Index: sys/x86/x86/msi.c
===================================================================
--- sys/x86/x86/msi.c
+++ sys/x86/x86/msi.c
@@ -246,7 +246,7 @@
 	struct msi_intsrc *sib, *msi = (struct msi_intsrc *)isrc;
 	int old_vector;
 	u_int old_id;
-	int i, vector;
+	int error, i, vector;
 
 	/*
 	 * Only allow CPUs to be assigned to the first message for an
@@ -286,42 +286,50 @@
 		return (ENOSPC);
 	}
 
-	msi->msi_cpu = apic_id;
-	msi->msi_vector = vector;
 	if (msi->msi_intsrc.is_handlers > 0)
-		apic_enable_vector(msi->msi_cpu, msi->msi_vector);
-	if (bootverbose)
-		printf("msi: Assigning %s IRQ %d to local APIC %u vector %u\n",
-		    msi->msi_msix ? "MSI-X" : "MSI", msi->msi_irq,
-		    msi->msi_cpu, msi->msi_vector);
+		apic_enable_vector(apic_id, vector);
 	for (i = 1; i < msi->msi_count; i++) {
 		sib = (struct msi_intsrc *)intr_lookup_source(msi->msi_irqs[i]);
-		sib->msi_cpu = apic_id;
-		sib->msi_vector = vector + i;
 		if (sib->msi_intsrc.is_handlers > 0)
-			apic_enable_vector(sib->msi_cpu, sib->msi_vector);
+			apic_enable_vector(apic_id, vector + i);
 		if (bootverbose)
 			printf(
 		    "msi: Assigning MSI IRQ %d to local APIC %u vector %u\n",
 			    sib->msi_irq, sib->msi_cpu, sib->msi_vector);
 	}
-	BUS_REMAP_INTR(device_get_parent(msi->msi_dev), msi->msi_dev,
+	error = BUS_REMAP_INTR(device_get_parent(msi->msi_dev), msi->msi_dev,
 	    msi->msi_irq);
+	if (error == 0) {
+		msi->msi_cpu = apic_id;
+		msi->msi_vector = vector;
+		if (bootverbose)
+			printf("msi: Assigning %s IRQ %d to local APIC %u vector %u\n",
+			    msi->msi_msix ? "MSI-X" : "MSI", msi->msi_irq,
+			    msi->msi_cpu, msi->msi_vector);
+	} else {
+		printf("%s: error %d from BUS_REMAP_INTR for irq %u\n",
+		    __func__, error, msi->msi_irq);
+		old_id = apic_id;
+		old_vector = vector;
+	}
 
 	/*
 	 * Free the old vector after the new one is established.  This is done
-	 * to prevent races where we could miss an interrupt.
+	 * to prevent races where we could miss an interrupt.  If BUS_REMAP_INTR
+	 * failed then we disable and free the new, unused vector(s).
 	 */
 	if (msi->msi_intsrc.is_handlers > 0)
 		apic_disable_vector(old_id, old_vector);
 	apic_free_vector(old_id, old_vector, msi->msi_irq);
 	for (i = 1; i < msi->msi_count; i++) {
 		sib = (struct msi_intsrc *)intr_lookup_source(msi->msi_irqs[i]);
+		sib->msi_cpu = apic_id;
+		sib->msi_vector = vector + i;
 		if (sib->msi_intsrc.is_handlers > 0)
 			apic_disable_vector(old_id, old_vector + i);
 		apic_free_vector(old_id, old_vector + i, msi->msi_irqs[i]);
 	}
-	return (0);
+	return (error);
 }
 
 void