3 The protocol provides support to allocate, free, map and umap a DMA buffer
4 for bus master (e.g PciHostBridge). When SEV is enabled, the DMA operations
5 must be performed on unencrypted buffer hence we use a bounce buffer to map
6 the guest buffer into an unencrypted DMA buffer.
8 Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
9 Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
11 SPDX-License-Identifier: BSD-2-Clause-Patent
15 #include "AmdSevIoMmu.h"
17 #define MAP_INFO_SIG SIGNATURE_64 ('M', 'A', 'P', '_', 'I', 'N', 'F', 'O')
22 EDKII_IOMMU_OPERATION Operation
;
25 EFI_PHYSICAL_ADDRESS CryptedAddress
;
26 EFI_PHYSICAL_ADDRESS PlainTextAddress
;
30 // List of the MAP_INFO structures that have been set up by IoMmuMap() and not
31 // yet torn down by IoMmuUnmap(). The list represents the full set of mappings
32 // currently in effect.
34 STATIC LIST_ENTRY mMapInfos
= INITIALIZE_LIST_HEAD_VARIABLE (mMapInfos
);
36 #define COMMON_BUFFER_SIG SIGNATURE_64 ('C', 'M', 'N', 'B', 'U', 'F', 'F', 'R')
39 // ASCII names for EDKII_IOMMU_OPERATION constants, for debug logging.
41 STATIC CONST CHAR8
* CONST
42 mBusMasterOperationName
[EdkiiIoMmuOperationMaximum
] = {
52 // The following structure enables Map() and Unmap() to perform in-place
53 // decryption and encryption, respectively, for BusMasterCommonBuffer[64]
54 // operations, without dynamic memory allocation or release.
56 // Both COMMON_BUFFER_HEADER and COMMON_BUFFER_HEADER.StashBuffer are allocated
57 // by AllocateBuffer() and released by FreeBuffer().
64 // Always allocated from EfiBootServicesData type memory, and always
70 // Followed by the actual common buffer, starting at the next page.
72 } COMMON_BUFFER_HEADER
;
76 Provides the controller-specific addresses required to access system memory
77 from a DMA bus master. On SEV guest, the DMA operations must be performed on
78 shared buffer hence we allocate a bounce buffer to map the HostAddress to a
79 DeviceAddress. The Encryption attribute is removed from the DeviceAddress
82 @param This The protocol instance pointer.
83 @param Operation Indicates if the bus master is going to read or
84 write to system memory.
85 @param HostAddress The system memory address to map to the PCI
87 @param NumberOfBytes On input the number of bytes to map. On output
88 the number of bytes that were mapped.
89 @param DeviceAddress The resulting map address for the bus master
90 PCI controller to use to access the hosts
92 @param Mapping A resulting value to pass to Unmap().
94 @retval EFI_SUCCESS The range was mapped for the returned
96 @retval EFI_UNSUPPORTED The HostAddress cannot be mapped as a common
98 @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
99 @retval EFI_OUT_OF_RESOURCES The request could not be completed due to a
101 @retval EFI_DEVICE_ERROR The system hardware could not map the requested
108 IN EDKII_IOMMU_PROTOCOL
*This
,
109 IN EDKII_IOMMU_OPERATION Operation
,
110 IN VOID
*HostAddress
,
111 IN OUT UINTN
*NumberOfBytes
,
112 OUT EFI_PHYSICAL_ADDRESS
*DeviceAddress
,
118 EFI_ALLOCATE_TYPE AllocateType
;
119 COMMON_BUFFER_HEADER
*CommonBufferHeader
;
120 VOID
*DecryptionSource
;
124 "%a: Operation=%a Host=0x%p Bytes=0x%Lx\n",
127 Operation
< ARRAY_SIZE (mBusMasterOperationName
)) ?
