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 - 2016, Intel Corporation. All rights reserved.<BR>
15 Copyright (c) 2017, AMD Inc, All rights reserved.<BR>
17 This program and the accompanying materials are licensed and made available
18 under the terms and conditions of the BSD License which accompanies this
19 distribution. The full text of the license may be found at
20 http://opensource.org/licenses/bsd-license.php
22 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
23 WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
27 #include <IndustryStandard/VirtioBlk.h>
28 #include <Library/BaseMemoryLib.h>
29 #include <Library/DebugLib.h>
30 #include <Library/MemoryAllocationLib.h>
31 #include <Library/UefiBootServicesTableLib.h>
32 #include <Library/UefiLib.h>
33 #include <Library/VirtioLib.h>
35 #include "VirtioBlk.h"
39 Convenience macros to read and write region 0 IO space elements of the
40 virtio-blk device, for configuration purposes.
42 The following macros make it possible to specify only the "core parameters"
43 for such accesses and to derive the rest. By the time VIRTIO_CFG_WRITE()
44 returns, the transaction will have been completed.
46 @param[in] Dev Pointer to the VBLK_DEV structure whose VirtIo space
47 we're accessing. Dev->VirtIo must be valid.
49 @param[in] Field A field name from VBLK_HDR, identifying the virtio-blk
50 configuration item to access.
52 @param[in] Value (VIRTIO_CFG_WRITE() only.) The value to write to the
53 selected configuration item.
55 @param[out] Pointer (VIRTIO_CFG_READ() only.) The object to receive the
56 value read from the configuration item. Its type must be
57 one of UINT8, UINT16, UINT32, UINT64.
60 @return Status code returned by Virtio->WriteDevice() /
65 #define VIRTIO_CFG_WRITE(Dev, Field, Value) ((Dev)->VirtIo->WriteDevice ( \
67 OFFSET_OF_VBLK (Field), \
68 SIZE_OF_VBLK (Field), \
72 #define VIRTIO_CFG_READ(Dev, Field, Pointer) ((Dev)->VirtIo->ReadDevice ( \
74 OFFSET_OF_VBLK (Field), \
75 SIZE_OF_VBLK (Field), \
82 // UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol
83 // Driver Writer's Guide for UEFI 2.3.1 v1.01,
84 // 24.2 Block I/O Protocol Implementations
89 IN EFI_BLOCK_IO_PROTOCOL
*This
,
90 IN BOOLEAN ExtendedVerification
94 // If we managed to initialize and install the driver, then the device is
102 Verify correctness of the read/write (not flush) request submitted to the
103 EFI_BLOCK_IO_PROTOCOL instance.
105 This function provides most verification steps described in:
107 UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol, 12.8 EFI Block I/O
109 - EFI_BLOCK_IO_PROTOCOL.ReadBlocks()
110 - EFI_BLOCK_IO_PROTOCOL.WriteBlocks()
112 Driver Writer's Guide for UEFI 2.3.1 v1.01,
113 - 24.2.2. ReadBlocks() and ReadBlocksEx() Implementation
114 - 24.2.3 WriteBlocks() and WriteBlockEx() Implementation
116 Request sizes are limited to 1 GB (checked). This is not a practical
117 limitation, just conformance to virtio-0.9.5, 2.3.2 Descriptor Table: "no
118 descriptor chain may be more than 2^32 bytes long in total".
120 Some Media characteristics are hardcoded in VirtioBlkInit() below (like
121 non-removable media, no restriction on buffer alignment etc); we rely on
122 those here without explicit mention.
124 @param[in] Media The EFI_BLOCK_IO_MEDIA characteristics for
125 this driver instance, extracted from the
126 underlying virtio-blk device at initialization
127 time. We validate the request against this set
131 @param[in] Lba Logical Block Address: number of logical
132 blocks to skip from the beginning of the
135 @param[in] PositiveBufferSize Size of buffer to transfer, in bytes. The
136 caller is responsible to ensure this parameter
139 @param[in] RequestIsWrite TRUE iff data transfer goes from guest to
143 @@return Validation result to be forwarded outwards by
144 ReadBlocks() and WriteBlocks, as required by
151 VerifyReadWriteRequest (
152 IN EFI_BLOCK_IO_MEDIA
*Media
,
154 IN UINTN PositiveBufferSize
,
155 IN BOOLEAN RequestIsWrite
160 ASSERT (PositiveBufferSize
> 0);
162 if (PositiveBufferSize
> SIZE_1GB
||
163 PositiveBufferSize
% Media
->BlockSize
> 0) {
164 return EFI_BAD_BUFFER_SIZE
;
166 BlockCount
= PositiveBufferSize
/ Media
->BlockSize
;
169 // Avoid unsigned wraparound on either side in the second comparison.
