Re: [PATCH v5 04/21] vfio: Introduce helper vfio_pci_from_vfio_device()

[Cédric Le Goater]

Zhenzhong,

On 8/22/25 08:40, Zhenzhong Duan wrote:

Introduce helper vfio_pci_from_vfio_device() to transform from VFIODevice
to VFIOPCIDevice, also to hide low level VFIO_DEVICE_TYPE_PCI type check.

Suggested-by: Cédric Le Goater <c...@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
Reviewed-by: Cédric Le Goater <c...@redhat.com>
Link: 
https://lore.kernel.org/qemu-devel/20250801023533.1458644-1-zhenzhong.d...@intel.com
[ clg: Added documentation ]
Signed-off-by: Cédric Le Goater <c...@redhat.com>

Would you like me to merge these VFIO changes upfront ?

They do not seem to conflict with the series I have queued for 10.2 so far.

C.

---
  hw/vfio/pci.h       | 12 ++++++++++++
  hw/vfio/container.c |  4 ++--
  hw/vfio/device.c    |  2 +-
  hw/vfio/iommufd.c   |  4 ++--
  hw/vfio/listener.c  |  4 ++--
  hw/vfio/pci.c       |  9 +++++++++
  6 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 810a842f4a..beb8fb9ee7 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -221,6 +221,18 @@ void vfio_pci_write_config(PCIDevice *pdev,
  uint64_t vfio_vga_read(void *opaque, hwaddr addr, unsigned size);
  void vfio_vga_write(void *opaque, hwaddr addr, uint64_t data, unsigned size);

+/**

+ * vfio_pci_from_vfio_device: Transform from VFIODevice to
+ * VFIOPCIDevice
+ *
+ * This function checks if the given @vbasedev is a VFIO PCI device.
+ * If it is, it returns the containing VFIOPCIDevice.
+ *
+ * @vbasedev: The VFIODevice to transform
+ *
+ * Return: The VFIOPCIDevice on success, NULL on failure.
+ */
+VFIOPCIDevice *vfio_pci_from_vfio_device(VFIODevice *vbasedev);
  void vfio_sub_page_bar_update_mappings(VFIOPCIDevice *vdev);
  bool vfio_opt_rom_in_denylist(VFIOPCIDevice *vdev);
  bool vfio_config_quirk_setup(VFIOPCIDevice *vdev, Error **errp);
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 3e13feaa74..134ddccc52 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -1087,7 +1087,7 @@ static int vfio_legacy_pci_hot_reset(VFIODevice 
*vbasedev, bool single)
          /* Prep dependent devices for reset and clear our marker. */
          QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
              if (!vbasedev_iter->dev->realized ||
-                vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
+                !vfio_pci_from_vfio_device(vbasedev_iter)) {
                  continue;
              }
              tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
@@ -1172,7 +1172,7 @@ out:

QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {

              if (!vbasedev_iter->dev->realized ||
-                vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
+                !vfio_pci_from_vfio_device(vbasedev_iter)) {
                  continue;
              }
              tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
diff --git a/hw/vfio/device.c b/hw/vfio/device.c
index 52a1996dc4..08f12ac31f 100644
--- a/hw/vfio/device.c
+++ b/hw/vfio/device.c
@@ -129,7 +129,7 @@ static inline const char *action_to_str(int action)

static const char *index_to_str(VFIODevice *vbasedev, int index)

  {
-    if (vbasedev->type != VFIO_DEVICE_TYPE_PCI) {
+    if (!vfio_pci_from_vfio_device(vbasedev)) {
          return NULL;
      }

diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c

index 48c590b6a9..8c27222f75 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -737,8 +737,8 @@ iommufd_cdev_dep_get_realized_vpdev(struct 
vfio_pci_dependent_device *dep_dev,
      }

vbasedev_tmp = iommufd_cdev_pci_find_by_devid(dep_dev->devid);

-    if (!vbasedev_tmp || !vbasedev_tmp->dev->realized ||
-        vbasedev_tmp->type != VFIO_DEVICE_TYPE_PCI) {
+    if (!vfio_pci_from_vfio_device(vbasedev_tmp) ||
+        !vbasedev_tmp->dev->realized) {
          return NULL;
      }

diff --git a/hw/vfio/listener.c b/hw/vfio/listener.c

index f498e23a93..903dfd8bf2 100644
--- a/hw/vfio/listener.c
+++ b/hw/vfio/listener.c
@@ -450,7 +450,7 @@ static void vfio_device_error_append(VFIODevice *vbasedev, 
Error **errp)
       * MMIO region mapping failures are not fatal but in this case PCI
       * peer-to-peer transactions are broken.
       */
-    if (vbasedev && vbasedev->type == VFIO_DEVICE_TYPE_PCI) {
+    if (vfio_pci_from_vfio_device(vbasedev)) {
          error_append_hint(errp, "%s: PCI peer-to-peer transactions "
                            "on BARs are not supported.\n", vbasedev->name);
      }
@@ -751,7 +751,7 @@ static bool vfio_section_is_vfio_pci(MemoryRegionSection 
*section,
      owner = memory_region_owner(section->mr);

QLIST_FOREACH(vbasedev, &bcontainer->device_list, container_next) {

-        if (vbasedev->type != VFIO_DEVICE_TYPE_PCI) {
+        if (!vfio_pci_from_vfio_device(vbasedev)) {
              continue;
          }
          pcidev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 07257d0fa0..3fe5b03eb1 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2833,6 +2833,15 @@ static int vfio_pci_load_config(VFIODevice *vbasedev, 
QEMUFile *f)
      return ret;
  }

+/* Transform from VFIODevice to VFIOPCIDevice. Return NULL if fails. */

+VFIOPCIDevice *vfio_pci_from_vfio_device(VFIODevice *vbasedev)
+{
+    if (vbasedev && vbasedev->type == VFIO_DEVICE_TYPE_PCI) {
+        return container_of(vbasedev, VFIOPCIDevice, vbasedev);
+    }
+    return NULL;
+}
+
  void vfio_sub_page_bar_update_mappings(VFIOPCIDevice *vdev)
  {
      PCIDevice *pdev = &vdev->pdev;