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
257 ASSERT_EFI_ERROR (Status
);
258 if (EFI_ERROR (Status
)) {
263 // If this is a read operation from the Bus Master's point of view,
264 // then copy the contents of the real buffer into the mapped buffer
265 // so the Bus Master can read the contents of the real buffer.
267 // For BusMasterCommonBuffer[64] operations, the CopyMem() below will decrypt
268 // the original data (from the stash buffer) back to the original location.
270 if (Operation
== EdkiiIoMmuOperationBusMasterRead
||
271 Operation
== EdkiiIoMmuOperationBusMasterRead64
||
272 Operation
== EdkiiIoMmuOperationBusMasterCommonBuffer
||
273 Operation
== EdkiiIoMmuOperationBusMasterCommonBuffer64
) {
275 (VOID
*) (UINTN
) MapInfo
->PlainTextAddress
,
277 MapInfo
->NumberOfBytes
282 // Track all MAP_INFO structures.
284 InsertHeadList (&mMapInfos
, &MapInfo
->Link
);
286 // Populate output parameters.
288 *DeviceAddress
= MapInfo
->PlainTextAddress
;
293 "%a: Mapping=0x%p Device(PlainText)=0x%Lx Crypted=0x%Lx Pages=0x%Lx\n",
296 MapInfo
->PlainTextAddress
,
297 MapInfo
->CryptedAddress
,
298 (UINT64
)MapInfo
->NumberOfPages
312 Completes the Map() operation and releases any corresponding resources.
314 This is an internal worker function that only extends the Map() API with
315 the MemoryMapLocked parameter.
317 @param This The protocol instance pointer.
318 @param Mapping The mapping value returned from Map().
319 @param MemoryMapLocked The function is executing on the stack of
320 gBS->ExitBootServices(); changes to the UEFI
321 memory map are forbidden.
323 @retval EFI_SUCCESS The range was unmapped.
324 @retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
326 @retval EFI_DEVICE_ERROR The data was not committed to the target system
333 IN EDKII_IOMMU_PROTOCOL
*This
,
335 IN BOOLEAN MemoryMapLocked
340 COMMON_BUFFER_HEADER
*CommonBufferHeader
;
341 VOID
*EncryptionTarget
;
345 "%a: Mapping=0x%p MemoryMapLocked=%d\n",
351 if (Mapping
== NULL
) {
352 return EFI_INVALID_PARAMETER
;
355 MapInfo
= (MAP_INFO
*)Mapping
;
358 // set CommonBufferHeader to suppress incorrect compiler/analyzer warnings
360 CommonBufferHeader
= NULL
;
363 // For BusMasterWrite[64] operations and BusMasterCommonBuffer[64] operations
364 // we have to encrypt the results, ultimately to the original place (i.e.,
365 // "MapInfo->CryptedAddress").
367 // For BusMasterCommonBuffer[64] operations however, this encryption has to
368 // land in-place, so divert the encryption to the stash buffer first.
370 EncryptionTarget
= (VOID
*)(UINTN
)MapInfo
->CryptedAddress
;
372 switch (MapInfo
->Operation
) {
373 case EdkiiIoMmuOperationBusMasterCommonBuffer
:
374 case EdkiiIoMmuOperationBusMasterCommonBuffer64
:
375 ASSERT (MapInfo
->PlainTextAddress
== MapInfo
->CryptedAddress
);
377 CommonBufferHeader
= (COMMON_BUFFER_HEADER
*)(
378 (UINTN
)MapInfo
->PlainTextAddress
- EFI_PAGE_SIZE
380 ASSERT (CommonBufferHeader
->Signature
== COMMON_BUFFER_SIG
);
381 EncryptionTarget
= CommonBufferHeader
->StashBuffer
;
386 case EdkiiIoMmuOperationBusMasterWrite
:
387 case EdkiiIoMmuOperationBusMasterWrite64
:
390 (VOID
*) (UINTN
) MapInfo
->PlainTextAddress
,
391 MapInfo
->NumberOfBytes
397 // nothing to encrypt after BusMasterRead[64] operations
403 // Restore the memory encryption mask on the area we used to hold the
406 Status
= MemEncryptSevSetPageEncMask (
408 MapInfo
->PlainTextAddress
,
409 MapInfo
->NumberOfPages
411 ASSERT_EFI_ERROR (Status
);
412 if (EFI_ERROR (Status
)) {
417 // For BusMasterCommonBuffer[64] operations, copy the stashed data to the
418 // original (now encrypted) location.
