diff options
Diffstat (limited to 'MdePkg')
| -rw-r--r-- | MdePkg/Include/Library/BaseLib.h | 39 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/BaseLib.inf | 2 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/Ia32/VmgExitSvsm.nasm | 39 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/X64/VmgExitSvsm.nasm | 94 |
4 files changed, 174 insertions, 0 deletions
diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h index 1fff0fb224..95f805599d 100644 --- a/MdePkg/Include/Library/BaseLib.h +++ b/MdePkg/Include/Library/BaseLib.h @@ -7876,6 +7876,45 @@ AsmVmgExit ( VOID
);
+///
+/// The structure used to supply and return data to and from the SVSM.
+///
+typedef struct {
+ VOID *Caa;
+ UINT64 RaxIn;
+ UINT64 RcxIn;
+ UINT64 RdxIn;
+ UINT64 R8In;
+ UINT64 R9In;
+ UINT64 RaxOut;
+ UINT64 RcxOut;
+ UINT64 RdxOut;
+ UINT64 R8Out;
+ UINT64 R9Out;
+ UINT8 *CallPending;
+} SVSM_CALL_DATA;
+
+/**
+ Executes a VMGEXIT instruction (VMMCALL with a REP prefix) with arguments
+ and return code
+
+ Executes a VMGEXIT instruction placing the specified arguments in the
+ corresponding registers before invocation. Upon return an XCHG is done to
+ atomically clear and retrieve the SVSM call pending value. The returned RAX
+ register value becomes the function return code. This function is intended
+ for use with an SVSM. This function is only available on IA-32 and x64.
+
+ @param[in,out] SvsmCallPending Pointer to the location of the SVSM call data
+
+ @return Value of the RAX register on return
+
+**/
+UINT32
+EFIAPI
+AsmVmgExitSvsm (
+ IN OUT SVSM_CALL_DATA *SvsmCallData
+ );
+
/**
Patch the immediate operand of an IA32 or X64 instruction such that the byte,
word, dword or qword operand is encoded at the end of the instruction's
diff --git a/MdePkg/Library/BaseLib/BaseLib.inf b/MdePkg/Library/BaseLib/BaseLib.inf index 4dbe94be71..26e66a8d67 100644 --- a/MdePkg/Library/BaseLib/BaseLib.inf +++ b/MdePkg/Library/BaseLib/BaseLib.inf @@ -187,6 +187,7 @@ Ia32/XGetBv.nasm
Ia32/XSetBv.nasm
Ia32/VmgExit.nasm
+ Ia32/VmgExitSvsm.nasm
Ia32/DivS64x64Remainder.c
Ia32/InternalSwitchStack.c | MSFT
@@ -328,6 +329,7 @@ X64/XGetBv.nasm
X64/XSetBv.nasm
X64/VmgExit.nasm
+ X64/VmgExitSvsm.nasm
ChkStkGcc.c | GCC
[Sources.EBC]
diff --git a/MdePkg/Library/BaseLib/Ia32/VmgExitSvsm.nasm b/MdePkg/Library/BaseLib/Ia32/VmgExitSvsm.nasm new file mode 100644 index 0000000000..14717bd1af --- /dev/null +++ b/MdePkg/Library/BaseLib/Ia32/VmgExitSvsm.nasm @@ -0,0 +1,39 @@ +;------------------------------------------------------------------------------
+;
+; Copyright (C) 2024, Advanced Micro Devices, Inc. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+; Module Name:
+;
+; VmgExitSvsm.Asm
+;
+; Abstract:
+;
+; AsmVmgExitSvsm function
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+ DEFAULT REL
+ SECTION .text
+
+;------------------------------------------------------------------------------
+; UINT32
+; EFIAPI
+; AsmVmgExitSvsm (
+; SVSM_CALL_DATA *SvsmCallData
+; );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmVmgExitSvsm)
+ASM_PFX(AsmVmgExitSvsm):
+;
+; NASM doesn't support the vmmcall instruction in 32-bit mode and NASM versions
+; before 2.12 cannot translate the 64-bit "rep vmmcall" instruction into elf32
+; format. Given that VMGEXIT does not make sense on IA32, provide a stub
+; implementation that is identical to CpuBreakpoint(). In practice,
+; AsmVmgExitSvsm() should never be called on IA32.
+;
+ int 3
+ ret
+
diff --git a/MdePkg/Library/BaseLib/X64/VmgExitSvsm.nasm b/MdePkg/Library/BaseLib/X64/VmgExitSvsm.nasm new file mode 100644 index 0000000000..b8af788906 --- /dev/null +++ b/MdePkg/Library/BaseLib/X64/VmgExitSvsm.nasm @@ -0,0 +1,94 @@ +;------------------------------------------------------------------------------
+;
+; Copyright (C) 2024, Advanced Micro Devices, Inc. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+; Module Name:
+;
+; VmgExitSvsm.Asm
+;
+; Abstract:
+;
+; AsmVmgExitSvsm function
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+ DEFAULT REL
+ SECTION .text
+
+;------------------------------------------------------------------------------
+; typedef struct {
+; VOID *Caa;
+; UINT64 RaxIn;
+; UINT64 RcxIn;
+; UINT64 RdxIn;
+; UINT64 R8In;
+; UINT64 R9In;
+; UINT64 RaxOut;
+; UINT64 RcxOut;
+; UINT64 RdxOut;
+; UINT64 R8Out;
+; UINT64 R9Out;
+; UINT8 *CallPending;
+; } SVSM_CALL_DATA;
+;
+; UINT32
+; EFIAPI
+; AsmVmgExitSvsm (
+; SVSM_CALL_DATA *SvsmCallData
+; );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmVmgExitSvsm)
+ASM_PFX(AsmVmgExitSvsm):
+ push r10
+ push r11
+ push r12
+
+;
+; Calling convention has SvsmCallData in RCX. Move RCX to R12 in order to
+; properly populate the SVSM register state.
+;
+ mov r12, rcx
+
+ mov rax, [r12 + 8]
+ mov rcx, [r12 + 16]
+ mov rdx, [r12 + 24]
+ mov r8, [r12 + 32]
+ mov r9, [r12 + 40]
+
+;
+; Set CA call pending
+;
+ mov r10, [r12]
+ mov byte [r10], 1
+
+ rep vmmcall
+
+ mov [r12 + 48], rax
+ mov [r12 + 56], rcx
+ mov [r12 + 64], rdx
+ mov [r12 + 72], r8
+ mov [r12 + 80], r9
+
+;
+; Perform the atomic exchange and return the CA call pending value.
+; The call pending value is a one-byte field at offset 0 into the CA,
+; which is currently the value in R10.
+;
+
+ mov r11, [r12 + 88] ; Get CallPending address
+ mov cl, byte [r11]
+ xchg byte [r10], cl
+ mov byte [r11], cl ; Return the exchanged value
+
+ pop r12
+ pop r11
+ pop r10
+
+;
+; RAX has the value to be returned from the SVSM
+;
+ ret
+
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