171 if (Lba
> Media
->LastBlock
|| BlockCount
- 1 > Media
->LastBlock
- Lba
) {
172 return EFI_INVALID_PARAMETER
;
175 if (RequestIsWrite
&& Media
->ReadOnly
) {
176 return EFI_WRITE_PROTECTED
;
187 Format a read / write / flush request as three consecutive virtio
188 descriptors, push them to the host, and poll for the response.
190 This is the main workhorse function. Two use cases are supported, read/write
191 and flush. The function may only be called after the request parameters have
193 - specific checks in ReadBlocks() / WriteBlocks() / FlushBlocks(), and
194 - VerifyReadWriteRequest() (for read/write only).
196 Parameters handled commonly:
198 @param[in] Dev The virtio-blk device the request is targeted
203 @param[in] Lba Must be zero.
205 @param[in] BufferSize Must be zero.
207 @param[in out] Buffer Ignored by the function.
209 @param[in] RequestIsWrite Must be TRUE.
213 @param[in] Lba Logical Block Address: number of logical blocks
214 to skip from the beginning of the device.
216 @param[in] BufferSize Size of buffer to transfer, in bytes. The caller
217 is responsible to ensure this parameter is
220 @param[in out] Buffer The guest side area to read data from the device
221 into, or write data to the device from.
223 @param[in] RequestIsWrite TRUE iff data transfer goes from guest to
226 Return values are common to both use cases, and are appropriate to be
227 forwarded by the EFI_BLOCK_IO_PROTOCOL functions (ReadBlocks(),
228 WriteBlocks(), FlushBlocks()).
231 @retval EFI_SUCCESS Transfer complete.
233 @retval EFI_DEVICE_ERROR Failed to notify host side via VirtIo write, or
234 unable to parse host response, or host response
235 is not VIRTIO_BLK_S_OK or failed to map Buffer
236 for a bus master operation.
247 IN OUT
volatile VOID
*Buffer
,
248 IN BOOLEAN RequestIsWrite
252 volatile VIRTIO_BLK_REQ Request
;
253 volatile UINT8
*HostStatus
;
254 VOID
*HostStatusBuffer
;
255 DESC_INDICES Indices
;
256 VOID
*RequestMapping
;
259 EFI_PHYSICAL_ADDRESS BufferDeviceAddress
;
260 EFI_PHYSICAL_ADDRESS HostStatusDeviceAddress
;
261 EFI_PHYSICAL_ADDRESS RequestDeviceAddress
;
263 EFI_STATUS UnmapStatus
;
265 BlockSize
= Dev
->BlockIoMedia
.BlockSize
;
268 // ensured by VirtioBlkInit()
270 ASSERT (BlockSize
> 0);
271 ASSERT (BlockSize
% 512 == 0);
274 // ensured by contract above, plus VerifyReadWriteRequest()
276 ASSERT (BufferSize
% BlockSize
== 0);
279 // Prepare virtio-blk request header, setting zero size for flush.
280 // IO Priority is homogeneously 0.
282 Request
.Type
= RequestIsWrite
?
283 (BufferSize
== 0 ? VIRTIO_BLK_T_FLUSH
: VIRTIO_BLK_T_OUT
) :
286 Request
.Sector
= MultU64x32(Lba
, BlockSize
/ 512);
289 // Host status is bi-directional (we preset with a value and expect the
290 // device to update it). Allocate a host status buffer which can be mapped
291 // to access equally by both processor and the device.
293 Status
= Dev
->VirtIo
->AllocateSharedPages (
295 EFI_SIZE_TO_PAGES (sizeof *HostStatus
),
298 if (EFI_ERROR (Status
)) {
299 return EFI_DEVICE_ERROR
;
302 HostStatus
= HostStatusBuffer
;
305 // Map virtio-blk request header (must be done after request header is
308 Status
= VirtioMapAllBytesInSharedBuffer (
310 VirtioOperationBusMasterRead
,
313 &RequestDeviceAddress
,
316 if (EFI_ERROR (Status
)) {
317 Status
= EFI_DEVICE_ERROR
;
318 goto FreeHostStatusBuffer
;
324 if (BufferSize
> 0) {
325 Status
= VirtioMapAllBytesInSharedBuffer (
328 VirtioOperationBusMasterRead
:
329 VirtioOperationBusMasterWrite
),
332 &BufferDeviceAddress
,
335 if (EFI_ERROR (Status
)) {
336 Status
= EFI_DEVICE_ERROR
;
337 goto UnmapRequestBuffer
;
342 // preset a host status for ourselves that we do not accept as success
344 *HostStatus
= VIRTIO_BLK_S_IOERR
;
347 // Map the Status Buffer with VirtioOperationBusMasterCommonBuffer so that
348 // both processor and device can access it.
