From: "Yao, Jiewen" <jiewen.yao@intel.com>
To: Tom Lendacky <thomas.lendacky@amd.com>,
"Xu, Min M" <min.m.xu@intel.com>,
"devel@edk2.groups.io" <devel@edk2.groups.io>
Cc: "Aktas, Erdem" <erdemaktas@google.com>,
James Bottomley <jejb@linux.ibm.com>,
Gerd Hoffmann <kraxel@redhat.com>
Subject: Re: [PATCH V1 1/3] OvmfPkg/IoMmuDxe: Reserve shared memory region for DMA operation
Date: Mon, 5 Dec 2022 17:21:19 +0000 [thread overview]
Message-ID: <MW4PR11MB58722688E09DA1AD4AD3AE928C189@MW4PR11MB5872.namprd11.prod.outlook.com> (raw)
In-Reply-To: <73a15a50-7657-479f-0cf8-6b8ef44db0cb@amd.com>
I suggest it be in same PR, and different patch. (E.g. the last one for SEV)
> -----Original Message-----
> From: Tom Lendacky <thomas.lendacky@amd.com>
> Sent: Tuesday, December 6, 2022 12:48 AM
> To: Xu, Min M <min.m.xu@intel.com>; devel@edk2.groups.io
> Cc: Aktas, Erdem <erdemaktas@google.com>; James Bottomley
> <jejb@linux.ibm.com>; Yao, Jiewen <jiewen.yao@intel.com>; Gerd
> Hoffmann <kraxel@redhat.com>
> Subject: Re: [PATCH V1 1/3] OvmfPkg/IoMmuDxe: Reserve shared memory
> region for DMA operation
>
> On 12/5/22 02:08, Min Xu wrote:
> > From: Min M Xu <min.m.xu@intel.com>
> >
> > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4171
> >
> > A typical QEMU fw_cfg read bytes with IOMMU for td guest is that:
> > (QemuFwCfgReadBytes@QemuFwCfgLib.c is the example)
> > 1) Allocate DMA Access buffer
> > 2) Map actual data buffer
> > 3) start the transfer and wait for the transfer to complete
> > 4) Free DMA Access buffer
> > 5) Un-map actual data buffer
> >
> > In step 1/2, Private memories are allocated, converted to shared
> memories.
> > In Step 4/5 the shared memories are converted to private memories and
> > accepted again. The final step is to free the pages.
> >
> > This is time-consuming and impacts td guest's boot perf (both direct boot
> > and grub boot) badly.
> >
> > In a typical grub boot, there are about 5000 calls of page allocation and
> > private/share conversion. Most of page size is less than 32KB.
> >
> > This patch allocates a memory region and initializes it into pieces of
> > memory with different sizes. A piece of such memory consists of 2 parts:
> > the first page is of private memory, and the other pages are shared
> > memory. This is to meet the layout of common buffer.
> >
> > When allocating bounce buffer in IoMmuMap(),
> IoMmuAllocateBounceBuffer()
> > is called to allocate the buffer. Accordingly when freeing bounce buffer
> > in IoMmuUnmapWorker(), IoMmuFreeBounceBuffer() is called to free the
> > bounce buffer. CommonBuffer is allocated by
> IoMmuAllocateCommonBuffer
> > and accordingly freed by IoMmuFreeCommonBuffer.
> >
> > This feature is tested in Intel TDX pre-production platform. It saves up
> > to hundreds of ms in a grub boot.
>
> This crashes SEV guests. I presume because the call to
> IoMmuReleaseReservedSharedMem() is not bracketed by a check for TDX.
>
> I plan to add support for SEV, which would avoid the crash, not sure if
> you want to integrate it into a single series or not. Here's the patch I
> was looking to add that should be pretty easy to integrate. Let me know if
> you would like to integrate it in your series or just have me submit it as
> a reply to your series:
>
>
> OvmfPkg/IoMmuDxe: Add SEV support for reserved shared memory
>
> From: Tom Lendacky <thomas.lendacky@amd.com>
>
> Add support to use the reserved shared memory within the IoMmu library.
> This improves boot times for all SEV guests, with SEV-SNP benefiting the
> most as it avoids the page state change call to the hypervisor.
>
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
> OvmfPkg/IoMmuDxe/CcIoMmu.c | 82 ++++++++++++++++++++---------
> -----------
> OvmfPkg/IoMmuDxe/IoMmuBuffer.c | 54 ++++++++++++++++++++------
> 2 files changed, 83 insertions(+), 53 deletions(-)
>
> diff --git a/OvmfPkg/IoMmuDxe/CcIoMmu.c
> b/OvmfPkg/IoMmuDxe/CcIoMmu.c
> index 1479af469881..7c2843cd238a 100644
> --- a/OvmfPkg/IoMmuDxe/CcIoMmu.c
> +++ b/OvmfPkg/IoMmuDxe/CcIoMmu.c
> @@ -223,30 +223,32 @@ IoMmuMap (
> goto FreeMapInfo;
> }
>
> - if (CC_GUEST_IS_SEV (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
> + if (MapInfo->ReservedMemBitmap == 0) {
> //
> - // Clear the memory encryption mask on the plaintext buffer.
> - //
> - Status = MemEncryptSevClearPageEncMask (
> - 0,
> - MapInfo->PlainTextAddress,
> - MapInfo->NumberOfPages
> - );
> - } else if (CC_GUEST_IS_TDX (PcdGet64
> (PcdConfidentialComputingGuestAttr))) {
> - //
> - // Set the memory shared bit.
> // If MapInfo->ReservedMemBitmap is 0, it means the bounce buffer is
> not allocated
> // from the pre-allocated shared memory, so it must be converted to
> shared memory here.
> //
> - if (MapInfo->ReservedMemBitmap == 0) {
> + if (CC_GUEST_IS_SEV (PcdGet64 (PcdConfidentialComputingGuestAttr)))
> {
> + //
> + // Clear the memory encryption mask on the plaintext buffer.
> + //
> + Status = MemEncryptSevClearPageEncMask (
> + 0,
> + MapInfo->PlainTextAddress,
> + MapInfo->NumberOfPages
> + );
> + } else if (CC_GUEST_IS_TDX (PcdGet64
> (PcdConfidentialComputingGuestAttr))) {
> + //
> + // Set the memory shared bit.
> + //
> Status = MemEncryptTdxSetPageSharedBit (
> 0,
> MapInfo->PlainTextAddress,
> MapInfo->NumberOfPages
> );
> + } else {
> + ASSERT (FALSE);
> }
> - } else {
> - ASSERT (FALSE);
> }
>
> ASSERT_EFI_ERROR (Status);
> @@ -396,30 +398,30 @@ IoMmuUnmapWorker (
> break;
> }
>
> - if (CC_GUEST_IS_SEV (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
> - //
> - // Restore the memory encryption mask on the area we used to hold the
> - // plaintext.
