[edk2-devel] [PATCH V2 8/9] MdeModulePkg/Variable: Add RT GetNextVariableName() cache support
Kubacki, Michael A
michael.a.kubacki at intel.com
Sat Sep 28 01:47:16 UTC 2019
https://bugzilla.tianocore.org/show_bug.cgi?id=2220
This change implements the Runtime Service GetNextVariableName()
using the Runtime Cache in VariableSmmRuntimeDxe. Runtime Service
calls to GetNextVariableName() will no longer trigger a SW SMI.
Overall system performance and stability will be improved by
eliminating an SMI for these calls as they typically result in a
relatively large number of invocations to retrieve all variable
names in all variable stores present.
Cc: Dandan Bi <dandan.bi at intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel at linaro.org>
Cc: Eric Dong <eric.dong at intel.com>
Cc: Laszlo Ersek <lersek at redhat.com>
Cc: Liming Gao <liming.gao at intel.com>
Cc: Michael D Kinney <michael.d.kinney at intel.com>
Cc: Ray Ni <ray.ni at intel.com>
Cc: Jian J Wang <jian.j.wang at intel.com>
Cc: Hao A Wu <hao.a.wu at intel.com>
Cc: Jiewen Yao <jiewen.yao at intel.com>
Signed-off-by: Michael Kubacki <michael.a.kubacki at intel.com>
---
MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c | 118 +++++++++-----------
1 file changed, 50 insertions(+), 68 deletions(-)
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c
index 46f69765a4..bc3b56b0ce 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c
@@ -799,87 +799,69 @@ RuntimeServiceGetNextVariableName (
IN OUT EFI_GUID *VendorGuid
)
{
- EFI_STATUS Status;
- UINTN PayloadSize;
- SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME *SmmGetNextVariableName;
- UINTN OutVariableNameSize;
- UINTN InVariableNameSize;
+ EFI_STATUS Status;
+ UINTN DelayIndex;
+ UINTN MaxLen;
+ UINTN VarNameSize;
+ VARIABLE_HEADER *VariablePtr;
+ VARIABLE_STORE_HEADER *VariableStoreHeader[VariableStoreTypeMax];
+
+ Status = EFI_NOT_FOUND;
if (VariableNameSize == NULL || VariableName == NULL || VendorGuid == NULL) {
return EFI_INVALID_PARAMETER;
}
- OutVariableNameSize = *VariableNameSize;
- InVariableNameSize = StrSize (VariableName);
- SmmGetNextVariableName = NULL;
-
//
- // If input string exceeds SMM payload limit. Return failure
+ // Calculate the possible maximum length of name string, including the Null terminator.
//
- if (InVariableNameSize > mVariableBufferPayloadSize - OFFSET_OF (SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME, Name)) {
+ MaxLen = *VariableNameSize / sizeof (CHAR16);
+ if ((MaxLen == 0) || (StrnLenS (VariableName, MaxLen) == MaxLen)) {
+ //
+ // Null-terminator is not found in the first VariableNameSize bytes of the input VariableName buffer,
+ // follow spec to return EFI_INVALID_PARAMETER.
+ //
return EFI_INVALID_PARAMETER;
}
- AcquireLockOnlyAtBootTime(&mVariableServicesLock);
+ AcquireLockOnlyAtBootTime (&mVariableServicesLock);
- //
- // Init the communicate buffer. The buffer data size is:
- // SMM_COMMUNICATE_HEADER_SIZE + SMM_VARIABLE_COMMUNICATE_HEADER_SIZE + PayloadSize.
