / FlushBlocks(), and
193 - VerifyReadWriteRequest() (for read/write only).
195 Parameters handled commonly:
197 @param[in] Dev The virtio-blk device the request is targeted
202 @param[in] Lba Must be zero.
204 @param[in] BufferSize Must be zero.
206 @param[in out] Buffer Ignored by the function.
208 @param[in] RequestIsWrite Must be TRUE.
212 @param[in] Lba Logical Block Address: number of logical blocks
213 to skip from the beginning of the device.
215 @param[in] BufferSize Size of buffer to transfer, in bytes. The caller
216 is responsible to ensure this parameter is
219 @param[in out] Buffer The guest side area to read data from the device
220 into, or write data to the device from.
222 @param[in] RequestIsWrite TRUE iff data transfer goes from guest to
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()).
230 @retval EFI_SUCCESS Transfer complete.
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.
245 IN OUT
volatile VOID
*Buffer
,
246 IN BOOLEAN RequestIsWrite
250 volatile VIRTIO_BLK_REQ Request
;
251 volatile UINT8 HostStatus
;
252 DESC_INDICES Indices
;
254 BlockSize
= Dev
->BlockIoMedia
.BlockSize
;
257 // ensured by VirtioBlkInit()
259 ASSERT (BlockSize
> 0);
260 ASSERT (BlockSize
% 512 == 0);
263 // ensured by contract above, plus VerifyReadWriteRequest()
265 ASSERT (BufferSize
% BlockSize
== 0);
268 // Prepare virtio-blk request header, setting zero size for flush.
269 // IO Priority is homogeneously 0.
271 Request
.Type
= RequestIsWrite
?
272 (BufferSize
== 0 ? VIRTIO_BLK_T_FLUSH
: VIRTIO_BLK_T_OUT
) :
275 Request
.Sector
= MultU64x32(Lba
, BlockSize
/ 512);
277 VirtioPrepare (&Dev
->Ring
, &Indices
);
280 // preset a host status for ourselves that we do not accept as success
282 HostStatus
= VIRTIO_BLK_S_IOERR
;
285 // ensured by VirtioBlkInit() -- this predicate, in combination with the
286 // lock-step progress, ensures we don't have to track free descriptors.
288 ASSERT (Dev
->Ring
.QueueSize
>= 3);
291 // virtio-blk header in first desc
293 VirtioAppendDesc (&Dev
->Ring
, (UINTN
) &Request
, sizeof Request
,
294 VRING_DESC_F_NEXT
, &Indices
);
297 // data buffer for read/write in second desc
299 if (BufferSize
> 0) {
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".
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.
308 ASSERT (BufferSize
<= SIZE_1GB
);
311 // VRING_DESC_F_WRITE is interpreted from the host's point of view.
313 VirtioAppendDesc (&Dev
->Ring
, (UINTN
) Buffer
, (UINT32
) BufferSize
,
314 VRING_DESC_F_NEXT
| (RequestIsWrite
? 0 : VRING_DESC_F_WRITE
),
319 // host status in last (second or third) desc
321 VirtioAppendDesc (&Dev
->Ring
, (UINTN
) &HostStatus
, sizeof HostStatus
,
322 VRING_DESC_F_WRITE
, &Indices
);
325 // virtio-blk's only virtqueue is #0, called "requestq" (see Appendix D).
327 if (VirtioFlush (Dev
->VirtIo
, 0, &Dev
->Ring
, &Indices
) == EFI_SUCCESS
&&
328 HostStatus
== VIRTIO_BLK_S_OK
) {
332 return EFI_DEVICE_ERROR
;
338 ReadBlocks() operation for virtio-blk.
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.
346 Parameter checks and conformant return values are implemented in
347 VerifyReadWriteRequest() and SynchronousRequest().
349 A zero BufferSize doesn't seem to be prohibited, so do nothing in that case,
356 VirtioBlkReadBlocks (
357 IN EFI_BLOCK_IO_PROTOCOL
*This
,
367 if (BufferSize
== 0) {
371 Dev
= VIRTIO_BLK_FROM_BLOCK_IO (This
);
372 Status
= VerifyReadWriteRequest (
376 FALSE
// RequestIsWrite
378 if (EFI_ERROR (Status
)) {
382 return SynchronousRequest (
387 FALSE
// RequestIsWrite
393 WriteBlocks() operation for virtio-blk.
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.
