Re: [RFC PATCH v2 11/20] hw/arm/smmuv3-accel: Allocate a vDEVICE object for device

[Eric Auger <eric.auger@redhat.com>]

Hi,

On 3/11/25 3:10 PM, Shameer Kolothum wrote:
> From: Nicolin Chen <nicolinc@nvidia.com>
>
> Allocate and associate a vDEVICE object for the Guest device
> with the vIOMMU. This will help the kernel to do the
> vSID --> sid translation whenever required (eg: device specific
s/sid/SID
> invalidations).
>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
>  hw/arm/smmuv3-accel.c         | 22 ++++++++++++++++++++++
>  include/hw/arm/smmuv3-accel.h |  6 ++++++
>  2 files changed, 28 insertions(+)
>
> diff --git a/hw/arm/smmuv3-accel.c b/hw/arm/smmuv3-accel.c
> index d3a5cf9551..056bd23b2e 100644
> --- a/hw/arm/smmuv3-accel.c
> +++ b/hw/arm/smmuv3-accel.c
> @@ -109,6 +109,20 @@ void smmuv3_accel_install_nested_ste(SMMUDevice *sdev, int sid)
>          return;
>      }
>  
> +    if (!accel_dev->vdev && accel_dev->idev) {
> +        SMMUVdev *vdev;
> +        uint32_t vdev_id;
> +        SMMUViommu *viommu = accel_dev->viommu;
> +
> +        iommufd_backend_alloc_vdev(viommu->core.iommufd, accel_dev->idev->devid,
> +                                   viommu->core.viommu_id, sid, &vdev_id,
> +                                   &error_abort);
> +        vdev = g_new0(SMMUVdev, 1);
nit: no need to use 0 variant if you set all fields
> +        vdev->vdev_id = vdev_id;
> +        vdev->sid = sid;
> +        accel_dev->vdev = vdev;
> +    }
> +
>      ret = smmu_find_ste(sdev->smmu, sid, &ste, &event);
>      if (ret) {
>          /*
> @@ -283,6 +297,7 @@ static bool smmuv3_accel_set_iommu_device(PCIBus *bus, void *opaque, int devfn,
>  static void smmuv3_accel_unset_iommu_device(PCIBus *bus, void *opaque,
>                                              int devfn)
>  {
> +    SMMUVdev *vdev;
>      SMMUDevice *sdev;
>      SMMUv3AccelDevice *accel_dev;
>      SMMUViommu *viommu;
> @@ -312,6 +327,13 @@ static void smmuv3_accel_unset_iommu_device(PCIBus *bus, void *opaque,
>      trace_smmuv3_accel_unset_iommu_device(devfn, smmu_get_sid(sdev));
>  
>      viommu = s_accel->viommu;
> +    vdev = accel_dev->vdev;
> +    if (vdev) {
> +        iommufd_backend_free_id(viommu->iommufd, vdev->vdev_id);
> +        g_free(vdev);
> +        accel_dev->vdev = NULL;
> +    }
> +
>      if (QLIST_EMPTY(&viommu->device_list)) {
>          iommufd_backend_free_id(viommu->iommufd, viommu->bypass_hwpt_id);
>          iommufd_backend_free_id(viommu->iommufd, viommu->abort_hwpt_id);
> diff --git a/include/hw/arm/smmuv3-accel.h b/include/hw/arm/smmuv3-accel.h
> index d6b0b1ca30..54b217ab4f 100644
> --- a/include/hw/arm/smmuv3-accel.h
> +++ b/include/hw/arm/smmuv3-accel.h
> @@ -35,6 +35,11 @@ typedef struct SMMUViommu {
>      QLIST_ENTRY(SMMUViommu) next;
>  } SMMUViommu;
>  
> +typedef struct SMMUVdev {
> +    uint32_t vdev_id;
> +    uint32_t sid;
> +} SMMUVdev;
> +
>  typedef struct SMMUS1Hwpt {
>      IOMMUFDBackend *iommufd;
>      uint32_t hwpt_id;
> @@ -45,6 +50,7 @@ typedef struct SMMUv3AccelDevice {
>      HostIOMMUDeviceIOMMUFD *idev;
>      SMMUS1Hwpt  *s1_hwpt;
>      SMMUViommu *viommu;
> +    SMMUVdev   *vdev;
>      QLIST_ENTRY(SMMUv3AccelDevice) next;
>  } SMMUv3AccelDevice;
>