mirror of https://github.com/acidanthera/audk.git
OvmfPkg/QemuFwCfgLib: rewrite fw_cfg probe
Move the code to a new QemuFwCfgProbe() function. Use direct Io*() calls instead of indirect QemuFwCfg*() calls to make sure we don't get recursive calls. Also simplify CC guest detection. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Ard Biesheuvel <ardb@kernel.org>
This commit is contained in:
Gerd Hoffmann
mergify[bot]
parent
e59747bd82
commit
81bbc1452c
|
|
@ -13,7 +13,6 @@
|
|||
#include <Library/IoLib.h>
|
||||
#include <Library/DebugLib.h>
|
||||
#include <Library/QemuFwCfgLib.h>
|
||||
#include <Library/MemEncryptSevLib.h>
|
||||
#include <WorkArea.h>
|
||||
|
||||
#include "QemuFwCfgLibInternal.h"
|
||||
|
|
@ -27,15 +26,16 @@ STATIC BOOLEAN mQemuFwCfgDmaSupported;
|
|||
@retval TRUE It is Tdx guest
|
||||
@retval FALSE It is not Tdx guest
|
||||
**/
|
||||
STATIC
|
||||
BOOLEAN
|
||||
QemuFwCfgIsTdxGuest (
|
||||
QemuFwCfgIsCcGuest (
|
||||
VOID
|
||||
)
|
||||
{
|
||||
CONFIDENTIAL_COMPUTING_WORK_AREA_HEADER *CcWorkAreaHeader;
|
||||
|
||||
CcWorkAreaHeader = (CONFIDENTIAL_COMPUTING_WORK_AREA_HEADER *)FixedPcdGet32 (PcdOvmfWorkAreaBase);
|
||||
return (CcWorkAreaHeader != NULL && CcWorkAreaHeader->GuestType == CcGuestTypeIntelTdx);
|
||||
return (CcWorkAreaHeader != NULL && CcWorkAreaHeader->GuestType != CcGuestTypeNonEncrypted);
|
||||
}
|
||||
|
||||
/**
|
||||
|
|
@ -57,62 +57,49 @@ QemuFwCfgIsAvailable (
|
|||
return InternalQemuFwCfgIsAvailable ();
|
||||
}
|
||||
|
||||
STATIC
|
||||
VOID
|
||||
QemuFwCfgProbe (
|
||||
BOOLEAN *Supported,
|
||||
BOOLEAN *DmaSupported
|
||||
)
|
||||
{
|
||||
UINT32 Signature;
|
||||
UINT32 Revision;
|
||||
BOOLEAN CcGuest;
|
||||
|
||||
// Use direct Io* calls for probing to avoid recursion.
|
||||
IoWrite16 (FW_CFG_IO_SELECTOR, (UINT16)QemuFwCfgItemSignature);
|
||||
IoReadFifo8 (FW_CFG_IO_DATA, sizeof Signature, &Signature);
|
||||
IoWrite16 (FW_CFG_IO_SELECTOR, (UINT16)QemuFwCfgItemInterfaceVersion);
|
||||
IoReadFifo8 (FW_CFG_IO_DATA, sizeof Revision, &Revision);
|
||||
CcGuest = QemuFwCfgIsCcGuest ();
|
||||
|
||||
*Supported = FALSE;
|
||||
*DmaSupported = FALSE;
|
||||
if ((Signature == SIGNATURE_32 ('Q', 'E', 'M', 'U')) && (Revision >= 1)) {
|
||||
*Supported = TRUE;
|
||||
if ((Revision & FW_CFG_F_DMA) && !CcGuest) {
|
||||
*DmaSupported = TRUE;
|
||||
}
|
||||
}
|
||||
|
||||
DEBUG ((
|
||||
DEBUG_INFO,
|
||||
"%a: Supported %d, DMA %d\n",
|
||||
__func__,
|
||||
*Supported,
|
||||
*DmaSupported
|
||||
));
|
||||
}
|
||||
|
||||
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 ((DEBUG_INFO, "FW CFG Signature: 0x%x\n", Signature));
|
||||
QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);
|
||||
Revision = QemuFwCfgRead32 ();
|
||||
DEBUG ((DEBUG_INFO, "FW CFG Revision: 0x%x\n", Revision));
|
||||
if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||
|
||||
(Revision < 1)
|
||||
)
|
||||
{
|
||||
DEBUG ((DEBUG_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 if (QemuFwCfgIsTdxGuest ()) {
|
||||
//
|
||||
// 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"));
|
||||
}
|
||||
}
|
||||
|
||||
QemuFwCfgProbe (&mQemuFwCfgSupported, &mQemuFwCfgDmaSupported);
|
||||
return RETURN_SUCCESS;
|
||||
}
|
||||
|
||||
|
|
@ -183,17 +170,11 @@ InternalQemuFwCfgDmaBytes (
|
|||
return;
|
||||
}
|
||||
|
||||
//
|
||||
// SEV does not support DMA operations in PEI stage, we should
|
||||
// not have reached here.
|
||||
//
|
||||
ASSERT (!MemEncryptSevIsEnabled ());
|
||||
|
||||
//
|
||||
// TDX does not support DMA operations in PEI stage, we should
|
||||
// not have reached here.
|
||||
//
|
||||
ASSERT (!QemuFwCfgIsTdxGuest ());
|
||||
ASSERT (!QemuFwCfgIsCcGuest ());
|
||||
|
||||
Access.Control = SwapBytes32 (Control);
|
||||
Access.Length = SwapBytes32 (Size);
|
||||
|
|
|
|||
|
|
@ -41,7 +41,6 @@
|
|||
DebugLib
|
||||
IoLib
|
||||
MemoryAllocationLib
|
||||
MemEncryptSevLib
|
||||
|
||||
[Pcd]
|
||||
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaBase
|
||||
|
|
|
|||
Loading…
Reference in New Issue