Re: [PATCH 0/3] arm64:msr: Add MSR driver

[Marc Zyngier]

On 2020-12-01 03:09, wangrongwei wrote:
> Hi
> We have validate this driver in vm and physical machine, and works 
> fine.

But what does "work fine" mean? None of these system registers are 
supposed
to be accessible from userspace, so please explain *what* you are trying 
to
do with this, other that introducing security holes and general system
instability?

> Actually, we used existing interfaces to realize this driver, likes
> aarch64_insn_read and aarch64_insn_patch_text.

Sure. At that stage, you could also directly expose the linear mapping 
to
userspace and start writing to it, it would probably be a fitting 
addition...

> These existing intefaces had validated a CPU.

If CPU validation is your goal, I suggest this is kept out of tree, as 
the
kernel is hardly a validation tool for the arm64 architecture.

Thanks,

        M.
--
Jazz is not dead. It just smells funny...