Re: [PATCH v6 06/18] virt: acrn: Introduce VM management interfaces

[Shuo A Liu]

On Tue  1.Dec'20 at 11:09:47 +0100, Greg Kroah-Hartman wrote:
> On Tue, Dec 01, 2020 at 05:38:41PM +0800, shuo.a.liu@xxxxxxxxx wrote:
> > +		vm_param->reserved0 = 0;
> > +		vm_param->reserved1 = 0;
>
> NO!
>
> This means that userspace can put whatever crud they want in those
> fields, and you will happily zero it out.  Then, when those reserved
> fields are wanted to be used in the future, you will take those values
> from userspace and accept them as a valid value.  But, since userspace
> was sending crud before, now you will take that crud and do something
> with it.
>
> TEST IT to verify that it is zero, that way userspace gets it right the
> first time, and you don't get it wrong later, as you can not change it
> later.

OK. Thanks for the elaboration. I will test it and return -EINVAL if
it is not zero.