420 // For all other operations, fill the late bounce buffer (which existed as
421 // plaintext at some point) with zeros, and then release it (unless the UEFI
422 // memory map is locked).
424 if (MapInfo
->Operation
== EdkiiIoMmuOperationBusMasterCommonBuffer
||
425 MapInfo
->Operation
== EdkiiIoMmuOperationBusMasterCommonBuffer64
) {
427 (VOID
*)(UINTN
)MapInfo
->CryptedAddress
,
428 CommonBufferHeader
->StashBuffer
,
429 MapInfo
->NumberOfBytes
433 (VOID
*)(UINTN
)MapInfo
->PlainTextAddress
,
434 EFI_PAGES_TO_SIZE (MapInfo
->NumberOfPages
)
436 if (!MemoryMapLocked
) {
437 gBS
->FreePages (MapInfo
->PlainTextAddress
, MapInfo
->NumberOfPages
);
442 // Forget the MAP_INFO structure, then free it (unless the UEFI memory map is
445 RemoveEntryList (&MapInfo
->Link
);
446 if (!MemoryMapLocked
) {
454 Completes the Map() operation and releases any corresponding resources.
456 @param This The protocol instance pointer.
457 @param Mapping The mapping value returned from Map().
459 @retval EFI_SUCCESS The range was unmapped.
460 @retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
462 @retval EFI_DEVICE_ERROR The data was not committed to the target system
468 IN EDKII_IOMMU_PROTOCOL
*This
,
472 return IoMmuUnmapWorker (
475 FALSE
// MemoryMapLocked
480 Allocates pages that are suitable for an OperationBusMasterCommonBuffer or
481 OperationBusMasterCommonBuffer64 mapping.
483 @param This The protocol instance pointer.
484 @param Type This parameter is not used and must be ignored.
485 @param MemoryType The type of memory to allocate,
486 EfiBootServicesData or EfiRuntimeServicesData.
487 @param Pages The number of pages to allocate.
488 @param HostAddress A pointer to store the base system memory
489 address of the allocated range.
490 @param Attributes The requested bit mask of attributes for the
493 @retval EFI_SUCCESS The requested memory pages were allocated.
494 @retval EFI_UNSUPPORTED Attributes is unsupported. The only legal
495 attribute bits are MEMORY_WRITE_COMBINE and
497 @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
498 @retval EFI_OUT_OF_RESOURCES The memory pages could not be allocated.
503 IoMmuAllocateBuffer (
504 IN EDKII_IOMMU_PROTOCOL
*This
,
505 IN EFI_ALLOCATE_TYPE Type
,
506 IN EFI_MEMORY_TYPE MemoryType
,
508 IN OUT VOID
**HostAddress
,
513 EFI_PHYSICAL_ADDRESS PhysicalAddress
;
515 UINTN CommonBufferPages
;
516 COMMON_BUFFER_HEADER
*CommonBufferHeader
;
520 "%a: MemoryType=%u Pages=0x%Lx Attributes=0x%Lx\n",
528 // Validate Attributes
530 if ((Attributes
& EDKII_IOMMU_ATTRIBUTE_INVALID_FOR_ALLOCATE_BUFFER
) != 0) {
531 return EFI_UNSUPPORTED
;
535 // Check for invalid inputs
537 if (HostAddress
== NULL
) {
538 return EFI_INVALID_PARAMETER
;
542 // The only valid memory types are EfiBootServicesData and
543 // EfiRuntimeServicesData
545 if (MemoryType
!= EfiBootServicesData
&&
546 MemoryType
!= EfiRuntimeServicesData
) {
547 return EFI_INVALID_PARAMETER
;
551 // We'll need a header page for the COMMON_BUFFER_HEADER structure.
