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

Shuo A Liu
2020-12-02T02:15:36Z

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@intel.com 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.