Re: [RFC PATCH 08/10] xsm-silo: convert silo over to domain roles

[Jan Beulich <jbeulich@suse.com>]

On 14.05.2021 22:54, Daniel P. Smith wrote:
> --- a/xen/xsm/silo.c
> +++ b/xen/xsm/silo.c
> @@ -17,9 +17,11 @@
>   * You should have received a copy of the GNU General Public License along with
>   * this program; If not, see <http://www.gnu.org/licenses/>.
>   */
> -#define XSM_NO_WRAPPERS
> -#include <xsm/dummy.h>
>  
> +#include <xsm/xsm.h>
> +#include <xsm/roles.h>
> +
> +#define SILO_ALLOWED_ROLES ( XSM_DOM_SUPER | XSM_DEV_BACK )

Assuming XSM_DEV_BACK means (or at least may also mean) a backend outside
of Dom0 serving another domain's frontend, ...

> @@ -29,8 +31,10 @@ static bool silo_mode_dom_check(const struct domain *ldom,
>  {
>      const struct domain *currd = current->domain;
>  
> -    return (is_control_domain(currd) || is_control_domain(ldom) ||
> -            is_control_domain(rdom) || ldom == rdom);
> +    return ( currd->xsm_roles & SILO_ALLOWED_ROLES ||
> +            ldom->xsm_roles & SILO_ALLOWED_ROLES ||
> +            rdom->xsm_roles & SILO_ALLOWED_ROLES ||
> +            ldom == rdom );

... I don't think this is an appropriate conversion. Aiui a backend in
a driver domain is out of reach for a domain in SILO mode.

Jan