[PATCH] KVM: x86: handle MSR_IA32_DEBUGCTLMSR with report_ignored_msrs

[Pankaj Gupta <pankaj.gupta.linux@gmail.com>]

From: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>

 Guest tries to enable LBR (last branch/interrupt/exception) repeatedly,
 thus spamming the host kernel logs. As MSR_IA32_DEBUGCTLMSR is not emulated by
 KVM, its better to add the error log only with "report_ignored_msrs".
 
Signed-off-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
---
 arch/x86/kvm/x86.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f5ede41bf9e6..99c69ae43c69 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3063,9 +3063,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 			/* Values other than LBR and BTF are vendor-specific,
 			   thus reserved and should throw a #GP */
 			return 1;
-		}
-		vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n",
-			    __func__, data);
+		} else if (report_ignored_msrs)
+			vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n",
+				    __func__, data);
 		break;
 	case 0x200 ... 0x2ff:
 		return kvm_mtrr_set_msr(vcpu, msr, data);
-- 
2.20.1