[d-kernel] [RFC] ALT: io_uring, sysctl: Add 'kernel.unprivileged_io_uring_disabled' sysctl

[Vladimir D. Seleznev]

On Fri, Jan 27, 2023 at 11:10:14PM +0300, Vitaly Chikunov wrote:
> Dmitry,
> 
> On Fri, Jan 27, 2023 at 08:30:22PM +0300, Dmitry V. Levin wrote:
> > On Thu, Jan 26, 2023 at 10:50:17PM +0300, Vitaly Chikunov wrote:
> > > `kernel.unprivileged_io_uring_disabled=1' is set to disable io_uring
> > > functionality for non-roots (default). Set to 0 to allow io_uring.
> > 
> > Makes sense.
> 
> Perhaps, p10 should have default 0 and Sisyphus default 1?
> Or both should have default 1?
> 
> (Only affected package that I care is qemu.)
> 
>   $ apt-cache whatdepends liburing | grep -v -e Depends -e liburing
>   qemu-img-7.2.0-alt3:sisyphus+312630.500.5.2 на 1673473326
>   librbd1-16.2.10-alt2:sisyphus+308894.1000.1.1 на 1666593027
>   qemu-guest-agent-7.2.0-alt3:sisyphus+312630.500.5.2 на 1673473326
>   xfstests-2022.09.25-alt1:sisyphus+308127.100.1.1 на 1665255814
>   libvitastor-client-0.8.4-alt1:sisyphus+313710.100.1.1 на 1674123626
>   libvitastor-blk-0.8.4-alt1:sisyphus+313710.100.1.1 на 1674123626
>   qemu-pr-helper-7.2.0-alt3:sisyphus+312630.500.5.2 на 1673473326
>   pve-qemu-img-1:7.1.0-alt4:sisyphus+310987.100.1.1 на 1669920082
>   glusterfs9-9.3-alt2:sisyphus+287347.100.1.1 на 1634390596

AFAIK, QEMU does not require io_uring in the runtime, it only uses this
for optional functionalities and works well on the kernels without
io_uring support.

-- 
   WBR,
   Vladimir D. Seleznev