> - //
> - Status = MemEncryptSevSetPageEncMask (
> - 0,
> - MapInfo->PlainTextAddress,
> - MapInfo->NumberOfPages
> - );
> - } else if (CC_GUEST_IS_TDX (PcdGet64
> (PcdConfidentialComputingGuestAttr))) {
> - //
> - // Restore the memory shared bit mask on the area we used to hold the
> - // plaintext.
> - //
> - if (MapInfo->ReservedMemBitmap == 0) {
> + if (MapInfo->ReservedMemBitmap == 0) {
> + if (CC_GUEST_IS_SEV (PcdGet64 (PcdConfidentialComputingGuestAttr)))
> {
> + //
> + // Restore the memory encryption mask on the area we used to hold
> the
> + // plaintext.
> + //
> + Status = MemEncryptSevSetPageEncMask (
> + 0,
> + MapInfo->PlainTextAddress,
> + MapInfo->NumberOfPages
> + );
> + } else if (CC_GUEST_IS_TDX (PcdGet64
> (PcdConfidentialComputingGuestAttr))) {
> + //
> + // Restore the memory shared bit mask on the area we used to hold
> the
> + // plaintext.
> + //
> Status = MemEncryptTdxClearPageSharedBit (
> 0,
> MapInfo->PlainTextAddress,
> MapInfo->NumberOfPages
> );
> + } else {
> + ASSERT (FALSE);
> }
> - } else {
> - ASSERT (FALSE);
> }
>
> ASSERT_EFI_ERROR (Status);
> @@ -924,16 +926,14 @@ InstallIoMmuProtocol (
> }
>
> //
> - // Currently only Tdx guest support Reserved shared memory for DMA
> operation.
> + // For CC guests, use reserved shared memory for DMA operation.
> //
> - if (CC_GUEST_IS_TDX (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
> - mReservedSharedMemSupported = TRUE;
> - Status = IoMmuInitReservedSharedMem ();
> - if (EFI_ERROR (Status)) {
> - mReservedSharedMemSupported = FALSE;
> - } else {
> - DEBUG ((DEBUG_INFO, "%a: Feature of reserved memory for DMA is
> supported.\n", __FUNCTION__));
> - }
> + mReservedSharedMemSupported = TRUE;
> + Status = IoMmuInitReservedSharedMem ();
> + if (EFI_ERROR (Status)) {
> + mReservedSharedMemSupported = FALSE;
> + } else {
> + DEBUG ((DEBUG_INFO, "%a: Feature of reserved memory for DMA is
> supported.\n", __FUNCTION__));
> }
>
> return EFI_SUCCESS;
> diff --git a/OvmfPkg/IoMmuDxe/IoMmuBuffer.c
> b/OvmfPkg/IoMmuDxe/IoMmuBuffer.c
> index 5ada8e9d57bd..d69969b6b763 100644
> --- a/OvmfPkg/IoMmuDxe/IoMmuBuffer.c
> +++ b/OvmfPkg/IoMmuDxe/IoMmuBuffer.c
> @@ -9,7 +9,9 @@
> #include <Library/BaseMemoryLib.h>
> #include <Library/DebugLib.h>
> #include <Library/MemoryAllocationLib.h>
> +#include <Library/MemEncryptSevLib.h>
> #include <Library/MemEncryptTdxLib.h>
> +#include <Library/PcdLib.h>
> #include <Library/UefiBootServicesTableLib.h>
> #include "IoMmuInternal.h"
>
> @@ -105,6 +107,7 @@ IoMmuInitReservedSharedMem (
> UINTN TotalPages;
> IOMMU_RESERVED_MEM_RANGE *MemRange;
> EFI_PHYSICAL_ADDRESS PhysicalAddress;
> + UINT64 SharedAddress;
>
> if (!mReservedSharedMemSupported) {
> return EFI_UNSUPPORTED;
> @@ -129,12 +132,25 @@ IoMmuInitReservedSharedMem (
> MemRange->StartAddressOfMemRange = PhysicalAddress;
>
> for (Index2 = 0; Index2 < MemRange->Slots; Index2++) {
> - Status = MemEncryptTdxSetPageSharedBit (
> - 0,
> - (UINT64)(UINTN)(MemRange->StartAddressOfMemRange +
> Index2 * SIZE_OF_MEM_RANGE (MemRange) + MemRange->HeaderSize),
> - EFI_SIZE_TO_PAGES (MemRange->DataSize)
> - );
> - ASSERT (!EFI_ERROR (Status));
> + SharedAddress = (UINT64)(UINTN)(MemRange-
> >StartAddressOfMemRange + Index2 * SIZE_OF_MEM_RANGE (MemRange)
> + MemRange->HeaderSize);
> +
> + if (CC_GUEST_IS_SEV (PcdGet64
> (PcdConfidentialComputingGuestAttr))) {
> + Status = MemEncryptSevClearPageEncMask (
> + 0,
> + SharedAddress,
> + EFI_SIZE_TO_PAGES (MemRange->DataSize)
> + );
> + ASSERT (!EFI_ERROR (Status));
> + } else if (CC_GUEST_IS_TDX (PcdGet64
> (PcdConfidentialComputingGuestAttr))) {
> + Status = MemEncryptTdxSetPageSharedBit (
> + 0,
> + SharedAddress,
> + EFI_SIZE_TO_PAGES (MemRange->DataSize)
> + );
> + ASSERT (!EFI_ERROR (Status));
> + } else {
> + ASSERT (FALSE);
> + }
> }
>
> PhysicalAddress += (MemRange->Slots * SIZE_OF_MEM_RANGE
> (MemRange));
> @@ -156,16 +172,30 @@ IoMmuReleaseReservedSharedMem (
> EFI_STATUS Status;
> UINT32 Index1, Index2;
> IOMMU_RESERVED_MEM_RANGE *MemRange;
> + UINT64 SharedAddress;
>
> for (Index1 = 0; Index1 < ARRAY_SIZE (mReservedMemRanges); Index1++)
> {
> MemRange = &mReservedMemRanges[Index1];
> for (Index2 = 0; Index2 < MemRange->Slots; Index2++) {
> - Status = MemEncryptTdxClearPageSharedBit (
> - 0,
> - (UINT64)(UINTN)(MemRange->StartAddressOfMemRange +
> Index2 * SIZE_OF_MEM_RANGE (MemRange) + MemRange->HeaderSize),
> - EFI_SIZE_TO_PAGES (MemRange->DataSize)
> - );
> - ASSERT (!EFI_ERROR (Status));
> + SharedAddress = (UINT64)(UINTN)(MemRange-
> >StartAddressOfMemRange + Index2 * SIZE_OF_MEM_RANGE (MemRange)
> + MemRange->HeaderSize);
> +
> + if (CC_GUEST_IS_SEV (PcdGet64
> (PcdConfidentialComputingGuestAttr))) {
> + Status = MemEncryptSevSetPageEncMask (
> + 0,
> + SharedAddress,
> + EFI_SIZE_TO_PAGES (MemRange->DataSize)
> + );
> + ASSERT (!EFI_ERROR (Status));
> + } else if (CC_GUEST_IS_TDX (PcdGet64
> (PcdConfidentialComputingGuestAttr))) {
