static int mem_event_enable(struct domain *d, mfn_t ring_mfn, mfn_t shared_mfn)
{
int rc;
/* Map ring and shared pages */
d->mem_event.ring_page = map_domain_page(mfn_x(ring_mfn));
if ( d->mem_event.ring_page == NULL )
goto err;
d->mem_event.shared_page = map_domain_page(mfn_x(shared_mfn));
if ( d->mem_event.shared_page == NULL )
goto err_ring;
/* Allocate event channel */
rc = alloc_unbound_xen_event_channel(d->vcpu[0],
current->domain->domain_id);
if ( rc < 0 )
goto err_shared;
((mem_event_shared_page_t *)d->mem_event.shared_page)->port = rc;
d->mem_event.xen_port = rc;
/* Prepare ring buffer */
FRONT_RING_INIT(&d->mem_event.front_ring,
(mem_event_sring_t *)d->mem_event.ring_page,
PAGE_SIZE);
mem_event_ring_lock_init(d);
/* Wake any VCPUs paused for memory events */
mem_event_unpause_vcpus(d);
return 0;
err_shared:
unmap_domain_page(d->mem_event.shared_page);
d->mem_event.shared_page = NULL;
err_ring:
unmap_domain_page(d->mem_event.ring_page);
d->mem_event.ring_page = NULL;
err:
return 1;
}
static int mem_event_enable(
struct domain *d,
xen_domctl_mem_event_op_t *mec,
struct mem_event_domain *med,
int pause_flag,
int param,
xen_event_channel_notification_t notification_fn)
{
int rc;
unsigned long ring_gfn = d->arch.hvm_domain.params[param];
/* Only one helper at a time. If the helper crashed,
* the ring is in an undefined state and so is the guest.
*/
if ( med->ring_page )
return -EBUSY;
/* The parameter defaults to zero, and it should be
* set to something */
if ( ring_gfn == 0 )
return -ENOSYS;
mem_event_ring_lock_init(med);
mem_event_ring_lock(med);
rc = prepare_ring_for_helper(d, ring_gfn, &med->ring_pg_struct,
&med->ring_page);
if ( rc < 0 )
goto err;
/* Set the number of currently blocked vCPUs to 0. */
med->blocked = 0;
/* Allocate event channel */
rc = alloc_unbound_xen_event_channel(d, 0, current->domain->domain_id,
notification_fn);
if ( rc < 0 )
goto err;
med->xen_port = mec->port = rc;
/* Prepare ring buffer */
FRONT_RING_INIT(&med->front_ring,
(mem_event_sring_t *)med->ring_page,
PAGE_SIZE);
/* Save the pause flag for this particular ring. */
med->pause_flag = pause_flag;
/* Initialize the last-chance wait queue. */
init_waitqueue_head(&med->wq);
mem_event_ring_unlock(med);
return 0;
err:
destroy_ring_for_helper(&med->ring_page,
med->ring_pg_struct);
mem_event_ring_unlock(med);
return rc;
}
