3 files changed, 69 insertions, 0 deletions

diff --git a/drivers/iommu/intel_intr_remapping.c b/drivers/iommu/intel_intr_remapping.c
index f495eba4b6ab..25372c1f3c8c 100644
--- a/drivers/iommu/intel_intr_remapping.c
+++ b/drivers/iommu/intel_intr_remapping.c
@@ -901,6 +901,59 @@ static int intel_setup_ioapic_entry(int irq,
         return 0;
 }
 
+/*
+ * Migrate the IO-APIC irq in the presence of intr-remapping.
+ *
+ * For both level and edge triggered, irq migration is a simple atomic
+ * update(of vector and cpu destination) of IRTE and flush the hardware cache.
+ *
+ * For level triggered, we eliminate the io-apic RTE modification (with the
+ * updated vector information), by using a virtual vector (io-apic pin number).
+ * Real vector that is used for interrupting cpu will be coming from
+ * the interrupt-remapping table entry.
+ *
+ * As the migration is a simple atomic update of IRTE, the same mechanism
+ * is used to migrate MSI irq's in the presence of interrupt-remapping.
+ */
+static int
+intel_ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask,
+                          bool force)
+{
+        struct irq_cfg *cfg = data->chip_data;
+        unsigned int dest, irq = data->irq;
+        struct irte irte;
+
+        if (!cpumask_intersects(mask, cpu_online_mask))
+                return -EINVAL;
+
+        if (get_irte(irq, &irte))
+                return -EBUSY;
+
+        if (assign_irq_vector(irq, cfg, mask))
+                return -EBUSY;
+
+        dest = apic->cpu_mask_to_apicid_and(cfg->domain, mask);
+
+        irte.vector = cfg->vector;
+        irte.dest_id = IRTE_DEST(dest);
+
+        /*
+         * Atomically updates the IRTE with the new destination, vector
+         * and flushes the interrupt entry cache.
+         */
+        modify_irte(irq, &irte);
+
+        /*
+         * After this point, all the interrupts will start arriving
+         * at the new destination. So, time to cleanup the previous
+         * vector allocation.
+         */
+        if (cfg->move_in_progress)
+                send_cleanup_vector(cfg);
+
+        cpumask_copy(data->affinity, mask);
+        return 0;
+}
 
 struct irq_remap_ops intel_irq_remap_ops = {
         .supported              = intel_intr_remapping_supported,
@@ -910,4 +963,5 @@ struct irq_remap_ops intel_irq_remap_ops = {
         .hardware_reenable      = reenable_intr_remapping,
         .enable_faulting        = enable_drhd_fault_handling,
         .setup_ioapic_entry     = intel_setup_ioapic_entry,
+        .set_affinity           = intel_ioapic_set_affinity,
 };
diff --git a/drivers/iommu/intr_remapping.c b/drivers/iommu/intr_remapping.c
index 739148ab2538..2f4f27ffb861 100644
--- a/drivers/iommu/intr_remapping.c
+++ b/drivers/iommu/intr_remapping.c
@@ -110,3 +110,12 @@ int intr_setup_ioapic_entry(int irq,
         return remap_ops->setup_ioapic_entry(irq, entry, destination,
                                              vector, attr);
 }
+
+int intr_set_affinity(struct irq_data *data, const struct cpumask *mask,
+                      bool force)
+{
+        if (!remap_ops || !remap_ops->set_affinity)
+                return 0;
+
+        return remap_ops->set_affinity(data, mask, force);
+}
diff --git a/drivers/iommu/intr_remapping.h b/drivers/iommu/intr_remapping.h
index e8994f2b3bbe..e0bc6e0ba1fb 100644
--- a/drivers/iommu/intr_remapping.h
+++ b/drivers/iommu/intr_remapping.h
@@ -26,6 +26,8 @@
 
 struct IO_APIC_route_entry;
 struct io_apic_irq_attr;
+struct irq_data;
+struct cpumask;
 
 extern int disable_intremap;
 extern int disable_sourceid_checking;
@@ -54,6 +56,10 @@ struct irq_remap_ops {
         int (*setup_ioapic_entry)(int irq, struct IO_APIC_route_entry *,
                                   unsigned int, int,
                                   struct io_apic_irq_attr *);
+
+        /* Set the CPU affinity of a remapped interrupt */
+        int (*set_affinity)(struct irq_data *data, const struct cpumask *mask,
+                            bool force);
 };
 
 extern struct irq_remap_ops intel_irq_remap_ops;