350 Status
= VirtioMapAllBytesInSharedBuffer (
352 VirtioOperationBusMasterCommonBuffer
,
355 &HostStatusDeviceAddress
,
358 if (EFI_ERROR (Status
)) {
359 Status
= EFI_DEVICE_ERROR
;
360 goto UnmapDataBuffer
;
363 VirtioPrepare (&Dev
->Ring
, &Indices
);
366 // ensured by VirtioBlkInit() -- this predicate, in combination with the
367 // lock-step progress, ensures we don't have to track free descriptors.
369 ASSERT (Dev
->Ring
.QueueSize
>= 3);
372 // virtio-blk header in first desc
376 RequestDeviceAddress
,
383 // data buffer for read/write in second desc
385 if (BufferSize
> 0) {
387 // From virtio-0.9.5, 2.3.2 Descriptor Table:
388 // "no descriptor chain may be more than 2^32 bytes long in total".
390 // The predicate is ensured by the call contract above (for flush), or
391 // VerifyReadWriteRequest() (for read/write). It also implies that
392 // converting BufferSize to UINT32 will not truncate it.
394 ASSERT (BufferSize
<= SIZE_1GB
);
397 // VRING_DESC_F_WRITE is interpreted from the host's point of view.
403 VRING_DESC_F_NEXT
| (RequestIsWrite
? 0 : VRING_DESC_F_WRITE
),
409 // host status in last (second or third) desc
413 HostStatusDeviceAddress
,
420 // virtio-blk's only virtqueue is #0, called "requestq" (see Appendix D).
422 if (VirtioFlush (Dev
->VirtIo
, 0, &Dev
->Ring
, &Indices
,
423 NULL
) == EFI_SUCCESS
&&
424 *HostStatus
== VIRTIO_BLK_S_OK
) {
425 Status
= EFI_SUCCESS
;
427 Status
= EFI_DEVICE_ERROR
;
430 Dev
->VirtIo
->UnmapSharedBuffer (Dev
->VirtIo
, StatusMapping
);
433 if (BufferSize
> 0) {
434 UnmapStatus
= Dev
->VirtIo
->UnmapSharedBuffer (Dev
->VirtIo
, BufferMapping
);
435 if (EFI_ERROR (UnmapStatus
) && !RequestIsWrite
&& !EFI_ERROR (Status
)) {
437 // Data from the bus master may not reach the caller; fail the request.
439 Status
= EFI_DEVICE_ERROR
;
444 Dev
->VirtIo
->UnmapSharedBuffer (Dev
->VirtIo
, RequestMapping
);
446 FreeHostStatusBuffer
:
447 Dev
->VirtIo
->FreeSharedPages (
449 EFI_SIZE_TO_PAGES (sizeof *HostStatus
),
459 ReadBlocks() operation for virtio-blk.
462 - UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol, 12.8 EFI Block I/O
463 Protocol, EFI_BLOCK_IO_PROTOCOL.ReadBlocks().
464 - Driver Writer's Guide for UEFI 2.3.1 v1.01, 24.2.2. ReadBlocks() and
465 ReadBlocksEx() Implementation.
467 Parameter checks and conformant return values are implemented in
468 VerifyReadWriteRequest() and SynchronousRequest().
470 A zero BufferSize doesn't seem to be prohibited, so do nothing in that case,
477 VirtioBlkReadBlocks (
478 IN EFI_BLOCK_IO_PROTOCOL
*This
,
488 if (BufferSize
== 0) {
492 Dev
= VIRTIO_BLK_FROM_BLOCK_IO (This
);
493 Status
= VerifyReadWriteRequest (
497 FALSE
// RequestIsWrite
499 if (EFI_ERROR (Status
)) {
503 return SynchronousRequest (
508 FALSE
// RequestIsWrite
514 WriteBlocks() operation for virtio-blk.
517 - UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol, 12.8 EFI Block I/O
518 Protocol, EFI_BLOCK_IO_PROTOCOL.WriteBlocks().
519 - Driver Writer's Guide for UEFI 2.3.1 v1.01, 24.2.3 WriteBlocks() and
520 WriteBlockEx() Implementation.
522 Parameter checks and conformant return values are implemented in
523 VerifyReadWriteRequest() and SynchronousRequest().
525 A zero BufferSize doesn't seem to be prohibited, so do nothing in that case,
532 VirtioBlkWriteBlocks (
533 IN EFI_BLOCK_IO_PROTOCOL
*This
,
543 if (BufferSize
== 0) {
547 Dev
= VIRTIO_BLK_FROM_BLOCK_IO (This
);