128 mBusMasterOperationName
[Operation
] :
131 (UINT64
)((NumberOfBytes
== NULL
) ? 0 : *NumberOfBytes
)
134 if (HostAddress
== NULL
|| NumberOfBytes
== NULL
|| DeviceAddress
== NULL
||
136 return EFI_INVALID_PARAMETER
;
140 // Allocate a MAP_INFO structure to remember the mapping when Unmap() is
143 MapInfo
= AllocatePool (sizeof (MAP_INFO
));
144 if (MapInfo
== NULL
) {
145 Status
= EFI_OUT_OF_RESOURCES
;
150 // Initialize the MAP_INFO structure, except the PlainTextAddress field
152 ZeroMem (&MapInfo
->Link
, sizeof MapInfo
->Link
);
153 MapInfo
->Signature
= MAP_INFO_SIG
;
154 MapInfo
->Operation
= Operation
;
155 MapInfo
->NumberOfBytes
= *NumberOfBytes
;
156 MapInfo
->NumberOfPages
= EFI_SIZE_TO_PAGES (MapInfo
->NumberOfBytes
);
157 MapInfo
->CryptedAddress
= (UINTN
)HostAddress
;
160 // In the switch statement below, we point "MapInfo->PlainTextAddress" to the
161 // plaintext buffer, according to Operation. We also set "DecryptionSource".
163 MapInfo
->PlainTextAddress
= MAX_ADDRESS
;
164 AllocateType
= AllocateAnyPages
;
165 DecryptionSource
= (VOID
*)(UINTN
)MapInfo
->CryptedAddress
;
168 // For BusMasterRead[64] and BusMasterWrite[64] operations, a bounce buffer
169 // is necessary regardless of whether the original (crypted) buffer crosses
170 // the 4GB limit or not -- we have to allocate a separate plaintext buffer.
171 // The only variable is whether the plaintext buffer should be under 4GB.
173 case EdkiiIoMmuOperationBusMasterRead
:
174 case EdkiiIoMmuOperationBusMasterWrite
:
175 MapInfo
->PlainTextAddress
= BASE_4GB
- 1;
176 AllocateType
= AllocateMaxAddress
;
180 case EdkiiIoMmuOperationBusMasterRead64
:
181 case EdkiiIoMmuOperationBusMasterWrite64
:
183 // Allocate the implicit plaintext bounce buffer.
185 Status
= gBS
->AllocatePages (
188 MapInfo
->NumberOfPages
,
189 &MapInfo
->PlainTextAddress
191 if (EFI_ERROR (Status
)) {
197 // For BusMasterCommonBuffer[64] operations, a to-be-plaintext buffer and a
198 // stash buffer (for in-place decryption) have been allocated already, with
199 // AllocateBuffer(). We only check whether the address of the to-be-plaintext
200 // buffer is low enough for the requested operation.
202 case EdkiiIoMmuOperationBusMasterCommonBuffer
:
203 if ((MapInfo
->CryptedAddress
> BASE_4GB
) ||
204 (EFI_PAGES_TO_SIZE (MapInfo
->NumberOfPages
) >
205 BASE_4GB
- MapInfo
->CryptedAddress
)) {
207 // CommonBuffer operations cannot be remapped. If the common buffer is
208 // above 4GB, then it is not possible to generate a mapping, so return an
211 Status
= EFI_UNSUPPORTED
;
217 case EdkiiIoMmuOperationBusMasterCommonBuffer64
:
219 // The buffer at MapInfo->CryptedAddress comes from AllocateBuffer().
221 MapInfo
->PlainTextAddress
= MapInfo
->CryptedAddress
;
223 // Stash the crypted data.
225 CommonBufferHeader
= (COMMON_BUFFER_HEADER
*)(
226 (UINTN
)MapInfo
->CryptedAddress
- EFI_PAGE_SIZE
228 ASSERT (CommonBufferHeader
->Signature
== COMMON_BUFFER_SIG
);
230 CommonBufferHeader
->StashBuffer
,
231 (VOID
*)(UINTN
)MapInfo
->CryptedAddress
,
232 MapInfo
->NumberOfBytes
235 // Point "DecryptionSource" to the stash buffer so that we decrypt
236 // it to the original location, after the switch statement.
