Re: [PATCH v5 21/22] libxl/arm: Introduce domctl command for IOMMU vSID mapping

[Jan Beulich <jbeulich@xxxxxxxx>]

On 03.11.2026 18:30, Milan Djokic wrote:
> --- a/xen/include/public/domctl.h
> +++ b/xen/include/public/domctl.h
> @@ -1279,6 +1279,26 @@ struct xen_domctl_get_domain_state {
>      uint64_t unique_id;      /* Unique domain identifier. */
>  };
>  
> +/*
> + * XEN_DOMCTL_viommu_alloc_vsid_range
> + *
> + * Allocate guest vSID range and
> + * establish pSID->vSID mapping for target range and physical IOMMU 
> (phandle).
> + * Allocated range is continous
> + */
> +struct xen_domctl_viommu_alloc_vsid_range {
> +    /* IN: Range first pSID  */
> +    uint32_t first_psid;
> +    /* IN: Physical IOMMU phandle behind which the target device streams are 
> configured */
> +    uint32_t phandle;
> +    /* IN: Number of vSIDs to allocate */
> +    uint16_t nr_sids;
> +    /* padding, must be 0 */
> +    uint16_t pad;
> +    /* OUT: Mapped range first vSID */
> +    uint32_t first_vsid;
> +};
> +
>  struct xen_domctl {
>  /* Stable domctl ops: interface_version is required to be 0.  */
>      uint32_t cmd;
> @@ -1371,6 +1391,7 @@ struct xen_domctl {
>  #define XEN_DOMCTL_gsi_permission                88
>  #define XEN_DOMCTL_set_llc_colors                89
>  #define XEN_DOMCTL_get_domain_state              90 /* stable interface */
> +#define XEN_DOMCTL_viommu_alloc_vsid_range       91
>  #define XEN_DOMCTL_gdbsx_guestmemio            1000
>  #define XEN_DOMCTL_gdbsx_pausevcpu             1001
>  #define XEN_DOMCTL_gdbsx_unpausevcpu           1002
> @@ -1439,6 +1460,7 @@ struct xen_domctl {
>  #endif
>          struct xen_domctl_set_llc_colors    set_llc_colors;
>          struct xen_domctl_get_domain_state  get_domain_state;
> +        struct xen_domctl_viommu_alloc_vsid_range viommu_alloc_vsid_range;
>          uint8_t                             pad[128];
>      } u;
>  };

One way or another this new sub-op wants explicitly marking as Arm-only.
The specific interface doesn't look like it might be meant to be arch-
independent, i.e. it's not just the fact that only Arm implements the
sub-op for now.

Jan