Re: [PATCH rfcv2 04/18] vfio: Add host iommu device instance into VFIODevice

[Eric Auger]

On 2/1/24 08:28, Zhenzhong Duan wrote:
> Either IOMMULegacyDevice or IOMMUFDDevice into VFIODevice, neither
> both.
>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> ---
>  include/hw/vfio/vfio-common.h | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index 8bfb9cbe94..1bbad003ee 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -32,6 +32,7 @@
>  #include "sysemu/sysemu.h"
>  #include "hw/vfio/vfio-container-base.h"
>  #include "sysemu/host_iommu_device.h"
> +#include "sysemu/iommufd.h"
>  
>  #define VFIO_MSG_PREFIX "vfio %s: "
>  
> @@ -132,8 +133,18 @@ typedef struct VFIODevice {
>      bool dirty_tracking;
>      int devid;
>      IOMMUFDBackend *iommufd;
> +    union {
> +        HostIOMMUDevice base_hdev;
> +        IOMMULegacyDevice legacy_dev;
> +        IOMMUFDDevice iommufd_dev;
I think you should rather have a HostIOMMUDevice handle.

host_iommu_device_init cb would allocate the right type of the derived object 
and you would store the base object pointer here.

Eric
> +    };
>  } VFIODevice;
>  
> +QEMU_BUILD_BUG_ON(offsetof(VFIODevice, legacy_dev.base) !=
> +                  offsetof(VFIODevice, base_hdev));
> +QEMU_BUILD_BUG_ON(offsetof(VFIODevice, iommufd_dev.base) !=
> +                  offsetof(VFIODevice, base_hdev));
> +
>  struct VFIODeviceOps {
>      void (*vfio_compute_needs_reset)(VFIODevice *vdev);
>      int (*vfio_hot_reset_multi)(VFIODevice *vdev);