238 DecryptionSource
= CommonBufferHeader
->StashBuffer
;
243 // Operation is invalid
245 Status
= EFI_INVALID_PARAMETER
;
250 // Clear the memory encryption mask on the plaintext buffer.
252 Status
= MemEncryptSevClearPageEncMask (
254 MapInfo
->PlainTextAddress
,
255 MapInfo
->NumberOfPages
,
258 ASSERT_EFI_ERROR (Status
);
259 if (EFI_ERROR (Status
)) {
264 // If this is a read operation from the Bus Master's point of view,
265 // then copy the contents of the real buffer into the mapped buffer
266 // so the Bus Master can read the contents of the real buffer.
268 // For BusMasterCommonBuffer[64] operations, the CopyMem() below will decrypt
269 // the original data (from the stash buffer) back to the original location.
271 if (Operation
== EdkiiIoMmuOperationBusMasterRead
||
272 Operation
== EdkiiIoMmuOperationBusMasterRead64
||
273 Operation
== EdkiiIoMmuOperationBusMasterCommonBuffer
||
274 Operation
== EdkiiIoMmuOperationBusMasterCommonBuffer64
) {
276 (VOID
*) (UINTN
) MapInfo
->PlainTextAddress
,
278 MapInfo
->NumberOfBytes
283 // Track all MAP_INFO structures.
285 InsertHeadList (&mMapInfos
, &MapInfo
->Link
);
287 // Populate output parameters.
289 *DeviceAddress
= MapInfo
->PlainTextAddress
;
294 "%a: Mapping=0x%p Device(PlainText)=0x%Lx Crypted=0x%Lx Pages=0x%Lx\n",
297 MapInfo
->PlainTextAddress
,
298 MapInfo
->CryptedAddress
,
299 (UINT64
)MapInfo
->NumberOfPages
313 Completes the Map() operation and releases any corresponding resources.
315 This is an internal worker function that only extends the Map() API with
316 the MemoryMapLocked parameter.
318 @param This The protocol instance pointer.
319 @param Mapping The mapping value returned from Map().
320 @param MemoryMapLocked The function is executing on the stack of
321 gBS->ExitBootServices(); changes to the UEFI
322 memory map are forbidden.
324 @retval EFI_SUCCESS The range was unmapped.
325 @retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
327 @retval EFI_DEVICE_ERROR The data was not committed to the target system
334 IN EDKII_IOMMU_PROTOCOL
*This
,
336 IN BOOLEAN MemoryMapLocked
341 COMMON_BUFFER_HEADER
*CommonBufferHeader
;
342 VOID
*EncryptionTarget
;
346 "%a: Mapping=0x%p MemoryMapLocked=%d\n",
352 if (Mapping
== NULL
) {
353 return EFI_INVALID_PARAMETER
;
356 MapInfo
= (MAP_INFO
*)Mapping
;
359 // set CommonBufferHeader to suppress incorrect compiler/analyzer warnings
361 CommonBufferHeader
= NULL
;
364 // For BusMasterWrite[64] operations and BusMasterCommonBuffer[64] operations
365 // we have to encrypt the results, ultimately to the original place (i.e.,
366 // "MapInfo->CryptedAddress").
368 // For BusMasterCommonBuffer[64] operations however, this encryption has to
369 // land in-place, so divert the encryption to the stash buffer first.