401 Parameter checks and conformant return values are implemented in
402 VerifyReadWriteRequest() and SynchronousRequest().
404 A zero BufferSize doesn't seem to be prohibited, so do nothing in that case,
411 VirtioBlkWriteBlocks (
412 IN EFI_BLOCK_IO_PROTOCOL
*This
,
422 if (BufferSize
== 0) {
426 Dev
= VIRTIO_BLK_FROM_BLOCK_IO (This
);
427 Status
= VerifyReadWriteRequest (
431 TRUE
// RequestIsWrite
433 if (EFI_ERROR (Status
)) {
437 return SynchronousRequest (
442 TRUE
// RequestIsWrite
449 FlushBlocks() operation for virtio-blk.
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.
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.
466 VirtioBlkFlushBlocks (
467 IN EFI_BLOCK_IO_PROTOCOL
*This
472 Dev
= VIRTIO_BLK_FROM_BLOCK_IO (This
);
473 return Dev
->BlockIoMedia
.WriteCaching
?
479 TRUE
// RequestIsWrite
487 Device probe function for this driver.
489 The DXE core calls this function for any given device in order to see if the
490 driver can drive the device.
492 Specs relevant in the general sense:
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
498 - Driver Writer's Guide for UEFI 2.3.1 v1.01:
499 - 5.1.3.4 OpenProtocol() and CloseProtocol() -- for accessing the
501 - 9 Driver Binding Protocol -- for exporting ourselves
503 @param[in] This The EFI_DRIVER_BINDING_PROTOCOL object
504 incorporating this driver (independently of
507 @param[in] DeviceHandle The device to probe.
509 @param[in] RemainingDevicePath Relevant only for bus drivers, ignored.
512 @retval EFI_SUCCESS The driver supports the device being probed.
514 @retval EFI_UNSUPPORTED Based on virtio-blk discovery, we do not support
517 @return Error codes from the OpenProtocol() boot service or
524 VirtioBlkDriverBindingSupported (
525 IN EFI_DRIVER_BINDING_PROTOCOL
*This
,
526 IN EFI_HANDLE DeviceHandle
,
527 IN EFI_DEVICE_PATH_PROTOCOL
*RemainingDevicePath
531 VIRTIO_DEVICE_PROTOCOL
*VirtIo
;
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).
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
548 if (EFI_ERROR (Status
)) {
552 if (VirtIo
->SubSystemDeviceId
!= VIRTIO_SUBSYSTEM_BLOCK_DEVICE
) {
553 Status
= EFI_UNSUPPORTED
;
557 // We needed VirtIo access only transitorily, to see whether we support the
560 gBS
->CloseProtocol (DeviceHandle
, &gVirtioDeviceProtocolGuid
,
561 This
->DriverBindingHandle
, DeviceHandle
);
568 Set up all BlockIo and virtio-blk aspects of this driver for the specified
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).
575 @retval EFI_SUCCESS Setup complete.
577 @retval EFI_UNSUPPORTED The driver is unable to work with the virtio ring or
578 virtio-blk attributes the host provides.
580 @return Error codes from VirtioRingInit() or
581 VIRTIO_CFG_READ() / VIRTIO_CFG_WRITE().
601 // Execute virtio-0.9.5, 2.2.1 Device Initialization Sequence.
603 NextDevStat
= 0; // step 1 -- reset device
604 Status
= Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, NextDevStat
);
605 if (EFI_ERROR (Status
)) {
609 NextDevStat
|= VSTAT_ACK
; // step 2 -- acknowledge device presence
610 Status
= Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, NextDevStat
);
611 if (EFI_ERROR (Status
)) {
615 NextDevStat
|= VSTAT_DRIVER
; // step 3 -- we know how to drive it
616 Status
= Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, NextDevStat
);
617 if (EFI_ERROR (Status
)) {
622 // Set Page Size - MMIO VirtIo Specific
624 Status
= Dev
->VirtIo
->SetPageSize (Dev
->VirtIo
, EFI_PAGE_SIZE
);
625 if (EFI_ERROR (Status
)) {
630 // step 4a -- retrieve and validate features
632 Status
= Dev
->VirtIo
->GetDeviceFeatures (Dev
->VirtIo
, &Features
);
633 if (EFI_ERROR (Status
)) {
637 Status
= VIRTIO_CFG_READ (Dev
, Capacity
, &NumSectors
);
638 if (EFI_ERROR (Status
)) {
641 if (NumSectors
== 0) {
642 Status
= EFI_UNSUPPORTED
;
646 if (Features
& VIRTIO_BLK_F_BLK_SIZE
) {
647 Status
= VIRTIO_CFG_READ (Dev
, BlkSize
, &BlockSize
);
648 if (EFI_ERROR (Status
)) {
651 if (BlockSize
== 0 || BlockSize
% 512 != 0 ||
652 ModU64x32 (NumSectors
, BlockSize
/ 512) != 0) {
654 // We can only handle a logical block consisting of whole sectors,
655 // and only a disk composed of whole logical blocks.