548 Status
= VerifyReadWriteRequest (
552 TRUE
// RequestIsWrite
554 if (EFI_ERROR (Status
)) {
558 return SynchronousRequest (
563 TRUE
// RequestIsWrite
570 FlushBlocks() operation for virtio-blk.
573 - UEFI Spec 2.3.1 + Errata C, 12.8 EFI Block I/O Protocol, 12.8 EFI Block I/O
574 Protocol, EFI_BLOCK_IO_PROTOCOL.FlushBlocks().
575 - Driver Writer's Guide for UEFI 2.3.1 v1.01, 24.2.4 FlushBlocks() and
576 FlushBlocksEx() Implementation.
578 If the underlying virtio-blk device doesn't support flushing (ie.
579 write-caching), then this function should not be called by higher layers,
580 according to EFI_BLOCK_IO_MEDIA characteristics set in VirtioBlkInit().
581 Should they do nonetheless, we do nothing, successfully.
587 VirtioBlkFlushBlocks (
588 IN EFI_BLOCK_IO_PROTOCOL
*This
593 Dev
= VIRTIO_BLK_FROM_BLOCK_IO (This
);
594 return Dev
->BlockIoMedia
.WriteCaching
?
600 TRUE
// RequestIsWrite
608 Device probe function for this driver.
610 The DXE core calls this function for any given device in order to see if the
611 driver can drive the device.
613 Specs relevant in the general sense:
615 - UEFI Spec 2.3.1 + Errata C:
616 - 6.3 Protocol Handler Services -- for accessing the underlying device
617 - 10.1 EFI Driver Binding Protocol -- for exporting ourselves
619 - Driver Writer's Guide for UEFI 2.3.1 v1.01:
620 - 5.1.3.4 OpenProtocol() and CloseProtocol() -- for accessing the
622 - 9 Driver Binding Protocol -- for exporting ourselves
624 @param[in] This The EFI_DRIVER_BINDING_PROTOCOL object
625 incorporating this driver (independently of
628 @param[in] DeviceHandle The device to probe.
630 @param[in] RemainingDevicePath Relevant only for bus drivers, ignored.
633 @retval EFI_SUCCESS The driver supports the device being probed.
635 @retval EFI_UNSUPPORTED Based on virtio-blk discovery, we do not support
638 @return Error codes from the OpenProtocol() boot service or
645 VirtioBlkDriverBindingSupported (
646 IN EFI_DRIVER_BINDING_PROTOCOL
*This
,
647 IN EFI_HANDLE DeviceHandle
,
648 IN EFI_DEVICE_PATH_PROTOCOL
*RemainingDevicePath
652 VIRTIO_DEVICE_PROTOCOL
*VirtIo
;
655 // Attempt to open the device with the VirtIo set of interfaces. On success,
656 // the protocol is "instantiated" for the VirtIo device. Covers duplicate
657 // open attempts (EFI_ALREADY_STARTED).
659 Status
= gBS
->OpenProtocol (
660 DeviceHandle
, // candidate device
661 &gVirtioDeviceProtocolGuid
, // for generic VirtIo access
662 (VOID
**)&VirtIo
, // handle to instantiate
663 This
->DriverBindingHandle
, // requestor driver identity
664 DeviceHandle
, // ControllerHandle, according to
665 // the UEFI Driver Model
666 EFI_OPEN_PROTOCOL_BY_DRIVER
// get exclusive VirtIo access to
667 // the device; to be released
669 if (EFI_ERROR (Status
)) {
673 if (VirtIo
->SubSystemDeviceId
!= VIRTIO_SUBSYSTEM_BLOCK_DEVICE
) {
674 Status
= EFI_UNSUPPORTED
;
678 // We needed VirtIo access only transitorily, to see whether we support the
681 gBS
->CloseProtocol (DeviceHandle
, &gVirtioDeviceProtocolGuid
,
682 This
->DriverBindingHandle
, DeviceHandle
);
689 Set up all BlockIo and virtio-blk aspects of this driver for the specified
692 @param[in out] Dev The driver instance to configure. The caller is
693 responsible for Dev->VirtIo's validity (ie. working IO
694 access to the underlying virtio-blk device).
696 @retval EFI_SUCCESS Setup complete.
698 @retval EFI_UNSUPPORTED The driver is unable to work with the virtio ring or
699 virtio-blk attributes the host provides.
701 @return Error codes from VirtioRingInit() or
702 VIRTIO_CFG_READ() / VIRTIO_CFG_WRITE or
720 UINT8 PhysicalBlockExp
;
721 UINT8 AlignmentOffset
;
724 UINT64 RingBaseShift
;
726 PhysicalBlockExp
= 0;
731 // Execute virtio-0.9.5, 2.2.1 Device Initialization Sequence.
