AmdSevIoMmu.c@ 89983

Last change on this file since 89983 was 80951, checked in by vboxsync, 6 years ago
EFI/IoMmuDxe: Fix compiler warning (treated as error)
Property svn:eol-style set to `native`
File size: 28.7 KB

Line
1	/** @file
2
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.
7
8	Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
9	Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
10
11	SPDX-License-Identifier: BSD-2-Clause-Patent
12
13	**/
14
15	#include "AmdSevIoMmu.h"
16
17	#define MAP_INFO_SIG SIGNATURE_64 ('M', 'A', 'P', '_', 'I', 'N', 'F', 'O')
18
19	typedef struct {
20	UINT64 Signature;
21	LIST_ENTRY Link;
22	EDKII_IOMMU_OPERATION Operation;
23	UINTN NumberOfBytes;
24	UINTN NumberOfPages;
25	EFI_PHYSICAL_ADDRESS CryptedAddress;
26	EFI_PHYSICAL_ADDRESS PlainTextAddress;
27	} MAP_INFO;
28
29	//
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.
33	//
34	STATIC LIST_ENTRY mMapInfos = INITIALIZE_LIST_HEAD_VARIABLE (mMapInfos);
35
36	#define COMMON_BUFFER_SIG SIGNATURE_64 ('C', 'M', 'N', 'B', 'U', 'F', 'F', 'R')
37
38	#ifndef MDEPKG_NDEBUG /* VBox addition to silence compiler warnings. */
39	//
40	// ASCII names for EDKII_IOMMU_OPERATION constants, for debug logging.
41	//
42	STATIC CONST CHAR8 * CONST
43	mBusMasterOperationName[EdkiiIoMmuOperationMaximum] = {
44	"Read",
45	"Write",
46	"CommonBuffer",
47	"Read64",
48	"Write64",
49	"CommonBuffer64"
50	};
51	#endif
52
53	//
54	// The following structure enables Map() and Unmap() to perform in-place
55	// decryption and encryption, respectively, for BusMasterCommonBuffer[64]
56	// operations, without dynamic memory allocation or release.
57	//
58	// Both COMMON_BUFFER_HEADER and COMMON_BUFFER_HEADER.StashBuffer are allocated
59	// by AllocateBuffer() and released by FreeBuffer().
60	//
61	#pragma pack (1)
62	typedef struct {
63	UINT64 Signature;
64
65	//
66	// Always allocated from EfiBootServicesData type memory, and always
67	// encrypted.
68	//
69	VOID *StashBuffer;
70
71	//
72	// Followed by the actual common buffer, starting at the next page.
73	//
74	} COMMON_BUFFER_HEADER;
75	#pragma pack ()
76
77	/**
78	Provides the controller-specific addresses required to access system memory
79	from a DMA bus master. On SEV guest, the DMA operations must be performed on
80	shared buffer hence we allocate a bounce buffer to map the HostAddress to a
81	DeviceAddress. The Encryption attribute is removed from the DeviceAddress
82	buffer.
83
84	@param This The protocol instance pointer.
85	@param Operation Indicates if the bus master is going to read or
86	write to system memory.
87	@param HostAddress The system memory address to map to the PCI
88	controller.
89	@param NumberOfBytes On input the number of bytes to map. On output
90	the number of bytes that were mapped.
91	@param DeviceAddress The resulting map address for the bus master
92	PCI controller to use to access the hosts
93	HostAddress.
94	@param Mapping A resulting value to pass to Unmap().
95
96	@retval EFI_SUCCESS The range was mapped for the returned
97	NumberOfBytes.
98	@retval EFI_UNSUPPORTED The HostAddress cannot be mapped as a common
99	buffer.
100	@retval EFI_INVALID_PARAMETER One or more parameters are invalid.
101	@retval EFI_OUT_OF_RESOURCES The request could not be completed due to a
102	lack of resources.
103	@retval EFI_DEVICE_ERROR The system hardware could not map the requested
104	address.
