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OvmfPkg/ResetVector: add the macro to request guest termination 

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275

The upcoming SEV-SNP support will need to make a few additional guest
termination requests depending on the failure type. Let's move the logic
to request the guest termination into a macro to keep the code readable.

Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Acked-by: Ard Biesheuvel <ardb+tianocore@kernel.org>
Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
This commit is contained in:
Brijesh Singh via groups.io 2021-07-28 02:10:24 +08:00 committed by mergify[bot]
parent 7f05102f65
commit dc485c556d
1 changed files with 45 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

87
OvmfPkg/ResetVector/Ia32/AmdSev.asm
View File

@ -38,6 +38,13 @@ BITS 32
%define SEV_GHCB_MSR 0xc0010130
%define SEV_STATUS_MSR 0xc0010131
; The #VC was not for CPUID
%define TERM_VC_NOT_CPUID 1
; The unexpected response code
%define TERM_UNEXPECTED_RESP_CODE 2
; Macro is used to issue the MSR protocol based VMGEXIT. The caller is
; responsible to populate values in the EDX:EAX registers. After the vmmcall
; returns, it verifies that the response code matches with the expected
@ -73,6 +80,43 @@ BITS 32
jne SevEsUnexpectedRespTerminate
%endmacro
; Macro to terminate the guest using the VMGEXIT.
; arg 1: reason code
%macro TerminateVmgExit 1
mov eax, %1
;
; Use VMGEXIT to request termination. At this point the reason code is
; located in EAX, so shift it left 16 bits to the proper location.
;
; EAX[11:0] => 0x100 - request termination
; EAX[15:12] => 0x1 - OVMF
; EAX[23:16] => 0xXX - REASON CODE
;
shl eax, 16
or eax, 0x1100
xor edx, edx
mov ecx, SEV_GHCB_MSR
wrmsr
;
; Issue VMGEXIT - NASM doesn't support the vmmcall instruction in 32-bit
; mode, so work around this by temporarily switching to 64-bit mode.
;
BITS 64
rep vmmcall
BITS 32
;
; We shouldn't come back from the VMGEXIT, but if we do, just loop.
;
%%TerminateHlt:
hlt
jmp %%TerminateHlt
%endmacro
; Terminate the guest due to unexpected response code.
SevEsUnexpectedRespTerminate:
TerminateVmgExit TERM_UNEXPECTED_RESP_CODE
; Check if Secure Encrypted Virtualization (SEV) features are enabled.
;
; Register usage is tight in this routine, so multiple calls for the
@ -227,48 +271,7 @@ SevEsDisabled:
;
SevEsIdtNotCpuid:
;
; Use VMGEXIT to request termination.
; 1 - #VC was not for CPUID
;
mov eax, 1
jmp SevEsIdtTerminate
SevEsUnexpectedRespTerminate:
;
; Use VMGEXIT to request termination.
; 2 - Unexpected Response is received
;
mov eax, 2
SevEsIdtTerminate:
;
; Use VMGEXIT to request termination. At this point the reason code is
; located in EAX, so shift it left 16 bits to the proper location.
;
; EAX[11:0] => 0x100 - request termination
; EAX[15:12] => 0x1 - OVMF
; EAX[23:16] => 0xXX - REASON CODE
;
shl eax, 16
or eax, 0x1100
xor edx, edx
mov ecx, SEV_GHCB_MSR
wrmsr
;
; Issue VMGEXIT - NASM doesn't support the vmmcall instruction in 32-bit
; mode, so work around this by temporarily switching to 64-bit mode.
;
BITS 64
rep vmmcall
BITS 32
;
; We shouldn't come back from the VMGEXIT, but if we do, just loop.
;
SevEsIdtHlt:
hlt
jmp SevEsIdtHlt
TerminateVmgExit TERM_VC_NOT_CPUID
iret
;