linux-kernel - Re: [RFC PATCH v1 01/15] x86/msr: Replace __wrmsr() with native

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Message-ID: <c316a6c6-b97c-48b2-9598-d44e2ec72fbc@zytor.com>
Date: Wed, 2 Apr 2025 22:09:21 -0700
From: Xin Li <xin@...or.com>
To: Ingo Molnar <mingo@...nel.org>, "H. Peter Anvin" <hpa@...or.com>
Cc: linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org,
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        Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [RFC PATCH v1 01/15] x86/msr: Replace __wrmsr() with
 native_wrmsrl()

On 4/1/2025 12:52 AM, Ingo Molnar wrote:
>> Should we rename the *msrl() functions to *msrq() as part of this
>> overhaul?
> Yeah, that's a good idea, and because talk is cheap I just implemented
> this in the tip:WIP.x86/msr branch with a couple of other cleanups in
> this area (see the shortlog & diffstat below), but the churn is high:
> 
>    144 files changed, 1034 insertions(+), 1034 deletions(-)

Hi Ingo,

I noticed that you keep the type of MSR index in these patches as
"unsigned int".

I'm thinking would it be better to standardize it as "u32"?

Because:
1) MSR index is placed in ECX to execute MSR instructions, and the
    high-order 32 bits of RCX are ignored on 64-bit.
2) MSR index is encoded as a 32-bit immediate in the new immediate form
    MSR instructions.

Thanks!
     Xin