> + Status = MemEncryptTdxClearPageSharedBit (
> + 0,
> + SharedAddress,
> + EFI_SIZE_TO_PAGES (MemRange->DataSize)
> + );
> + ASSERT (!EFI_ERROR (Status));
> + } else {
> + ASSERT (FALSE);
> + }
> }
> }
>
>
> >
> > Cc: Erdem Aktas <erdemaktas@google.com>
> > Cc: James Bottomley <jejb@linux.ibm.com>
> > Cc: Jiewen Yao <jiewen.yao@intel.com>
> > Cc: Tom Lendacky <thomas.lendacky@amd.com>
> > Cc: Gerd Hoffmann <kraxel@redhat.com>
> > Signed-off-by: Min Xu <min.m.xu@intel.com>
> > ---
> > OvmfPkg/IoMmuDxe/AmdSevIoMmu.c | 142 +++++------
> > OvmfPkg/IoMmuDxe/IoMmuBuffer.c | 425
> +++++++++++++++++++++++++++++++
> > OvmfPkg/IoMmuDxe/IoMmuDxe.inf | 1 +
> > OvmfPkg/IoMmuDxe/IoMmuInternal.h | 179 +++++++++++++
> > 4 files changed, 676 insertions(+), 71 deletions(-)
> > create mode 100644 OvmfPkg/IoMmuDxe/IoMmuBuffer.c
> > create mode 100644 OvmfPkg/IoMmuDxe/IoMmuInternal.h
> >
> > diff --git a/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c
> b/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c
> > index 6b65897f032a..77e46bbf4a60 100644
> > --- a/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c
> > +++ b/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c
> > @@ -15,18 +15,7 @@
> > #include <Library/PcdLib.h>
> > #include <ConfidentialComputingGuestAttr.h>
> > #include "AmdSevIoMmu.h"
> > -
> > -#define MAP_INFO_SIG SIGNATURE_64 ('M', 'A', 'P', '_', 'I', 'N', 'F', 'O')
> > -
> > -typedef struct {
> > - UINT64 Signature;
> > - LIST_ENTRY Link;
> > - EDKII_IOMMU_OPERATION Operation;
> > - UINTN NumberOfBytes;
> > - UINTN NumberOfPages;
> > - EFI_PHYSICAL_ADDRESS CryptedAddress;
> > - EFI_PHYSICAL_ADDRESS PlainTextAddress;
> > -} MAP_INFO;
> > +#include "IoMmuInternal.h"
> >
> > //
> > // List of the MAP_INFO structures that have been set up by
> IoMmuMap() and not
> > @@ -35,7 +24,10 @@ typedef struct {
> > //
> > STATIC LIST_ENTRY mMapInfos = INITIALIZE_LIST_HEAD_VARIABLE
> (mMapInfos);
> >
> > -#define COMMON_BUFFER_SIG SIGNATURE_64 ('C', 'M', 'N', 'B', 'U', 'F',
> 'F', 'R')
> > +//
> > +// Indicate if the feature of reserved memory is supported in DMA
> operation.
> > +//
> > +BOOLEAN mReservedSharedMemSupported = FALSE;
> >
> > //
> > // ASCII names for EDKII_IOMMU_OPERATION constants, for debug
> logging.
> > @@ -50,30 +42,6 @@
> mBusMasterOperationName[EdkiiIoMmuOperationMaximum] = {
> > "CommonBuffer64"
> > };
> >
> > -//
> > -// The following structure enables Map() and Unmap() to perform in-
> place
> > -// decryption and encryption, respectively, for
> BusMasterCommonBuffer[64]
> > -// operations, without dynamic memory allocation or release.
> > -//
> > -// Both COMMON_BUFFER_HEADER and
> COMMON_BUFFER_HEADER.StashBuffer are allocated
> > -// by AllocateBuffer() and released by FreeBuffer().
> > -//
> > -#pragma pack (1)
> > -typedef struct {
> > - UINT64 Signature;
> > -
> > - //
> > - // Always allocated from EfiBootServicesData type memory, and always
> > - // encrypted.
> > - //
> > - VOID *StashBuffer;
> > -
> > - //
> > - // Followed by the actual common buffer, starting at the next page.
> > - //
> > -} COMMON_BUFFER_HEADER;
> > -#pragma pack ()
> > -
> > /**
> > Provides the controller-specific addresses required to access system
> memory
> > from a DMA bus master. On SEV/TDX guest, the DMA operations must
> be performed on
> > @@ -139,6 +107,8 @@ IoMmuMap (
> > return EFI_INVALID_PARAMETER;
> > }
> >
> > + Status = EFI_SUCCESS;
> > +
> > //
> > // Allocate a MAP_INFO structure to remember the mapping when
> Unmap() is
> > // called later.
> > @@ -153,11 +123,12 @@ IoMmuMap (
> > // Initialize the MAP_INFO structure, except the PlainTextAddress field
> > //
> > ZeroMem (&MapInfo->Link, sizeof MapInfo->Link);
> > - MapInfo->Signature = MAP_INFO_SIG;
> > - MapInfo->Operation = Operation;
> > - MapInfo->NumberOfBytes = *NumberOfBytes;
> > - MapInfo->NumberOfPages = EFI_SIZE_TO_PAGES (MapInfo-
> >NumberOfBytes);
> > - MapInfo->CryptedAddress = (UINTN)HostAddress;
> > + MapInfo->Signature = MAP_INFO_SIG;
> > + MapInfo->Operation = Operation;
> > + MapInfo->NumberOfBytes = *NumberOfBytes;
> > + MapInfo->NumberOfPages = EFI_SIZE_TO_PAGES (MapInfo-
> >NumberOfBytes);
> > + MapInfo->CryptedAddress = (UINTN)HostAddress;
> > + MapInfo->ReservedMemBitmap = 0;
> >
> > //
> > // In the switch statement below, we point "MapInfo-
> >PlainTextAddress" to the
> > @@ -185,12 +156,11 @@ IoMmuMap (
> > //
> > // Allocate the implicit plaintext bounce buffer.
> > //
> > - Status = gBS->AllocatePages (
> > - AllocateType,
> > - EfiBootServicesData,
> > - MapInfo->NumberOfPages,
> > - &MapInfo->PlainTextAddress
> > - );
> > + Status = IoMmuAllocateBounceBuffer (
> > + AllocateType,
> > + EfiBootServicesData,
> > + MapInfo
> > + );
> > if (EFI_ERROR (Status)) {
> > goto FreeMapInfo;
> > }
> > @@ -241,7 +211,8 @@ IoMmuMap (
> > // Point "DecryptionSource" to the stash buffer so that we decrypt
> > // it to the original location, after the switch statement.
