On 05/22/20 16:48, Laszlo Ersek wrote:
> On 05/19/20 23:50, Lendacky, Thomas wrote:
>> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198
>>
>> Under SEV-ES, a VMMCALL intercept generates a #VC exception. VMGEXIT must
>> be used to allow the hypervisor to handle this intercept.
>>
>> Cc: Jordan Justen <jordan.l.jus...@intel.com>
>> Cc: Laszlo Ersek <ler...@redhat.com>
>> Cc: Ard Biesheuvel <ard.biesheu...@arm.com>
>> Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
>> ---
>>  .../Library/VmgExitLib/X64/VmgExitVcHandler.c | 48 +++++++++++++++++++
>>  1 file changed, 48 insertions(+)
>>
>> diff --git a/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c 
>> b/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c
>> index 0b7f24fd962c..bf1555234d69 100644
>> --- a/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c
>> +++ b/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c
>> @@ -875,6 +875,50 @@ WbinvdExit (
>>    return 0;
>>  }
>>  
>> +/**
>> +  Handle a VMMCALL event.
>> +
>> +  Use the VMGEXIT instruction to handle either a VMMCALL event.

(2) pls drop the word "either".

Thanks
Laszlo

>> +
>> +  @param[in, out] Ghcb             Pointer to the Guest-Hypervisor 
>> Communication
>> +                                   Block
>> +  @param[in, out] Regs             x64 processor context
>> +  @param[in]      InstructionData  Instruction parsing context
>> +
>> +  @retval 0                        Event handled successfully
>> +  @retval Others                   New exception value to propagate
>> +
>> +**/
>> +STATIC
>> +UINT64
>> +VmmCallExit (
>> +  IN OUT GHCB                     *Ghcb,
>> +  IN OUT EFI_SYSTEM_CONTEXT_X64   *Regs,
>> +  IN     SEV_ES_INSTRUCTION_DATA  *InstructionData
>> +  )
>> +{
>> +  UINT64  Status;
>> +
>> +  DecodeModRm (Regs, InstructionData);
>> +
>> +  Ghcb->SaveArea.Rax = Regs->Rax;
>> +  GhcbSetRegValid (Ghcb, GhcbRax);
>> +  Ghcb->SaveArea.Cpl = (UINT8) (Regs->Cs & 0x3);
>> +  GhcbSetRegValid (Ghcb, GhcbCpl);
>> +
>> +  Status = VmgExit (Ghcb, SVM_EXIT_VMMCALL, 0, 0);
>> +  if (Status) {
> 
> (1) Please write (Status > 0) or (Status != 0).
> 
> Acked-by: Laszlo Ersek <ler...@redhat.com>
> 
> Thanks
> Laszlo
> 
>> +    return Status;
>> +  }
>> +
>> +  if (!GhcbIsRegValid (Ghcb, GhcbRax)) {
>> +    return UnsupportedExit (Ghcb, Regs, InstructionData);
>> +  }
>> +  Regs->Rax = Ghcb->SaveArea.Rax;
>> +
>> +  return 0;
>> +}
>> +
>>  /**
>>    Handle an MSR event.
>>  
>> @@ -1395,6 +1439,10 @@ VmgExitHandleVc (
>>      NaeExit = MsrExit;
>>      break;
>>  
>> +  case SVM_EXIT_VMMCALL:
>> +    NaeExit = VmmCallExit;
>> +    break;
>> +
>>    case SVM_EXIT_WBINVD:
>>      NaeExit = WbinvdExit;
>>      break;
>>
> 


-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.

View/Reply Online (#60151): https://edk2.groups.io/g/devel/message/60151
Mute This Topic: https://groups.io/mt/74336577/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub  [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-

Reply via email to