[PATCH v2 3/4] libxl: add rt scheduler

[Meng Xu <mengxu@cis.upenn.edu>]

Add libxl functions to set/get domain's parameters for rt scheduler
Note: VCPU's information (period, budget) is in microsecond (us).

Signed-off-by: Meng Xu <mengxu@cis.upenn.edu>
Signed-off-by: Sisu Xi <xisisu@gmail.com>
---
 tools/libxl/libxl.c         |   75 +++++++++++++++++++++++++++++++++++++++++++
 tools/libxl/libxl.h         |    1 +
 tools/libxl/libxl_types.idl |    2 ++
 3 files changed, 78 insertions(+)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 2ae5fca..6840c92 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -5155,6 +5155,75 @@ static int sched_sedf_domain_set(libxl__gc *gc, uint32_t domid,
     return 0;
 }
 
+static int sched_rt_domain_get(libxl__gc *gc, uint32_t domid,
+                               libxl_domain_sched_params *scinfo)
+{
+    struct xen_domctl_sched_rt sdom;
+    int rc;
+
+    rc = xc_sched_rt_domain_get(CTX->xch, domid, &sdom);
+    if (rc != 0) {
+        LOGE(ERROR, "getting domain sched rt");
+        return ERROR_FAIL;
+    }
+
+    libxl_domain_sched_params_init(scinfo);
+    
+    scinfo->sched = LIBXL_SCHEDULER_RT_DS;
+    scinfo->period = sdom.period;
+    scinfo->budget = sdom.budget;
+    
+    return 0;
+}
+
+#define SCHED_RT_DS_VCPU_PERIOD_UINT_MAX    4294967295U /* 2^32 - 1 us */
+#define SCHED_RT_DS_VCPU_BUDGET_UINT_MAX    SCHED_RT_DS_VCPU_PERIOD_UINT_MAX
+
+static int sched_rt_domain_set(libxl__gc *gc, uint32_t domid,
+                               const libxl_domain_sched_params *scinfo)
+{
+    struct xen_domctl_sched_rt sdom;
+    int rc;
+ 
+    rc = xc_sched_rt_domain_get(CTX->xch, domid, &sdom);
+
+    if (scinfo->period != LIBXL_DOMAIN_SCHED_PARAM_PERIOD_DEFAULT) {
+        if (scinfo->period < 1 ||
+            scinfo->period > SCHED_RT_DS_VCPU_PERIOD_UINT_MAX) {
+            LOG(ERROR, "VCPU period is not set or out of range, "
+                       "valid values are within range from 0 to %u",
+                       SCHED_RT_DS_VCPU_PERIOD_UINT_MAX);
+            return ERROR_INVAL;
+        }
+        sdom.period = scinfo->period;
+    }
+
+    if (scinfo->budget != LIBXL_DOMAIN_SCHED_PARAM_BUDGET_DEFAULT) {
+        if (scinfo->budget < 1 ||
+            scinfo->budget > SCHED_RT_DS_VCPU_BUDGET_UINT_MAX) {
+            LOG(ERROR, "VCPU budget is not set or out of range, "
+                       "valid values are within range from 0 to %u",
+                       SCHED_RT_DS_VCPU_BUDGET_UINT_MAX);
+            return ERROR_INVAL;
+        }
+        sdom.budget = scinfo->budget;
+    }
+
+    if (sdom.budget > sdom.period) {
+        LOG(ERROR, "VCPU budget is larger than VCPU period, "
+                   "VCPU budget should be no larger than VCPU period");
+        return ERROR_INVAL;
+    }
+
+    rc = xc_sched_rt_domain_set(CTX->xch, domid, &sdom);
+    if (rc < 0) {
+        LOGE(ERROR, "setting domain sched rt");
+        return ERROR_FAIL;
+    }
+
+    return 0;
+}
+
 int libxl_domain_sched_params_set(libxl_ctx *ctx, uint32_t domid,
                                   const libxl_domain_sched_params *scinfo)
 {
@@ -5178,6 +5247,9 @@ int libxl_domain_sched_params_set(libxl_ctx *ctx, uint32_t domid,
     case LIBXL_SCHEDULER_ARINC653:
         ret=sched_arinc653_domain_set(gc, domid, scinfo);
         break;
+    case LIBXL_SCHEDULER_RT_DS:
+        ret=sched_rt_domain_set(gc, domid, scinfo);
+        break;
     default:
         LOG(ERROR, "Unknown scheduler");
         ret=ERROR_INVAL;
@@ -5208,6 +5280,9 @@ int libxl_domain_sched_params_get(libxl_ctx *ctx, uint32_t domid,
     case LIBXL_SCHEDULER_CREDIT2:
         ret=sched_credit2_domain_get(gc, domid, scinfo);
         break;
+    case LIBXL_SCHEDULER_RT_DS:
+        ret=sched_rt_domain_get(gc, domid, scinfo);
+        break;
     default:
         LOG(ERROR, "Unknown scheduler");
         ret=ERROR_INVAL;
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 460207b..dbe736c 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -1280,6 +1280,7 @@ int libxl_sched_credit_params_set(libxl_ctx *ctx, uint32_t poolid,
 #define LIBXL_DOMAIN_SCHED_PARAM_SLICE_DEFAULT     -1
 #define LIBXL_DOMAIN_SCHED_PARAM_LATENCY_DEFAULT   -1
 #define LIBXL_DOMAIN_SCHED_PARAM_EXTRATIME_DEFAULT -1
+#define LIBXL_DOMAIN_SCHED_PARAM_BUDGET_DEFAULT     -1
 
 int libxl_domain_sched_params_get(libxl_ctx *ctx, uint32_t domid,
                                   libxl_domain_sched_params *params);
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 931c9e9..72f24fe 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -153,6 +153,7 @@ libxl_scheduler = Enumeration("scheduler", [
     (5, "credit"),
     (6, "credit2"),
     (7, "arinc653"),
+    (8, "rt_ds"),
     ])
 
 # Consistent with SHUTDOWN_* in sched.h (apart from UNKNOWN)
@@ -315,6 +316,7 @@ libxl_domain_sched_params = Struct("domain_sched_params",[
     ("slice",        integer, {'init_val': 'LIBXL_DOMAIN_SCHED_PARAM_SLICE_DEFAULT'}),
     ("latency",      integer, {'init_val': 'LIBXL_DOMAIN_SCHED_PARAM_LATENCY_DEFAULT'}),
     ("extratime",    integer, {'init_val': 'LIBXL_DOMAIN_SCHED_PARAM_EXTRATIME_DEFAULT'}),
+    ("budget",       integer, {'init_val': 'LIBXL_DOMAIN_SCHED_PARAM_BUDGET_DEFAULT'}),
     ])
 
 libxl_domain_build_info = Struct("domain_build_info",[
-- 
1.7.9.5