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UefiCpuPkg/MpInitLib: Reduce the size when loading microcode patches
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REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2429

This commit will attempt to reduce the copy size when loading the
microcode patches data from flash into memory.

Such optimization is done by a pre-process of the microcode patch headers
(on flash). A microcode patch will be loaded into memory only when the
below 3 criteria are met:

A. With a microcode patch header (which means the data is not padding data
   between microcode patches);
B. The 'ProcessorSignature' & 'ProcessorFlags' fields in the header match
   at least one processor within system;
C. If the Extended Signature Table exists in a microcode patch, the
   'ProcessorSignature' & 'ProcessorFlag' fields in the table entries
   match at least one processor within system.

Criterion B and C will require all the processors to be woken up once to
collect their CPUID and Platform ID information. Hence, this commit will
move the copy, detect and apply of microcode patch on BSP and APs after
all the processors have been woken up.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Siyuan Fu <siyuan.fu@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Signed-off-by: Hao A Wu <hao.a.wu@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
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@hwu25 @mergify
hwu25 authored and mergify[bot] committed Jan 2, 2020
1 parent 999463c commit d786a17
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288 changes: 288 additions & 0 deletions UefiCpuPkg/Library/MpInitLib/Microcode.c
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Original file line number Diff line number Diff line change
Expand Up @@ -331,3 +331,291 @@ MicrocodeDetect (
MicroData [0x%08x], Revision [0x%08x]\n", Eax.Uint32, ProcessorFlags, (UINTN) MicrocodeData, LatestRevision));
}
}

/**
Determine if a microcode patch will be loaded into memory.
@param[in] CpuMpData The pointer to CPU MP Data structure.
@param[in] ProcessorSignature The processor signature field value
supported by a microcode patch.
@param[in] ProcessorFlags The prcessor flags field value supported by
a microcode patch.
@retval TRUE The specified microcode patch will be loaded.
@retval FALSE The specified microcode patch will not be loaded.
**/
BOOLEAN
IsMicrocodePatchNeedLoad (
IN CPU_MP_DATA *CpuMpData,
IN UINT32 ProcessorSignature,
IN UINT32 ProcessorFlags
)
{
UINTN Index;
CPU_AP_DATA *CpuData;

for (Index = 0; Index < CpuMpData->CpuCount; Index++) {
CpuData = &CpuMpData->CpuData[Index];
if ((ProcessorSignature == CpuData->ProcessorSignature) &&
(ProcessorFlags & (1 << CpuData->PlatformId)) != 0) {
return TRUE;
}
}

return FALSE;
}

/**
Actual worker function that loads the required microcode patches into memory.
@param[in, out] CpuMpData The pointer to CPU MP Data structure.
@param[in] Patches The pointer to an array of information on
the microcode patches that will be loaded
into memory.
@param[in] PatchCount The number of microcode patches that will
be loaded into memory.
@param[in] TotalLoadSize The total size of all the microcode patches
to be loaded.
**/
VOID
LoadMicrocodePatchWorker (
IN OUT CPU_MP_DATA *CpuMpData,
IN MICROCODE_PATCH_INFO *Patches,
IN UINTN PatchCount,
IN UINTN TotalLoadSize
)
{
UINTN Index;
VOID *MicrocodePatchInRam;
UINT8 *Walker;

ASSERT ((Patches != NULL) && (PatchCount != 0));

MicrocodePatchInRam = AllocatePages (EFI_SIZE_TO_PAGES (TotalLoadSize));
if (MicrocodePatchInRam == NULL) {
return;
}

//
// Load all the required microcode patches into memory
//
for (Walker = MicrocodePatchInRam, Index = 0; Index < PatchCount; Index++) {
CopyMem (
Walker,
(VOID *) Patches[Index].Address,
Patches[Index].Size
);

//
// Zero-fill the padding area
// Please note that AlignedSize will be no less than Size
//
ZeroMem (
Walker + Patches[Index].Size,
Patches[Index].AlignedSize - Patches[Index].Size
);

