On 05/11/17 00:09, Brijesh Singh wrote:
> 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(-)
Reviewed-by: Laszlo Ersek <ler...@redhat.com>
Thanks,
Laszlo
> 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 ();
> +}
>
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