On 13.12.2024 17:24, Juergen Gross wrote:
> @@ -138,6 +139,60 @@ bool __read_mostly vmtrace_available;
>
> bool __read_mostly vpmu_is_available;
>
> +static DEFINE_SPINLOCK(dom_state_changed_lock);
> +static unsigned long *dom_state_changed;
__read_mostly?
> +int domain_init_states(void)
> +{
> + const struct domain *d;
> + int rc = -ENOMEM;
> +
> + spin_lock(&dom_state_changed_lock);
> +
> + if ( dom_state_changed )
> + bitmap_zero(dom_state_changed, DOMID_FIRST_RESERVED);
> + else
> + {
> + dom_state_changed = xvzalloc_array(unsigned long,
> +
> BITS_TO_LONGS(DOMID_FIRST_RESERVED));
> + if ( !dom_state_changed )
> + goto unlock;
> + }
> +
> + rcu_read_lock(&domlist_read_lock);
> +
> + for_each_domain ( d )
> + set_bit(d->domain_id, dom_state_changed);
Use the cheaper __set_bit() here?
> +static void domain_changed_state(const struct domain *d)
> +{
> + spin_lock(&dom_state_changed_lock);
> +
> + if ( dom_state_changed )
> + set_bit(d->domain_id, dom_state_changed);
And perhaps even here, considering everything's under lock now?
> --- a/xen/common/event_channel.c
> +++ b/xen/common/event_channel.c
> @@ -485,6 +485,13 @@ int evtchn_bind_virq(evtchn_bind_virq_t *bind,
> evtchn_port_t port)
> if ( (v = domain_vcpu(d, vcpu)) == NULL )
> return -ENOENT;
>
> + if ( virq == VIRQ_DOM_EXC )
> + {
> + rc = domain_init_states();
> + if ( rc )
> + goto deinit;
> + }
This is tied to VIRQ_DOM_EXC. How come ...
> @@ -527,6 +534,10 @@ int evtchn_bind_virq(evtchn_bind_virq_t *bind,
> evtchn_port_t port)
> out:
> write_unlock(&d->event_lock);
>
> + deinit:
> + if ( rc )
> + domain_deinit_states();
> +
> return rc;
> }
... de-init happens upon any error, regardless of vIRQ? Even checking
the virq isn't sufficient, as we also need to gracefully deal with the
-EEXIST path.
Jan
