Re: [edk2-devel] [PATCH v8 3/6] OvmfPkg/BaseMemEncryptLib: Invoke page encryption state change hypercall

[nikunj@amd.com]

Hi Ashish,

On 6/7/2022 10:58 PM, Kalra, Ashish wrote:
> 
> Hello Nikunj,
> 
> Yes we can move MemEncryptSevLiveMigrationIsEnabled() check here before calling SetMemoryEncDecHypercall3()
> 
> but then we also need to remove the same check from inside SetMemoryEncDecHypercall3() function.

Sure, and we will have to check this at all places that are calling SetMemoryEncDecHypercall3()

Regards
Nikunj

>  
> 
> Thanks,
> 
> Ashish
> 
>  
> 
> *From:* nikunj via groups.io <nikunj=amd.com@groups.io>
> *Sent:* Tuesday, June 7, 2022 3:39 AM
> *To:* Kalra, Ashish <Ashish.Kalra@amd.com>; devel@edk2.groups.io
> *Subject:* Re: [edk2-devel] [PATCH v8 3/6] OvmfPkg/BaseMemEncryptLib: Invoke page encryption state change hypercall
> 
>  
> 
> Hi Ashish,
> 
> For case with latest OVMF and older qemu that does not enable live migrations,
> SetMemoryEncDecHypercall3() returns RETURN_UNSUPPORTED, which is correct.
> But then its actually treated as an error and OVMF sees an assert. This is a valid usecase
> and OVMF should move ahead without live migration and HC_MAP_GPA_RANGE.
> ....
> 
>> + //
>> + // Notify Hypervisor on C-bit status
>> + //
>> + if (CBitChanged) {
> 
> Should we call the SetMemoryEncDecHypercall() only if migration is enabled like below?
> 
> if (CBitChanged && MemEncryptSevLiveMigrationIsEnabled () {
> 
>> + Status = SetMemoryEncDecHypercall3 (
>> + OrigPhysicalAddress,
>> + EFI_SIZE_TO_PAGES (OrigLength),
>> + (Mode == SetCBit) ? TRUE : FALSE
>> + );
>> + }
>> +
>> ...
>>
>> return Status;
> 
> Regards
> Nikunj
>