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From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Tony Luck <tony.luck@intel.com>, Borislav Petkov <bp@alien8.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>,
	linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>,
	kvm@vger.kernel.org,
	Sean Christopherson <sean.j.christopherson@intel.com>
Subject: [PATCH v2 02/16] x86/mce: WARN once if IA32_FEATURE_CONTROL MSR is left unlocked
Date: Mon, 21 Oct 2019 16:56:42 -0700	[thread overview]
Message-ID: <20191021235642.418-1-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20191021234632.32363-1-sean.j.christopherson@intel.com>

WARN if the IA32_FEATURE_CONTROL MSR is somehow left unlocked now that
CPU initialization unconditionally locks the MSR.

Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kernel/cpu/mce/intel.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/intel.c b/arch/x86/kernel/cpu/mce/intel.c
index 88cd9598fa57..1008f14b803b 100644
--- a/arch/x86/kernel/cpu/mce/intel.c
+++ b/arch/x86/kernel/cpu/mce/intel.c
@@ -117,11 +117,10 @@ static bool lmce_supported(void)
 	 * generate a #GP fault.
 	 */
 	rdmsrl(MSR_IA32_FEATURE_CONTROL, tmp);
-	if ((tmp & (FEATURE_CONTROL_LOCKED | FEATURE_CONTROL_LMCE)) ==
-		   (FEATURE_CONTROL_LOCKED | FEATURE_CONTROL_LMCE))
-		return true;
+	if (WARN_ON_ONCE(!(tmp & FEATURE_CONTROL_LOCKED)))
+		return false;
 
-	return false;
+	return tmp & FEATURE_CONTROL_LMCE;
 }
 
 bool mce_intel_cmci_poll(void)
-- 
2.22.0


  parent reply	other threads:[~2019-10-21 23:56 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-21 23:46 [PATCH v2 00/16] x86/cpu: Clean up handling of VMX features Sean Christopherson
2019-10-21 23:54 ` [PATCH v2 01/16] x86/intel: Initialize IA32_FEATURE_CONTROL MSR at boot Sean Christopherson
2019-10-22  0:15   ` Sean Christopherson
2019-10-25 14:09   ` Borislav Petkov
2019-10-25 15:11     ` Sean Christopherson
2019-10-21 23:56 ` Sean Christopherson [this message]
2019-10-25 14:22   ` [PATCH v2 02/16] x86/mce: WARN once if IA32_FEATURE_CONTROL MSR is left unlocked Borislav Petkov
2019-10-22  0:08 ` [PATCH v2 03/16] x86/centaur: Use common IA32_FEATURE_CONTROL MSR initialization Sean Christopherson
2019-10-22  0:08 ` [PATCH v2 04/16] x86/zhaoxin: " Sean Christopherson
2019-10-22  0:08 ` [PATCH v2 05/16] KVM: VMX: Drop initialization of IA32_FEATURE_CONTROL MSR Sean Christopherson
2019-10-22 10:51   ` Paolo Bonzini
2019-10-22 15:16     ` Sean Christopherson
2019-11-14 18:34       ` Sean Christopherson
2019-11-15 10:10         ` Paolo Bonzini
2019-10-25 16:26   ` Borislav Petkov
2019-10-25 16:39     ` Borislav Petkov
2019-10-22  0:08 ` [PATCH v2 06/16] x86/cpu: Clear VMX feature flag if VMX is not fully enabled Sean Christopherson
2019-10-25 16:38   ` Borislav Petkov
2019-11-14 18:32     ` Sean Christopherson
2019-11-15 10:05       ` Paolo Bonzini
2019-11-15 10:34         ` Borislav Petkov
2019-11-15 15:34           ` Sean Christopherson
2019-11-15 15:39             ` Borislav Petkov
2019-10-22  0:08 ` [PATCH v2 07/16] KVM: VMX: Use VMX feature flag to query BIOS enabling Sean Christopherson
2019-10-22  0:08 ` [PATCH v2 08/16] KVM: VMX: Check for full VMX support when verifying CPU compatibility Sean Christopherson
2019-10-22  0:08 ` [PATCH v2 09/16] x86/vmx: Introduce VMX_FEATURES_* Sean Christopherson
2019-10-22  0:08 ` [PATCH v2 10/16] x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs Sean Christopherson
2019-10-22  0:08 ` [PATCH v2 11/16] x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_* Sean Christopherson
2019-10-22  0:08 ` [PATCH v2 12/16] x86/cpufeatures: Drop synthetic VMX feature flags Sean Christopherson
2019-10-22  0:08 ` [PATCH v2 13/16] KVM: VMX: Use VMX_FEATURE_* flags to define VMCS control bits Sean Christopherson
2019-10-22  0:09 ` [PATCH v2 14/16] x86/cpufeatures: Clean up synthetic virtualization flags Sean Christopherson
2019-10-22  0:12 ` [PATCH v2 15/16] perf/x86: Provide stubs of KVM helpers for non-Intel CPUs Sean Christopherson
2019-10-22  0:12 ` [PATCH v2 16/16] KVM: VMX: Allow KVM_INTEL when building for Centaur and/or Zhaoxin CPUs Sean Christopherson

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