---

yaml
---
r: 215814
b: refs/heads/master
c: 84e0cef
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9ed049c3b6230b68985da31f8243d4bec95e0b3a
+refs/heads/master: 84e0cefa8ddd5d5018d3b582e1e90585ed551757

trunk/arch/x86/kvm/x86.c

@@ -1449,6 +1449,16 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 		pr_unimpl(vcpu, "unimplemented perfctr wrmsr: "
 			"0x%x data 0x%llx\n", msr, data);
 		break;
+	case MSR_K7_CLK_CTL:
+		/*
+		 * Ignore all writes to this no longer documented MSR.
+		 * Writes are only relevant for old K7 processors,
+		 * all pre-dating SVM, but a recommended workaround from
+		 * AMD for these chips. It is possible to speicify the
+		 * affected processor models on the command line, hence
+		 * the need to ignore the workaround.
+		 */
+		break;
 	case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
 		if (kvm_hv_msr_partition_wide(msr)) {
 			int r;
@@ -1674,6 +1684,18 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
 	case MSR_IA32_MCG_STATUS:
 	case MSR_IA32_MC0_CTL ... MSR_IA32_MC0_CTL + 4 * KVM_MAX_MCE_BANKS - 1:
 		return get_msr_mce(vcpu, msr, pdata);
+	case MSR_K7_CLK_CTL:
+		/*
+		 * Provide expected ramp-up count for K7. All other
+		 * are set to zero, indicating minimum divisors for
+		 * every field.
+		 *
+		 * This prevents guest kernels on AMD host with CPU
+		 * type 6, model 8 and higher from exploding due to
+		 * the rdmsr failing.
+		 */
+		data = 0x20000000;
+		break;
 	case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
 		if (kvm_hv_msr_partition_wide(msr)) {
 			int r;