Re: [Patch v3 1/2] cgroup: sev: Add misc cgroup controller

Jacob Pan
2021-03-24T16:15:40Z

Hi Vipin,

On Mon, 22 Mar 2021 11:54:39 -0700, Vipin Sharma <vipinsh@google.com> wrote:

> On Fri, Mar 19, 2021 at 02:28:01PM -0700, Jacob Pan wrote:
> > On Thu, 4 Mar 2021 15:19:45 -0800, Vipin Sharma <vipinsh@google.com>
> > wrote:
> > > +#ifndef _MISC_CGROUP_H_
> > > +#define _MISC_CGROUP_H_
> > > +
> > nit: should you do #include <linux/cgroup.h>?
> > Otherwise, css may be undefined.
>
> User of this controller will use get_curernt_misc_cg() API which returns
> a pointer. Ideally the user should use this pointer and they shouldn't
> have any need to access "css" in their code. They also don't need to
> create a object of 'struct misc_cg{}', because that won't be correct misc
> cgroup object. They should just declare a pointer like we are doing here
> in 'struct kvm_sev_info {}'.
>
> If they do need to use "css" then they can include cgroup header in their
> code.
>
I didn't mean the users of misc_cgroup will use css directly. I meant if I
want to use misc cgruop in ioasid.c, I have to do the following to avoid
undefined css:
#include <linux/cgroup.h>
#include <linux/misc_cgroup.h>

So it might be simpler if you do #include <linux/cgroup.h> inside
misc_cgroup.h. Then in ioasid.c, I only need to do
#include <linux/misc_cgroup.h>.

> Let me know if I am overlooking something here.
>
> Thanks
> Vipin Sharma

Thanks,

Jacob