105
106	**/
107	EFI_STATUS
108	EFIAPI
109	IoMmuMap (
110	IN EDKII_IOMMU_PROTOCOL *This,
111	IN EDKII_IOMMU_OPERATION Operation,
112	IN VOID *HostAddress,
113	IN OUT UINTN *NumberOfBytes,
114	OUT EFI_PHYSICAL_ADDRESS *DeviceAddress,
115	OUT VOID **Mapping
116	)
117	{
118	EFI_STATUS Status;
119	MAP_INFO *MapInfo;
120	EFI_ALLOCATE_TYPE AllocateType;
121	COMMON_BUFFER_HEADER *CommonBufferHeader;
122	VOID *DecryptionSource;
123
124	DEBUG ((
125	DEBUG_VERBOSE,
126	"%a: Operation=%a Host=0x%p Bytes=0x%Lx\n",
127	__FUNCTION__,
128	((Operation >= 0 &&
129	Operation < ARRAY_SIZE (mBusMasterOperationName)) ?
130	mBusMasterOperationName[Operation] :
131	"Invalid"),
132	HostAddress,
133	(UINT64)((NumberOfBytes == NULL) ? 0 : *NumberOfBytes)
134	));
135
136	if (HostAddress == NULL \|\| NumberOfBytes == NULL \|\| DeviceAddress == NULL \|\|
137	Mapping == NULL) {
138	return EFI_INVALID_PARAMETER;
139	}
140
141	//
142	// Allocate a MAP_INFO structure to remember the mapping when Unmap() is
143	// called later.
144	//
145	MapInfo = AllocatePool (sizeof (MAP_INFO));
146	if (MapInfo == NULL) {
147	Status = EFI_OUT_OF_RESOURCES;
148	goto Failed;
149	}
150
151	//
152	// Initialize the MAP_INFO structure, except the PlainTextAddress field
153	//
154	ZeroMem (&MapInfo->Link, sizeof MapInfo->Link);
155	MapInfo->Signature = MAP_INFO_SIG;
156	MapInfo->Operation = Operation;
157	MapInfo->NumberOfBytes = *NumberOfBytes;
158	MapInfo->NumberOfPages = EFI_SIZE_TO_PAGES (MapInfo->NumberOfBytes);
159	MapInfo->CryptedAddress = (UINTN)HostAddress;
160
161	//
162	// In the switch statement below, we point "MapInfo->PlainTextAddress" to the
163	// plaintext buffer, according to Operation. We also set "DecryptionSource".
164	//
165	MapInfo->PlainTextAddress = MAX_ADDRESS;
166	AllocateType = AllocateAnyPages;
167	DecryptionSource = (VOID *)(UINTN)MapInfo->CryptedAddress;
168	switch (Operation) {
169	//
170	// For BusMasterRead[64] and BusMasterWrite[64] operations, a bounce buffer
171	// is necessary regardless of whether the original (crypted) buffer crosses
172	// the 4GB limit or not -- we have to allocate a separate plaintext buffer.
173	// The only variable is whether the plaintext buffer should be under 4GB.
174	//
175	case EdkiiIoMmuOperationBusMasterRead:
176	case EdkiiIoMmuOperationBusMasterWrite:
177	MapInfo->PlainTextAddress = BASE_4GB - 1;
178	AllocateType = AllocateMaxAddress;
179	//
180	// fall through
181	//
182	case EdkiiIoMmuOperationBusMasterRead64:
183	case EdkiiIoMmuOperationBusMasterWrite64:
184	//
185	// Allocate the implicit plaintext bounce buffer.
186	//
187	Status = gBS->AllocatePages (
188	AllocateType,
189	EfiBootServicesData,
190	MapInfo->NumberOfPages,
191	&MapInfo->PlainTextAddress
192	);
193	if (EFI_ERROR (Status)) {
194	goto FreeMapInfo;
195	}
196	break;
197
198	//
199	// For BusMasterCommonBuffer[64] operations, a to-be-plaintext buffer and a
200	// stash buffer (for in-place decryption) have been allocated already, with
201	// AllocateBuffer(). We only check whether the address of the to-be-plaintext
202	// buffer is low enough for the requested operation.
203	//
204	case EdkiiIoMmuOperationBusMasterCommonBuffer:
205	if ((MapInfo->CryptedAddress > BASE_4GB) \|\|
206	(EFI_PAGES_TO_SIZE (MapInfo->NumberOfPages) >
207	BASE_4GB - MapInfo->CryptedAddress)) {
208	//
209	// CommonBuffer operations cannot be remapped. If the common buffer is
210	// above 4GB, then it is not possible to generate a mapping, so return an
211	// error.
