Re: [PATCH v14 14/14] selftests/sgx: Add scripts for EPC cgroup testing

["Haitao Huang" <haitao.huang@linux.intel.com>]

On Mon, 10 Jun 2024 17:39:53 -0500, Huang, Kai <kai.huang@intel.com> wrote:

>
>> --- a/arch/x86/kernel/cpu/sgx/main.c
>> +++ b/arch/x86/kernel/cpu/sgx/main.c
>> @@ -1045,7 +1045,7 @@ static int __init sgx_init(void)
>>        if (!sgx_page_cache_init())
>>            return -ENOMEM;
>>  -    if (!sgx_page_reclaimer_init()) {
>> +    if (!sgx_page_reclaimer_init() || !sgx_cgroup_init()) {
>>            ret = -ENOMEM;
>>            goto err_page_cache;
>>        }
>
> Does it make more sense to move the sgx_cgroup_init() to the  
> sgx_drv_init()?  The SGX cgroup only works for the driver side anyway.  
> In this case, if something went wrong in sgx_cgroup_init(), the  
> sgx_vepc_init() could still have a chance to work.
>

vepc reclamation is not done by cgroup/ksgxd but try_charge() won't work  
if user expecting cgroup to limit vepc allocation. Would it be more  
consistent to just disable vepc, i.e., on system with MISC, sgx/vepc  
always go with cgroup enabled?

> And IIUC we need to reset the "capacity" to 0 if sgx_cgroup_init()  
> fails, no matter it is called inside sgx_drv_init() or sgx_init(),  
> otherwise the "epc" would appear in the cgroup hierarchy as a misc  
> cgroup resource.
>
> Another option is to defer setting the capacity to the point where we  
> have made sure sgx_drv_init() and sgx_cgroup_init() cannot fail.
>

Yes agree we need do this.
> Btw, I plan to review the rest from late of this week or next week  
> because this week I have some other staff needs to be finished first.
>

Sure. Thanks
Haitao