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Date:   Fri, 19 Aug 2022 16:38:57 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     kan.liang@linux.intel.com
Cc:     acme@redhat.com, linux-kernel@vger.kernel.org,
        alexander.shishkin@linux.intel.com, ak@linux.intel.com,
        Jianfeng Gao <jianfeng.gao@intel.com>
Subject: Re: [RESEND PATCH] perf/x86/intel: Fix unchecked MSR access error
 for Alder Lake N
Message-ID: <Yv+ggf6PRjL8Eio1@worktop.programming.kicks-ass.net>
References: <20220818181530.2355034-1-kan.liang@linux.intel.com>
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On Thu, Aug 18, 2022 at 11:15:30AM -0700, kan.liang@linux.intel.com wrote:
> From: Kan Liang <kan.liang@linux.intel.com>
> 
> For some Alder Lake N machine, the below unchecked MSR access error may be
> triggered.
> 
> [ 0.088017] rcu: Hierarchical SRCU implementation.
> [ 0.088017] unchecked MSR access error: WRMSR to 0x38f (tried to write
> 0x0001000f0000003f) at rIP: 0xffffffffb5684de8 (native_write_msr+0x8/0x30)
> [ 0.088017] Call Trace:
> [ 0.088017] <TASK>
> [ 0.088017] __intel_pmu_enable_all.constprop.46+0x4a/0xa0

FWIW, I seem to get the same error when booting KVM on my ADL. I'm
fairly sure the whole CPUID vs vCPU thing is a trainwreck.