212	//
213	Status = EFI_UNSUPPORTED;
214	goto FreeMapInfo;
215	}
216	//
217	// fall through
218	//
219	case EdkiiIoMmuOperationBusMasterCommonBuffer64:
220	//
221	// The buffer at MapInfo->CryptedAddress comes from AllocateBuffer().
222	//
223	MapInfo->PlainTextAddress = MapInfo->CryptedAddress;
224	//
225	// Stash the crypted data.
226	//
227	CommonBufferHeader = (COMMON_BUFFER_HEADER *)(
228	(UINTN)MapInfo->CryptedAddress - EFI_PAGE_SIZE
229	);
230	ASSERT (CommonBufferHeader->Signature == COMMON_BUFFER_SIG);
231	CopyMem (
232	CommonBufferHeader->StashBuffer,
233	(VOID *)(UINTN)MapInfo->CryptedAddress,
234	MapInfo->NumberOfBytes
235	);
236	//
237	// Point "DecryptionSource" to the stash buffer so that we decrypt
238	// it to the original location, after the switch statement.
239	//
240	DecryptionSource = CommonBufferHeader->StashBuffer;
241	break;
242
243	default:
244	//
245	// Operation is invalid
246	//
247	Status = EFI_INVALID_PARAMETER;
248	goto FreeMapInfo;
249	}
250
251	//
252	// Clear the memory encryption mask on the plaintext buffer.
253	//
254	Status = MemEncryptSevClearPageEncMask (
255	0,
256	MapInfo->PlainTextAddress,
257	MapInfo->NumberOfPages,
258	TRUE
259	);
260	ASSERT_EFI_ERROR (Status);
261	if (EFI_ERROR (Status)) {
262	CpuDeadLoop ();
263	}
264
265	//
266	// If this is a read operation from the Bus Master's point of view,
267	// then copy the contents of the real buffer into the mapped buffer
268	// so the Bus Master can read the contents of the real buffer.
269	//
270	// For BusMasterCommonBuffer[64] operations, the CopyMem() below will decrypt
271	// the original data (from the stash buffer) back to the original location.
272	//
273	if (Operation == EdkiiIoMmuOperationBusMasterRead \|\|
274	Operation == EdkiiIoMmuOperationBusMasterRead64 \|\|
275	Operation == EdkiiIoMmuOperationBusMasterCommonBuffer \|\|
276	Operation == EdkiiIoMmuOperationBusMasterCommonBuffer64) {
277	CopyMem (
278	(VOID *) (UINTN) MapInfo->PlainTextAddress,
279	DecryptionSource,
280	MapInfo->NumberOfBytes
281	);
282	}
283
284	//
285	// Track all MAP_INFO structures.
286	//
287	InsertHeadList (&mMapInfos, &MapInfo->Link);
288	//
289	// Populate output parameters.
290	//
291	*DeviceAddress = MapInfo->PlainTextAddress;
292	*Mapping = MapInfo;
293
294	DEBUG ((
295	DEBUG_VERBOSE,
296	"%a: Mapping=0x%p Device(PlainText)=0x%Lx Crypted=0x%Lx Pages=0x%Lx\n",
297	__FUNCTION__,
298	MapInfo,
299	MapInfo->PlainTextAddress,
300	MapInfo->CryptedAddress,
301	(UINT64)MapInfo->NumberOfPages
302	));
303
304	return EFI_SUCCESS;
305
306	FreeMapInfo:
307	FreePool (MapInfo);
308
309	Failed:
310	*NumberOfBytes = 0;
311	return Status;
312	}
313
314	/**
315	Completes the Map() operation and releases any corresponding resources.
316
317	This is an internal worker function that only extends the Map() API with
318	the MemoryMapLocked parameter.
319
320	@param This The protocol instance pointer.
321	@param Mapping The mapping value returned from Map().
322	@param MemoryMapLocked The function is executing on the stack of
323	gBS->ExitBootServices(); changes to the UEFI
324	memory map are forbidden.
325
326	@retval EFI_SUCCESS The range was unmapped.
327	@retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
328	Map().
329	@retval EFI_DEVICE_ERROR The data was not committed to the target system
330	memory.