371 EncryptionTarget
= (VOID
*)(UINTN
)MapInfo
->CryptedAddress
;
373 switch (MapInfo
->Operation
) {
374 case EdkiiIoMmuOperationBusMasterCommonBuffer
:
375 case EdkiiIoMmuOperationBusMasterCommonBuffer64
:
376 ASSERT (MapInfo
->PlainTextAddress
== MapInfo
->CryptedAddress
);
378 CommonBufferHeader
= (COMMON_BUFFER_HEADER
*)(
379 (UINTN
)MapInfo
->PlainTextAddress
- EFI_PAGE_SIZE
381 ASSERT (CommonBufferHeader
->Signature
== COMMON_BUFFER_SIG
);
382 EncryptionTarget
= CommonBufferHeader
->StashBuffer
;
387 case EdkiiIoMmuOperationBusMasterWrite
:
388 case EdkiiIoMmuOperationBusMasterWrite64
:
391 (VOID
*) (UINTN
) MapInfo
->PlainTextAddress
,
392 MapInfo
->NumberOfBytes
398 // nothing to encrypt after BusMasterRead[64] operations
404 // Restore the memory encryption mask on the area we used to hold the
407 Status
= MemEncryptSevSetPageEncMask (
409 MapInfo
->PlainTextAddress
,
410 MapInfo
->NumberOfPages
,
413 ASSERT_EFI_ERROR (Status
);
414 if (EFI_ERROR (Status
)) {
419 // For BusMasterCommonBuffer[64] operations, copy the stashed data to the
420 // original (now encrypted) location.
422 // For all other operations, fill the late bounce buffer (which existed as
423 // plaintext at some point) with zeros, and then release it (unless the UEFI
424 // memory map is locked).
426 if (MapInfo
->Operation
== EdkiiIoMmuOperationBusMasterCommonBuffer
||
427 MapInfo
->Operation
== EdkiiIoMmuOperationBusMasterCommonBuffer64
) {
429 (VOID
*)(UINTN
)MapInfo
->CryptedAddress
,
430 CommonBufferHeader
->StashBuffer
,
431 MapInfo
->NumberOfBytes
435 (VOID
*)(UINTN
)MapInfo
->PlainTextAddress
,
436 EFI_PAGES_TO_SIZE (MapInfo
->NumberOfPages
)
438 if (!MemoryMapLocked
) {
439 gBS
->FreePages (MapInfo
->PlainTextAddress
, MapInfo
->NumberOfPages
);
444 // Forget the MAP_INFO structure, then free it (unless the UEFI memory map is
447 RemoveEntryList (&MapInfo
->Link
);
448 if (!MemoryMapLocked
) {
456 Completes the Map() operation and releases any corresponding resources.
458 @param This The protocol instance pointer.
459 @param Mapping The mapping value returned from Map().
461 @retval EFI_SUCCESS The range was unmapped.
462 @retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
464 @retval EFI_DEVICE_ERROR The data was not committed to the target system
470 IN EDKII_IOMMU_PROTOCOL
*This
,
474 return IoMmuUnmapWorker (
477 FALSE
// MemoryMapLocked
482 Allocates pages that are suitable for an OperationBusMasterCommonBuffer or
483 OperationBusMasterCommonBuffer64 mapping.
485 @param This The protocol instance pointer.
486 @param Type This parameter is not used and must be ignored.
487 @param MemoryType The type of memory to allocate,
488 EfiBootServicesData or EfiRuntimeServicesData.
489 @param Pages The number of pages to allocate.
490 @param HostAddress A pointer to store the base system memory
491 address of the allocated range.
492 @param Attributes The requested bit mask of attributes for the
495 @retval EFI_SUCCESS The requested memory pages were allocated.
496 @retval EFI_UNSUPPORTED Attributes is unsupported. The only legal
497 attribute bits are MEMORY_WRITE_COMBINE and
499 @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
500 @retval EFI_OUT_OF_RESOURCES The memory pages could not be allocated.