Walker += Patches[Index].AlignedSize;
}

//
// Update the microcode patch related fields in CpuMpData
//
CpuMpData->MicrocodePatchAddress = (UINTN) MicrocodePatchInRam;
CpuMpData->MicrocodePatchRegionSize = TotalLoadSize;

DEBUG ((
DEBUG_INFO,
"%a: Required microcode patches have been loaded at 0x%lx, with size 0x%lx.\n",
__FUNCTION__, CpuMpData->MicrocodePatchAddress, CpuMpData->MicrocodePatchRegionSize
));

return;
}

/**
Load the required microcode patches data into memory.
@param[in, out] CpuMpData The pointer to CPU MP Data structure.
**/
VOID
LoadMicrocodePatch (
IN OUT CPU_MP_DATA *CpuMpData
)
{
CPU_MICROCODE_HEADER *MicrocodeEntryPoint;
UINTN MicrocodeEnd;
UINTN DataSize;
UINTN TotalSize;
CPU_MICROCODE_EXTENDED_TABLE_HEADER *ExtendedTableHeader;
UINT32 ExtendedTableCount;
CPU_MICROCODE_EXTENDED_TABLE *ExtendedTable;
MICROCODE_PATCH_INFO *PatchInfoBuffer;
UINTN MaxPatchNumber;
UINTN PatchCount;
UINTN TotalLoadSize;
UINTN Index;
BOOLEAN NeedLoad;

//
// Initialize the microcode patch related fields in CpuMpData as the values
// specified by the PCD pair. If the microcode patches are loaded into memory,
// these fields will be updated.
//
CpuMpData->MicrocodePatchAddress = PcdGet64 (PcdCpuMicrocodePatchAddress);
CpuMpData->MicrocodePatchRegionSize = PcdGet64 (PcdCpuMicrocodePatchRegionSize);

MicrocodeEntryPoint = (CPU_MICROCODE_HEADER *) (UINTN) CpuMpData->MicrocodePatchAddress;
MicrocodeEnd = (UINTN) MicrocodeEntryPoint +
(UINTN) CpuMpData->MicrocodePatchRegionSize;
if ((MicrocodeEntryPoint == NULL) || ((UINTN) MicrocodeEntryPoint == MicrocodeEnd)) {
//
// There is no microcode patches
//
return;
}

PatchCount = 0;
MaxPatchNumber = DEFAULT_MAX_MICROCODE_PATCH_NUM;
TotalLoadSize = 0;
PatchInfoBuffer = AllocatePool (MaxPatchNumber * sizeof (MICROCODE_PATCH_INFO));
if (PatchInfoBuffer == NULL) {
return;
}

//
// Process the header of each microcode patch within the region.
// The purpose is to decide which microcode patch(es) will be loaded into memory.
//
do {
if (MicrocodeEntryPoint->HeaderVersion != 0x1) {
//
// Padding data between the microcode patches, skip 1KB to check next entry.
//
MicrocodeEntryPoint = (CPU_MICROCODE_HEADER *) (((UINTN) MicrocodeEntryPoint) + SIZE_1KB);
continue;
}

DataSize = MicrocodeEntryPoint->DataSize;
TotalSize = (DataSize == 0) ? 2048 : MicrocodeEntryPoint->TotalSize;
if ( (UINTN)MicrocodeEntryPoint > (MAX_ADDRESS - TotalSize) ||
((UINTN)MicrocodeEntryPoint + TotalSize) > MicrocodeEnd ||
(DataSize & 0x3) != 0 ||
(TotalSize & (SIZE_1KB - 1)) != 0 ||
TotalSize < DataSize
) {
//
// Not a valid microcode header, skip 1KB to check next entry.
//
MicrocodeEntryPoint = (CPU_MICROCODE_HEADER *) (((UINTN) MicrocodeEntryPoint) + SIZE_1KB);
continue;
}

