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

[Jürgen Groß <jgross@xxxxxxxx>]

On 29.06.26 10:06, Arnd Bergmann wrote:
> 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
There is no RDMSRQ instruction on any x86 CPU. Are you mixing this up with
WRMSRNS/RDMSR using an immediate for addressing the MSR?


Juergen

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