Re: [PATCH rfcv1 4/6] vfio: initialize IOMMUFDDevice and pass to vIOMMU

[Cédric Le Goater]

On 1/15/24 11:13, Zhenzhong Duan wrote:

Initialize IOMMUFDDevice in vfio and pass to vIOMMU, so that vIOMMU
could get hw IOMMU information.

In VFIO legacy backend mode, we still pass a NULL IOMMUFDDevice to vIOMMU,
in case vIOMMU needs some processing for VFIO legacy backend mode.

Originally-by: Yi Liu <yi.l....@intel.com>
Signed-off-by: Nicolin Chen <nicol...@nvidia.com>
Signed-off-by: Yi Sun <yi.y....@linux.intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
---
  include/hw/vfio/vfio-common.h |  2 ++
  hw/vfio/iommufd.c             |  2 ++
  hw/vfio/pci.c                 | 24 +++++++++++++++++++-----
  3 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 9b7ef7d02b..fde0d0ca60 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -31,6 +31,7 @@
  #endif
  #include "sysemu/sysemu.h"
  #include "hw/vfio/vfio-container-base.h"
+#include "sysemu/iommufd_device.h"

#define VFIO_MSG_PREFIX "vfio %s: " @@ -126,6 +127,7 @@ typedef struct VFIODevice {

      bool dirty_tracking;
      int devid;
      IOMMUFDBackend *iommufd;
+    IOMMUFDDevice idev;
  } VFIODevice;

struct VFIODeviceOps {

diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 9bfddc1360..cbd035f148 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -309,6 +309,7 @@ static int iommufd_cdev_attach(const char *name, VFIODevice 
*vbasedev,
      VFIOContainerBase *bcontainer;
      VFIOIOMMUFDContainer *container;
      VFIOAddressSpace *space;
+    IOMMUFDDevice *idev = &vbasedev->idev;
      struct vfio_device_info dev_info = { .argsz = sizeof(dev_info) };
      int ret, devfd;
      uint32_t ioas_id;
@@ -428,6 +429,7 @@ found_container:
      QLIST_INSERT_HEAD(&bcontainer->device_list, vbasedev, container_next);
      QLIST_INSERT_HEAD(&vfio_device_list, vbasedev, global_next);

+ iommufd_device_init(idev, sizeof(*idev), container->be, vbasedev->devid);

      trace_iommufd_cdev_device_info(vbasedev->name, devfd, vbasedev->num_irqs,
                                     vbasedev->num_regions, vbasedev->flags);
      return 0;
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index d7fe06715c..2c3a5d267b 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3107,11 +3107,21 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)

vfio_bars_register(vdev); - ret = vfio_add_capabilities(vdev, errp);

+    if (vbasedev->iommufd) {
+        ret = pci_device_set_iommu_device(pdev, &vbasedev->idev, errp);
+    } else {
+        ret = pci_device_set_iommu_device(pdev, 0, errp);

AFAICT, pci_device_set_iommu_device() with a NULL IOMMUFDDevice will do
nothing. Why call it ?


Thanks,

C.

+    }
      if (ret) {
+        error_prepend(errp, "Failed to set iommu_device: ");
          goto out_teardown;
      }

+ ret = vfio_add_capabilities(vdev, errp);

+    if (ret) {
+        goto out_unset_idev;
+    }
+
      if (vdev->vga) {
          vfio_vga_quirk_setup(vdev);
      }
@@ -3128,7 +3138,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
              error_setg(errp,
                         "cannot support IGD OpRegion feature on hotplugged "
                         "device");
-            goto out_teardown;
+            goto out_unset_idev;
          }

ret = vfio_get_dev_region_info(vbasedev,

@@ -3137,13 +3147,13 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
          if (ret) {
              error_setg_errno(errp, -ret,
                               "does not support requested IGD OpRegion 
feature");
-            goto out_teardown;
+            goto out_unset_idev;
          }

ret = vfio_pci_igd_opregion_init(vdev, opregion, errp);

          g_free(opregion);
          if (ret) {
-            goto out_teardown;
+            goto out_unset_idev;
          }
      }

@@ -3229,6 +3239,8 @@ out_deregister:

      if (vdev->intx.mmap_timer) {
          timer_free(vdev->intx.mmap_timer);
      }
+out_unset_idev:
+    pci_device_unset_iommu_device(pdev);
  out_teardown:
      vfio_teardown_msi(vdev);
      vfio_bars_exit(vdev);
@@ -3257,6 +3269,7 @@ static void vfio_instance_finalize(Object *obj)
  static void vfio_exitfn(PCIDevice *pdev)
  {
      VFIOPCIDevice *vdev = VFIO_PCI(pdev);
+    VFIODevice *vbasedev = &vdev->vbasedev;

vfio_unregister_req_notifier(vdev);

      vfio_unregister_err_notifier(vdev);
@@ -3271,7 +3284,8 @@ static void vfio_exitfn(PCIDevice *pdev)
      vfio_teardown_msi(vdev);
      vfio_pci_disable_rp_atomics(vdev);
      vfio_bars_exit(vdev);
-    vfio_migration_exit(&vdev->vbasedev);
+    vfio_migration_exit(vbasedev);
+    pci_device_unset_iommu_device(pdev);
  }

static void vfio_pci_reset(DeviceState *dev)