Re: [PATCH 00/32] x86/msr: Drop 32-bit MSR interfaces

On Mon, Jun 29, 2026, at 09:01, Jürgen Groß wrote:
> On 29.06.26 08:52, Arnd Bergmann wrote:
>> On Mon, Jun 29, 2026, at 08:04, Juergen Gross wrote:
>> 
>> I assume this is fine, but since you don't mention it explicitly here,
>> please clarify what this means for 32-bit CPUs without the rdmsrq
>> instruction. Those will continue using the same instructions as before
>> and just change the calling conventions, right?
>
> Yes. I thought this would be clear from the following:
>
>    - They are based on primitives using 64-bit sized values anyway.

Right, that was my reading of it as well, but it's not entirely
clear when the function name is the same as the mnemonic of an
instruction that only exists on newer CPUs and the later patch
descriptions (e.g. 25/32 that I was Cc's on) have a much shorter
explanation.

>>> Note that most patches of this series are independent from each other.
>>> Only the patches removing a specific interface (patches 7, 15, 26 and
>>> 30) and the last two patches of the series depend on all previous
>>> patches.
>> 
>> It looks like you are touching most files twice or more here, to
>> first convert from rdmsr to rdmsrq and then to change the
>> two-argument rdmsrq() macro to a single-argument inline. If you
>> introduce the inline version of rdmsrq() first, you should be
>> able to skip the second step (patch 31) as they could be able
>> to coexist.
>
> I've discussed how to structure the series with Ingo Molnar before [1]. The
> current approach was his preference.

Ok.

      Arnd