diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 27d5b3f3d6..37ebcb3abb 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -1162,6 +1162,7 @@ long arch_do_domctl(
                 if ( msr.reserved )
                     break;
 
+                ret = -ENXIO;
                 switch ( msr.index )
                 {
                 case MSR_SPEC_CTRL:
@@ -1170,9 +1171,16 @@ long arch_do_domctl(
                 case MSR_AMD64_DR0_ADDRESS_MASK:
                 case MSR_AMD64_DR1_ADDRESS_MASK ... MSR_AMD64_DR3_ADDRESS_MASK:
                     if ( guest_wrmsr(v, msr.index, msr.value) != X86EMUL_OKAY )
+                    {
+                        printk(XENLOG_G_ERR
+                               "%pv load MSR %#x with value %#lx failed\n",
+                               v, msr.index, msr.value);
                         break;
+                    }
                     continue;
                 }
+                printk(XENLOG_G_ERR "%pv attempted load of unhandled MSR %#x\n",
+                       v, msr.index);
                 break;
             }
 
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 7b2e1c9813..3b803e15e0 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -1535,10 +1535,17 @@ static int cf_check hvm_load_cpu_msrs(struct domain *d, hvm_domain_context_t *h)
             rc = guest_wrmsr(v, ctxt->msr[i].index, ctxt->msr[i].val);
 
             if ( rc != X86EMUL_OKAY )
+            {
+                printk(XENLOG_G_ERR
+                       "HVM %pv load MSR %#x with value %#lx failed\n",
+                       v, ctxt->msr[i].index, ctxt->msr[i].val);
                 return -ENXIO;
+            }
             break;
 
         default:
+            printk(XENLOG_G_ERR "HVM %pv attempted load of unhandled MSR %#x\n",
+                   v, ctxt->msr[i].index);
             return -ENXIO;
         }
     }