> > //
> > - DecryptionSource = CommonBufferHeader->StashBuffer;
> > + DecryptionSource = CommonBufferHeader->StashBuffer;
> > + MapInfo->ReservedMemBitmap = CommonBufferHeader-
> >ReservedMemBitmap;
> > break;
> >
> > default:
> > @@ -264,12 +235,16 @@ IoMmuMap (
> > } else if (CC_GUEST_IS_TDX (PcdGet64
> (PcdConfidentialComputingGuestAttr))) {
> > //
> > // Set the memory shared bit.
> > + // If MapInfo->ReservedMemBitmap is 0, it means the bounce buffer
> is not allocated
> > + // from the pre-allocated shared memory, so it must be converted to
> shared memory here.
> > //
> > - Status = MemEncryptTdxSetPageSharedBit (
> > - 0,
> > - MapInfo->PlainTextAddress,
> > - MapInfo->NumberOfPages
> > - );
> > + if (MapInfo->ReservedMemBitmap == 0) {
> > + Status = MemEncryptTdxSetPageSharedBit (
> > + 0,
> > + MapInfo->PlainTextAddress,
> > + MapInfo->NumberOfPages
> > + );
> > + }
> > } else {
> > ASSERT (FALSE);
> > }
> > @@ -311,12 +286,13 @@ IoMmuMap (
> >
> > DEBUG ((
> > DEBUG_VERBOSE,
> > - "%a: Mapping=0x%p Device(PlainText)=0x%Lx Crypted=0x%Lx
> Pages=0x%Lx\n",
> > + "%a: Mapping=0x%p Device(PlainText)=0x%Lx Crypted=0x%Lx
> Pages=0x%Lx, ReservedMemBitmap=0x%Lx\n",
> > __FUNCTION__,
> > MapInfo,
> > MapInfo->PlainTextAddress,
> > MapInfo->CryptedAddress,
> > - (UINT64)MapInfo->NumberOfPages
> > + (UINT64)MapInfo->NumberOfPages,
> > + MapInfo->ReservedMemBitmap
> > ));
> >
> > return EFI_SUCCESS;
> > @@ -435,11 +411,13 @@ IoMmuUnmapWorker (
> > // Restore the memory shared bit mask on the area we used to hold
> the
> > // plaintext.
> > //
> > - Status = MemEncryptTdxClearPageSharedBit (
> > - 0,
> > - MapInfo->PlainTextAddress,
> > - MapInfo->NumberOfPages
> > - );
> > + if (MapInfo->ReservedMemBitmap == 0) {
> > + Status = MemEncryptTdxClearPageSharedBit (
> > + 0,
> > + MapInfo->PlainTextAddress,
> > + MapInfo->NumberOfPages
> > + );
> > + }
> > } else {
> > ASSERT (FALSE);
> > }
> > @@ -470,8 +448,9 @@ IoMmuUnmapWorker (
> > (VOID *)(UINTN)MapInfo->PlainTextAddress,
> > EFI_PAGES_TO_SIZE (MapInfo->NumberOfPages)
> > );
> > +
> > if (!MemoryMapLocked) {
> > - gBS->FreePages (MapInfo->PlainTextAddress, MapInfo-
> >NumberOfPages);
> > + IoMmuFreeBounceBuffer (MapInfo);
> > }
> > }
> >
> > @@ -551,6 +530,7 @@ IoMmuAllocateBuffer (
> > VOID *StashBuffer;
> > UINTN CommonBufferPages;
> > COMMON_BUFFER_HEADER *CommonBufferHeader;
> > + UINT32 ReservedMemBitmap;
> >
> > DEBUG ((
> > DEBUG_VERBOSE,
> > @@ -620,12 +600,13 @@ IoMmuAllocateBuffer (
> > PhysicalAddress = SIZE_4GB - 1;
> > }
> >
> > - Status = gBS->AllocatePages (
> > - AllocateMaxAddress,
> > - MemoryType,
> > - CommonBufferPages,
> > - &PhysicalAddress
> > - );
> > + Status = IoMmuAllocateCommonBuffer (
> > + MemoryType,
> > + CommonBufferPages,
> > + &PhysicalAddress,
> > + &ReservedMemBitmap
> > + );
> > +
> > if (EFI_ERROR (Status)) {
> > goto FreeStashBuffer;
> > }
> > @@ -633,8 +614,9 @@ IoMmuAllocateBuffer (
> > CommonBufferHeader = (VOID *)(UINTN)PhysicalAddress;
> > PhysicalAddress += EFI_PAGE_SIZE;
> >
> > - CommonBufferHeader->Signature = COMMON_BUFFER_SIG;
> > - CommonBufferHeader->StashBuffer = StashBuffer;
> > + CommonBufferHeader->Signature = COMMON_BUFFER_SIG;
> > + CommonBufferHeader->StashBuffer = StashBuffer;
> > + CommonBufferHeader->ReservedMemBitmap = ReservedMemBitmap;
> >
> > *HostAddress = (VOID *)(UINTN)PhysicalAddress;
> >
> > @@ -707,7 +689,7 @@ IoMmuFreeBuffer (
> > // Release the common buffer itself. Unmap() has re-encrypted it in-
> place, so
> > // no need to zero it.
> > //
> > - return gBS->FreePages ((UINTN)CommonBufferHeader,
> CommonBufferPages);
> > + return IoMmuFreeCommonBuffer (CommonBufferHeader,
> CommonBufferPages);
> > }
> >
> > /**
> > @@ -878,6 +860,11 @@ IoMmuUnmapAllMappings (
> > TRUE // MemoryMapLocked
> > );
> > }
> > +
> > + //
> > + // Release the reserved shared memory as well.
> > + //
> > + IoMmuReleaseReservedSharedMem (TRUE);
> > }
> >
> > /**
> > @@ -936,6 +923,19 @@ InstallIoMmuProtocol (
> > goto CloseExitBootEvent;
> > }
> >
> > + //
> > + // Currently only Tdx guest support Reserved shared memory for DMA
> operation.
> > + //
> > + if (CC_GUEST_IS_TDX (PcdGet64 (PcdConfidentialComputingGuestAttr)))
> {
> > + mReservedSharedMemSupported = TRUE;
> > + Status = IoMmuInitReservedSharedMem ();
> > + if (EFI_ERROR (Status)) {
> > + mReservedSharedMemSupported = FALSE;
> > + } else {
> > + DEBUG ((DEBUG_INFO, "%a: Feature of reserved memory for DMA is
> supported.\n", __FUNCTION__));
> > + }
> > + }
> > +
> > return EFI_SUCCESS;
> >
> > CloseExitBootEvent:
> > diff --git a/OvmfPkg/IoMmuDxe/IoMmuBuffer.c
> b/OvmfPkg/IoMmuDxe/IoMmuBuffer.c
> > new file mode 100644
> > index 000000000000..5ada8e9d57bd
> > --- /dev/null
> > +++ b/OvmfPkg/IoMmuDxe/IoMmuBuffer.c
> > @@ -0,0 +1,425 @@
> > +/** @file
> > +
> > + Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
> > +
> > + SPDX-License-Identifier: BSD-2-Clause-Patent
> > +
> > +**/
> > +#include <Library/BaseLib.h>
> > +#include <Library/BaseMemoryLib.h>
> > +#include <Library/DebugLib.h>
> > +#include <Library/MemoryAllocationLib.h>
> > +#include <Library/MemEncryptTdxLib.h>
> > +#include <Library/UefiBootServicesTableLib.h>
> > +#include "IoMmuInternal.h"
> > +
> > +extern BOOLEAN mReservedSharedMemSupported;
> > +
> > +#define SIZE_OF_MEM_RANGE(MemRange) (MemRange->HeaderSize +
> MemRange->DataSize)
> > +
> > +#define RESERVED_MEM_BITMAP_4K_MASK 0xf
> > +#define RESERVED_MEM_BITMAP_32K_MASK 0xff0
> > +#define RESERVED_MEM_BITMAP_128K_MASK 0x3000
> > +#define RESERVED_MEM_BITMAP_1M_MASK 0x40000
> > +#define RESERVED_MEM_BITMAP_2M_MASK 0x180000
> > +#define RESERVED_MEM_BITMAP_MASK 0x1fffff
> > +
> > +STATIC IOMMU_RESERVED_MEM_RANGE mReservedMemRanges[] = {
> > + { RESERVED_MEM_BITMAP_4K_MASK, 0, 4, SIZE_4KB, SIZE_4KB, 0 },
> > + { RESERVED_MEM_BITMAP_32K_MASK, 4, 8, SIZE_32KB, SIZE_4KB,
> 0 },
> > + { RESERVED_MEM_BITMAP_128K_MASK, 12, 2, SIZE_128KB, SIZE_4KB,
> 0 },
> > + { RESERVED_MEM_BITMAP_1M_MASK, 14, 1, SIZE_1MB, SIZE_4KB,
> 0 },
> > + { RESERVED_MEM_BITMAP_2M_MASK, 15, 2, SIZE_2MB, SIZE_4KB,
> 0 },
> > +};
> > +
> > +//
> > +// Bitmap of the allocation of reserved memory.
> > +//
> > +STATIC UINT32 mReservedMemBitmap = 0;
> > +
> > +//
> > +// Start address of the reserved memory region.
> > +//
> > +STATIC EFI_PHYSICAL_ADDRESS mReservedSharedMemAddress = 0;
> > +
> > +//
> > +// Total size of the reserved memory region.
> > +//
> > +STATIC UINT32 mReservedSharedMemSize = 0;
> > +
> > +/**
> > + * Calculate the size of reserved memory.
> > + *
> > + * @retval UINT32 Size of the reserved memory
> > + */
> > +STATIC
> > +UINT32
> > +CalcuateReservedMemSize (
> > + VOID
> > + )
> > +{
> > + UINT32 Index;
> > + IOMMU_RESERVED_MEM_RANGE *MemRange;
> > +
> > + if (mReservedSharedMemSize != 0) {
> > + return mReservedSharedMemSize;
> > + }
> > +
> > + for (Index = 0; Index < ARRAY_SIZE (mReservedMemRanges); Index++) {
> > + MemRange = &mReservedMemRanges[Index];
> > + mReservedSharedMemSize += (SIZE_OF_MEM_RANGE (MemRange) *
> MemRange->Slots);
> > + }
> > +
> > + return mReservedSharedMemSize;
> > +}
> > +
> > +/**
> > + * Allocate a memory region and convert it to be shared. This memory
> region will be
> > + * used in the DMA operation.
> > + *
> > + * The pre-alloc memory contains pieces of memory regions with
> different size. The
> > + * allocation of the shared memory regions are indicated by a 32-bit
> bitmap (mReservedMemBitmap).
> > + *
> > + * The memory regions are consumed by IoMmuAllocateBuffer (in which
> CommonBuffer is allocated) and
> > + * IoMmuMap (in which bounce buffer is allocated).
> > + *
> > + * The CommonBuffer contains 2 parts, one page for
> CommonBufferHeader which is private memory,
> > + * the other part is shared memory. So the layout of a piece of memory
> region after initialization
> > + * looks like:
> > + *
> > + * |------------|----------------------------|
> > + * | Header | Data | <-- a piece of pre-alloc memory
> region
> > + * | 4k, private| 4k/32k/128k/etc, shared |
> > + * |-----------------------------------------|
> > + *
> > + * @retval EFI_SUCCESS Successfully initialize the reserved memory.
> > + * @retval EFI_UNSUPPORTED This feature is not supported.
> > + */
> > +EFI_STATUS
> > +IoMmuInitReservedSharedMem (
> > + VOID
> > + )
> > +{
> > + EFI_STATUS Status;
> > + UINT32 Index1, Index2;
> > + UINTN TotalPages;
> > + IOMMU_RESERVED_MEM_RANGE *MemRange;
> > + EFI_PHYSICAL_ADDRESS PhysicalAddress;
> > +
> > + if (!mReservedSharedMemSupported) {
> > + return EFI_UNSUPPORTED;
> > + }
> > +
> > + TotalPages = EFI_SIZE_TO_PAGES (CalcuateReservedMemSize ());
> > +
> > + PhysicalAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocatePages
> (TotalPages);
> > + DEBUG ((
> > + DEBUG_VERBOSE,
> > + "%a: ReservedMem (%d pages) address = 0x%llx\n",
> > + __FUNCTION__,
> > + TotalPages,
> > + PhysicalAddress
> > + ));
> > +
> > + mReservedMemBitmap = 0;
> > + mReservedSharedMemAddress = PhysicalAddress;
> > +
> > + for (Index1 = 0; Index1 < ARRAY_SIZE (mReservedMemRanges);
> Index1++) {
> > + MemRange = &mReservedMemRanges[Index1];
> > + MemRange->StartAddressOfMemRange = PhysicalAddress;
> > +
> > + for (Index2 = 0; Index2 < MemRange->Slots; Index2++) {
> > + Status = MemEncryptTdxSetPageSharedBit (
> > + 0,
> > + (UINT64)(UINTN)(MemRange->StartAddressOfMemRange +
> Index2 * SIZE_OF_MEM_RANGE (MemRange) + MemRange->HeaderSize),
> > + EFI_SIZE_TO_PAGES (MemRange->DataSize)
> > + );
> > + ASSERT (!EFI_ERROR (Status));
> > + }
> > +
> > + PhysicalAddress += (MemRange->Slots * SIZE_OF_MEM_RANGE
> (MemRange));
> > + }
> > +
> > + return EFI_SUCCESS;
> > +}
> > +
> > +/**
> > + * Release the pre-alloc shared memory.