733 NextDevStat
= 0; // step 1 -- reset device
734 Status
= Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, NextDevStat
);
735 if (EFI_ERROR (Status
)) {
739 NextDevStat
|= VSTAT_ACK
; // step 2 -- acknowledge device presence
740 Status
= Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, NextDevStat
);
741 if (EFI_ERROR (Status
)) {
745 NextDevStat
|= VSTAT_DRIVER
; // step 3 -- we know how to drive it
746 Status
= Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, NextDevStat
);
747 if (EFI_ERROR (Status
)) {
752 // Set Page Size - MMIO VirtIo Specific
754 Status
= Dev
->VirtIo
->SetPageSize (Dev
->VirtIo
, EFI_PAGE_SIZE
);
755 if (EFI_ERROR (Status
)) {
760 // step 4a -- retrieve and validate features
762 Status
= Dev
->VirtIo
->GetDeviceFeatures (Dev
->VirtIo
, &Features
);
763 if (EFI_ERROR (Status
)) {
767 Status
= VIRTIO_CFG_READ (Dev
, Capacity
, &NumSectors
);
768 if (EFI_ERROR (Status
)) {
771 if (NumSectors
== 0) {
772 Status
= EFI_UNSUPPORTED
;
776 if (Features
& VIRTIO_BLK_F_BLK_SIZE
) {
777 Status
= VIRTIO_CFG_READ (Dev
, BlkSize
, &BlockSize
);
778 if (EFI_ERROR (Status
)) {
781 if (BlockSize
== 0 || BlockSize
% 512 != 0 ||
782 ModU64x32 (NumSectors
, BlockSize
/ 512) != 0) {
784 // We can only handle a logical block consisting of whole sectors,
785 // and only a disk composed of whole logical blocks.
787 Status
= EFI_UNSUPPORTED
;
795 if (Features
& VIRTIO_BLK_F_TOPOLOGY
) {
796 Status
= VIRTIO_CFG_READ (Dev
, Topology
.PhysicalBlockExp
,
798 if (EFI_ERROR (Status
)) {
801 if (PhysicalBlockExp
>= 32) {
802 Status
= EFI_UNSUPPORTED
;
806 Status
= VIRTIO_CFG_READ (Dev
, Topology
.AlignmentOffset
, &AlignmentOffset
);
807 if (EFI_ERROR (Status
)) {
811 Status
= VIRTIO_CFG_READ (Dev
, Topology
.OptIoSize
, &OptIoSize
);
812 if (EFI_ERROR (Status
)) {
817 Features
&= VIRTIO_BLK_F_BLK_SIZE
| VIRTIO_BLK_F_TOPOLOGY
| VIRTIO_BLK_F_RO
|
818 VIRTIO_BLK_F_FLUSH
| VIRTIO_F_VERSION_1
|
819 VIRTIO_F_IOMMU_PLATFORM
;
822 // In virtio-1.0, feature negotiation is expected to complete before queue
823 // discovery, and the device can also reject the selected set of features.
825 if (Dev
->VirtIo
->Revision
>= VIRTIO_SPEC_REVISION (1, 0, 0)) {
826 Status
= Virtio10WriteFeatures (Dev
->VirtIo
, Features
, &NextDevStat
);
827 if (EFI_ERROR (Status
)) {
833 // step 4b -- allocate virtqueue
835 Status
= Dev
->VirtIo
->SetQueueSel (Dev
->VirtIo
, 0);
836 if (EFI_ERROR (Status
)) {
839 Status
= Dev
->VirtIo
->GetQueueNumMax (Dev
->VirtIo
, &QueueSize
);
840 if (EFI_ERROR (Status
)) {
843 if (QueueSize
< 3) { // SynchronousRequest() uses at most three descriptors
844 Status
= EFI_UNSUPPORTED
;
848 Status
= VirtioRingInit (Dev
->VirtIo
, QueueSize
, &Dev
->Ring
);
849 if (EFI_ERROR (Status
)) {
854 // If anything fails from here on, we must release the ring resources
856 Status
= VirtioRingMap (
862 if (EFI_ERROR (Status
)) {
867 // Additional steps for MMIO: align the queue appropriately, and set the
868 // size. If anything fails from here on, we must unmap the ring resources.
870 Status
= Dev
->VirtIo
->SetQueueNum (Dev
->VirtIo
, QueueSize
);
871 if (EFI_ERROR (Status
)) {
875 Status
= Dev
->VirtIo
->SetQueueAlign (Dev
->VirtIo
, EFI_PAGE_SIZE
);
876 if (EFI_ERROR (Status
)) {
881 // step 4c -- Report GPFN (guest-physical frame number) of queue.
