On 23.06.2025 20:28, dm...@proton.me wrote:
> --- a/xen/common/domain.c
> +++ b/xen/common/domain.c
> @@ -492,7 +492,7 @@ static int late_hwdom_init(struct domain *d)
> struct domain *dom0;
> int rv;
>
> - if ( d != hardware_domain || d->domain_id == 0 )
> + if ( d != hardware_domain || d->domain_id == get_initial_domain_id() )
> return 0;
>
> rv = xsm_init_hardware_domain(XSM_HOOK, d);
> @@ -501,7 +501,7 @@ static int late_hwdom_init(struct domain *d)
>
> printk("Initialising hardware domain %d\n", hardware_domid);
>
> - dom0 = rcu_lock_domain_by_id(0);
> + dom0 = rcu_lock_domain_by_id(get_initial_domain_id());
> ASSERT(dom0 != NULL);
For both changes above you're introducing a subtle (largely theoretical)
behavioral change: In shim mode, this assertion, if we somehow made it
here, would suddenly not trigger anymore. Similarly for the earlier
change the return path may wrongly be taken then.
> @@ -2479,7 +2479,7 @@ domid_t domid_alloc(domid_t domid)
> if ( domid == DOMID_FIRST_RESERVED )
> domid = find_next_zero_bit(domid_bitmap,
> DOMID_FIRST_RESERVED,
> - 1);
> + get_initial_domain_id() + 1);
This imo is the worst of the changes. get_initial_domain_id() can return
non-zero. In that case we still would (in principle) want to re-start
from 1 here.
Jan