- //
- if (OutVariableNameSize > mVariableBufferPayloadSize - OFFSET_OF (SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME, Name)) {
- //
- // If output buffer exceed SMM payload limit. Trim output buffer to SMM payload size
- //
- OutVariableNameSize = mVariableBufferPayloadSize - OFFSET_OF (SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME, Name);
+ for (DelayIndex = 0; mVariableRuntimeCacheReadLock && DelayIndex < VARIABLE_RT_CACHE_READ_LOCK_TIMEOUT; DelayIndex++) {
+ MicroSecondDelay (10);
}
- //
- // Payload should be Guid + NameSize + MAX of Input & Output buffer
- //
- PayloadSize = OFFSET_OF (SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME, Name) + MAX (OutVariableNameSize, InVariableNameSize);
-
- Status = InitCommunicateBuffer ((VOID **)&SmmGetNextVariableName, PayloadSize, SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME);
- if (EFI_ERROR (Status)) {
- goto Done;
- }
- ASSERT (SmmGetNextVariableName != NULL);
-
- //
- // SMM comm buffer->NameSize is buffer size for return string
- //
- SmmGetNextVariableName->NameSize = OutVariableNameSize;
-
- CopyGuid (&SmmGetNextVariableName->Guid, VendorGuid);
- //
- // Copy whole string
- //
- CopyMem (SmmGetNextVariableName->Name, VariableName, InVariableNameSize);
- if (OutVariableNameSize > InVariableNameSize) {
- ZeroMem ((UINT8 *) SmmGetNextVariableName->Name + InVariableNameSize, OutVariableNameSize - InVariableNameSize);
- }
-
- //
- // Send data to SMM
- //
- Status = SendCommunicateBuffer (PayloadSize);
-
- //
- // Get data from SMM.
- //
- if (Status == EFI_SUCCESS || Status == EFI_BUFFER_TOO_SMALL) {
- //
- // SMM CommBuffer NameSize can be a trimed value
- // Only update VariableNameSize when needed
- //
- *VariableNameSize = SmmGetNextVariableName->NameSize;
- }
- if (EFI_ERROR (Status)) {
- goto Done;
+ if (DelayIndex < VARIABLE_RT_CACHE_READ_LOCK_TIMEOUT) {
+ ASSERT (!mVariableRuntimeCacheReadLock);
+
+ CheckForRuntimeCacheSync ();
+ mVariableRuntimeCacheReadLock = TRUE;
+
+ if (!mVariableRuntimeCachePendingUpdate) {
+ //
+ // 0: Volatile, 1: HOB, 2: Non-Volatile.
+ // The index and attributes mapping must be kept in this order as FindVariable
+ // makes use of this mapping to implement search algorithm.
+ //
+ VariableStoreHeader[VariableStoreTypeVolatile] = mVariableRuntimeVolatileCacheBuffer;
+ VariableStoreHeader[VariableStoreTypeHob] = mVariableRuntimeHobCacheBuffer;
+ VariableStoreHeader[VariableStoreTypeNv] = mVariableRuntimeNvCacheBuffer;
+
+ Status = GetNextVariableEx (VariableName, VendorGuid, VariableStoreHeader, &VariablePtr);
+ if (!EFI_ERROR (Status)) {
+ VarNameSize = NameSizeOfVariable (VariablePtr);
+ ASSERT (VarNameSize != 0);
+ if (VarNameSize <= *VariableNameSize) {
+ CopyMem (VariableName, GetVariableNamePtr (VariablePtr), VarNameSize);
+ CopyMem (VendorGuid, GetVendorGuidPtr (VariablePtr), sizeof (EFI_GUID));
+ Status = EFI_SUCCESS;
+ } else {
+ Status = EFI_BUFFER_TOO_SMALL;
+ }
+
+ *VariableNameSize = VarNameSize;
+ }
+ }
}
-
- CopyGuid (VendorGuid, &SmmGetNextVariableName->Guid);
- CopyMem (VariableName, SmmGetNextVariableName->Name, SmmGetNextVariableName->NameSize);
-
-Done:
+ mVariableRuntimeCacheReadLock = FALSE;
ReleaseLockOnlyAtBootTime (&mVariableServicesLock);
return Status;
}
--
2.16.2.windows.1
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