331	**/
332	STATIC
333	EFI_STATUS
334	EFIAPI
335	IoMmuUnmapWorker (
336	IN EDKII_IOMMU_PROTOCOL *This,
337	IN VOID *Mapping,
338	IN BOOLEAN MemoryMapLocked
339	)
340	{
341	MAP_INFO *MapInfo;
342	EFI_STATUS Status;
343	COMMON_BUFFER_HEADER *CommonBufferHeader;
344	VOID *EncryptionTarget;
345
346	DEBUG ((
347	DEBUG_VERBOSE,
348	"%a: Mapping=0x%p MemoryMapLocked=%d\n",
349	__FUNCTION__,
350	Mapping,
351	MemoryMapLocked
352	));
353
354	if (Mapping == NULL) {
355	return EFI_INVALID_PARAMETER;
356	}
357
358	MapInfo = (MAP_INFO *)Mapping;
359
360	//
361	// set CommonBufferHeader to suppress incorrect compiler/analyzer warnings
362	//
363	CommonBufferHeader = NULL;
364
365	//
366	// For BusMasterWrite[64] operations and BusMasterCommonBuffer[64] operations
367	// we have to encrypt the results, ultimately to the original place (i.e.,
368	// "MapInfo->CryptedAddress").
369	//
370	// For BusMasterCommonBuffer[64] operations however, this encryption has to
371	// land in-place, so divert the encryption to the stash buffer first.
372	//
373	EncryptionTarget = (VOID *)(UINTN)MapInfo->CryptedAddress;
374
375	switch (MapInfo->Operation) {
376	case EdkiiIoMmuOperationBusMasterCommonBuffer:
377	case EdkiiIoMmuOperationBusMasterCommonBuffer64:
378	ASSERT (MapInfo->PlainTextAddress == MapInfo->CryptedAddress);
379
380	CommonBufferHeader = (COMMON_BUFFER_HEADER *)(
381	(UINTN)MapInfo->PlainTextAddress - EFI_PAGE_SIZE
382	);
383	ASSERT (CommonBufferHeader->Signature == COMMON_BUFFER_SIG);
384	EncryptionTarget = CommonBufferHeader->StashBuffer;
385	//
386	// fall through
387	//
388
389	case EdkiiIoMmuOperationBusMasterWrite:
390	case EdkiiIoMmuOperationBusMasterWrite64:
391	CopyMem (
392	EncryptionTarget,
393	(VOID *) (UINTN) MapInfo->PlainTextAddress,
394	MapInfo->NumberOfBytes
395	);
396	break;
397
398	default:
399	//
400	// nothing to encrypt after BusMasterRead[64] operations
401	//
402	break;
403	}
404
405	//
406	// Restore the memory encryption mask on the area we used to hold the
407	// plaintext.
408	//
409	Status = MemEncryptSevSetPageEncMask (
410	0,
411	MapInfo->PlainTextAddress,
412	MapInfo->NumberOfPages,
413	TRUE
414	);
415	ASSERT_EFI_ERROR (Status);
416	if (EFI_ERROR (Status)) {
417	CpuDeadLoop ();
418	}
419
420	//
421	// For BusMasterCommonBuffer[64] operations, copy the stashed data to the
422	// original (now encrypted) location.
423	//
424	// For all other operations, fill the late bounce buffer (which existed as
425	// plaintext at some point) with zeros, and then release it (unless the UEFI
426	// memory map is locked).
427	//
428	if (MapInfo->Operation == EdkiiIoMmuOperationBusMasterCommonBuffer \|\|
429	MapInfo->Operation == EdkiiIoMmuOperationBusMasterCommonBuffer64) {
430	CopyMem (
431	(VOID *)(UINTN)MapInfo->CryptedAddress,
432	CommonBufferHeader->StashBuffer,
433	MapInfo->NumberOfBytes
434	);
435	} else {
436	ZeroMem (
437	(VOID *)(UINTN)MapInfo->PlainTextAddress,
438	EFI_PAGES_TO_SIZE (MapInfo->NumberOfPages)
439	);
440	if (!MemoryMapLocked) {
441	gBS->FreePages (MapInfo->PlainTextAddress, MapInfo->NumberOfPages);
442	}
443	}
444
445	//
446	// Forget the MAP_INFO structure, then free it (unless the UEFI memory map is
447	// locked).
448	//
449	RemoveEntryList (&MapInfo->Link);
450	if (!MemoryMapLocked) {
451	FreePool (MapInfo);
452	}
453
454	return EFI_SUCCESS;
455	}
456
457	/**
458	Completes the Map() operation and releases any corresponding resources.
459
460	@param This The protocol instance pointer.
