RE: [PATCH v10 03/38] x86/msr: Add the WRMSRNS instruction support

From: Thomas Gleixner
Date: Fri Sep 22 2023 - 11:00:09 EST


On Fri, Sep 22 2023 at 08:16, Xin3 Li wrote:
>> > > +static __always_inline void __wrmsrns(u32 msr, u32 low, u32 high)
>> >
>> > Shouldn't this be named wrmsrns_safe since it has exception handling, similar
>> to
>> > the current wrmsrl_safe.
>> >
>>
>> Both safe and unsafe versions have exception handling, while the safe
>> version returns an integer to its caller to indicate an exception did
>> happen or not.
>
> I notice there are several call sites using the safe version w/o
> checking the return value, should the unsafe version be a better
> choice in such cases?

Depends. The safe version does not emit a warning on fail. So if the
callsite truly does not care about the error it's fine.