Re: [PATCH v9 04/15] x86/sgx: Implement basic EPC misc cgroup functionality

["Haitao Huang" <haitao.huang@xxxxxxxxxxxxxxx>]

On Tue, 27 Feb 2024 15:35:38 -0600, Haitao Huang  
<haitao.huang@xxxxxxxxxxxxxxx> wrote:

> On Mon, 26 Feb 2024 12:25:58 -0600, Michal Koutný <mkoutny@xxxxxxxx>  
> wrote:
>
> > On Mon, Feb 05, 2024 at 01:06:27PM -0800, Haitao Huang  
> > <haitao.huang@xxxxxxxxxxxxxxx> wrote:
> > > +static int sgx_epc_cgroup_alloc(struct misc_cg *cg);
> > > +
> > > +const struct misc_res_ops sgx_epc_cgroup_ops = {
> > > +	.alloc = sgx_epc_cgroup_alloc,
> > > +	.free = sgx_epc_cgroup_free,
> > > +};
> > > +
> > > +static void sgx_epc_misc_init(struct misc_cg *cg, struct  
> > > sgx_epc_cgroup *epc_cg)
> > > +{
> > > +	cg->res[MISC_CG_RES_SGX_EPC].priv = epc_cg;
> > > +	epc_cg->cg = cg;
> > > +}
> >
> > This is a possibly a nit pick but I share it here for consideration.
> >
> > Would it be more prudent to have the signature like
> >   alloc(struct misc_res *res, struct misc_cg *cg)
> > so that implementations are free of the assumption of how cg and res are
> > stored?
> >
> >
> > Thanks,
> > Michal
>
> Will do.
>
> Thanks
> Haitao
Actually, because the root node is initialized in sgx_cgroup_init(), which  
only has access to misc_cg_root() so we can't pass a misc_res struct  
without knowing cg->res relationship. We could hide it with a getter, but  
I think it's a little overkill at the moment. I can sign up for adding  
this improvement if we feel it needed in future.

Thanks
Haitao