RFC： https://bugzilla.tianocore.org/show_bug.cgi?id=3429
If TDX is enabled then we do not support DMA operation in PEI phase. This is mainly because DMA in TDX guest requires using bounce buffer (which need to allocate dynamic memory and allocating a PAGE size'd buffer can be challenge in PEI phase). Cc: Ard Biesheuvel <[email protected]> Cc: Jordan Justen <[email protected]> Cc: Brijesh Singh <[email protected]> Cc: Erdem Aktas <[email protected]> Cc: James Bottomley <[email protected]> Cc: Jiewen Yao <[email protected]> Cc: Tom Lendacky <[email protected]> Signed-off-by: Min Xu <[email protected]> --- OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c | 15 +++++++++++++++ OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf | 1 + 2 files changed, 16 insertions(+) diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c index ecabd88fab66..aae5f2fcb51f 100644 --- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c @@ -14,6 +14,7 @@ #include <Library/DebugLib.h> #include <Library/QemuFwCfgLib.h> #include <Library/MemEncryptSevLib.h> +#include <Library/TdxProbeLib.h> #include "QemuFwCfgLibInternal.h" @@ -82,6 +83,14 @@ QemuFwCfgInitialize ( // if (MemEncryptSevIsEnabled ()) { DEBUG ((DEBUG_INFO, "SEV: QemuFwCfg fallback to IO Port interface.\n")); + } else if (TdxIsEnabled ()) { + // + // If TDX is enabled then we do not support DMA operations in PEI phase. + // This is mainly because DMA in TDX guest requires using bounce buffer + // (which need to allocate dynamic memory and allocating a PAGE size'd + // buffer can be challenge in PEI phase) + // + DEBUG ((DEBUG_INFO, "TDX: QemuFwCfg fallback to IO Port interface.\n")); } else { mQemuFwCfgDmaSupported = TRUE; DEBUG ((DEBUG_INFO, "QemuFwCfg interface (DMA) is supported.\n")); @@ -162,6 +171,12 @@ InternalQemuFwCfgDmaBytes ( // ASSERT (!MemEncryptSevIsEnabled ()); + // + // TDX does not support DMA operations in PEI stage, we should + // not have reached here. + // + ASSERT (!TdxIsEnabled ()); + Access.Control = SwapBytes32 (Control); Access.Length = SwapBytes32 (Size); Access.Address = SwapBytes64 ((UINTN)Buffer); diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf index 9f9af7d03201..808cb16f75e1 100644 --- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf @@ -42,4 +42,5 @@ IoLib MemoryAllocationLib MemEncryptSevLib + TdxProbeLib -- 2.29.2.windows.2 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#79175): https://edk2.groups.io/g/devel/message/79175 Mute This Topic: https://groups.io/mt/84837915/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
