vfio: Collect container iova range info

Collect iova range information if VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE
capability is supported.

This allows to propagate the information though the IOMMU MR
set_iova_ranges() callback so that virtual IOMMUs
get aware of those aperture constraints. This is only done if
the info is available and the number of iova ranges is greater than
0.

A new vfio_get_info_iova_range helper is introduced matching
the coding style of existing vfio_get_info_dma_avail. The
boolean returned value isn't used though. Code is aligned
between both.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Yanghang Liu <yanghliu@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/vfio/common.c

@@ -693,6 +693,15 @@ static void vfio_listener_region_add(MemoryListener *listener,
             goto fail;
         }
 
+        if (container->iova_ranges) {
+            ret = memory_region_iommu_set_iova_ranges(giommu->iommu_mr,
+                    container->iova_ranges, &err);
+            if (ret) {
+                g_free(giommu);
+                goto fail;
+            }
+        }
+
         ret = memory_region_register_iommu_notifier(section->mr, &giommu->n,
                                                     &err);
         if (ret) {

hw/vfio/container.c

@@ -382,7 +382,7 @@ bool vfio_get_info_dma_avail(struct vfio_iommu_type1_info *info,
     /* If the capability cannot be found, assume no DMA limiting */
     hdr = vfio_get_iommu_type1_info_cap(info,
                                         VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL);
-    if (hdr == NULL) {
+    if (!hdr) {
         return false;
     }
 
@@ -394,6 +394,32 @@ bool vfio_get_info_dma_avail(struct vfio_iommu_type1_info *info,
     return true;
 }
 
+static bool vfio_get_info_iova_range(struct vfio_iommu_type1_info *info,
+                                     VFIOContainer *container)
+{
+    struct vfio_info_cap_header *hdr;
+    struct vfio_iommu_type1_info_cap_iova_range *cap;
+
+    hdr = vfio_get_iommu_type1_info_cap(info,
+                                        VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE);
+    if (!hdr) {
+        return false;
+    }
+
+    cap = (void *)hdr;
+
+    for (int i = 0; i < cap->nr_iovas; i++) {
+        Range *range = g_new(Range, 1);
+
+        range_set_bounds(range, cap->iova_ranges[i].start,
+                         cap->iova_ranges[i].end);
+        container->iova_ranges =
+            range_list_insert(container->iova_ranges, range);
+    }
+
+    return true;
+}
+
 static void vfio_kvm_device_add_group(VFIOGroup *group)
 {
     Error *err = NULL;
@@ -535,6 +561,12 @@ static void vfio_get_iommu_info_migration(VFIOContainer *container,
     }
 }
 
+static void vfio_free_container(VFIOContainer *container)
+{
+    g_list_free_full(container->iova_ranges, g_free);
+    g_free(container);
+}
+
 static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
                                   Error **errp)
 {
@@ -616,6 +648,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
     container->error = NULL;
     container->dirty_pages_supported = false;
     container->dma_max_mappings = 0;
+    container->iova_ranges = NULL;
     QLIST_INIT(&container->giommu_list);
     QLIST_INIT(&container->hostwin_list);
     QLIST_INIT(&container->vrdl_list);
@@ -652,6 +685,9 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
         if (!vfio_get_info_dma_avail(info, &container->dma_max_mappings)) {
             container->dma_max_mappings = 65535;
         }
+
+        vfio_get_info_iova_range(info, container);
+
         vfio_get_iommu_info_migration(container, info);
         g_free(info);
 
@@ -765,7 +801,7 @@ enable_discards_exit:
     vfio_ram_block_discard_disable(container, false);
 
 free_container_exit:
-    g_free(container);
+    vfio_free_container(container);
 
 close_fd_exit:
     close(fd);
@@ -819,7 +855,7 @@ static void vfio_disconnect_container(VFIOGroup *group)
 
         trace_vfio_disconnect_container(container->fd);
         close(container->fd);
-        g_free(container);
+        vfio_free_container(container);
 
         vfio_put_address_space(space);
     }

include/hw/vfio/vfio-common.h

@@ -99,6 +99,7 @@ typedef struct VFIOContainer {
     QLIST_HEAD(, VFIORamDiscardListener) vrdl_list;
     QLIST_ENTRY(VFIOContainer) next;
     QLIST_HEAD(, VFIODevice) device_list;
+    GList *iova_ranges;
 } VFIOContainer;
 
 typedef struct VFIOGuestIOMMU {