Re: [PATCH rfcv2 08/20] iommufd: Implement query of HOST_IOMMU_DEVICE_CAP_ERRATA

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

On 2/19/25 9:22 AM, Zhenzhong Duan wrote:
> Implement query of HOST_IOMMU_DEVICE_CAP_ERRATA for IOMMUFD
> backed host IOMMU device.
>
> Query on this capability is not supported for legacy backend
> because there is no plan to support nesting with leacy backend
legacy
> backed host device.
>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> ---
>  include/system/host_iommu_device.h | 2 ++
>  backends/iommufd.c                 | 2 ++
>  hw/vfio/iommufd.c                  | 1 +
>  3 files changed, 5 insertions(+)
>
> diff --git a/include/system/host_iommu_device.h b/include/system/host_iommu_device.h
> index 18f8b5e5cf..250600fc1d 100644
> --- a/include/system/host_iommu_device.h
> +++ b/include/system/host_iommu_device.h
> @@ -32,6 +32,7 @@ typedef struct HostIOMMUDeviceCaps {
>      uint64_t hw_caps;
>      bool nesting;
>      bool fs1gp;
> +    uint32_t errata;
to be consistent with the others yu may have introduced this alongside
with the 2 others?
This is also not usable by other IOMMUs.

Eric
>  } HostIOMMUDeviceCaps;
>  
>  #define TYPE_HOST_IOMMU_DEVICE "host-iommu-device"
> @@ -130,6 +131,7 @@ struct HostIOMMUDeviceClass {
>  #define HOST_IOMMU_DEVICE_CAP_AW_BITS           1
>  #define HOST_IOMMU_DEVICE_CAP_NESTING           2
>  #define HOST_IOMMU_DEVICE_CAP_FS1GP             3
> +#define HOST_IOMMU_DEVICE_CAP_ERRATA            4
>  
>  #define HOST_IOMMU_DEVICE_CAP_AW_BITS_MAX       64
>  #endif
> diff --git a/backends/iommufd.c b/backends/iommufd.c
> index 0a1a40cbba..3c23caef96 100644
> --- a/backends/iommufd.c
> +++ b/backends/iommufd.c
> @@ -374,6 +374,8 @@ static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap, Error **errp)
>          return caps->nesting;
>      case HOST_IOMMU_DEVICE_CAP_FS1GP:
>          return caps->fs1gp;
> +    case HOST_IOMMU_DEVICE_CAP_ERRATA:
> +        return caps->errata;
>      default:
>          error_setg(errp, "%s: unsupported capability %x", hiod->name, cap);
>          return -EINVAL;
> diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
> index df6a12d200..58bff030e1 100644
> --- a/hw/vfio/iommufd.c
> +++ b/hw/vfio/iommufd.c
> @@ -848,6 +848,7 @@ static bool hiod_iommufd_vfio_realize(HostIOMMUDevice *hiod, void *opaque,
>      case IOMMU_HW_INFO_TYPE_INTEL_VTD:
>          caps->nesting = !!(data.vtd.ecap_reg & VTD_ECAP_NEST);
>          caps->fs1gp = !!(data.vtd.cap_reg & VTD_CAP_FS1GP);
> +        caps->errata = data.vtd.flags & IOMMU_HW_INFO_VTD_ERRATA_772415_SPR17;
>          break;
>      case IOMMU_HW_INFO_TYPE_ARM_SMMUV3:
>      case IOMMU_HW_INFO_TYPE_NONE: