Re: [PATCH v4 02/12] vfio/iommufd: Don't initialize nor set a HOST_IOMMU_DEVICE with mdev

[Eric Auger]

On 7/12/24 13:46, Joao Martins wrote:
> mdevs aren't "physical" devices and when asking for backing IOMMU info, it
> fails the entire provisioning of the guest. Fix that by skipping
> HostIOMMUDevice initialization in the presence of mdevs, and skip setting
> an iommu device when it is known to be an mdev.
>
> Cc: Zhenzhong Duan <zhenzhong.duan@intel.com>
> Fixes: 930589520128 ("vfio/iommufd: Implement HostIOMMUDeviceClass::realize() 
> handler")
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
With or without Cédric's suggestion
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric
> ---
>  hw/vfio/common.c |  4 ++++
>  hw/vfio/pci.c    | 10 +++++++---
>  2 files changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 7cdb969fd396..b0beed44116e 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -1556,6 +1556,10 @@ bool vfio_attach_device(char *name, VFIODevice 
> *vbasedev,
>          return false;
>      }
>  
> +    if (vbasedev->mdev) {
> +        return true;
> +    }
> +
>      hiod = HOST_IOMMU_DEVICE(object_new(ops->hiod_typename));
>      if (!HOST_IOMMU_DEVICE_GET_CLASS(hiod)->realize(hiod, vbasedev, errp)) {
>          object_unref(hiod);
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 585f23a18406..3fc72e898a25 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -3116,7 +3116,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
>  
>      vfio_bars_register(vdev);
>  
> -    if (!pci_device_set_iommu_device(pdev, vbasedev->hiod, errp)) {
> +    if (!is_mdev && !pci_device_set_iommu_device(pdev, vbasedev->hiod, 
> errp)) {
>          error_prepend(errp, "Failed to set iommu_device: ");
>          goto out_teardown;
>      }
> @@ -3239,7 +3239,9 @@ out_deregister:
>          timer_free(vdev->intx.mmap_timer);
>      }
>  out_unset_idev:
> -    pci_device_unset_iommu_device(pdev);
> +    if (!is_mdev) {
> +        pci_device_unset_iommu_device(pdev);
> +    }
>  out_teardown:
>      vfio_teardown_msi(vdev);
>      vfio_bars_exit(vdev);
> @@ -3284,7 +3286,9 @@ static void vfio_exitfn(PCIDevice *pdev)
>      vfio_pci_disable_rp_atomics(vdev);
>      vfio_bars_exit(vdev);
>      vfio_migration_exit(vbasedev);
> -    pci_device_unset_iommu_device(pdev);
> +    if (!vbasedev->mdev) {
> +        pci_device_unset_iommu_device(pdev);
> +    }
>  }
>  
>  static void vfio_pci_reset(DeviceState *dev)