883 Status
= Dev
->VirtIo
->SetQueueAddress (
888 if (EFI_ERROR (Status
)) {
894 // step 5 -- Report understood features.
896 if (Dev
->VirtIo
->Revision
< VIRTIO_SPEC_REVISION (1, 0, 0)) {
897 Features
&= ~(UINT64
)(VIRTIO_F_VERSION_1
| VIRTIO_F_IOMMU_PLATFORM
);
898 Status
= Dev
->VirtIo
->SetGuestFeatures (Dev
->VirtIo
, Features
);
899 if (EFI_ERROR (Status
)) {
905 // step 6 -- initialization complete
907 NextDevStat
|= VSTAT_DRIVER_OK
;
908 Status
= Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, NextDevStat
);
909 if (EFI_ERROR (Status
)) {
914 // Populate the exported interface's attributes; see UEFI spec v2.4, 12.9 EFI
915 // Block I/O Protocol.
917 Dev
->BlockIo
.Revision
= 0;
918 Dev
->BlockIo
.Media
= &Dev
->BlockIoMedia
;
919 Dev
->BlockIo
.Reset
= &VirtioBlkReset
;
920 Dev
->BlockIo
.ReadBlocks
= &VirtioBlkReadBlocks
;
921 Dev
->BlockIo
.WriteBlocks
= &VirtioBlkWriteBlocks
;
922 Dev
->BlockIo
.FlushBlocks
= &VirtioBlkFlushBlocks
;
923 Dev
->BlockIoMedia
.MediaId
= 0;
924 Dev
->BlockIoMedia
.RemovableMedia
= FALSE
;
925 Dev
->BlockIoMedia
.MediaPresent
= TRUE
;
926 Dev
->BlockIoMedia
.LogicalPartition
= FALSE
;
927 Dev
->BlockIoMedia
.ReadOnly
= (BOOLEAN
) ((Features
& VIRTIO_BLK_F_RO
) != 0);
928 Dev
->BlockIoMedia
.WriteCaching
= (BOOLEAN
) ((Features
& VIRTIO_BLK_F_FLUSH
) != 0);
929 Dev
->BlockIoMedia
.BlockSize
= BlockSize
;
930 Dev
->BlockIoMedia
.IoAlign
= 0;
931 Dev
->BlockIoMedia
.LastBlock
= DivU64x32 (NumSectors
,
932 BlockSize
/ 512) - 1;
934 DEBUG ((DEBUG_INFO
, "%a: LbaSize=0x%x[B] NumBlocks=0x%Lx[Lba]\n",
935 __FUNCTION__
, Dev
->BlockIoMedia
.BlockSize
,
936 Dev
->BlockIoMedia
.LastBlock
+ 1));
938 if (Features
& VIRTIO_BLK_F_TOPOLOGY
) {
939 Dev
->BlockIo
.Revision
= EFI_BLOCK_IO_PROTOCOL_REVISION3
;
941 Dev
->BlockIoMedia
.LowestAlignedLba
= AlignmentOffset
;
942 Dev
->BlockIoMedia
.LogicalBlocksPerPhysicalBlock
= 1u << PhysicalBlockExp
;
943 Dev
->BlockIoMedia
.OptimalTransferLengthGranularity
= OptIoSize
;
945 DEBUG ((DEBUG_INFO
, "%a: FirstAligned=0x%Lx[Lba] PhysBlkSize=0x%x[Lba]\n",
946 __FUNCTION__
, Dev
->BlockIoMedia
.LowestAlignedLba
,
947 Dev
->BlockIoMedia
.LogicalBlocksPerPhysicalBlock
));
948 DEBUG ((DEBUG_INFO
, "%a: OptimalTransferLengthGranularity=0x%x[Lba]\n",
949 __FUNCTION__
, Dev
->BlockIoMedia
.OptimalTransferLengthGranularity
));
954 Dev
->VirtIo
->UnmapSharedBuffer (Dev
->VirtIo
, Dev
->RingMap
);
957 VirtioRingUninit (Dev
->VirtIo
, &Dev
->Ring
);
961 // Notify the host about our failure to setup: virtio-0.9.5, 2.2.2.1 Device
962 // Status. VirtIo access failure here should not mask the original error.
964 NextDevStat
|= VSTAT_FAILED
;
965 Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, NextDevStat
);
967 return Status
; // reached only via Failed above
973 Uninitialize the internals of a virtio-blk device that has been successfully
974 set up with VirtioBlkInit().
976 @param[in out] Dev The device to clean up.
988 // Reset the virtual device -- see virtio-0.9.5, 2.2.2.1 Device Status. When
989 // VIRTIO_CFG_WRITE() returns, the host will have learned to stay away from
990 // the old comms area.