461	@param Mapping The mapping value returned from Map().
462
463	@retval EFI_SUCCESS The range was unmapped.
464	@retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
465	Map().
466	@retval EFI_DEVICE_ERROR The data was not committed to the target system
467	memory.
468	**/
469	EFI_STATUS
470	EFIAPI
471	IoMmuUnmap (
472	IN EDKII_IOMMU_PROTOCOL *This,
473	IN VOID *Mapping
474	)
475	{
476	return IoMmuUnmapWorker (
477	This,
478	Mapping,
479	FALSE // MemoryMapLocked
480	);
481	}
482
483	/**
484	Allocates pages that are suitable for an OperationBusMasterCommonBuffer or
485	OperationBusMasterCommonBuffer64 mapping.
486
487	@param This The protocol instance pointer.
488	@param Type This parameter is not used and must be ignored.
489	@param MemoryType The type of memory to allocate,
490	EfiBootServicesData or EfiRuntimeServicesData.
491	@param Pages The number of pages to allocate.
492	@param HostAddress A pointer to store the base system memory
493	address of the allocated range.
494	@param Attributes The requested bit mask of attributes for the
495	allocated range.
496
497	@retval EFI_SUCCESS The requested memory pages were allocated.
498	@retval EFI_UNSUPPORTED Attributes is unsupported. The only legal
499	attribute bits are MEMORY_WRITE_COMBINE and
500	MEMORY_CACHED.
501	@retval EFI_INVALID_PARAMETER One or more parameters are invalid.
502	@retval EFI_OUT_OF_RESOURCES The memory pages could not be allocated.
503
504	**/
505	EFI_STATUS
506	EFIAPI
507	IoMmuAllocateBuffer (
508	IN EDKII_IOMMU_PROTOCOL *This,
509	IN EFI_ALLOCATE_TYPE Type,
510	IN EFI_MEMORY_TYPE MemoryType,
511	IN UINTN Pages,
512	IN OUT VOID **HostAddress,
513	IN UINT64 Attributes
514	)
515	{
516	EFI_STATUS Status;
517	EFI_PHYSICAL_ADDRESS PhysicalAddress;
518	VOID *StashBuffer;
519	UINTN CommonBufferPages;
520	COMMON_BUFFER_HEADER *CommonBufferHeader;
521
522	DEBUG ((
523	DEBUG_VERBOSE,
524	"%a: MemoryType=%u Pages=0x%Lx Attributes=0x%Lx\n",
525	__FUNCTION__,
526	(UINT32)MemoryType,
527	(UINT64)Pages,
528	Attributes
529	));
530
531	//
532	// Validate Attributes
533	//
534	if ((Attributes & EDKII_IOMMU_ATTRIBUTE_INVALID_FOR_ALLOCATE_BUFFER) != 0) {
535	return EFI_UNSUPPORTED;
536	}
537
538	//
539	// Check for invalid inputs
540	//
541	if (HostAddress == NULL) {
542	return EFI_INVALID_PARAMETER;
543	}
544
545	//
546	// The only valid memory types are EfiBootServicesData and
547	// EfiRuntimeServicesData
548	//
549	if (MemoryType != EfiBootServicesData &&
550	MemoryType != EfiRuntimeServicesData) {
551	return EFI_INVALID_PARAMETER;
552	}
553
554	//
555	// We'll need a header page for the COMMON_BUFFER_HEADER structure.
556	//
557	if (Pages > MAX_UINTN - 1) {
558	return EFI_OUT_OF_RESOURCES;
559	}
560	CommonBufferPages = Pages + 1;
561
562	//
563	// Allocate the stash in EfiBootServicesData type memory.
564	//
565	// Map() will temporarily save encrypted data in the stash for
566	// BusMasterCommonBuffer[64] operations, so the data can be decrypted to the
567	// original location.
568	//
569	// Unmap() will temporarily save plaintext data in the stash for
570	// BusMasterCommonBuffer[64] operations, so the data can be encrypted to the
571	// original location.
572	//
573	// StashBuffer always resides in encrypted memory.
