Cc: Jordan Justen <jordan.l.jus...@intel.com> Cc: Laszlo Ersek <ler...@redhat.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Brijesh Singh <brijesh.si...@amd.com> --- OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf | 1 + OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c | 72 +++++++++++++++++++- 2 files changed, 71 insertions(+), 2 deletions(-)
diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf index 4f966a85088a..b97b475c7cad 100644 --- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf @@ -47,4 +47,5 @@ [LibraryClasses] DebugLib IoLib MemoryAllocationLib + MemEncryptSevLib diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c index ac05f4c347f3..1696512bccaf 100644 --- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c @@ -4,6 +4,7 @@ Copyright (C) 2013, Red Hat, Inc. Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR> + Copyright (c) 2017, Advanced Micro Devices. All rights reserved.<BR> This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this @@ -14,8 +15,10 @@ WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. **/ +#include <Library/BaseLib.h> #include <Library/DebugLib.h> #include <Library/QemuFwCfgLib.h> +#include <Library/MemEncryptSevLib.h> #include "QemuFwCfgLibInternal.h" @@ -76,8 +79,18 @@ QemuFwCfgInitialize ( if ((Revision & FW_CFG_F_DMA) == 0) { DEBUG ((DEBUG_INFO, "QemuFwCfg interface (IO Port) is supported.\n")); } else { - mQemuFwCfgDmaSupported = TRUE; - DEBUG ((DEBUG_INFO, "QemuFwCfg interface (DMA) is supported.\n")); + // + // If SEV is enabled then we do not support DMA operations in PEI phase. + // This is mainly because DMA in SEV guest requires using bounce buffer + // (which need to allocate dynamic memory and allocating a PAGE size'd + // buffer can be challenge in PEI phase) + // + if (InternalQemuFwCfgSevIsEnabled ()) { + DEBUG ((DEBUG_INFO, "SEV: QemuFwCfg fallback to IO Port interface.\n")); + } else { + mQemuFwCfgDmaSupported = TRUE; + DEBUG ((DEBUG_INFO, "QemuFwCfg interface (DMA) is supported.\n")); + } } return RETURN_SUCCESS; } @@ -114,3 +127,58 @@ InternalQemuFwCfgDmaIsAvailable ( { return mQemuFwCfgDmaSupported; } + +/** + + Returns a boolean indicating whether SEV is enabled + + @retval TRUE SEV is enabled + @retval FALSE SEV is disabled +**/ +BOOLEAN +InternalQemuFwCfgSevIsEnabled ( + VOID + ) +{ + return MemEncryptSevIsEnabled (); +} + +/** + Allocate a bounce buffer for SEV DMA. + + @param[in] NumPage Number of pages. + @param[out] Buffer Allocated DMA Buffer pointer + +**/ +VOID +InternalQemuFwCfgSevDmaAllocateBuffer ( + IN UINT32 NumPages, + OUT VOID **Buffer + ) +{ + // + // We should never reach here + // + ASSERT (FALSE); + CpuDeadLoop (); +} + +/** + Free the DMA buffer allocated using InternalQemuFwCfgSevDmaAllocateBuffer + + @param[in] NumPage Number of pages. + @param[in] Buffer DMA Buffer pointer + +**/ +VOID +InternalQemuFwCfgSevDmaFreeBuffer ( + IN VOID *Buffer, + IN UINT32 NumPages + ) +{ + // + // We should never reach here + // + ASSERT (FALSE); + CpuDeadLoop (); +} -- 2.7.4 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel