RETURN_STATUS
EFIAPI
QemuFwCfgInitialize (
VOID
)
{
UINT32 Signature;
UINT32 Revision;
//
// Enable the access routines while probing to see if it is supported.
// For probing we always use the IO Port (IoReadFifo8()) access method.
//
mQemuFwCfgSupported = TRUE;
mQemuFwCfgDmaSupported = FALSE;
QemuFwCfgSelectItem (QemuFwCfgItemSignature);
Signature = QemuFwCfgRead32 ();
DEBUG ((EFI_D_INFO, "FW CFG Signature: 0x%x\n", Signature));
QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);
Revision = QemuFwCfgRead32 ();
DEBUG ((EFI_D_INFO, "FW CFG Revision: 0x%x\n", Revision));
if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||
(Revision < 1)
) {
DEBUG ((EFI_D_INFO, "QemuFwCfg interface not supported.\n"));
mQemuFwCfgSupported = FALSE;
return RETURN_SUCCESS;
}
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 (mQemuFwCfgDmaSupported && MemEncryptSevIsEnabled ()) {
EFI_STATUS Status;
//
// IoMmuDxe driver must have installed the IOMMU protocol. If we are not
// able to locate the protocol then something must have gone wrong.
//
Status = gBS->LocateProtocol (&gEdkiiIoMmuProtocolGuid, NULL,
(VOID **)&mIoMmuProtocol);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR,
"QemuFwCfgSevDma %a:%a Failed to locate IOMMU protocol.\n",
gEfiCallerBaseName, __FUNCTION__));
ASSERT (FALSE);
CpuDeadLoop ();
}
}
return RETURN_SUCCESS;
}
RETURN_STATUS
EFIAPI
QemuFwCfgInitialize (
VOID
)
{
UINT32 Signature;
UINT32 Revision;
//
// Enable the access routines while probing to see if it is supported.
// For probing we always use the IO Port (IoReadFifo8()) access method.
//
mQemuFwCfgSupported = TRUE;
mQemuFwCfgDmaSupported = FALSE;
QemuFwCfgSelectItem (QemuFwCfgItemSignature);
Signature = QemuFwCfgRead32 ();
DEBUG ((EFI_D_INFO, "FW CFG Signature: 0x%x\n", Signature));
QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);
Revision = QemuFwCfgRead32 ();
DEBUG ((EFI_D_INFO, "FW CFG Revision: 0x%x\n", Revision));
if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||
(Revision < 1)
) {
DEBUG ((EFI_D_INFO, "QemuFwCfg interface not supported.\n"));
mQemuFwCfgSupported = FALSE;
return RETURN_SUCCESS;
}
if ((Revision & FW_CFG_F_DMA) == 0) {
DEBUG ((DEBUG_INFO, "QemuFwCfg interface (IO Port) is supported.\n"));
} else {
//
// 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 (MemEncryptSevIsEnabled ()) {
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;
}
EFI_STATUS
EFIAPI
AmdSevDxeEntryPoint (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
EFI_GCD_MEMORY_SPACE_DESCRIPTOR *AllDescMap;
UINTN NumEntries;
UINTN Index;
//
// Do nothing when SEV is not enabled
//
if (!MemEncryptSevIsEnabled ()) {
return EFI_UNSUPPORTED;
}
//
// Iterate through the GCD map and clear the C-bit from MMIO and NonExistent
// memory space. The NonExistent memory space will be used for mapping the MMIO
// space added later (eg PciRootBridge). By clearing both known MMIO and
// NonExistent memory space can gurantee that current and furture MMIO adds
// will have C-bit cleared.
//
Status = gDS->GetMemorySpaceMap (&NumEntries, &AllDescMap);
if (!EFI_ERROR (Status)) {
for (Index = 0; Index < NumEntries; Index++) {
CONST EFI_GCD_MEMORY_SPACE_DESCRIPTOR *Desc;
Desc = &AllDescMap[Index];
if (Desc->GcdMemoryType == EfiGcdMemoryTypeMemoryMappedIo ||
Desc->GcdMemoryType == EfiGcdMemoryTypeNonExistent) {
Status = MemEncryptSevClearPageEncMask (0,
Desc->BaseAddress,
EFI_SIZE_TO_PAGES(Desc->Length),
FALSE);
ASSERT_EFI_ERROR (Status);
}
}
FreePool (AllDescMap);
}
return EFI_SUCCESS;
}