> > + *
> > + * @retval EFI_SUCCESS Successfully release the shared memory
> > + */
> > +EFI_STATUS
> > +IoMmuReleaseReservedSharedMem (
> > + BOOLEAN MemoryMapLocked
> > + )
> > +{
> > + EFI_STATUS Status;
> > + UINT32 Index1, Index2;
> > + IOMMU_RESERVED_MEM_RANGE *MemRange;
> > +
> > + for (Index1 = 0; Index1 < ARRAY_SIZE (mReservedMemRanges);
> Index1++) {
> > + MemRange = &mReservedMemRanges[Index1];
> > + for (Index2 = 0; Index2 < MemRange->Slots; Index2++) {
> > + Status = MemEncryptTdxClearPageSharedBit (
> > + 0,
> > + (UINT64)(UINTN)(MemRange->StartAddressOfMemRange +
> Index2 * SIZE_OF_MEM_RANGE (MemRange) + MemRange->HeaderSize),
> > + EFI_SIZE_TO_PAGES (MemRange->DataSize)
> > + );
> > + ASSERT (!EFI_ERROR (Status));
> > + }
> > + }
> > +
> > + if (!MemoryMapLocked) {
> > + FreePages ((VOID *)(UINTN)mReservedSharedMemAddress,
> EFI_SIZE_TO_PAGES (CalcuateReservedMemSize ()));
> > + mReservedSharedMemAddress = 0;
> > + mReservedMemBitmap = 0;
> > + }
> > +
> > + return EFI_SUCCESS;
> > +}
> > +
> > +/**
> > + * Allocate from the reserved memory pool.
> > + * If the reserved shared memory is exausted or there is no suitalbe size,
> it turns
> > + * to the LegacyAllocateBuffer.
> > + *
> > + * @param Type Allocate type
> > + * @param MemoryType The memory type to be allocated
> > + * @param Pages Pages to be allocated.
> > + * @param ReservedMemBitmap Bitmap of the allocated memory
> region
> > + * @param PhysicalAddress Pointer to the data part of allocated
> memory region
> > + *
> > + * @retval EFI_SUCCESS Successfully allocate the buffer
> > + * @retval Other As the error code indicates
> > + */
> > +STATIC
> > +EFI_STATUS
> > +InternalAllocateBuffer (
> > + IN EFI_ALLOCATE_TYPE Type,
> > + IN EFI_MEMORY_TYPE MemoryType,
> > + IN UINTN Pages,
> > + IN OUT UINT32 *ReservedMemBitmap,
> > + IN OUT EFI_PHYSICAL_ADDRESS *PhysicalAddress
> > + )
> > +{
> > + UINT32 MemBitmap;
> > + UINT8 Index;
> > + IOMMU_RESERVED_MEM_RANGE *MemRange;
> > + UINTN PagesOfLastMemRange;
> > +
> > + *ReservedMemBitmap = 0;
> > +
> > + if (Pages == 0) {
> > + ASSERT (FALSE);
> > + return EFI_INVALID_PARAMETER;
> > + }
> > +
> > + if (!mReservedSharedMemSupported) {
> > + goto LegacyAllocateBuffer;
> > + }
> > +
> > + if (mReservedSharedMemAddress == 0) {
> > + goto LegacyAllocateBuffer;
> > + }
> > +
> > + PagesOfLastMemRange = 0;
> > +
> > + for (Index = 0; Index < ARRAY_SIZE (mReservedMemRanges); Index++) {
> > + if ((Pages > PagesOfLastMemRange) && (Pages <= EFI_SIZE_TO_PAGES
> (mReservedMemRanges[Index].DataSize))) {
> > + break;
> > + }
> > +
> > + PagesOfLastMemRange = EFI_SIZE_TO_PAGES
> (mReservedMemRanges[Index].DataSize);
> > + }
> > +
> > + if (Index == ARRAY_SIZE (mReservedMemRanges)) {
> > + // There is no suitable size of reserved memory. Turn to legacy
> allocate.
> > + goto LegacyAllocateBuffer;
> > + }
> > +
> > + MemRange = &mReservedMemRanges[Index];
> > +
> > + if ((mReservedMemBitmap & MemRange->BitmapMask) ==
> MemRange->BitmapMask) {
> > + // The reserved memory is exausted. Turn to legacy allocate.
> > + goto LegacyAllocateBuffer;
> > + }
> > +
> > + MemBitmap = (mReservedMemBitmap & MemRange->BitmapMask) >>
> MemRange->Shift;
> > +
> > + for (Index = 0; Index < MemRange->Slots; Index++) {
> > + if ((MemBitmap & (UINT8)(1<<Index)) == 0) {
> > + break;
> > + }
> > + }
> > +
> > + ASSERT (Index != MemRange->Slots);
> > +
> > + *PhysicalAddress = MemRange->StartAddressOfMemRange + Index *
> SIZE_OF_MEM_RANGE (MemRange) + MemRange->HeaderSize;
> > + *ReservedMemBitmap = (UINT32)(1 << (Index + MemRange->Shift));
> > +
> > + DEBUG ((
> > + DEBUG_VERBOSE,
> > + "%a: range-size: %lx, start-address=0x%llx, pages=0x%llx, bits=0x%lx,
> bitmap: %lx => %lx\n",
> > + __FUNCTION__,
> > + MemRange->DataSize,
> > + *PhysicalAddress,
> > + Pages,
> > + *ReservedMemBitmap,
> > + mReservedMemBitmap,
> > + mReservedMemBitmap | *ReservedMemBitmap
> > + ));
> > +
> > + return EFI_SUCCESS;
> > +
> > +LegacyAllocateBuffer:
> > +
> > + *ReservedMemBitmap = 0;
> > + return gBS->AllocatePages (Type, MemoryType, Pages, PhysicalAddress);
> > +}
> > +
> > +/**
> > + * Allocate reserved shared memory for bounce buffer.
> > + *
> > + * @param Type Allocate type
> > + * @param MemoryType The memory type to be allocated
> > + * @param MapInfo Pointer to the MAP_INFO
> > + *
> > + * @retval EFI_SUCCESS Successfully allocate the bounce buffer
> > + * @retval Other As the error code indicates
> > +
> > + */
> > +EFI_STATUS
> > +IoMmuAllocateBounceBuffer (
> > + IN EFI_ALLOCATE_TYPE Type,
> > + IN EFI_MEMORY_TYPE MemoryType,
> > + IN OUT MAP_INFO *MapInfo
> > + )
> > +{
> > + EFI_STATUS Status;
> > + UINT32 ReservedMemBitmap;
> > +
> > + ReservedMemBitmap = 0;
> > + Status = InternalAllocateBuffer (
> > + Type,
> > + MemoryType,
> > + MapInfo->NumberOfPages,
> > + &ReservedMemBitmap,
> > + &MapInfo->PlainTextAddress
> > + );
> > + MapInfo->ReservedMemBitmap = ReservedMemBitmap;
> > + mReservedMemBitmap |= ReservedMemBitmap;
> > +
> > + ASSERT (Status == EFI_SUCCESS);
> > +
> > + return Status;
> > +}
> > +
> > +/**
> > + * Free the bounce buffer allocated in IoMmuAllocateBounceBuffer.
