xen: allow for explicitly specifying node-affinity

Make it possible to pass the node-affinity of a domain to the hypervisor
from the upper layers, instead of always being computed automatically.

Note that this also required generalizing the Flask hooks for setting
and getting the affinity, so that they now deal with both vcpu and
node affinity.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Juergen Gross <juergen.gross@ts.fujitsu.com>
Acked-by: Keir Fraser <keir@xen.org>

1 files changed, 56 insertions, 4 deletions

diff --git a/xen/common/domain.c b/xen/common/domain.c
index 590548e101..ce45d66b45 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -224,6 +224,7 @@ struct domain *domain_create(
 
     spin_lock_init(&d->node_affinity_lock);
     d->node_affinity = NODE_MASK_ALL;
+    d->auto_node_affinity = 1;
 
     spin_lock_init(&d->shutdown_lock);
     d->shutdown_code = -1;
@@ -364,11 +365,32 @@ void domain_update_node_affinity(struct domain *d)
         cpumask_or(cpumask, cpumask, online_affinity);
     }
 
-    for_each_online_node ( node )
-        if ( cpumask_intersects(&node_to_cpumask(node), cpumask) )
-            node_set(node, nodemask);
+    if ( d->auto_node_affinity )
+    {
+        /* Node-affinity is automaically computed from all vcpu-affinities */
+        for_each_online_node ( node )
+            if ( cpumask_intersects(&node_to_cpumask(node), cpumask) )
+                node_set(node, nodemask);
+
+        d->node_affinity = nodemask;
+    }
+    else
+    {
+        /* Node-affinity is provided by someone else, just filter out cpus
+         * that are either offline or not in the affinity of any vcpus. */
+        nodemask = d->node_affinity;
+        for_each_node_mask ( node, d->node_affinity )
+            if ( !cpumask_intersects(&node_to_cpumask(node), cpumask) )
+                node_clear(node, nodemask);//d->node_affinity);
+
+        /* Avoid loosing track of node-affinity because of a bad
+         * vcpu-affinity has been specified. */
+        if ( !nodes_empty(nodemask) )
+            d->node_affinity = nodemask;
+    }
+
+    sched_set_node_affinity(d, &d->node_affinity);
 
-    d->node_affinity = nodemask;
     spin_unlock(&d->node_affinity_lock);
 
     free_cpumask_var(online_affinity);
@@ -376,6 +398,36 @@ void domain_update_node_affinity(struct domain *d)
 }
 
 
+int domain_set_node_affinity(struct domain *d, const nodemask_t *affinity)
+{
+    /* Being affine with no nodes is just wrong */
+    if ( nodes_empty(*affinity) )
+        return -EINVAL;
+
+    spin_lock(&d->node_affinity_lock);
+
+    /*
+     * Being/becoming explicitly affine to all nodes is not particularly
+     * useful. Let's take it as the `reset node affinity` command.
+     */
+    if ( nodes_full(*affinity) )
+    {
+        d->auto_node_affinity = 1;
+        goto out;
+    }
+
+    d->auto_node_affinity = 0;
+    d->node_affinity = *affinity;
+
+out:
+    spin_unlock(&d->node_affinity_lock);
+
+    domain_update_node_affinity(d);
+
+    return 0;
+}
+
+
 struct domain *get_domain_by_id(domid_t dom)
 {
     struct domain *d;