505 IoMmuAllocateBuffer (
506 IN EDKII_IOMMU_PROTOCOL
*This
,
507 IN EFI_ALLOCATE_TYPE Type
,
508 IN EFI_MEMORY_TYPE MemoryType
,
510 IN OUT VOID
**HostAddress
,
515 EFI_PHYSICAL_ADDRESS PhysicalAddress
;
517 UINTN CommonBufferPages
;
518 COMMON_BUFFER_HEADER
*CommonBufferHeader
;
522 "%a: MemoryType=%u Pages=0x%Lx Attributes=0x%Lx\n",
530 // Validate Attributes
532 if ((Attributes
& EDKII_IOMMU_ATTRIBUTE_INVALID_FOR_ALLOCATE_BUFFER
) != 0) {
533 return EFI_UNSUPPORTED
;
537 // Check for invalid inputs
539 if (HostAddress
== NULL
) {
540 return EFI_INVALID_PARAMETER
;
544 // The only valid memory types are EfiBootServicesData and
545 // EfiRuntimeServicesData
547 if (MemoryType
!= EfiBootServicesData
&&
548 MemoryType
!= EfiRuntimeServicesData
) {
549 return EFI_INVALID_PARAMETER
;
553 // We'll need a header page for the COMMON_BUFFER_HEADER structure.
555 if (Pages
> MAX_UINTN
- 1) {
556 return EFI_OUT_OF_RESOURCES
;
558 CommonBufferPages
= Pages
+ 1;
561 // Allocate the stash in EfiBootServicesData type memory.
563 // Map() will temporarily save encrypted data in the stash for
564 // BusMasterCommonBuffer[64] operations, so the data can be decrypted to the
565 // original location.
567 // Unmap() will temporarily save plaintext data in the stash for
568 // BusMasterCommonBuffer[64] operations, so the data can be encrypted to the
569 // original location.
571 // StashBuffer always resides in encrypted memory.
573 StashBuffer
= AllocatePages (Pages
);
574 if (StashBuffer
== NULL
) {
575 return EFI_OUT_OF_RESOURCES
;
578 PhysicalAddress
= (UINTN
)-1;
579 if ((Attributes
& EDKII_IOMMU_ATTRIBUTE_DUAL_ADDRESS_CYCLE
) == 0) {
581 // Limit allocations to memory below 4GB
583 PhysicalAddress
= SIZE_4GB
- 1;
585 Status
= gBS
->AllocatePages (
591 if (EFI_ERROR (Status
)) {
592 goto FreeStashBuffer
;
595 CommonBufferHeader
= (VOID
*)(UINTN
)PhysicalAddress
;
596 PhysicalAddress
+= EFI_PAGE_SIZE
;
598 CommonBufferHeader
->Signature
= COMMON_BUFFER_SIG
;
599 CommonBufferHeader
->StashBuffer
= StashBuffer
;
601 *HostAddress
= (VOID
*)(UINTN
)PhysicalAddress
;
605 "%a: Host=0x%Lx Stash=0x%p\n",
613 FreePages (StashBuffer
, Pages
);
618 Frees memory that was allocated with AllocateBuffer().
620 @param This The protocol instance pointer.
621 @param Pages The number of pages to free.
622 @param HostAddress The base system memory address of the allocated
625 @retval EFI_SUCCESS The requested memory pages were freed.
626 @retval EFI_INVALID_PARAMETER The memory range specified by HostAddress and
627 Pages was not allocated with AllocateBuffer().
633 IN EDKII_IOMMU_PROTOCOL
*This
,
638 UINTN CommonBufferPages
;
639 COMMON_BUFFER_HEADER
*CommonBufferHeader
;
643 "%a: Host=0x%p Pages=0x%Lx\n",
649 CommonBufferPages
= Pages
+ 1;
650 CommonBufferHeader
= (COMMON_BUFFER_HEADER
*)(
651 (UINTN
)HostAddress
- EFI_PAGE_SIZE
655 // Check the signature.
657 ASSERT (CommonBufferHeader
->Signature
== COMMON_BUFFER_SIG
);
658 if (CommonBufferHeader
->Signature
!= COMMON_BUFFER_SIG
) {
659 return EFI_INVALID_PARAMETER
;
663 // Free the stash buffer. This buffer was always encrypted, so no need to
666 FreePages (CommonBufferHeader
->StashBuffer
, Pages
);
669 // Release the common buffer itself. Unmap() has re-encrypted it in-place, so
670 // no need to zero it.
