[edk2-devel] [PATCH RFC v2 20/28] UefiCpuPkg/MpLib: add support to register GHCB GPA when SEV-SNP is enabled
Brijesh Singh
brijesh.singh at amd.com
Fri Apr 30 11:51:40 UTC 2021
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275
An SEV-SNP guest requires that the physical address of the GHCB must
be registered with the hypervisor before using it. See the GHCB
specification for the futher detail.
Cc: James Bottomley <jejb at linux.ibm.com>
Cc: Min Xu <min.m.xu at intel.com>
Cc: Jiewen Yao <jiewen.yao at intel.com>
Cc: Tom Lendacky <thomas.lendacky at amd.com>
Cc: Jordan Justen <jordan.l.justen at intel.com>
Cc: Ard Biesheuvel <ardb+tianocore at kernel.org>
Cc: Laszlo Ersek <lersek at redhat.com>
Cc: Erdem Aktas <erdemaktas at google.com>
Signed-off-by: Brijesh Singh <brijesh.singh at amd.com>
---
UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf | 1 +
UefiCpuPkg/Library/MpInitLib/MpEqu.inc | 1 +
UefiCpuPkg/Library/MpInitLib/MpLib.c | 2 +
UefiCpuPkg/Library/MpInitLib/MpLib.h | 2 +
UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf | 1 +
UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm | 51 ++++++++++++++++++++
6 files changed, 58 insertions(+)
diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
index d34419c2a5..48d7dfa445 100644
--- a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
+++ b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
@@ -76,3 +76,4 @@
gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaBase ## SOMETIMES_CONSUMES
gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard ## CONSUMES
gEfiMdeModulePkgTokenSpaceGuid.PcdGhcbBase ## CONSUMES
+ gUefiCpuPkgTokenSpaceGuid.PcdSevSnpIsEnabled ## CONSUMES
diff --git a/UefiCpuPkg/Library/MpInitLib/MpEqu.inc b/UefiCpuPkg/Library/MpInitLib/MpEqu.inc
index 2e9368a374..01668638f2 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpEqu.inc
+++ b/UefiCpuPkg/Library/MpInitLib/MpEqu.inc
@@ -92,6 +92,7 @@ struc MP_CPU_EXCHANGE_INFO
.ModeHighSegment: CTYPE_UINT16 1
.Enable5LevelPaging: CTYPE_BOOLEAN 1
.SevEsIsEnabled: CTYPE_BOOLEAN 1
+ .SevSnpIsEnabled CTYPE_BOOLEAN 1
.GhcbBase: CTYPE_UINTN 1
endstruc
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index 3d945972a0..c5a5da3984 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -1040,6 +1040,7 @@ FillExchangeInfoData (
DEBUG ((DEBUG_INFO, "%a: 5-Level Paging = %d\n", gEfiCallerBaseName, ExchangeInfo->Enable5LevelPaging));
ExchangeInfo->SevEsIsEnabled = CpuMpData->SevEsIsEnabled;
+ ExchangeInfo->SevSnpIsEnabled = CpuMpData->SevSnpIsEnabled;
ExchangeInfo->GhcbBase = (UINTN) CpuMpData->GhcbBase;
//
@@ -2016,6 +2017,7 @@ MpInitLibInitialize (
CpuMpData->CpuInfoInHob = (UINT64) (UINTN) (CpuMpData->CpuData + MaxLogicalProcessorNumber);
InitializeSpinLock(&CpuMpData->MpLock);
CpuMpData->SevEsIsEnabled = PcdGetBool (PcdSevEsIsEnabled);
+ CpuMpData->SevSnpIsEnabled = PcdGetBool (PcdSevSnpIsEnabled);
CpuMpData->SevEsAPBuffer = (UINTN) -1;
CpuMpData->GhcbBase = PcdGet64 (PcdGhcbBase);
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h b/UefiCpuPkg/Library/MpInitLib/MpLib.h
index e88a5355c9..4abaa2243d 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
@@ -218,6 +218,7 @@ typedef struct {
//
BOOLEAN Enable5LevelPaging;
BOOLEAN SevEsIsEnabled;
+ BOOLEAN SevSnpIsEnabled;
UINTN GhcbBase;
} MP_CPU_EXCHANGE_INFO;
@@ -287,6 +288,7 @@ struct _CPU_MP_DATA {
BOOLEAN WakeUpByInitSipiSipi;
BOOLEAN SevEsIsEnabled;
+ BOOLEAN SevSnpIsEnabled;
UINTN SevEsAPBuffer;
UINTN SevEsAPResetStackStart;
CPU_MP_DATA *NewCpuMpData;
diff --git a/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf b/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf
index 36fcb96b58..ab8279df59 100644
--- a/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf
+++ b/UefiCpuPkg/Library/MpInitLib/PeiMpInitLib.inf
@@ -65,6 +65,7 @@
gUefiCpuPkgTokenSpaceGuid.PcdSevEsIsEnabled ## CONSUMES
gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaBase ## SOMETIMES_CONSUMES
gEfiMdeModulePkgTokenSpaceGuid.PcdGhcbBase ## CONSUMES
+ gUefiCpuPkgTokenSpaceGuid.PcdSevSnpIsEnabled ## CONSUMES
[Ppis]
gEdkiiPeiShadowMicrocodePpiGuid ## SOMETIMES_CONSUMES
diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
index 50df802d1f..19939c093d 100644
--- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
+++ b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
@@ -194,9 +194,60 @@ LongModeStart:
mov rdx, rax
shr rdx, 32
mov rcx, 0xc0010130
+
+ ;
+ ; Register GHCB GPA when SEV-SNP is enabled
+ ;
+ lea edi, [esi + MP_CPU_EXCHANGE_INFO_FIELD (SevSnpIsEnabled)]
+ cmp byte [edi], 1 ; SevSnpIsEnabled
+ jne SetGhcbAddress
+
+ ; Save the rdi and rsi to used for later comparison
+ push rdi
+ push rsi
+ mov edi, eax
+ mov esi, edx
+ or eax, 18 ; Ghcb registration request
+ wrmsr
+ rep vmmcall
+ rdmsr
+ mov r12, rax
+ and r12, 0fffh
+ cmp r12, 19 ; Ghcb registration response
+ jne GhcbGpaRegisterFailure
+
+ ; Verify that GPA is not changed
+ and eax, 0fffff000h
+ cmp edi, eax
+ jne GhcbGpaRegisterFailure
+ cmp esi, edx
+ jne GhcbGpaRegisterFailure
+ pop rsi
+ pop rdi
+
+ ;
+ ; Program GHCB
+ ;
+SetGhcbAddress:
wrmsr
jmp CProcedureInvoke
+ ;
+ ; Request the guest termination
+ ;
+GhcbGpaRegisterFailure:
+ xor edx, edx
+ mov eax, 256 ; GHCB terminate
+ wrmsr
+ rep vmmcall
+
+ ; We should not return from the above terminate request, but if we do
+ ; then enter into the hlt loop.
+DoHltLoop:
+ cli
+ hlt
+ jmp DoHltLoop
+
GetApicId:
lea edi, [esi + MP_CPU_EXCHANGE_INFO_FIELD (SevEsIsEnabled)]
cmp byte [edi], 1 ; SevEsIsEnabled
--
2.17.1
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