657 Status
= EFI_UNSUPPORTED
;
666 // step 4b -- allocate virtqueue
668 Status
= Dev
->VirtIo
->SetQueueSel (Dev
->VirtIo
, 0);
669 if (EFI_ERROR (Status
)) {
672 Status
= Dev
->VirtIo
->GetQueueNumMax (Dev
->VirtIo
, &QueueSize
);
673 if (EFI_ERROR (Status
)) {
676 if (QueueSize
< 3) { // SynchronousRequest() uses at most three descriptors
677 Status
= EFI_UNSUPPORTED
;
681 Status
= VirtioRingInit (QueueSize
, &Dev
->Ring
);
682 if (EFI_ERROR (Status
)) {
687 // Additional steps for MMIO: align the queue appropriately, and set the
688 // size. If anything fails from here on, we must release the ring resources.
690 Status
= Dev
->VirtIo
->SetQueueNum (Dev
->VirtIo
, QueueSize
);
691 if (EFI_ERROR (Status
)) {
695 Status
= Dev
->VirtIo
->SetQueueAlign (Dev
->VirtIo
, EFI_PAGE_SIZE
);
696 if (EFI_ERROR (Status
)) {
701 // step 4c -- Report GPFN (guest-physical frame number) of queue.
703 Status
= Dev
->VirtIo
->SetQueueAddress (Dev
->VirtIo
,
704 (UINT32
) ((UINTN
) Dev
->Ring
.Base
>> EFI_PAGE_SHIFT
));
705 if (EFI_ERROR (Status
)) {
711 // step 5 -- Report understood features. There are no virtio-blk specific
712 // features to negotiate in virtio-0.9.5, plus we do not want any of the
713 // device-independent (known or unknown) VIRTIO_F_* capabilities (see
716 Status
= Dev
->VirtIo
->SetGuestFeatures (Dev
->VirtIo
, 0);
717 if (EFI_ERROR (Status
)) {
722 // step 6 -- initialization complete
724 NextDevStat
|= VSTAT_DRIVER_OK
;
725 Status
= Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, NextDevStat
);
726 if (EFI_ERROR (Status
)) {
731 // Populate the exported interface's attributes; see UEFI spec v2.3.1 +
732 // Errata C, 12.8 EFI Block I/O Protocol. We stick to the lowest possible
733 // EFI_BLOCK_IO_PROTOCOL revision for now.
735 Dev
->BlockIo
.Revision
= 0;
736 Dev
->BlockIo
.Media
= &Dev
->BlockIoMedia
;
737 Dev
->BlockIo
.Reset
= &VirtioBlkReset
;
738 Dev
->BlockIo
.ReadBlocks
= &VirtioBlkReadBlocks
;
739 Dev
->BlockIo
.WriteBlocks
= &VirtioBlkWriteBlocks
;
740 Dev
->BlockIo
.FlushBlocks
= &VirtioBlkFlushBlocks
;
741 Dev
->BlockIoMedia
.MediaId
= 0;
742 Dev
->BlockIoMedia
.RemovableMedia
= FALSE
;
743 Dev
->BlockIoMedia
.MediaPresent
= TRUE
;
744 Dev
->BlockIoMedia
.LogicalPartition
= FALSE
;
745 Dev
->BlockIoMedia
.ReadOnly
= !!(Features
& VIRTIO_BLK_F_RO
);
746 Dev
->BlockIoMedia
.WriteCaching
= !!(Features
& VIRTIO_BLK_F_FLUSH
);
747 Dev
->BlockIoMedia
.BlockSize
= BlockSize
;
748 Dev
->BlockIoMedia
.IoAlign
= 0;
749 Dev
->BlockIoMedia
.LastBlock
= DivU64x32 (NumSectors
,
750 BlockSize
/ 512) - 1;
754 VirtioRingUninit (&Dev
->Ring
);
758 // Notify the host about our failure to setup: virtio-0.9.5, 2.2.2.1 Device
759 // Status. VirtIo access failure here should not mask the original error.
