linux-kernel - Shut up unhandled MSR warnings

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Message-ID: <20151112101317.GA3649@pd.tnic>
Date:	Thu, 12 Nov 2015 11:13:17 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Paolo Bonzini <pbonzini@...hat.com>
Cc:	Jörg Rödel <joro@...tes.org>,
	kvm ML <kvm@...r.kernel.org>,
	lkml <linux-kernel@...r.kernel.org>
Subject: Shut up unhandled MSR warnings

Hey Paolo,

do we apply stuff like that below?

When booting guests all the time here, dmesg gets filled up with those
"unhandled rdmsr" useless warnings. The patch below shuts them up.

The only problem is that the IC CFG MSR has those fields
defined starting from F15h and I don't see a way to check the
family/model/stepping of the guest CPU in kvm. Is there?

Thanks.

---
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index b8c14bb7fc8f..08b880818fb9 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -315,6 +315,7 @@
 #define MSR_F15H_PERF_CTR		0xc0010201
 #define MSR_F15H_NB_PERF_CTL		0xc0010240
 #define MSR_F15H_NB_PERF_CTR		0xc0010241
+#define MSR_F15H_IC_CFG			0xc0011021
 
 /* Fam 10h MSRs */
 #define MSR_FAM10H_MMIO_CONF_BASE	0xc0010058
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 4a70fc6d400a..1d76dcdf7e55 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -665,9 +665,9 @@ static void init_amd_bd(struct cpuinfo_x86 *c)
 	 * Disable it on the affected CPUs.
 	 */
 	if ((c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
-		if (!rdmsrl_safe(0xc0011021, &value) && !(value & 0x1E)) {
+		if (!rdmsrl_safe(MSR_F15H_IC_CFG, &value) && !(value & 0x1E)) {
 			value |= 0x1E;
-			wrmsrl_safe(0xc0011021, value);
+			wrmsrl_safe(MSR_F15H_IC_CFG, value);
 		}
 	}
 }
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 2f9ed1ff0632..7948cdeacbfe 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3141,6 +3141,9 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	case MSR_IA32_UCODE_REV:
 		msr_info->data = 0x01000065;
 		break;
+	case MSR_F15H_IC_CFG:
+		msr_info->data = 0x1E;
+		break;
 	default:
 		return kvm_get_msr_common(vcpu, msr_info);
 	}

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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