672 return gBS
->FreePages ((UINTN
)CommonBufferHeader
, CommonBufferPages
);
677 Set IOMMU attribute for a system memory.
679 If the IOMMU protocol exists, the system memory cannot be used
682 When a device requests a DMA access for a system memory,
683 the device driver need use SetAttribute() to update the IOMMU
684 attribute to request DMA access (read and/or write).
686 The DeviceHandle is used to identify which device submits the request.
687 The IOMMU implementation need translate the device path to an IOMMU device
688 ID, and set IOMMU hardware register accordingly.
689 1) DeviceHandle can be a standard PCI device.
690 The memory for BusMasterRead need set EDKII_IOMMU_ACCESS_READ.
691 The memory for BusMasterWrite need set EDKII_IOMMU_ACCESS_WRITE.
692 The memory for BusMasterCommonBuffer need set
693 EDKII_IOMMU_ACCESS_READ|EDKII_IOMMU_ACCESS_WRITE.
694 After the memory is used, the memory need set 0 to keep it being
696 2) DeviceHandle can be an ACPI device (ISA, I2C, SPI, etc).
697 The memory for DMA access need set EDKII_IOMMU_ACCESS_READ and/or
698 EDKII_IOMMU_ACCESS_WRITE.
700 @param[in] This The protocol instance pointer.
701 @param[in] DeviceHandle The device who initiates the DMA access
703 @param[in] Mapping The mapping value returned from Map().
704 @param[in] IoMmuAccess The IOMMU access.
706 @retval EFI_SUCCESS The IoMmuAccess is set for the memory range
707 specified by DeviceAddress and Length.
708 @retval EFI_INVALID_PARAMETER DeviceHandle is an invalid handle.
709 @retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
711 @retval EFI_INVALID_PARAMETER IoMmuAccess specified an illegal combination
713 @retval EFI_UNSUPPORTED DeviceHandle is unknown by the IOMMU.
714 @retval EFI_UNSUPPORTED The bit mask of IoMmuAccess is not supported
716 @retval EFI_UNSUPPORTED The IOMMU does not support the memory range
717 specified by Mapping.
718 @retval EFI_OUT_OF_RESOURCES There are not enough resources available to
719 modify the IOMMU access.
720 @retval EFI_DEVICE_ERROR The IOMMU device reported an error while
721 attempting the operation.
727 IN EDKII_IOMMU_PROTOCOL
*This
,
728 IN EFI_HANDLE DeviceHandle
,
730 IN UINT64 IoMmuAccess
733 return EFI_UNSUPPORTED
;
736 EDKII_IOMMU_PROTOCOL mAmdSev
= {
737 EDKII_IOMMU_PROTOCOL_REVISION
,
746 Notification function that is queued when gBS->ExitBootServices() signals the
747 EFI_EVENT_GROUP_EXIT_BOOT_SERVICES event group. This function signals another
748 event, received as Context, and returns.
750 Signaling an event in this context is safe. The UEFI spec allows
751 gBS->SignalEvent() to return EFI_SUCCESS only; EFI_OUT_OF_RESOURCES is not
752 listed, hence memory is not allocated. The edk2 implementation also does not
753 release memory (and we only have to care about the edk2 implementation
754 because EDKII_IOMMU_PROTOCOL is edk2-specific anyway).
756 @param[in] Event Event whose notification function is being invoked.
757 Event is permitted to request the queueing of this
758 function at TPL_CALLBACK or TPL_NOTIFY task
761 @param[in] EventToSignal Identifies the EFI_EVENT to signal. EventToSignal
762 is permitted to request the queueing of its
763 notification function only at TPL_CALLBACK level.
770 IN VOID
*EventToSignal
774 // (1) The NotifyFunctions of all the events in
775 // EFI_EVENT_GROUP_EXIT_BOOT_SERVICES will have been queued before
776 // AmdSevExitBoot() is entered.
778 // (2) AmdSevExitBoot() is executing minimally at TPL_CALLBACK.