> > + *
> > + * @param MapInfo Pointer to the MAP_INFO
> > + * @return EFI_SUCCESS Successfully free the bounce buffer.
> > + */
> > +EFI_STATUS
> > +IoMmuFreeBounceBuffer (
> > + IN OUT MAP_INFO *MapInfo
> > + )
> > +{
> > + if (MapInfo->ReservedMemBitmap == 0) {
> > + gBS->FreePages (MapInfo->PlainTextAddress, MapInfo-
> >NumberOfPages);
> > + } else {
> > + DEBUG ((
> > + DEBUG_VERBOSE,
> > + "%a: PlainTextAddress=0x%Lx, bits=0x%Lx, bitmap: %Lx => %Lx\n",
> > + __FUNCTION__,
> > + MapInfo->PlainTextAddress,
> > + MapInfo->ReservedMemBitmap,
> > + mReservedMemBitmap,
> > + mReservedMemBitmap & ((UINT32)(~MapInfo-
> >ReservedMemBitmap))
> > + ));
> > + MapInfo->PlainTextAddress = 0;
> > + mReservedMemBitmap &= (UINT32)(~MapInfo-
> >ReservedMemBitmap);
> > + MapInfo->ReservedMemBitmap = 0;
> > + }
> > +
> > + return EFI_SUCCESS;
> > +}
> > +
> > +/**
> > + * Allocate CommonBuffer from pre-allocated shared memory.
> > + *
> > + * @param MemoryType Memory type
> > + * @param CommonBufferPages Pages of CommonBuffer
> > + * @param PhysicalAddress Allocated physical address
> > + * @param ReservedMemBitmap Bitmap which indicates the allocation
> of reserved memory
> > + *
> > + * @retval EFI_SUCCESS Successfully allocate the common buffer
> > + * @retval Other As the error code indicates
> > + */
> > +EFI_STATUS
> > +IoMmuAllocateCommonBuffer (
> > + IN EFI_MEMORY_TYPE MemoryType,
> > + IN UINTN CommonBufferPages,
> > + OUT EFI_PHYSICAL_ADDRESS *PhysicalAddress,
> > + OUT UINT32 *ReservedMemBitmap
> > + )
> > +{
> > + EFI_STATUS Status;
> > +
> > + Status = InternalAllocateBuffer (
> > + AllocateMaxAddress,
> > + MemoryType,
> > + CommonBufferPages,
> > + ReservedMemBitmap,
> > + PhysicalAddress
> > + );
> > + ASSERT (Status == EFI_SUCCESS);
> > +
> > + mReservedMemBitmap |= *ReservedMemBitmap;
> > +
> > + if (*ReservedMemBitmap != 0) {
> > + *PhysicalAddress -= SIZE_4KB;
> > + }
> > +
> > + return Status;
> > +}
> > +
> > +/**
> > + * Free CommonBuffer which is allocated by
> IoMmuAllocateCommonBuffer().
> > + *
> > + * @param CommonBufferHeader Pointer to the CommonBufferHeader
> > + * @param CommonBufferPages Pages of CommonBuffer
> > + *
> > + * @retval EFI_SUCCESS Successfully free the common buffer
> > + * @retval Other As the error code indicates
> > + */
> > +EFI_STATUS
> > +IoMmuFreeCommonBuffer (
> > + IN COMMON_BUFFER_HEADER *CommonBufferHeader,
> > + IN UINTN CommonBufferPages
> > + )
> > +{
> > + if (!mReservedSharedMemSupported) {
> > + goto LegacyFreeCommonBuffer;
> > + }
> > +
> > + if (CommonBufferHeader->ReservedMemBitmap == 0) {
> > + goto LegacyFreeCommonBuffer;
> > + }
> > +
> > + DEBUG ((
> > + DEBUG_VERBOSE,
> > + "%a: CommonBuffer=0x%Lx, bits=0x%Lx, bitmap: %Lx => %Lx\n",
> > + __FUNCTION__,
> > + (UINT64)(UINTN)CommonBufferHeader + SIZE_4KB,
> > + CommonBufferHeader->ReservedMemBitmap,
> > + mReservedMemBitmap,
> > + mReservedMemBitmap & ((UINT32)(~CommonBufferHeader-
> >ReservedMemBitmap))
> > + ));
> > +
> > + mReservedMemBitmap &= (UINT32)(~CommonBufferHeader-
> >ReservedMemBitmap);
> > + return EFI_SUCCESS;
> > +
> > +LegacyFreeCommonBuffer:
> > + return gBS->FreePages ((UINTN)CommonBufferHeader,
> CommonBufferPages);
> > +}
> > diff --git a/OvmfPkg/IoMmuDxe/IoMmuDxe.inf
> b/OvmfPkg/IoMmuDxe/IoMmuDxe.inf
> > index e10be1dcff49..2192145ea661 100644
> > --- a/OvmfPkg/IoMmuDxe/IoMmuDxe.inf
> > +++ b/OvmfPkg/IoMmuDxe/IoMmuDxe.inf
> > @@ -21,6 +21,7 @@
> > AmdSevIoMmu.c
> > AmdSevIoMmu.h
> > IoMmuDxe.c
> > + IoMmuBuffer.c
> >
> > [Packages]
> > MdePkg/MdePkg.dec
> > diff --git a/OvmfPkg/IoMmuDxe/IoMmuInternal.h
> b/OvmfPkg/IoMmuDxe/IoMmuInternal.h
> > new file mode 100644
> > index 000000000000..936c35aa536c
> > --- /dev/null
> > +++ b/OvmfPkg/IoMmuDxe/IoMmuInternal.h
> > @@ -0,0 +1,179 @@
> > +/** @file
> > +
> > + Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
> > +
> > + SPDX-License-Identifier: BSD-2-Clause-Patent
> > +
> > +**/
> > +
> > +#ifndef IOMMU_INTERNAL_H_
> > +#define IOMMU_INTERNAL_H_
> > +
> > +#include <Base.h>
> > +#include <Protocol/IoMmu.h>
> > +#include <Uefi/UefiBaseType.h>
> > +#include <Uefi/UefiSpec.h>
> > +
> > +#define MAP_INFO_SIG SIGNATURE_64 ('M', 'A', 'P', '_', 'I', 'N', 'F', 'O')
> > +
> > +typedef struct {
> > + UINT64 Signature;
> > + LIST_ENTRY Link;
> > + EDKII_IOMMU_OPERATION Operation;
> > + UINTN NumberOfBytes;
> > + UINTN NumberOfPages;
> > + EFI_PHYSICAL_ADDRESS CryptedAddress;
> > + EFI_PHYSICAL_ADDRESS PlainTextAddress;
> > + UINT32 ReservedMemBitmap;
> > +} MAP_INFO;
> > +
> > +#define COMMON_BUFFER_SIG SIGNATURE_64 ('C', 'M', 'N', 'B', 'U', 'F',
> 'F', 'R')
> > +
> > +#pragma pack (1)
> > +//
> > +// The following structure enables Map() and Unmap() to perform in-
> place
> > +// decryption and encryption, respectively, for
> BusMasterCommonBuffer[64]
> > +// operations, without dynamic memory allocation or release.
