Re: [PATCH 06/17] virt: acrn: Introduce VM management interfaces

[Shuo A Liu]

Hi Greg,

On Sun 30.Aug'20 at  9:23:42 +0200, Greg Kroah-Hartman wrote:
> On Sat, Aug 29, 2020 at 07:04:36PM +0800, Shuo A Liu wrote:
> > On Fri 28.Aug'20 at 12:27:38 +0200, Greg Kroah-Hartman wrote:
> > > On Tue, Aug 25, 2020 at 10:45:06AM +0800, shuo.a.liu@xxxxxxxxx wrote:
> > > > +	default:
> > > > +		pr_warn("Unknown IOCTL 0x%x!\n", cmd);
> > > > +		ret = -EINVAL;
> > >
> > > Wrong error value here, right?
> >
> > Right, it should be -ENOIOCTLCMD.
>
> It could, but really, just return the correct error for this, to prevent
> the core from having to do the conversion.
>
> The reviewers at Intel who should have read this before submitting it,
> know the correct value to return for an illegal ioctl, please go ask
> them.
>
> > However, i found many instances in kernel drivers return -EINVAL for no
> > ioctl command support. :)
>
> Then they too are wrong.  No need to add known bugs before the code is
> accepted.
>
> See the comments above the is_unrecognized_ioctl() in block/ioctl.c for
> all of the details and why -EINVAL is not the correct thing to do here.

Thanks for the information. -ENOTTY will be used.

Thanks
shuo