992 Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, 0);
994 Dev
->VirtIo
->UnmapSharedBuffer (Dev
->VirtIo
, Dev
->RingMap
);
995 VirtioRingUninit (Dev
->VirtIo
, &Dev
->Ring
);
997 SetMem (&Dev
->BlockIo
, sizeof Dev
->BlockIo
, 0x00);
998 SetMem (&Dev
->BlockIoMedia
, sizeof Dev
->BlockIoMedia
, 0x00);
1004 Event notification function enqueued by ExitBootServices().
1006 @param[in] Event Event whose notification function is being invoked.
1008 @param[in] Context Pointer to the VBLK_DEV structure.
1022 DEBUG ((DEBUG_VERBOSE
, "%a: Context=0x%p\n", __FUNCTION__
, Context
));
1024 // Reset the device. This causes the hypervisor to forget about the virtio
1027 // We allocated said ring in EfiBootServicesData type memory, and code
1028 // executing after ExitBootServices() is permitted to overwrite it.
1031 Dev
->VirtIo
->SetDeviceStatus (Dev
->VirtIo
, 0);
1036 After we've pronounced support for a specific device in
1037 DriverBindingSupported(), we start managing said device (passed in by the
1038 Driver Execution Environment) with the following service.
1040 See DriverBindingSupported() for specification references.
1042 @param[in] This The EFI_DRIVER_BINDING_PROTOCOL object
1043 incorporating this driver (independently of
1046 @param[in] DeviceHandle The supported device to drive.
1048 @param[in] RemainingDevicePath Relevant only for bus drivers, ignored.
1051 @retval EFI_SUCCESS Driver instance has been created and
1052 initialized for the virtio-blk device, it
1053 is now accessible via EFI_BLOCK_IO_PROTOCOL.
1055 @retval EFI_OUT_OF_RESOURCES Memory allocation failed.
1057 @return Error codes from the OpenProtocol() boot
1058 service, the VirtIo protocol, VirtioBlkInit(),
1059 or the InstallProtocolInterface() boot service.
1065 VirtioBlkDriverBindingStart (
1066 IN EFI_DRIVER_BINDING_PROTOCOL
*This
,
1067 IN EFI_HANDLE DeviceHandle
,
1068 IN EFI_DEVICE_PATH_PROTOCOL
*RemainingDevicePath
1074 Dev
= (VBLK_DEV
*) AllocateZeroPool (sizeof *Dev
);
1076 return EFI_OUT_OF_RESOURCES
;
1079 Status
= gBS
->OpenProtocol (DeviceHandle
, &gVirtioDeviceProtocolGuid
,
1080 (VOID
**)&Dev
->VirtIo
, This
->DriverBindingHandle
,
1081 DeviceHandle
, EFI_OPEN_PROTOCOL_BY_DRIVER
);
1082 if (EFI_ERROR (Status
)) {
1087 // VirtIo access granted, configure virtio-blk device.
1089 Status
= VirtioBlkInit (Dev
);
1090 if (EFI_ERROR (Status
)) {
1094 Status
= gBS
->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES
, TPL_CALLBACK
,
1095 &VirtioBlkExitBoot
, Dev
, &Dev
->ExitBoot
);
1096 if (EFI_ERROR (Status
)) {
1101 // Setup complete, attempt to export the driver instance's BlockIo interface.
1103 Dev
->Signature
= VBLK_SIG
;
1104 Status
= gBS
->InstallProtocolInterface (&DeviceHandle
,
1105 &gEfiBlockIoProtocolGuid
, EFI_NATIVE_INTERFACE
,
1107 if (EFI_ERROR (Status
)) {
1114 gBS
->CloseEvent (Dev
->ExitBoot
);
1117 VirtioBlkUninit (Dev
);
1120 gBS
->CloseProtocol (DeviceHandle
, &gVirtioDeviceProtocolGuid
,
1121 This
->DriverBindingHandle
, DeviceHandle
);
1132 Stop driving a virtio-blk device and remove its BlockIo interface.
1134 This function replays the success path of DriverBindingStart() in reverse.
1135 The host side virtio-blk device is reset, so that the OS boot loader or the
1136 OS may reinitialize it.
1138 @param[in] This The EFI_DRIVER_BINDING_PROTOCOL object
1139 incorporating this driver (independently of any
1142 @param[in] DeviceHandle Stop driving this device.
1144 @param[in] NumberOfChildren Since this function belongs to a device driver
1145 only (as opposed to a bus driver), the caller
1146 environment sets NumberOfChildren to zero, and
1149 @param[in] ChildHandleBuffer Ignored (corresponding to NumberOfChildren).