574	//
575	StashBuffer = AllocatePages (Pages);
576	if (StashBuffer == NULL) {
577	return EFI_OUT_OF_RESOURCES;
578	}
579
580	PhysicalAddress = (UINTN)-1;
581	if ((Attributes & EDKII_IOMMU_ATTRIBUTE_DUAL_ADDRESS_CYCLE) == 0) {
582	//
583	// Limit allocations to memory below 4GB
584	//
585	PhysicalAddress = SIZE_4GB - 1;
586	}
587	Status = gBS->AllocatePages (
588	AllocateMaxAddress,
589	MemoryType,
590	CommonBufferPages,
591	&PhysicalAddress
592	);
593	if (EFI_ERROR (Status)) {
594	goto FreeStashBuffer;
595	}
596
597	CommonBufferHeader = (VOID *)(UINTN)PhysicalAddress;
598	PhysicalAddress += EFI_PAGE_SIZE;
599
600	CommonBufferHeader->Signature = COMMON_BUFFER_SIG;
601	CommonBufferHeader->StashBuffer = StashBuffer;
602
603	HostAddress = (VOID )(UINTN)PhysicalAddress;
604
605	DEBUG ((
606	DEBUG_VERBOSE,
607	"%a: Host=0x%Lx Stash=0x%p\n",
608	__FUNCTION__,
609	PhysicalAddress,
610	StashBuffer
611	));
612	return EFI_SUCCESS;
613
614	FreeStashBuffer:
615	FreePages (StashBuffer, Pages);
616	return Status;
617	}
618
619	/**
620	Frees memory that was allocated with AllocateBuffer().
621
622	@param This The protocol instance pointer.
623	@param Pages The number of pages to free.
624	@param HostAddress The base system memory address of the allocated
625	range.
626
627	@retval EFI_SUCCESS The requested memory pages were freed.
628	@retval EFI_INVALID_PARAMETER The memory range specified by HostAddress and
629	Pages was not allocated with AllocateBuffer().
630
631	**/
632	EFI_STATUS
633	EFIAPI
634	IoMmuFreeBuffer (
635	IN EDKII_IOMMU_PROTOCOL *This,
636	IN UINTN Pages,
637	IN VOID *HostAddress
638	)
639	{
640	UINTN CommonBufferPages;
641	COMMON_BUFFER_HEADER *CommonBufferHeader;
642
643	DEBUG ((
644	DEBUG_VERBOSE,
645	"%a: Host=0x%p Pages=0x%Lx\n",
646	__FUNCTION__,
647	HostAddress,
648	(UINT64)Pages
649	));
650
651	CommonBufferPages = Pages + 1;
652	CommonBufferHeader = (COMMON_BUFFER_HEADER *)(
653	(UINTN)HostAddress - EFI_PAGE_SIZE
654	);
655
656	//
657	// Check the signature.
658	//
659	ASSERT (CommonBufferHeader->Signature == COMMON_BUFFER_SIG);
660	if (CommonBufferHeader->Signature != COMMON_BUFFER_SIG) {
661	return EFI_INVALID_PARAMETER;
662	}
663
664	//
665	// Free the stash buffer. This buffer was always encrypted, so no need to
666	// zero it.
667	//
668	FreePages (CommonBufferHeader->StashBuffer, Pages);
669
670	//
671	// Release the common buffer itself. Unmap() has re-encrypted it in-place, so
672	// no need to zero it.
673	//
674	return gBS->FreePages ((UINTN)CommonBufferHeader, CommonBufferPages);
675	}
676
677
678	/**
679	Set IOMMU attribute for a system memory.
680
681	If the IOMMU protocol exists, the system memory cannot be used
682	for DMA by default.
683
684	When a device requests a DMA access for a system memory,
685	the device driver need use SetAttribute() to update the IOMMU
686	attribute to request DMA access (read and/or write).
687
688	The DeviceHandle is used to identify which device submits the request.
689	The IOMMU implementation need translate the device path to an IOMMU device
690	ID, and set IOMMU hardware register accordingly.
691	1) DeviceHandle can be a standard PCI device.
692	The memory for BusMasterRead need set EDKII_IOMMU_ACCESS_READ.
693	The memory for BusMasterWrite need set EDKII_IOMMU_ACCESS_WRITE.
694	The memory for BusMasterCommonBuffer need set
695	EDKII_IOMMU_ACCESS_READ\|EDKII_IOMMU_ACCESS_WRITE.
696	After the memory is used, the memory need set 0 to keep it being
697	protected.
