From: Peter Zijlstra <peterz@infradead.org>
To: "Liang, Kan" <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
Date: Mon, 22 Aug 2022 15:48:12 +0200 [thread overview]
Message-ID: <YwOJHLuX57Q4e/wH@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <80eea4f7-bb1e-ebb9-37db-9317b8d9c28f@linux.intel.com>
On Mon, Aug 22, 2022 at 09:28:31AM -0400, Liang, Kan wrote:
>
>
> On 2022-08-19 10:38 a.m., Peter Zijlstra wrote:
> > 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.
>
> We will enhance the CPUID to address the issues. Hopefully, we can have
> them supported in the next generation.
How!? A vCPU can readily migrate between a big and small CPU. There is
no way the guest can sanely program the (v)MSRs and expect it to work.
next prev parent reply other threads:[~2022-08-22 13:48 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-18 18:15 [RESEND PATCH] perf/x86/intel: Fix unchecked MSR access error for Alder Lake N kan.liang
2022-08-19 8:05 ` Peter Zijlstra
2022-08-19 8:33 ` Peter Zijlstra
2022-08-22 13:24 ` Liang, Kan
2022-08-22 13:55 ` Peter Zijlstra
2022-08-22 15:20 ` Liang, Kan
2022-08-19 14:38 ` Peter Zijlstra
2022-08-22 13:28 ` Liang, Kan
2022-08-22 13:48 ` Peter Zijlstra [this message]
2022-08-22 14:31 ` Andi Kleen
2022-08-22 14:39 ` Peter Zijlstra
2022-08-22 14:51 ` Andrew Cooper
2022-08-22 14:59 ` Liang, Kan
2022-08-22 15:21 ` Peter Zijlstra
2022-08-22 15:08 ` Andi Kleen
2022-08-22 15:47 ` Peter Zijlstra
2022-08-22 18:21 ` Sean Christopherson
2022-08-22 19:21 ` Andi Kleen
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