Re: [PATCH 0/8] x86/msr: Drop 32-bit variants of *_on_cpu() MSR functions

["Jürgen Groß" <jgross@suse.com>]

[-- Attachment #1.1.1: Type: text/plain, Size: 2883 bytes --]

On 05.06.26 11:18, Ingo Molnar wrote:
> 
> * Jürgen Groß <jgross@suse.com> wrote:
> 
>> On 05.06.26 11:05, Ingo Molnar wrote:
>>>
>>> * Juergen Gross <jgross@suse.com> wrote:
>>>
>>>> Drop the variants using 2 32-bit values instead of a single 64-bit one
>>>> of the *_on_cpu() MSR access functions.
>>>>
>>>> Juergen Gross (8):
>>>>     x86/msr: Switch rdmsr_on_cpu() to return a 64-bit quantity
>>>>     x86/msr: Switch all callers of rdmsrq_on_cpu() to use rdmsr_on_cpu()
>>>>     x86/msr: Switch wrmsr_on_cpu() to use a 64-bit quantity
>>>>     x86/msr: Switch all callers of wrmsrq_on_cpu() to use wrmsr_on_cpu()
>>>>     x86/msr: Switch rdmsr_safe_on_cpu() to return a 64-bit quantity
>>>>     x86/msr: Switch all callers of rdmsrq_safe_on_cpu() to use rdmsr_safe_on_cpu()
>>>>     x86/msr: Switch wrmsr_safe_on_cpu() to use a 64-bit quantity
>>>>     x86/msr: Switch all callers of wrmsrq_safe_on_cpu() to use  wrmsr_safe_on_cpu()
>>>
>>> To sum up my review feedback for the invididual patches, we want
>>> to do this instead:
>>>
>>>     x86/msr: Convert rdmsrl_on_cpu() users to rdmsrq_on_cpu()
>>>     x86/msr: Drop the rdmsrl_on_cpu() alias to rdmsrq_on_cpu()
>>>
>>>     x86/msr: Switch all callers of rdmsr_on_cpu() to use rdmsrq_on_cpu()
>>>     x86/msr: Remove the unused rdmsr_on_cpu() API
>>>
>>>     x86/msr: Switch all callers of wrmsr_on_cpu() to use wrmsrq_on_cpu()
>>>     x86/msr: Remove unused wrmsr_on_cpu() API
>>>
>>>     x86/msr: Switch all callers of rdmsr_safe_on_cpu() to use rdmsrq_safe_on_cpu()
>>>     x86/msr: Remove unused rdmsr_safe_on_cpu() API
>>>
>>>     x86/msr: Switch all callers of wrmsr_safe_on_cpu() to use wrmsrq_safe_on_cpu()
>>>     x86/mrs: Remove unused wrmsrq_safe_on_cpu() API
>>>
>>> Note how there's no "conversion" of the 32-bit API itself in this
>>> approach, we just do a straightforward migration of the users to
>>> the already existing 64-bit APIs, then remove any unused APIs.
>>
>> Fine with me, but I just wanted to get rid of the "q" and "l" suffices
>> completely, as they serve no special purpose after dropping all other
>> variants.
>>
>> OTOH if wanted such a switch could be done later easily.
> 
> Well, we had a similar discussion back when we standardized on
> rdmsrq() and wrmsrq(), and we use them as our primary 64-bit
> MSR handling APIs. Why have a different pattern in any of the
> derived APIs? It should really use the same conceptual namespace,
> not some confusing mixture of two naming schemes.

In the long run I'd like to do the same conversion for the rdmsr*() and
wrmsr*() interfaces, too (so only offering and using the 64-bit variants).

I understand that this is not guaranteed to be accepted immediately after
this series, so I agree that it is better to keep the "q" suffix for now
in order to avoid confusion.


Juergen

[-- Attachment #1.1.2: OpenPGP public key --]
[-- Type: application/pgp-keys, Size: 3743 bytes --]

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 495 bytes --]