int libxl_vcpu_sched_params_get_all(libxl_ctx *ctx, uint32_t domid,
libxl_vcpu_sched_params *scinfo)
{
GC_INIT(ctx);
int rc;
scinfo->sched = libxl__domain_scheduler(gc, domid);
switch (scinfo->sched) {
case LIBXL_SCHEDULER_SEDF:
LOGD(ERROR, domid, "SEDF scheduler is no longer available");
rc = ERROR_FEATURE_REMOVED;
break;
case LIBXL_SCHEDULER_CREDIT:
case LIBXL_SCHEDULER_CREDIT2:
case LIBXL_SCHEDULER_ARINC653:
case LIBXL_SCHEDULER_NULL:
LOGD(ERROR, domid, "per-VCPU parameter getting not supported for this scheduler");
rc = ERROR_INVAL;
break;
case LIBXL_SCHEDULER_RTDS:
rc = sched_rtds_vcpu_get_all(gc, domid, scinfo);
break;
default:
LOGD(ERROR, domid, "Unknown scheduler");
rc = ERROR_INVAL;
break;
}
GC_FREE;
return rc;
}
static int sched_params_valid(libxl__gc *gc,
uint32_t domid, libxl_domain_sched_params *scp)
{
int has_weight = scp->weight != LIBXL_DOMAIN_SCHED_PARAM_WEIGHT_DEFAULT;
int has_period = scp->period != LIBXL_DOMAIN_SCHED_PARAM_PERIOD_DEFAULT;
int has_slice = scp->slice != LIBXL_DOMAIN_SCHED_PARAM_SLICE_DEFAULT;
int has_extratime =
scp->extratime != LIBXL_DOMAIN_SCHED_PARAM_EXTRATIME_DEFAULT;
/* The sedf scheduler needs some more consistency checking */
if (libxl__domain_scheduler(gc, domid) == LIBXL_SCHEDULER_SEDF) {
if (has_weight && (has_period || has_slice))
return 0;
/* If you want a real-time domain, with its own period and
* slice, please, do provide both! */
if (has_period != has_slice)
return 0;
/*
* Idea is, if we specify a weight, then both period and
* slice has to be zero. OTOH, if we do specify a period and
* slice, it is weight that should be zeroed. See
* docs/misc/sedf_scheduler_mini-HOWTO.txt for more details
* on the meaningful combinations and their meanings.
*/
if (has_weight) {
scp->slice = 0;
scp->period = 0;
}
else if (!has_period) {
/* No weight nor slice/period means best effort. Parameters needs
* some mangling in order to properly ask for that, though. */
/*
* Providing no weight does not make any sense if we do not allow
* the domain to run in extra time. On the other hand, if we have
* extra time, weight will be ignored (and zeroed) by Xen, but it
* can't be zero here, or the call for setting the scheduling
* parameters will fail. So, avoid the latter by setting a random
* weight (namely, 1), as it will be ignored anyway.
*/
/* We can setup a proper best effort domain (extra time only)
* iff we either already have or are asking for some extra time. */
scp->weight = has_extratime ? scp->extratime : 1;
scp->period = 0;
} else {
/* Real-time domain: will get slice CPU time over every period */
scp->weight = 0;
}
}
return 1;
}
int libxl_domain_sched_params_set(libxl_ctx *ctx, uint32_t domid,
const libxl_domain_sched_params *scinfo)
{
GC_INIT(ctx);
libxl_scheduler sched = scinfo->sched;
int ret;
if (sched == LIBXL_SCHEDULER_UNKNOWN)
sched = libxl__domain_scheduler(gc, domid);
switch (sched) {
case LIBXL_SCHEDULER_SEDF:
LOGD(ERROR, domid, "SEDF scheduler no longer available");
ret=ERROR_FEATURE_REMOVED;
break;
case LIBXL_SCHEDULER_CREDIT:
ret=sched_credit_domain_set(gc, domid, scinfo);
break;
case LIBXL_SCHEDULER_CREDIT2:
ret=sched_credit2_domain_set(gc, domid, scinfo);
break;
case LIBXL_SCHEDULER_ARINC653:
ret=sched_arinc653_domain_set(gc, domid, scinfo);
break;
case LIBXL_SCHEDULER_RTDS:
ret=sched_rtds_domain_set(gc, domid, scinfo);
break;
case LIBXL_SCHEDULER_NULL:
ret=sched_null_domain_set(gc, domid, scinfo);
break;
default:
LOGD(ERROR, domid, "Unknown scheduler");
ret=ERROR_INVAL;
break;
}
GC_FREE;
return ret;
}
