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OvmfPkg/IoMmuDxe: Add SEV support for reserved shared memory

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Add support to use the reserved shared memory within the IoMmu library.
This improves boot times for all SEV guests, with SEV-SNP benefiting the
most as it avoids the page state change call to the hypervisor.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
This commit is contained in:
Tom Lendacky
2022-12-15 13:18:09 +08:00
committed by mergify[bot]
parent 09f01d4efb
commit 47b9521513
2 changed files with 83 additions and 53 deletions
Download Patch File Download Diff File Expand all files Collapse all files

82
OvmfPkg/IoMmuDxe/CcIoMmu.c
View File

@@ -223,30 +223,32 @@ IoMmuMap (
goto FreeMapInfo;
}
if (CC_GUEST_IS_SEV (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
if (MapInfo->ReservedMemBitmap == 0) {
//
// Clear the memory encryption mask on the plaintext buffer.
//
Status = MemEncryptSevClearPageEncMask (
0,
MapInfo->PlainTextAddress,
MapInfo->NumberOfPages
);
} else if (CC_GUEST_IS_TDX (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
//
// Set the memory shared bit.
// If MapInfo->ReservedMemBitmap is 0, it means the bounce buffer is not allocated
// from the pre-allocated shared memory, so it must be converted to shared memory here.
//
if (MapInfo->ReservedMemBitmap == 0) {
if (CC_GUEST_IS_SEV (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
//
// Clear the memory encryption mask on the plaintext buffer.
//
Status = MemEncryptSevClearPageEncMask (
0,
MapInfo->PlainTextAddress,
MapInfo->NumberOfPages
);
} else if (CC_GUEST_IS_TDX (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
//
// Set the memory shared bit.
//
Status = MemEncryptTdxSetPageSharedBit (
0,
MapInfo->PlainTextAddress,
MapInfo->NumberOfPages
);
} else {
ASSERT (FALSE);
}
} else {
ASSERT (FALSE);
}
ASSERT_EFI_ERROR (Status);
@@ -396,30 +398,30 @@ IoMmuUnmapWorker (
break;
}
if (CC_GUEST_IS_SEV (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
//
// Restore the memory encryption mask on the area we used to hold the
// plaintext.
//
Status = MemEncryptSevSetPageEncMask (
0,
MapInfo->PlainTextAddress,
MapInfo->NumberOfPages
);
} else if (CC_GUEST_IS_TDX (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
//
// Restore the memory shared bit mask on the area we used to hold the
// plaintext.
//
if (MapInfo->ReservedMemBitmap == 0) {
if (MapInfo->ReservedMemBitmap == 0) {
if (CC_GUEST_IS_SEV (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
//
// Restore the memory encryption mask on the area we used to hold the
// plaintext.
//
Status = MemEncryptSevSetPageEncMask (
0,
MapInfo->PlainTextAddress,
MapInfo->NumberOfPages
);
} else if (CC_GUEST_IS_TDX (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
//
// Restore the memory shared bit mask on the area we used to hold the
// plaintext.
//
Status = MemEncryptTdxClearPageSharedBit (
0,
MapInfo->PlainTextAddress,
MapInfo->NumberOfPages
);
} else {
ASSERT (FALSE);
}
} else {
ASSERT (FALSE);
}
ASSERT_EFI_ERROR (Status);
@@ -924,16 +926,14 @@ InstallIoMmuProtocol (
}
//
// Currently only Tdx guest support Reserved shared memory for DMA operation.
// For CC guests, use reserved shared memory for DMA operation.
//
if (CC_GUEST_IS_TDX (PcdGet64 (PcdConfidentialComputingGuestAttr))) {
mReservedSharedMemSupported = TRUE;
Status = IoMmuInitReservedSharedMem ();
if (EFI_ERROR (Status)) {
mReservedSharedMemSupported = FALSE;
} else {
DEBUG ((DEBUG_INFO, "%a: Feature of reserved memory for DMA is supported.\n", __FUNCTION__));
}
mReservedSharedMemSupported = TRUE;
Status = IoMmuInitReservedSharedMem ();
if (EFI_ERROR (Status)) {
mReservedSharedMemSupported = FALSE;
} else {
DEBUG ((DEBUG_INFO, "%a: Feature of reserved memory for DMA is supported.\n", __FUNCTION__));
}
return EFI_SUCCESS;