Re: [PATCH 04/22] hw/vfio/container.c: use QOM casts where appropriate

[Cédric Le Goater]

On 7/15/25 11:25, Mark Cave-Ayland wrote:

Use QOM casts to convert between VFIOContainer and VFIOContainerBase instead
of accessing bcontainer directly.

Signed-off-by: Mark Cave-Ayland <mark.caveayl...@nutanix.com>

Reviewed-by: Cédric Le Goater <c...@redhat.com>

Thanks,

C.

---
  hw/vfio/container.c | 31 +++++++++++++------------------
  1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 3e13feaa74..f4337741b3 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -71,7 +71,7 @@ static int vfio_dma_unmap_bitmap(const VFIOContainer 
*container,
                                   hwaddr iova, ram_addr_t size,
                                   IOMMUTLBEntry *iotlb)
  {
-    const VFIOContainerBase *bcontainer = &container->bcontainer;
+    const VFIOContainerBase *bcontainer = VFIO_IOMMU(container);
      struct vfio_iommu_type1_dma_unmap *unmap;
      struct vfio_bitmap *bitmap;
      VFIOBitmap vbmap;
@@ -124,8 +124,7 @@ static int vfio_legacy_dma_unmap_one(const 
VFIOContainerBase *bcontainer,
                                       hwaddr iova, ram_addr_t size,
                                       IOMMUTLBEntry *iotlb)
  {
-    const VFIOContainer *container = container_of(bcontainer, VFIOContainer,
-                                                  bcontainer);
+    const VFIOContainer *container = VFIO_IOMMU_LEGACY(bcontainer);
      struct vfio_iommu_type1_dma_unmap unmap = {
          .argsz = sizeof(unmap),
          .flags = 0,
@@ -213,8 +212,7 @@ static int vfio_legacy_dma_map(const VFIOContainerBase 
*bcontainer, hwaddr iova,
                                 ram_addr_t size, void *vaddr, bool readonly,
                                 MemoryRegion *mr)
  {
-    const VFIOContainer *container = container_of(bcontainer, VFIOContainer,
-                                                  bcontainer);
+    const VFIOContainer *container = VFIO_IOMMU_LEGACY(bcontainer);
      struct vfio_iommu_type1_dma_map map = {
          .argsz = sizeof(map),
          .flags = VFIO_DMA_MAP_FLAG_READ,
@@ -246,8 +244,7 @@ static int
  vfio_legacy_set_dirty_page_tracking(const VFIOContainerBase *bcontainer,
                                      bool start, Error **errp)
  {
-    const VFIOContainer *container = container_of(bcontainer, VFIOContainer,
-                                                  bcontainer);
+    const VFIOContainer *container = VFIO_IOMMU_LEGACY(bcontainer);
      int ret;
      struct vfio_iommu_type1_dirty_bitmap dirty = {
          .argsz = sizeof(dirty),
@@ -272,8 +269,7 @@ vfio_legacy_set_dirty_page_tracking(const VFIOContainerBase 
*bcontainer,
  static int vfio_legacy_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
                        VFIOBitmap *vbmap, hwaddr iova, hwaddr size, Error 
**errp)
  {
-    const VFIOContainer *container = container_of(bcontainer, VFIOContainer,
-                                                  bcontainer);
+    const VFIOContainer *container = VFIO_IOMMU_LEGACY(bcontainer);
      struct vfio_iommu_type1_dirty_bitmap *dbitmap;
      struct vfio_iommu_type1_dirty_bitmap_get *range;
      int ret;
@@ -495,7 +491,7 @@ static void vfio_get_iommu_info_migration(VFIOContainer 
*container,
  {
      struct vfio_info_cap_header *hdr;
      struct vfio_iommu_type1_info_cap_migration *cap_mig;
-    VFIOContainerBase *bcontainer = &container->bcontainer;
+    VFIOContainerBase *bcontainer = VFIO_IOMMU(container);

hdr = vfio_get_iommu_info_cap(info, VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION);

      if (!hdr) {
@@ -518,8 +514,7 @@ static void vfio_get_iommu_info_migration(VFIOContainer 
*container,

static bool vfio_legacy_setup(VFIOContainerBase *bcontainer, Error **errp)

  {
-    VFIOContainer *container = container_of(bcontainer, VFIOContainer,
-                                            bcontainer);
+    VFIOContainer *container = VFIO_IOMMU_LEGACY(bcontainer);
      g_autofree struct vfio_iommu_type1_info *info = NULL;
      int ret;

@@ -634,7 +629,7 @@ static bool vfio_container_connect(VFIOGroup *group, AddressSpace *as, if (!cpr_is_incoming()) {

          QLIST_FOREACH(bcontainer, &space->containers, next) {
-            container = container_of(bcontainer, VFIOContainer, bcontainer);
+            container = VFIO_IOMMU_LEGACY(bcontainer);
              if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
                  return vfio_container_group_add(container, group, errp);
              }
@@ -652,7 +647,7 @@ static bool vfio_container_connect(VFIOGroup *group, 
AddressSpace *as,
           * create the container struct and group list.
           */
          QLIST_FOREACH(bcontainer, &space->containers, next) {
-            container = container_of(bcontainer, VFIOContainer, bcontainer);
+            container = VFIO_IOMMU_LEGACY(bcontainer);

if (vfio_cpr_container_match(container, group, fd)) {

                  return vfio_container_group_add(container, group, errp);
@@ -672,7 +667,7 @@ static bool vfio_container_connect(VFIOGroup *group, 
AddressSpace *as,
          goto fail;
      }
      new_container = true;
-    bcontainer = &container->bcontainer;
+    bcontainer = VFIO_IOMMU(container);

if (!vfio_legacy_cpr_register_container(container, errp)) {

          goto fail;
@@ -735,7 +730,7 @@ fail:
  static void vfio_container_disconnect(VFIOGroup *group)
  {
      VFIOContainer *container = group->container;
-    VFIOContainerBase *bcontainer = &container->bcontainer;
+    VFIOContainerBase *bcontainer = VFIO_IOMMU(container);
      VFIOIOMMUClass *vioc = VFIO_IOMMU_GET_CLASS(bcontainer);

QLIST_REMOVE(group, container_next);

@@ -781,7 +776,7 @@ static VFIOGroup *vfio_group_get(int groupid, AddressSpace 
*as, Error **errp)
      QLIST_FOREACH(group, &vfio_group_list, next) {
          if (group->groupid == groupid) {
              /* Found it.  Now is it already in the right context? */
-            if (group->container->bcontainer.space->as == as) {
+            if (VFIO_IOMMU(group->container)->space->as == as) {
                  return group;
              } else {
                  error_setg(errp, "group %d used in multiple address spaces",
@@ -895,7 +890,7 @@ static bool vfio_device_get(VFIOGroup *group, const char 
*name,
          }
      }

- vfio_device_prepare(vbasedev, &group->container->bcontainer, info);

+    vfio_device_prepare(vbasedev, VFIO_IOMMU(group->container), info);

vbasedev->fd = fd;

      vbasedev->group = group;