> > +//
> > +// Both COMMON_BUFFER_HEADER and
> COMMON_BUFFER_HEADER.StashBuffer are allocated
> > +// by AllocateBuffer() and released by FreeBuffer().
> > +//
> > +typedef struct {
> > + UINT64 Signature;
> > +
> > + //
> > + // Always allocated from EfiBootServicesData type memory, and always
> > + // encrypted.
> > + //
> > + VOID *StashBuffer;
> > +
> > + //
> > + // Bitmap of reserved memory
> > + //
> > + UINT32 ReservedMemBitmap;
> > +
> > + //
> > + // Followed by the actual common buffer, starting at the next page.
> > + //
> > +} COMMON_BUFFER_HEADER;
> > +
> > +//
> > +// This data structure defines a memory range in the reserved memory
> region.
> > +// Please refer to IoMmuInitReservedSharedMem() for detailed
> information.
> > +//
> > +// The memory region looks like:
> > +// |------------|----------------------------|
> > +// | Header | Data |
> > +// | 4k, private| 4k/32k/128k/etc, shared |
> > +// |-----------------------------------------|
> > +//
> > +typedef struct {
> > + UINT32 BitmapMask;
> > + UINT32 Shift;
> > + UINT32 Slots;
> > + UINT32 DataSize;
> > + UINT32 HeaderSize;
> > + EFI_PHYSICAL_ADDRESS StartAddressOfMemRange;
> > +} IOMMU_RESERVED_MEM_RANGE;
> > +#pragma pack()
> > +
> > +/**
> > + * Allocate a memory region and convert it to be shared. This memory
> region will be
> > + * used in the DMA operation.
> > + *
> > + * The pre-alloc memory contains pieces of memory regions with
> different size. The
> > + * allocation of the shared memory regions are indicated by a 32-bit
> bitmap (mReservedMemBitmap).
> > + *
> > + * The memory regions are consumed by IoMmuAllocateBuffer (in which
> CommonBuffer is allocated) and
> > + * IoMmuMap (in which bounce buffer is allocated).
> > + *
> > + * The CommonBuffer contains 2 parts, one page for
> CommonBufferHeader which is private memory,
> > + * the other part is shared memory. So the layout of a piece of memory
> region after initialization
> > + * looks like:
> > + *
> > + * |------------|----------------------------|
> > + * | Header | Data | <-- a piece of pre-alloc memory
> region
> > + * | 4k, private| 4k/32k/128k/etc, shared |
> > + * |-----------------------------------------|
> > + *
> > + * @retval EFI_SUCCESS Successfully initialize the reserved memory.
> > + * @retval EFI_UNSUPPORTED This feature is not supported.
> > + */
> > +EFI_STATUS
> > +IoMmuInitReservedSharedMem (
> > + VOID
> > + );
> > +
> > +/**
> > + * Release the pre-alloc shared memory.
> > + *
> > + * @retval EFI_SUCCESS Successfully release the shared memory
> > + */
> > +EFI_STATUS
> > +IoMmuReleaseReservedSharedMem (
> > + BOOLEAN MemoryMapLocked
> > + );
> > +
> > +/**
> > + * Allocate reserved shared memory for bounce buffer.
> > + *
> > + * @param Type Allocate type
> > + * @param MemoryType The memory type to be allocated
> > + * @param MapInfo Pointer to the MAP_INFO
> > + *
> > + * @retval EFI_SUCCESS Successfully allocate the bounce buffer
> > + * @retval Other As the error code indicates
> > + */
> > +EFI_STATUS
> > +IoMmuAllocateBounceBuffer (
> > + IN EFI_ALLOCATE_TYPE Type,
> > + IN EFI_MEMORY_TYPE MemoryType,
> > + IN OUT MAP_INFO *MapInfo
> > + );
> > +
> > +/**
> > + * Free the bounce buffer allocated in IoMmuAllocateBounceBuffer.
> > + *
> > + * @param MapInfo Pointer to the MAP_INFO
> > + * @return EFI_SUCCESS Successfully free the bounce buffer.
> > + */
> > +EFI_STATUS
> > +IoMmuFreeBounceBuffer (
> > + IN OUT MAP_INFO *MapInfo
> > + );
> > +
> > +/**
> > + * Allocate CommonBuffer from pre-allocated shared memory.
> > + *
> > + * @param MemoryType Memory type
> > + * @param CommonBufferPages Pages of CommonBuffer
> > + * @param PhysicalAddress Allocated physical address
> > + * @param ReservedMemBitmap Bitmap which indicates the allocation
> of reserved memory
> > + *
> > + * @retval EFI_SUCCESS Successfully allocate the common buffer
> > + * @retval Other As the error code indicates
> > + */
> > +EFI_STATUS
> > +IoMmuAllocateCommonBuffer (
> > + IN EFI_MEMORY_TYPE MemoryType,
> > + IN UINTN CommonBufferPages,
> > + OUT EFI_PHYSICAL_ADDRESS *PhysicalAddress,
> > + OUT UINT32 *ReservedMemBitmap
> > + );
> > +
> > +/**
> > + * Free CommonBuffer which is allocated by
> IoMmuAllocateCommonBuffer().
> > + *
> > + * @param CommonBufferHeader Pointer to the CommonBufferHeader
> > + * @param CommonBufferPages Pages of CommonBuffer
> > + *
> > + * @retval EFI_SUCCESS Successfully free the common buffer
> > + * @retval Other As the error code indicates
> > + */
> > +EFI_STATUS
> > +IoMmuFreeCommonBuffer (
> > + IN COMMON_BUFFER_HEADER *CommonBufferHeader,
> > + IN UINTN CommonBufferPages
> > + );
> > +
> > +#endif
next prev parent reply other threads:[~2022-12-05 17:21 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-05 8:08 [PATCH V1 0/3] Reserve shared memory for DMA operation Min Xu
2022-12-05 8:08 ` [PATCH V1 1/3] OvmfPkg/IoMmuDxe: Reserve shared memory region " Min Xu
2022-12-05 16:48 ` Lendacky, Thomas
2022-12-05 17:21 ` Yao, Jiewen [this message]
2022-12-09 14:28 ` Yao, Jiewen
2022-12-11 2:04 ` Min Xu
2022-12-05 8:08 ` [PATCH V1 2/3] OvmfPkg/IoMmuDxe: Rename AmdSevIoMmu to CcIoMmu Min Xu
2022-12-05 8:08 ` [PATCH V1 3/3] Maintainers: Update OvmfPkg/IoMmuDxe Min Xu
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