Re: [PATCH v15 2/3] mem_sharing: allow forking domain with IOMMU enabled

[Jan Beulich <jbeulich@xxxxxxxx>]

On 17.04.2020 19:06, Tamas K Lengyel wrote:
> @@ -2063,9 +2065,10 @@ int 
> mem_sharing_memop(XEN_GUEST_HANDLE_PARAM(xen_mem_sharing_op_t) arg)
>      case XENMEM_sharing_op_fork:
>      {
>          struct domain *pd;
> +        bool allow_iommu;
>  
>          rc = -EINVAL;
> -        if ( mso.u.fork.pad[0] || mso.u.fork.pad[1] || mso.u.fork.pad[2] )
> +        if ( mso.u.fork.pad[0] || mso.u.fork.pad[1] )
>              goto out;

Rather than outright dropping this, you now want to bail on
any bits set in flags except the one that's currently defined.

Jan