698	2) DeviceHandle can be an ACPI device (ISA, I2C, SPI, etc).
699	The memory for DMA access need set EDKII_IOMMU_ACCESS_READ and/or
700	EDKII_IOMMU_ACCESS_WRITE.
701
702	@param[in] This The protocol instance pointer.
703	@param[in] DeviceHandle The device who initiates the DMA access
704	request.
705	@param[in] Mapping The mapping value returned from Map().
706	@param[in] IoMmuAccess The IOMMU access.
707
708	@retval EFI_SUCCESS The IoMmuAccess is set for the memory range
709	specified by DeviceAddress and Length.
710	@retval EFI_INVALID_PARAMETER DeviceHandle is an invalid handle.
711	@retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
712	Map().
713	@retval EFI_INVALID_PARAMETER IoMmuAccess specified an illegal combination
714	of access.
715	@retval EFI_UNSUPPORTED DeviceHandle is unknown by the IOMMU.
716	@retval EFI_UNSUPPORTED The bit mask of IoMmuAccess is not supported
717	by the IOMMU.
718	@retval EFI_UNSUPPORTED The IOMMU does not support the memory range
719	specified by Mapping.
720	@retval EFI_OUT_OF_RESOURCES There are not enough resources available to
721	modify the IOMMU access.
722	@retval EFI_DEVICE_ERROR The IOMMU device reported an error while
723	attempting the operation.
724
725	**/
726	EFI_STATUS
727	EFIAPI
728	IoMmuSetAttribute (
729	IN EDKII_IOMMU_PROTOCOL *This,
730	IN EFI_HANDLE DeviceHandle,
731	IN VOID *Mapping,
732	IN UINT64 IoMmuAccess
733	)
734	{
735	return EFI_UNSUPPORTED;
736	}
737
738	EDKII_IOMMU_PROTOCOL mAmdSev = {
739	EDKII_IOMMU_PROTOCOL_REVISION,
740	IoMmuSetAttribute,
741	IoMmuMap,
742	IoMmuUnmap,
743	IoMmuAllocateBuffer,
744	IoMmuFreeBuffer,
745	};
746
747	/**
748	Notification function that is queued when gBS->ExitBootServices() signals the
749	EFI_EVENT_GROUP_EXIT_BOOT_SERVICES event group. This function signals another
750	event, received as Context, and returns.
751
752	Signaling an event in this context is safe. The UEFI spec allows
753	gBS->SignalEvent() to return EFI_SUCCESS only; EFI_OUT_OF_RESOURCES is not
754	listed, hence memory is not allocated. The edk2 implementation also does not
755	release memory (and we only have to care about the edk2 implementation
756	because EDKII_IOMMU_PROTOCOL is edk2-specific anyway).
757
758	@param[in] Event Event whose notification function is being invoked.
759	Event is permitted to request the queueing of this
760	function at TPL_CALLBACK or TPL_NOTIFY task
761	priority level.
762
763	@param[in] EventToSignal Identifies the EFI_EVENT to signal. EventToSignal
764	is permitted to request the queueing of its
765	notification function only at TPL_CALLBACK level.
766	**/
767	STATIC
768	VOID
769	EFIAPI
770	AmdSevExitBoot (
771	IN EFI_EVENT Event,
772	IN VOID *EventToSignal
773	)
774	{
775	//
776	// (1) The NotifyFunctions of all the events in
777	// EFI_EVENT_GROUP_EXIT_BOOT_SERVICES will have been queued before
778	// AmdSevExitBoot() is entered.
779	//
780	// (2) AmdSevExitBoot() is executing minimally at TPL_CALLBACK.
781	//
782	// (3) AmdSevExitBoot() has been queued in unspecified order relative to the
783	// NotifyFunctions of all the other events in
784	// EFI_EVENT_GROUP_EXIT_BOOT_SERVICES whose NotifyTpl is the same as
785	// Event's.
786	//
787	// Consequences:
788	//
789	// - If Event's NotifyTpl is TPL_CALLBACK, then some other NotifyFunctions
790	// queued at TPL_CALLBACK may be invoked after AmdSevExitBoot() returns.
791	//
792	// - If Event's NotifyTpl is TPL_NOTIFY, then some other NotifyFunctions
793	// queued at TPL_NOTIFY may be invoked after AmdSevExitBoot() returns; plus
794	// all NotifyFunctions queued at TPL_CALLBACK will be invoked strictly
795	// after all NotifyFunctions queued at TPL_NOTIFY, including
796	// AmdSevExitBoot(), have been invoked.