//
// Check the 'ProcessorSignature' and 'ProcessorFlags' of the microcode
// patch header with the CPUID and PlatformID of the processors within
// system to decide if it will be copied into memory
//
NeedLoad = IsMicrocodePatchNeedLoad (
CpuMpData,
MicrocodeEntryPoint->ProcessorSignature.Uint32,
MicrocodeEntryPoint->ProcessorFlags
);

//
// If the Extended Signature Table exists, check if the processor is in the
// support list
//
if ((!NeedLoad) && (DataSize != 0) &&
(TotalSize - DataSize > sizeof (CPU_MICROCODE_HEADER) +
sizeof (CPU_MICROCODE_EXTENDED_TABLE_HEADER))) {
ExtendedTableHeader = (CPU_MICROCODE_EXTENDED_TABLE_HEADER *) ((UINT8 *) (MicrocodeEntryPoint)
+ DataSize + sizeof (CPU_MICROCODE_HEADER));
ExtendedTableCount = ExtendedTableHeader->ExtendedSignatureCount;
ExtendedTable = (CPU_MICROCODE_EXTENDED_TABLE *) (ExtendedTableHeader + 1);

for (Index = 0; Index < ExtendedTableCount; Index ++) {
//
// Avoid access content beyond MicrocodeEnd
//
if ((UINTN) ExtendedTable > MicrocodeEnd - sizeof (CPU_MICROCODE_EXTENDED_TABLE)) {
break;
}

//
// Check the 'ProcessorSignature' and 'ProcessorFlag' of the Extended
// Signature Table entry with the CPUID and PlatformID of the processors
// within system to decide if it will be copied into memory
//
NeedLoad = IsMicrocodePatchNeedLoad (
CpuMpData,
ExtendedTable->ProcessorSignature.Uint32,
ExtendedTable->ProcessorFlag
);
if (NeedLoad) {
break;
}
ExtendedTable ++;
}
}

if (NeedLoad) {
PatchCount++;
if (PatchCount > MaxPatchNumber) {
//
// Current 'PatchInfoBuffer' cannot hold the information, double the size
// and allocate a new buffer.
//
if (MaxPatchNumber > MAX_UINTN / 2 / sizeof (MICROCODE_PATCH_INFO)) {
//
// Overflow check for MaxPatchNumber
//
goto OnExit;
}

PatchInfoBuffer = ReallocatePool (
MaxPatchNumber * sizeof (MICROCODE_PATCH_INFO),
2 * MaxPatchNumber * sizeof (MICROCODE_PATCH_INFO),
PatchInfoBuffer
);
if (PatchInfoBuffer == NULL) {
goto OnExit;
}
MaxPatchNumber = MaxPatchNumber * 2;
}

//
// Store the information of this microcode patch
//
if (TotalSize > ALIGN_VALUE (TotalSize, SIZE_1KB) ||
ALIGN_VALUE (TotalSize, SIZE_1KB) > MAX_UINTN - TotalLoadSize) {
goto OnExit;
}
PatchInfoBuffer[PatchCount - 1].Address = (UINTN) MicrocodeEntryPoint;
PatchInfoBuffer[PatchCount - 1].Size = TotalSize;
PatchInfoBuffer[PatchCount - 1].AlignedSize = ALIGN_VALUE (TotalSize, SIZE_1KB);
TotalLoadSize += PatchInfoBuffer[PatchCount - 1].AlignedSize;
}

//
// Process the next microcode patch
//
MicrocodeEntryPoint = (CPU_MICROCODE_HEADER *) (((UINTN) MicrocodeEntryPoint) + TotalSize);
} while (((UINTN) MicrocodeEntryPoint < MicrocodeEnd));

if (PatchCount != 0) {
DEBUG ((
DEBUG_INFO,
"%a: 0x%x microcode patches will be loaded into memory, with size 0x%x.\n",
__FUNCTION__, PatchCount, TotalLoadSize
));

LoadMicrocodePatchWorker (CpuMpData, PatchInfoBuffer, PatchCount, TotalLoadSize);
}

OnExit:
if (PatchInfoBuffer != NULL) {
FreePool (PatchInfoBuffer);
}
return;
}
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