1155 VirtioBlkDriverBindingStop (
1156 IN EFI_DRIVER_BINDING_PROTOCOL
*This
,
1157 IN EFI_HANDLE DeviceHandle
,
1158 IN UINTN NumberOfChildren
,
1159 IN EFI_HANDLE
*ChildHandleBuffer
1163 EFI_BLOCK_IO_PROTOCOL
*BlockIo
;
1166 Status
= gBS
->OpenProtocol (
1167 DeviceHandle
, // candidate device
1168 &gEfiBlockIoProtocolGuid
, // retrieve the BlockIo iface
1169 (VOID
**)&BlockIo
, // target pointer
1170 This
->DriverBindingHandle
, // requestor driver identity
1171 DeviceHandle
, // requesting lookup for dev.
1172 EFI_OPEN_PROTOCOL_GET_PROTOCOL
// lookup only, no ref. added
1174 if (EFI_ERROR (Status
)) {
1178 Dev
= VIRTIO_BLK_FROM_BLOCK_IO (BlockIo
);
1181 // Handle Stop() requests for in-use driver instances gracefully.
1183 Status
= gBS
->UninstallProtocolInterface (DeviceHandle
,
1184 &gEfiBlockIoProtocolGuid
, &Dev
->BlockIo
);
1185 if (EFI_ERROR (Status
)) {
1189 gBS
->CloseEvent (Dev
->ExitBoot
);
1191 VirtioBlkUninit (Dev
);
1193 gBS
->CloseProtocol (DeviceHandle
, &gVirtioDeviceProtocolGuid
,
1194 This
->DriverBindingHandle
, DeviceHandle
);
1203 // The static object that groups the Supported() (ie. probe), Start() and
1204 // Stop() functions of the driver together. Refer to UEFI Spec 2.3.1 + Errata
1205 // C, 10.1 EFI Driver Binding Protocol.
1207 STATIC EFI_DRIVER_BINDING_PROTOCOL gDriverBinding
= {
1208 &VirtioBlkDriverBindingSupported
,
1209 &VirtioBlkDriverBindingStart
,
1210 &VirtioBlkDriverBindingStop
,
1211 0x10, // Version, must be in [0x10 .. 0xFFFFFFEF] for IHV-developed drivers
1212 NULL
, // ImageHandle, to be overwritten by
1213 // EfiLibInstallDriverBindingComponentName2() in VirtioBlkEntryPoint()
1214 NULL
// DriverBindingHandle, ditto
1219 // The purpose of the following scaffolding (EFI_COMPONENT_NAME_PROTOCOL and
1220 // EFI_COMPONENT_NAME2_PROTOCOL implementation) is to format the driver's name
1221 // in English, for display on standard console devices. This is recommended for
1222 // UEFI drivers that follow the UEFI Driver Model. Refer to the Driver Writer's
1223 // Guide for UEFI 2.3.1 v1.01, 11 UEFI Driver and Controller Names.
1225 // Device type names ("Virtio Block Device") are not formatted because the
1226 // driver supports only that device type. Therefore the driver name suffices
1227 // for unambiguous identification.
1231 EFI_UNICODE_STRING_TABLE mDriverNameTable
[] = {
1232 { "eng;en", L
"Virtio Block Driver" },
1237 EFI_COMPONENT_NAME_PROTOCOL gComponentName
;
1241 VirtioBlkGetDriverName (
1242 IN EFI_COMPONENT_NAME_PROTOCOL
*This
,
1244 OUT CHAR16
**DriverName
1247 return LookupUnicodeString2 (
1249 This
->SupportedLanguages
,
1252 (BOOLEAN
)(This
== &gComponentName
) // Iso639Language
1258 VirtioBlkGetDeviceName (
1259 IN EFI_COMPONENT_NAME_PROTOCOL
*This
,
1260 IN EFI_HANDLE DeviceHandle
,
1261 IN EFI_HANDLE ChildHandle
,
1263 OUT CHAR16
**ControllerName
1266 return EFI_UNSUPPORTED
;
1270 EFI_COMPONENT_NAME_PROTOCOL gComponentName
= {
1271 &VirtioBlkGetDriverName
,
1272 &VirtioBlkGetDeviceName
,
1273 "eng" // SupportedLanguages, ISO 639-2 language codes
1277 EFI_COMPONENT_NAME2_PROTOCOL gComponentName2
= {
1278 (EFI_COMPONENT_NAME2_GET_DRIVER_NAME
) &VirtioBlkGetDriverName
,
1279 (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME
) &VirtioBlkGetDeviceName
,
1280 "en" // SupportedLanguages, RFC 4646 language codes
1285 // Entry point of this driver.
1289 VirtioBlkEntryPoint (
1290 IN EFI_HANDLE ImageHandle
,
1291 IN EFI_SYSTEM_TABLE
*SystemTable
1294 return EfiLibInstallDriverBindingComponentName2 (