761 NextDevStat
|= VSTAT_FAILED
;
762 Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, NextDevStat
);
764 return Status
; // reached only via Failed above
770 Uninitialize the internals of a virtio-blk device that has been successfully
771 set up with VirtioBlkInit().
773 @param[in out] Dev The device to clean up.
785 // Reset the virtual device -- see virtio-0.9.5, 2.2.2.1 Device Status. When
786 // VIRTIO_CFG_WRITE() returns, the host will have learned to stay away from
787 // the old comms area.
789 Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, 0);
791 VirtioRingUninit (&Dev
->Ring
);
793 SetMem (&Dev
->BlockIo
, sizeof Dev
->BlockIo
, 0x00);
794 SetMem (&Dev
->BlockIoMedia
, sizeof Dev
->BlockIoMedia
, 0x00);
800 After we've pronounced support for a specific device in
801 DriverBindingSupported(), we start managing said device (passed in by the
802 Driver Exeuction Environment) with the following service.
804 See DriverBindingSupported() for specification references.
806 @param[in] This The EFI_DRIVER_BINDING_PROTOCOL object
807 incorporating this driver (independently of
810 @param[in] DeviceHandle The supported device to drive.
812 @param[in] RemainingDevicePath Relevant only for bus drivers, ignored.
815 @retval EFI_SUCCESS Driver instance has been created and
816 initialized for the virtio-blk device, it
817 is now accessibla via EFI_BLOCK_IO_PROTOCOL.
819 @retval EFI_OUT_OF_RESOURCES Memory allocation failed.
821 @return Error codes from the OpenProtocol() boot
822 service, the VirtIo protocol, VirtioBlkInit(),
823 or the InstallProtocolInterface() boot service.
829 VirtioBlkDriverBindingStart (
830 IN EFI_DRIVER_BINDING_PROTOCOL
*This
,
831 IN EFI_HANDLE DeviceHandle
,
832 IN EFI_DEVICE_PATH_PROTOCOL
*RemainingDevicePath
838 Dev
= (VBLK_DEV
*) AllocateZeroPool (sizeof *Dev
);
840 return EFI_OUT_OF_RESOURCES
;
843 Status
= gBS
->OpenProtocol (DeviceHandle
, &gVirtioDeviceProtocolGuid
,
844 (VOID
**)&Dev
->VirtIo
, This
->DriverBindingHandle
,
845 DeviceHandle
, EFI_OPEN_PROTOCOL_BY_DRIVER
);
846 if (EFI_ERROR (Status
)) {
851 // VirtIo access granted, configure virtio-blk device.
853 Status
= VirtioBlkInit (Dev
);
854 if (EFI_ERROR (Status
)) {
859 // Setup complete, attempt to export the driver instance's BlockIo interface.
861 Dev
->Signature
= VBLK_SIG
;
862 Status
= gBS
->InstallProtocolInterface (&DeviceHandle
,
863 &gEfiBlockIoProtocolGuid
, EFI_NATIVE_INTERFACE
,
865 if (EFI_ERROR (Status
)) {
872 VirtioBlkUninit (Dev
);
875 gBS
->CloseProtocol (DeviceHandle
, &gVirtioDeviceProtocolGuid
,
876 This
->DriverBindingHandle
, DeviceHandle
);
887 Stop driving a virtio-blk device and remove its BlockIo interface.
889 This function replays the success path of DriverBindingStart() in reverse.
890 The host side virtio-blk device is reset, so that the OS boot loader or the
891 OS may reinitialize it.
893 @param[in] This The EFI_DRIVER_BINDING_PROTOCOL object
894 incorporating this driver (independently of any
897 @param[in] DeviceHandle Stop driving this device.
899 @param[in] NumberOfChildren Since this function belongs to a device driver
900 only (as opposed to a bus driver), the caller
901 environment sets NumberOfChildren to zero, and
904 @param[in] ChildHandleBuffer Ignored (corresponding to NumberOfChildren).