553 if (Pages
> MAX_UINTN
- 1) {
554 return EFI_OUT_OF_RESOURCES
;
556 CommonBufferPages
= Pages
+ 1;
559 // Allocate the stash in EfiBootServicesData type memory.
561 // Map() will temporarily save encrypted data in the stash for
562 // BusMasterCommonBuffer[64] operations, so the data can be decrypted to the
563 // original location.
565 // Unmap() will temporarily save plaintext data in the stash for
566 // BusMasterCommonBuffer[64] operations, so the data can be encrypted to the
567 // original location.
569 // StashBuffer always resides in encrypted memory.
571 StashBuffer
= AllocatePages (Pages
);
572 if (StashBuffer
== NULL
) {
573 return EFI_OUT_OF_RESOURCES
;
576 PhysicalAddress
= (UINTN
)-1;
577 if ((Attributes
& EDKII_IOMMU_ATTRIBUTE_DUAL_ADDRESS_CYCLE
) == 0) {
579 // Limit allocations to memory below 4GB
581 PhysicalAddress
= SIZE_4GB
- 1;
583 Status
= gBS
->AllocatePages (
589 if (EFI_ERROR (Status
)) {
590 goto FreeStashBuffer
;
593 CommonBufferHeader
= (VOID
*)(UINTN
)PhysicalAddress
;
594 PhysicalAddress
+= EFI_PAGE_SIZE
;
596 CommonBufferHeader
->Signature
= COMMON_BUFFER_SIG
;
597 CommonBufferHeader
->StashBuffer
= StashBuffer
;
599 *HostAddress
= (VOID
*)(UINTN
)PhysicalAddress
;
603 "%a: Host=0x%Lx Stash=0x%p\n",
611 FreePages (StashBuffer
, Pages
);
616 Frees memory that was allocated with AllocateBuffer().
618 @param This The protocol instance pointer.
619 @param Pages The number of pages to free.
620 @param HostAddress The base system memory address of the allocated
623 @retval EFI_SUCCESS The requested memory pages were freed.
624 @retval EFI_INVALID_PARAMETER The memory range specified by HostAddress and
625 Pages was not allocated with AllocateBuffer().
631 IN EDKII_IOMMU_PROTOCOL
*This
,
636 UINTN CommonBufferPages
;
637 COMMON_BUFFER_HEADER
*CommonBufferHeader
;
641 "%a: Host=0x%p Pages=0x%Lx\n",
647 CommonBufferPages
= Pages
+ 1;
648 CommonBufferHeader
= (COMMON_BUFFER_HEADER
*)(
649 (UINTN
)HostAddress
- EFI_PAGE_SIZE
653 // Check the signature.
655 ASSERT (CommonBufferHeader
->Signature
== COMMON_BUFFER_SIG
);
656 if (CommonBufferHeader
->Signature
!= COMMON_BUFFER_SIG
) {
657 return EFI_INVALID_PARAMETER
;
661 // Free the stash buffer. This buffer was always encrypted, so no need to
664 FreePages (CommonBufferHeader
->StashBuffer
, Pages
);
667 // Release the common buffer itself. Unmap() has re-encrypted it in-place, so
668 // no need to zero it.
670 return gBS
->FreePages ((UINTN
)CommonBufferHeader
, CommonBufferPages
);
675 Set IOMMU attribute for a system memory.
677 If the IOMMU protocol exists, the system memory cannot be used
680 When a device requests a DMA access for a system memory,
681 the device driver need use SetAttribute() to update the IOMMU
682 attribute to request DMA access (read and/or write).
