Re: [PATCH] xen/privcmd: remove privcmd_ioctl_mmap()

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 15 Sep 2022, Jan Beulich wrote:
> On 15.09.2022 12:20, Juergen Gross wrote:
> > On 15.09.22 11:32, Jan Beulich wrote:
> >> On 15.09.2022 10:39, Juergen Gross wrote:
> >>> The IOCTL_PRIVCMD_MMAP isn't in use by Xen since at least Xen 4.0.
> >>>
> >>> Remove it from the privcmd driver.
> >>>
> >>> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> >>
> >> Can we reasonably remove an IOCTL, without being entirely certain that
> >> no users exist outside of xen.git?
> > 
> > This is a valid question. I'm not sure how probable it is that such a user
> > is existing. Are there any Xen tool stacks not using the Xen libraries?
> > 
> > If so, why? Do we want to support those use cases?
> 
> I'm afraid I have no answers to these questions, and hence would generally
> want to be conservative with removal of functionality.

I don't know either, but maybe we could at least mark IOCTL_PRIVCMD_MMAP
as deprecated in include/uapi/xen/privcmd.h ?