910 VirtioBlkDriverBindingStop (
911 IN EFI_DRIVER_BINDING_PROTOCOL
*This
,
912 IN EFI_HANDLE DeviceHandle
,
913 IN UINTN NumberOfChildren
,
914 IN EFI_HANDLE
*ChildHandleBuffer
918 EFI_BLOCK_IO_PROTOCOL
*BlockIo
;
921 Status
= gBS
->OpenProtocol (
922 DeviceHandle
, // candidate device
923 &gEfiBlockIoProtocolGuid
, // retrieve the BlockIo iface
924 (VOID
**)&BlockIo
, // target pointer
925 This
->DriverBindingHandle
, // requestor driver identity
926 DeviceHandle
, // requesting lookup for dev.
927 EFI_OPEN_PROTOCOL_GET_PROTOCOL
// lookup only, no ref. added
929 if (EFI_ERROR (Status
)) {
933 Dev
= VIRTIO_BLK_FROM_BLOCK_IO (BlockIo
);
936 // Handle Stop() requests for in-use driver instances gracefully.
938 Status
= gBS
->UninstallProtocolInterface (DeviceHandle
,
939 &gEfiBlockIoProtocolGuid
, &Dev
->BlockIo
);
940 if (EFI_ERROR (Status
)) {
944 VirtioBlkUninit (Dev
);
946 gBS
->CloseProtocol (DeviceHandle
, &gVirtioDeviceProtocolGuid
,
947 This
->DriverBindingHandle
, DeviceHandle
);
956 // The static object that groups the Supported() (ie. probe), Start() and
957 // Stop() functions of the driver together. Refer to UEFI Spec 2.3.1 + Errata
958 // C, 10.1 EFI Driver Binding Protocol.
960 STATIC EFI_DRIVER_BINDING_PROTOCOL gDriverBinding
= {
961 &VirtioBlkDriverBindingSupported
,
962 &VirtioBlkDriverBindingStart
,
963 &VirtioBlkDriverBindingStop
,
964 0x10, // Version, must be in [0x10 .. 0xFFFFFFEF] for IHV-developed drivers
965 NULL
, // ImageHandle, to be overwritten by
966 // EfiLibInstallDriverBindingComponentName2() in VirtioBlkEntryPoint()
967 NULL
// DriverBindingHandle, ditto
972 // The purpose of the following scaffolding (EFI_COMPONENT_NAME_PROTOCOL and
973 // EFI_COMPONENT_NAME2_PROTOCOL implementation) is to format the driver's name
974 // in English, for display on standard console devices. This is recommended for
975 // UEFI drivers that follow the UEFI Driver Model. Refer to the Driver Writer's
976 // Guide for UEFI 2.3.1 v1.01, 11 UEFI Driver and Controller Names.
978 // Device type names ("Virtio Block Device") are not formatted because the
979 // driver supports only that device type. Therefore the driver name suffices
980 // for unambiguous identification.
984 EFI_UNICODE_STRING_TABLE mDriverNameTable
[] = {
985 { "eng;en", L
"Virtio Block Driver" },
990 EFI_COMPONENT_NAME_PROTOCOL gComponentName
;
994 VirtioBlkGetDriverName (
995 IN EFI_COMPONENT_NAME_PROTOCOL
*This
,
997 OUT CHAR16
**DriverName
1000 return LookupUnicodeString2 (
1002 This
->SupportedLanguages
,
1005 (BOOLEAN
)(This
== &gComponentName
) // Iso639Language
1011 VirtioBlkGetDeviceName (
1012 IN EFI_COMPONENT_NAME_PROTOCOL
*This
,
1013 IN EFI_HANDLE DeviceHandle
,
1014 IN EFI_HANDLE ChildHandle
,
1016 OUT CHAR16
**ControllerName
1019 return EFI_UNSUPPORTED
;
1023 EFI_COMPONENT_NAME_PROTOCOL gComponentName
= {
1024 &VirtioBlkGetDriverName
,
1025 &VirtioBlkGetDeviceName
,
1026 "eng" // SupportedLanguages, ISO 639-2 language codes
1030 EFI_COMPONENT_NAME2_PROTOCOL gComponentName2
= {
1031 (EFI_COMPONENT_NAME2_GET_DRIVER_NAME
) &VirtioBlkGetDriverName
,
1032 (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME
) &VirtioBlkGetDeviceName
,
1033 "en" // SupportedLanguages, RFC 4646 language codes
1038 // Entry point of this driver.
1042 VirtioBlkEntryPoint (
1043 IN EFI_HANDLE ImageHandle
,
1044 IN EFI_SYSTEM_TABLE
*SystemTable
1047 return EfiLibInstallDriverBindingComponentName2 (