684 The DeviceHandle is used to identify which device submits the request.
685 The IOMMU implementation need translate the device path to an IOMMU device
686 ID, and set IOMMU hardware register accordingly.
687 1) DeviceHandle can be a standard PCI device.
688 The memory for BusMasterRead need set EDKII_IOMMU_ACCESS_READ.
689 The memory for BusMasterWrite need set EDKII_IOMMU_ACCESS_WRITE.
690 The memory for BusMasterCommonBuffer need set
691 EDKII_IOMMU_ACCESS_READ|EDKII_IOMMU_ACCESS_WRITE.
692 After the memory is used, the memory need set 0 to keep it being
694 2) DeviceHandle can be an ACPI device (ISA, I2C, SPI, etc).
695 The memory for DMA access need set EDKII_IOMMU_ACCESS_READ and/or
696 EDKII_IOMMU_ACCESS_WRITE.
698 @param[in] This The protocol instance pointer.
699 @param[in] DeviceHandle The device who initiates the DMA access
701 @param[in] Mapping The mapping value returned from Map().
702 @param[in] IoMmuAccess The IOMMU access.
704 @retval EFI_SUCCESS The IoMmuAccess is set for the memory range
705 specified by DeviceAddress and Length.
706 @retval EFI_INVALID_PARAMETER DeviceHandle is an invalid handle.
707 @retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
709 @retval EFI_INVALID_PARAMETER IoMmuAccess specified an illegal combination
711 @retval EFI_UNSUPPORTED DeviceHandle is unknown by the IOMMU.
712 @retval EFI_UNSUPPORTED The bit mask of IoMmuAccess is not supported
714 @retval EFI_UNSUPPORTED The IOMMU does not support the memory range
715 specified by Mapping.
716 @retval EFI_OUT_OF_RESOURCES There are not enough resources available to
717 modify the IOMMU access.
718 @retval EFI_DEVICE_ERROR The IOMMU device reported an error while
719 attempting the operation.
725 IN EDKII_IOMMU_PROTOCOL
*This
,
726 IN EFI_HANDLE DeviceHandle
,
728 IN UINT64 IoMmuAccess
731 return EFI_UNSUPPORTED
;
734 EDKII_IOMMU_PROTOCOL mAmdSev
= {
735 EDKII_IOMMU_PROTOCOL_REVISION
,
744 Notification function that is queued when gBS->ExitBootServices() signals the
745 EFI_EVENT_GROUP_EXIT_BOOT_SERVICES event group. This function signals another
746 event, received as Context, and returns.
748 Signaling an event in this context is safe. The UEFI spec allows
749 gBS->SignalEvent() to return EFI_SUCCESS only; EFI_OUT_OF_RESOURCES is not
750 listed, hence memory is not allocated. The edk2 implementation also does not
751 release memory (and we only have to care about the edk2 implementation
752 because EDKII_IOMMU_PROTOCOL is edk2-specific anyway).
754 @param[in] Event Event whose notification function is being invoked.
755 Event is permitted to request the queueing of this
756 function at TPL_CALLBACK or TPL_NOTIFY task
759 @param[in] EventToSignal Identifies the EFI_EVENT to signal. EventToSignal
760 is permitted to request the queueing of its
761 notification function only at TPL_CALLBACK level.
768 IN VOID
*EventToSignal
772 // (1) The NotifyFunctions of all the events in
773 // EFI_EVENT_GROUP_EXIT_BOOT_SERVICES will have been queued before
774 // AmdSevExitBoot() is entered.
776 // (2) AmdSevExitBoot() is executing minimally at TPL_CALLBACK.
778 // (3) AmdSevExitBoot() has been queued in unspecified order relative to the
779 // NotifyFunctions of all the other events in
780 // EFI_EVENT_GROUP_EXIT_BOOT_SERVICES whose NotifyTpl is the same as
785 // - If Event's NotifyTpl is TPL_CALLBACK, then some other NotifyFunctions
786 // queued at TPL_CALLBACK may be invoked after AmdSevExitBoot() returns.
788 // - If Event's NotifyTpl is TPL_NOTIFY, then some other NotifyFunctions
789 // queued at TPL_NOTIFY may be invoked after AmdSevExitBoot() returns; plus
790 // *all* NotifyFunctions queued at TPL_CALLBACK will be invoked strictly
791 // after all NotifyFunctions queued at TPL_NOTIFY, including
792 // AmdSevExitBoot(), have been invoked.
794 // - By signaling EventToSignal here, whose NotifyTpl is TPL_CALLBACK, we
795 // queue EventToSignal's NotifyFunction after the NotifyFunctions of *all*
796 // events in EFI_EVENT_GROUP_EXIT_BOOT_SERVICES.
798 DEBUG ((DEBUG_VERBOSE
, "%a\n", __FUNCTION__
));
799 gBS
->SignalEvent (EventToSignal
);
803 Notification function that is queued after the notification functions of all
804 events in the EFI_EVENT_GROUP_EXIT_BOOT_SERVICES event group. The same memory
805 map restrictions apply.
807 This function unmaps all currently existing IOMMU mappings.
809 @param[in] Event Event whose notification function is being invoked. Event
810 is permitted to request the queueing of this function
811 only at TPL_CALLBACK task priority level.
813 @param[in] Context Ignored.
818 AmdSevUnmapAllMappings (
824 LIST_ENTRY
*NextNode
;
827 DEBUG ((DEBUG_VERBOSE
, "%a\n", __FUNCTION__
));
830 // All drivers that had set up IOMMU mappings have halted their respective
831 // controllers by now; tear down the mappings.
833 for (Node
= GetFirstNode (&mMapInfos
); Node
!= &mMapInfos
; Node
= NextNode
) {
834 NextNode
= GetNextNode (&mMapInfos
, Node
);
835 MapInfo
= CR (Node
, MAP_INFO
, Link
, MAP_INFO_SIG
);
839 TRUE
// MemoryMapLocked
845 Initialize Iommu Protocol.
850 AmdSevInstallIoMmuProtocol (
855 EFI_EVENT UnmapAllMappingsEvent
;
856 EFI_EVENT ExitBootEvent
;
860 // Create the "late" event whose notification function will tear down all
861 // left-over IOMMU mappings.
863 Status
= gBS
->CreateEvent (
864 EVT_NOTIFY_SIGNAL
, // Type
865 TPL_CALLBACK
, // NotifyTpl
866 AmdSevUnmapAllMappings
, // NotifyFunction
867 NULL
, // NotifyContext
868 &UnmapAllMappingsEvent
// Event
870 if (EFI_ERROR (Status
)) {
875 // Create the event whose notification function will be queued by
876 // gBS->ExitBootServices() and will signal the event created above.
878 Status
= gBS
->CreateEvent (
879 EVT_SIGNAL_EXIT_BOOT_SERVICES
, // Type
880 TPL_CALLBACK
, // NotifyTpl
881 AmdSevExitBoot
, // NotifyFunction
882 UnmapAllMappingsEvent
, // NotifyContext
883 &ExitBootEvent
// Event
885 if (EFI_ERROR (Status
)) {
886 goto CloseUnmapAllMappingsEvent
;
890 Status
= gBS
->InstallMultipleProtocolInterfaces (
892 &gEdkiiIoMmuProtocolGuid
, &mAmdSev
,
895 if (EFI_ERROR (Status
)) {
896 goto CloseExitBootEvent
;
902 gBS
->CloseEvent (ExitBootEvent
);
904 CloseUnmapAllMappingsEvent
:
905 gBS
->CloseEvent (UnmapAllMappingsEvent
);