780 // (3) AmdSevExitBoot() has been queued in unspecified order relative to the
781 // NotifyFunctions of all the other events in
782 // EFI_EVENT_GROUP_EXIT_BOOT_SERVICES whose NotifyTpl is the same as
787 // - If Event's NotifyTpl is TPL_CALLBACK, then some other NotifyFunctions
788 // queued at TPL_CALLBACK may be invoked after AmdSevExitBoot() returns.
790 // - If Event's NotifyTpl is TPL_NOTIFY, then some other NotifyFunctions
791 // queued at TPL_NOTIFY may be invoked after AmdSevExitBoot() returns; plus
792 // *all* NotifyFunctions queued at TPL_CALLBACK will be invoked strictly
793 // after all NotifyFunctions queued at TPL_NOTIFY, including
794 // AmdSevExitBoot(), have been invoked.
796 // - By signaling EventToSignal here, whose NotifyTpl is TPL_CALLBACK, we
797 // queue EventToSignal's NotifyFunction after the NotifyFunctions of *all*
798 // events in EFI_EVENT_GROUP_EXIT_BOOT_SERVICES.
800 DEBUG ((DEBUG_VERBOSE
, "%a\n", __FUNCTION__
));
801 gBS
->SignalEvent (EventToSignal
);
805 Notification function that is queued after the notification functions of all
806 events in the EFI_EVENT_GROUP_EXIT_BOOT_SERVICES event group. The same memory
807 map restrictions apply.
809 This function unmaps all currently existing IOMMU mappings.
811 @param[in] Event Event whose notification function is being invoked. Event
812 is permitted to request the queueing of this function
813 only at TPL_CALLBACK task priority level.
815 @param[in] Context Ignored.
820 AmdSevUnmapAllMappings (
826 LIST_ENTRY
*NextNode
;
829 DEBUG ((DEBUG_VERBOSE
, "%a\n", __FUNCTION__
));
832 // All drivers that had set up IOMMU mappings have halted their respective
833 // controllers by now; tear down the mappings.
835 for (Node
= GetFirstNode (&mMapInfos
); Node
!= &mMapInfos
; Node
= NextNode
) {
836 NextNode
= GetNextNode (&mMapInfos
, Node
);
837 MapInfo
= CR (Node
, MAP_INFO
, Link
, MAP_INFO_SIG
);
841 TRUE
// MemoryMapLocked
847 Initialize Iommu Protocol.
852 AmdSevInstallIoMmuProtocol (
857 EFI_EVENT UnmapAllMappingsEvent
;
858 EFI_EVENT ExitBootEvent
;
862 // Create the "late" event whose notification function will tear down all
863 // left-over IOMMU mappings.
865 Status
= gBS
->CreateEvent (
866 EVT_NOTIFY_SIGNAL
, // Type
867 TPL_CALLBACK
, // NotifyTpl
868 AmdSevUnmapAllMappings
, // NotifyFunction
869 NULL
, // NotifyContext
870 &UnmapAllMappingsEvent
// Event
872 if (EFI_ERROR (Status
)) {
877 // Create the event whose notification function will be queued by
878 // gBS->ExitBootServices() and will signal the event created above.
880 Status
= gBS
->CreateEvent (
881 EVT_SIGNAL_EXIT_BOOT_SERVICES
, // Type
882 TPL_CALLBACK
, // NotifyTpl
883 AmdSevExitBoot
, // NotifyFunction
884 UnmapAllMappingsEvent
, // NotifyContext
885 &ExitBootEvent
// Event
887 if (EFI_ERROR (Status
)) {
888 goto CloseUnmapAllMappingsEvent
;
892 Status
= gBS
->InstallMultipleProtocolInterfaces (
894 &gEdkiiIoMmuProtocolGuid
, &mAmdSev
,
897 if (EFI_ERROR (Status
)) {
898 goto CloseExitBootEvent
;
904 gBS
->CloseEvent (ExitBootEvent
);
906 CloseUnmapAllMappingsEvent
:
907 gBS
->CloseEvent (UnmapAllMappingsEvent
);