From 13a47cf9251b11d07e25027dc13d3f4a0f5c17ed Mon Sep 17 00:00:00 2001 From: Ruiyu Ni Date: Mon, 21 Jan 2019 23:16:22 +0800 Subject: [PATCH] UefiCpuPkg/MtrrLib: Fix a bug that may wrongly set memory <1MB to UC REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1481 Today's MtrrLib contains a bug, for example: when the original cache setting is WB for [0xF_0000, 0xF_8000) and, a new request to set [0xF_0000, 0xF_4000) to WP, the cache setting for [0xF_4000, 0xF_8000) is reset to UC. The reason is when MtrrLibSetBelow1MBMemoryAttribute() is called the WorkingFixedSettings doesn't contain the actual MSR value stored in hardware, but when writing the fixed MTRRs, the code logic assumes WorkingFixedSettings contains the actual MSR value. The new fix is to change MtrrLibSetBelow1MBMemoryAttribute() to calculate the correct ClearMasks[] and OrMasks[], and use them directly when writing the fixed MTRRs. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ray Ni Reviewed-by: Eric Dong Reviewed-by: Chasel Chiu --- UefiCpuPkg/Library/MtrrLib/MtrrLib.c | 59 +++++++++------------------- 1 file changed, 18 insertions(+), 41 deletions(-) diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c index 086f7ad8f0..590b91abf5 100644 --- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c +++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c @@ -5,7 +5,7 @@ Most of services in this library instance are suggested to be invoked by BSP only, except for MtrrSetAllMtrrs() which is used to sync BSP's MTRR setting to APs. - Copyright (c) 2008 - 2018, Intel Corporation. All rights reserved.
+ Copyright (c) 2008 - 2019, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -2099,8 +2099,8 @@ MtrrLibSetMemoryRanges ( Set the below-1MB memory attribute to fixed MTRR buffer. Modified flag array indicates which fixed MTRR is modified. - @param [in, out] FixedSettings Fixed MTRR buffer. - @param [out] Modified Flag array indicating which MTRR is modified. + @param [in, out] ClearMasks The bits (when set) to clear in the fixed MTRR MSR. + @param [in, out] OrMasks The bits to set in the fixed MTRR MSR. @param [in] BaseAddress Base address. @param [in] Length Length. @param [in] Type Memory type. @@ -2111,8 +2111,8 @@ MtrrLibSetMemoryRanges ( **/ RETURN_STATUS MtrrLibSetBelow1MBMemoryAttribute ( - IN OUT MTRR_FIXED_SETTINGS *FixedSettings, - OUT BOOLEAN *Modified, + IN OUT UINT64 *ClearMasks, + IN OUT UINT64 *OrMasks, IN PHYSICAL_ADDRESS BaseAddress, IN UINT64 Length, IN MTRR_MEMORY_CACHE_TYPE Type @@ -2122,36 +2122,17 @@ MtrrLibSetBelow1MBMemoryAttribute ( UINT32 MsrIndex; UINT64 ClearMask; UINT64 OrMask; - UINT64 ClearMasks[ARRAY_SIZE (mMtrrLibFixedMtrrTable)]; - UINT64 OrMasks[ARRAY_SIZE (mMtrrLibFixedMtrrTable)]; - BOOLEAN LocalModified[ARRAY_SIZE (mMtrrLibFixedMtrrTable)]; ASSERT (BaseAddress < BASE_1MB); - SetMem (LocalModified, sizeof (LocalModified), FALSE); - - // - // (Value & ~0 | 0) still equals to (Value) - // - SetMem (ClearMasks, sizeof (ClearMasks), 0); - SetMem (OrMasks, sizeof (OrMasks), 0); - MsrIndex = (UINT32)-1; while ((BaseAddress < BASE_1MB) && (Length != 0)) { Status = MtrrLibProgramFixedMtrr (Type, &BaseAddress, &Length, &MsrIndex, &ClearMask, &OrMask); if (RETURN_ERROR (Status)) { return Status; } - ClearMasks[MsrIndex] = ClearMask; - OrMasks[MsrIndex] = OrMask; - Modified[MsrIndex] = TRUE; - LocalModified[MsrIndex] = TRUE; - } - - for (MsrIndex = 0; MsrIndex < ARRAY_SIZE (mMtrrLibFixedMtrrTable); MsrIndex++) { - if (LocalModified[MsrIndex]) { - FixedSettings->Mtrr[MsrIndex] = (FixedSettings->Mtrr[MsrIndex] & ~ClearMasks[MsrIndex]) | OrMasks[MsrIndex]; - } + ClearMasks[MsrIndex] = ClearMasks[MsrIndex] | ClearMask; + OrMasks[MsrIndex] = (OrMasks[MsrIndex] & ~ClearMask) | OrMask; } return RETURN_SUCCESS; } @@ -2213,8 +2194,8 @@ MtrrSetMemoryAttributesInMtrrSettings ( MTRR_MEMORY_RANGE WorkingVariableMtrr[ARRAY_SIZE (MtrrSetting->Variables.Mtrr)]; BOOLEAN VariableSettingModified[ARRAY_SIZE (MtrrSetting->Variables.Mtrr)]; - BOOLEAN FixedSettingsModified[ARRAY_SIZE (mMtrrLibFixedMtrrTable)]; - MTRR_FIXED_SETTINGS WorkingFixedSettings; + UINT64 ClearMasks[ARRAY_SIZE (mMtrrLibFixedMtrrTable)]; + UINT64 OrMasks[ARRAY_SIZE (mMtrrLibFixedMtrrTable)]; MTRR_CONTEXT MtrrContext; BOOLEAN MtrrContextValid; @@ -2226,10 +2207,6 @@ MtrrSetMemoryAttributesInMtrrSettings ( // TRUE indicating the accordingly Variable setting needs modificaiton in OriginalVariableMtrr. // SetMem (VariableSettingModified, ARRAY_SIZE (VariableSettingModified), FALSE); - // - // TRUE indicating the accordingly Fixed setting needs modification in WorkingFixedSettings. - // - SetMem (FixedSettingsModified, ARRAY_SIZE (FixedSettingsModified), FALSE); // // TRUE indicating the caller requests to set variable MTRRs. @@ -2405,14 +2382,17 @@ MtrrSetMemoryAttributesInMtrrSettings ( // // 3. Apply the below-1MB memory attribute settings. // - ZeroMem (WorkingFixedSettings.Mtrr, sizeof (WorkingFixedSettings.Mtrr)); + // (Value & ~0 | 0) still equals to (Value) + // + ZeroMem (ClearMasks, sizeof (ClearMasks)); + ZeroMem (OrMasks, sizeof (OrMasks)); for (Index = 0; Index < RangeCount; Index++) { if (Ranges[Index].BaseAddress >= BASE_1MB) { continue; } Status = MtrrLibSetBelow1MBMemoryAttribute ( - &WorkingFixedSettings, FixedSettingsModified, + ClearMasks, OrMasks, Ranges[Index].BaseAddress, Ranges[Index].Length, Ranges[Index].Type ); if (RETURN_ERROR (Status)) { @@ -2424,19 +2404,16 @@ MtrrSetMemoryAttributesInMtrrSettings ( // // 4. Write fixed MTRRs that have been modified // - for (Index = 0; Index < ARRAY_SIZE (FixedSettingsModified); Index++) { - if (FixedSettingsModified[Index]) { + for (Index = 0; Index < ARRAY_SIZE (ClearMasks); Index++) { + if (ClearMasks[Index] != 0) { if (MtrrSetting != NULL) { - MtrrSetting->Fixed.Mtrr[Index] = WorkingFixedSettings.Mtrr[Index]; + MtrrSetting->Fixed.Mtrr[Index] = (MtrrSetting->Fixed.Mtrr[Index] & ~ClearMasks[Index]) | OrMasks[Index]; } else { if (!MtrrContextValid) { MtrrLibPreMtrrChange (&MtrrContext); MtrrContextValid = TRUE; } - AsmWriteMsr64 ( - mMtrrLibFixedMtrrTable[Index].Msr, - WorkingFixedSettings.Mtrr[Index] - ); + AsmMsrAndThenOr64 (mMtrrLibFixedMtrrTable[Index].Msr, ~ClearMasks[Index], OrMasks[Index]); } } } -- 2.39.2