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UefiCpuPkg/MpInitLib: Always use AP Create if GhcbApicIds HOB is present

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BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654

Currently, the first time an AP is started for an SEV-SNP guest, it relies
on the VMSA as set by the hypervisor. If the list of APIC IDs has been
retrieved, this is not necessary. The list of APIC IDs will be identified
by a GUIDed HOB. If the GUIDed HOB is present, use the SEV-SNP AP Create
protocol to start the AP for the first time and each time thereafter.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Ray Ni <ray.ni@intel.com>
This commit is contained in:
Tom Lendacky
2024-03-08 07:30:33 -08:00
committed by mergify[bot]
parent 8a6471819b
commit 5bdb091133
8 changed files with 133 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

78
UefiCpuPkg/Library/MpInitLib/X64/AmdSev.c
View File

@@ -2,7 +2,7 @@
AMD SEV helper function.
Copyright (c) 2021, AMD Incorporated. All rights reserved.<BR>
Copyright (c) 2021 - 2024, AMD Incorporated. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -268,20 +268,55 @@ SevSnpCreateAP (
IN INTN ProcessorNumber
)
{
CPU_INFO_IN_HOB *CpuInfoInHob;
CPU_AP_DATA *CpuData;
UINTN Index;
UINT32 ApicId;
CPU_INFO_IN_HOB *CpuInfoInHob;
CPU_AP_DATA *CpuData;
UINTN Index;
UINTN MaxIndex;
UINT32 ApicId;
EFI_HOB_GUID_TYPE *GuidHob;
GHCB_APIC_IDS *GhcbApicIds;
ASSERT (CpuMpData->MpCpuExchangeInfo->BufferStart < 0x100000);
CpuInfoInHob = (CPU_INFO_IN_HOB *)(UINTN)CpuMpData->CpuInfoInHob;
if (ProcessorNumber < 0) {
for (Index = 0; Index < CpuMpData->CpuCount; Index++) {
if (CpuMpData->InitFlag == ApInitConfig) {
//
// APs have not been started, so CpuCount is not "known" yet. Use the
// retrieved APIC IDs to start the APs and fill out the MpLib CPU
// information properly. CanUseSevSnpCreateAP() guarantees we have a
// HOB when InitFlag is ApInitConfig.
//
GuidHob = GetFirstGuidHob (&gGhcbApicIdsGuid);
GhcbApicIds = (GHCB_APIC_IDS *)(*(UINTN *)GET_GUID_HOB_DATA (GuidHob));
MaxIndex = MIN (GhcbApicIds->NumEntries, PcdGet32 (PcdCpuMaxLogicalProcessorNumber));
} else {
//
// APs have been previously started.
//
MaxIndex = CpuMpData->CpuCount;
}
for (Index = 0; Index < MaxIndex; Index++) {
if (Index != CpuMpData->BspNumber) {
CpuData = &CpuMpData->CpuData[Index];
ApicId = CpuInfoInHob[Index].ApicId,
if (CpuMpData->InitFlag == ApInitConfig) {
ApicId = GhcbApicIds->ApicIds[Index];
//
// For the first boot, use the BSP register information.
//
CopyMem (
&CpuData->VolatileRegisters,
&CpuMpData->CpuData[0].VolatileRegisters,
sizeof (CpuData->VolatileRegisters)
);
} else {
ApicId = CpuInfoInHob[Index].ApicId;
}
SevSnpCreateSaveArea (CpuMpData, CpuData, ApicId);
}
}
@@ -325,3 +360,32 @@ SevSnpRmpAdjust (
return AsmRmpAdjust ((UINT64)PageAddress, 0, Rdx);
}
/**
Determine if the SEV-SNP AP Create protocol should be used.
@param[in] CpuMpData Pointer to CPU MP Data
@retval TRUE Use SEV-SNP AP Create protocol
@retval FALSE Do not use SEV-SNP AP Create protocol
**/
BOOLEAN
CanUseSevSnpCreateAP (
IN CPU_MP_DATA *CpuMpData
)
{
//
// The AP Create protocol is used for an SEV-SNP guest if
// - The initial configuration has been performed already or
// - The APIC IDs GUIDed HOB is non-zero.
//
if (!CpuMpData->SevSnpIsEnabled) {
return FALSE;
}
if ((CpuMpData->InitFlag == ApInitConfig) && (GetFirstGuidHob (&gGhcbApicIdsGuid) == NULL)) {
return FALSE;
}
return TRUE;
}