Re: [RESEND PATCH 05/32] vl: Add "sgx-epc" option to expose SGX EPC sections to guest

[Paolo Bonzini]

On 04/05/21 02:09, Sean Christopherson wrote:
> Is there a way to process "-device sgx-epc..." before vCPUs are realized?  The
> ordering problem was the only reason I added a dedicated option.

If it's just CPUID, one possibility could be to mark the EPC sections 
specially in KVM_SET_USER_MEMORY_REGION and synthesize the leaves within 
KVM; or even look inside the VMA structs and detect EPC regions that way.

Otherwise, the -M solution would work.

Paolo

>  From the changelog:
>
>    Because SGX EPC is enumerated through CPUID, EPC "devices" need to be
>    realized prior to realizing the vCPUs themselves, i.e. long before
>    generic devices are parsed and realized.
>
>    So even though EPC sections could be realized through the generic
>    -devices command, they need to be created much earlier for them to
>    actually be usable by the guest.