From: Sean Christopherson <seanjc@google.com>
To: Chenyi Qiang <chenyi.qiang@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Xiaoyao Li <xiaoyao.li@intel.com>,
linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: [PATCH] x86/bus_lock: Don't assume the init value of DEBUGCTLMSR.BUS_LOCK_DETECT to be zero
Date: Tue, 19 Oct 2021 17:05:46 +0000 [thread overview]
Message-ID: <YW766qk0W6K5rhrU@google.com> (raw)
In-Reply-To: <20210901084004.5393-1-chenyi.qiang@intel.com>
On Wed, Sep 01, 2021, Chenyi Qiang wrote:
> It's possible that BIOS/firmware has set DEBUGCTLMSR_BUS_LOCK_DETECT, or
> this kernel has been kexec'd from a kernel that enabled bus lock
> detection.
This feels like the kernel should explicitly zero out the entire MSR somewhere
in the generic boot flow. E.g. something like this somewhere.
#ifndef CONFIG_X86_DEBUGCTLMSR
if (boot_cpu_data.x86 < 6)
return;
#endifa
wrmsrl(MSR_IA32_DEBUGCTLMSR, 0);
next prev parent reply other threads:[~2021-10-19 17:05 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-01 8:40 Chenyi Qiang
2021-09-17 2:52 ` Chenyi Qiang
2021-10-19 7:34 ` Chenyi Qiang
2021-10-19 17:05 ` Sean Christopherson [this message]
2021-10-25 6:14 ` Chenyi Qiang
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