797	//
798	// - By signaling EventToSignal here, whose NotifyTpl is TPL_CALLBACK, we
799	// queue EventToSignal's NotifyFunction after the NotifyFunctions of all
800	// events in EFI_EVENT_GROUP_EXIT_BOOT_SERVICES.
801	//
802	DEBUG ((DEBUG_VERBOSE, "%a\n", __FUNCTION__));
803	gBS->SignalEvent (EventToSignal);
804	}
805
806	/**
807	Notification function that is queued after the notification functions of all
808	events in the EFI_EVENT_GROUP_EXIT_BOOT_SERVICES event group. The same memory
809	map restrictions apply.
810
811	This function unmaps all currently existing IOMMU mappings.
812
813	@param[in] Event Event whose notification function is being invoked. Event
814	is permitted to request the queueing of this function
815	only at TPL_CALLBACK task priority level.
816
817	@param[in] Context Ignored.
818	**/
819	STATIC
820	VOID
821	EFIAPI
822	AmdSevUnmapAllMappings (
823	IN EFI_EVENT Event,
824	IN VOID *Context
825	)
826	{
827	LIST_ENTRY *Node;
828	LIST_ENTRY *NextNode;
829	MAP_INFO *MapInfo;
830
831	DEBUG ((DEBUG_VERBOSE, "%a\n", __FUNCTION__));
832
833	//
834	// All drivers that had set up IOMMU mappings have halted their respective
835	// controllers by now; tear down the mappings.
836	//
837	for (Node = GetFirstNode (&mMapInfos); Node != &mMapInfos; Node = NextNode) {
838	NextNode = GetNextNode (&mMapInfos, Node);
839	MapInfo = CR (Node, MAP_INFO, Link, MAP_INFO_SIG);
840	IoMmuUnmapWorker (
841	&mAmdSev, // This
842	MapInfo, // Mapping
843	TRUE // MemoryMapLocked
844	);
845	}
846	}
847
848	/**
849	Initialize Iommu Protocol.
850
851	**/
852	EFI_STATUS
853	EFIAPI
854	AmdSevInstallIoMmuProtocol (
855	VOID
856	)
857	{
858	EFI_STATUS Status;
859	EFI_EVENT UnmapAllMappingsEvent;
860	EFI_EVENT ExitBootEvent;
861	EFI_HANDLE Handle;
862
863	//
864	// Create the "late" event whose notification function will tear down all
865	// left-over IOMMU mappings.
866	//
867	Status = gBS->CreateEvent (
868	EVT_NOTIFY_SIGNAL, // Type
869	TPL_CALLBACK, // NotifyTpl
870	AmdSevUnmapAllMappings, // NotifyFunction
871	NULL, // NotifyContext
872	&UnmapAllMappingsEvent // Event
873	);
874	if (EFI_ERROR (Status)) {
875	return Status;
876	}
877
878	//
879	// Create the event whose notification function will be queued by
880	// gBS->ExitBootServices() and will signal the event created above.
881	//
882	Status = gBS->CreateEvent (
883	EVT_SIGNAL_EXIT_BOOT_SERVICES, // Type
884	TPL_CALLBACK, // NotifyTpl
885	AmdSevExitBoot, // NotifyFunction
886	UnmapAllMappingsEvent, // NotifyContext
887	&ExitBootEvent // Event
888	);
889	if (EFI_ERROR (Status)) {
890	goto CloseUnmapAllMappingsEvent;
891	}
892
893	Handle = NULL;
894	Status = gBS->InstallMultipleProtocolInterfaces (
895	&Handle,
896	&gEdkiiIoMmuProtocolGuid, &mAmdSev,
897	NULL
898	);
899	if (EFI_ERROR (Status)) {
900	goto CloseExitBootEvent;
901	}
902
903	return EFI_SUCCESS;
904
905	CloseExitBootEvent:
906	gBS->CloseEvent (ExitBootEvent);
907
908	CloseUnmapAllMappingsEvent:
909	gBS->CloseEvent (UnmapAllMappingsEvent);
910
911	return Status;
912	}

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source: vbox/trunk/src/VBox/Devices/EFI/FirmwareNew/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c@ 89983

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