linux-kernel - Time to drop wrmsrl()/rdmsrl()?

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Message-Id: <6CB34103-3BF6-43ED-890A-650429CBC491@zytor.com>
Date: Mon, 15 Dec 2025 00:27:59 -0800
From: Xin Li <xin@...or.com>
To: Ingo Molnar <mingo@...nel.org>
Cc: LKML <linux-kernel@...r.kernel.org>, ML X86 <x86@...nel.org>,
        Sean Christopherson <seanjc@...gle.com>, Chao Gao <chao.gao@...el.com>
Subject: Time to drop wrmsrl()/rdmsrl()?

Hi Ingo,

Keeping them around only causes churn now, so probably it is time to drop
them?

https://lore.kernel.org/lkml/aK8fmMGH0rB2LuA9@google.com/

https://lore.kernel.org/lkml/aR0vK3z1owwM8X8H@intel.com/


I think all of their uses were changed to wrmsrq()/rdmsrq(), but they are
coming back, and with the latest Linux 6.19-rc1 tag, I get:

$git grep -w rdmsrl
arch/x86/events/amd/uncore.c:   rdmsrl(hwc->event_base, new);
arch/x86/include/asm/msr.h:#define rdmsrl(msr, val) rdmsrq(msr, val)
arch/x86/kernel/cpu/resctrl/monitor.c:  rdmsrl(MSR_IA32_QM_CTR, msr_val);
drivers/hv/mshv_vtl_main.c:                             rdmsrl(reg_table[i].msr_addr, *reg64);
drivers/idle/intel_idle.c:      rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_val);
drivers/idle/intel_idle.c:      rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_val);


Thanks!
    Xin