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

From: Shuo A Liu
Date: Tue Dec 15 2020 - 04:54:09 EST


On Wed 2.Dec'20 at 10:14:29 +0800, Shuo A Liu wrote:
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.


Hi Greg,

Would you like to review other patches in this series on this version?
This version got only this one comment, so doesn't have too much update.
I can send out a new version if you prefer to.

Thanks for review.

shuo