[PATCH 1/4] xen: report how much memory a domain has on each NUMA node

[Dario Faggioli <dario.faggioli@citrix.com>]

by means of a new hypercal, XEN_DOMCTL_numainfo, doing something
similar to what XEN_SYSCTL_numainfo does, but on a per domain basis.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
---
 xen/common/domctl.c                 |   45 +++++++++++++++++++++++++++++++++++
 xen/include/public/domctl.h         |   22 +++++++++++++++++
 xen/xsm/flask/hooks.c               |    3 ++
 xen/xsm/flask/policy/access_vectors |    2 ++
 4 files changed, 72 insertions(+)

diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index 7cf610a..96bf326 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -574,6 +574,51 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
     }
     break;
 
+    case XEN_DOMCTL_numainfo:
+    {
+        uint32_t node, max_node_index, last_online_node;
+        xen_domctl_numainfo_t *ni = &op->u.numainfo;
+        uint64_t *memkb_on_node;
+        struct page_info *page;
+
+        /*
+         * We report back info about the min number of nodes between how
+         * much of them the caller can handle and the number of them that
+         * are actually online.
+         */
+        last_online_node = last_node(node_online_map);
+        max_node_index = min_t(uint32_t, ni->max_node_index, last_online_node);
+        ni->max_node_index = max_node_index;
+
+        ret = -ENOMEM;
+        memkb_on_node = xzalloc_array(uint64_t, max_node_index);
+        if ( !memkb_on_node )
+            break;
+
+        spin_lock(&d->page_alloc_lock);
+        page_list_for_each(page, &d->page_list)
+        {
+            node = phys_to_nid((paddr_t)page_to_mfn(page) << PAGE_SHIFT);
+            /* For nodes that are offline, don't touch the counter */
+            if ( node <= max_node_index && node_online(node) )
+                memkb_on_node[node]++;
+        }
+        spin_unlock(&d->page_alloc_lock);
+
+        for ( node = 0; node <= max_node_index; node++ )
+        {
+            memkb_on_node[node] <<= (PAGE_SHIFT-10);
+            if ( copy_to_guest_offset(ni->memkb_on_node, node,
+                                      &memkb_on_node[node], 1) )
+                break;
+        }
+
+        ret = ((node <= max_node_index) || copy_to_guest(u_domctl, op, 1))
+            ? -EFAULT : 0;
+        xfree(memkb_on_node);
+    }
+    break;
+
     case XEN_DOMCTL_destroydomain:
     {
         ret = domain_kill(d);
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index f22fe2e..a455d78 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -315,6 +315,26 @@ typedef struct xen_domctl_max_vcpus xen_domctl_max_vcpus_t;
 DEFINE_XEN_GUEST_HANDLE(xen_domctl_max_vcpus_t);
 
 
+/* XEN_DOMCTL_numainfo */
+struct xen_domctl_numainfo {
+    /*
+     * IN: maximum addressable entry in the caller-provided arrays.
+     * OUT: minimum between the maximum addressable entry in the
+     *      caller-provided arrays and largest online node identifier
+     *      in the system.
+     */
+    uint32_t max_node_index;
+
+    /*
+     * OUT: memory, in Kb, on each node. i-eth element equal to 0 means
+     *      either "no memory on node i" or "node i offline".
+     */
+    XEN_GUEST_HANDLE_64(uint64) memkb_on_node;
+};
+typedef struct xen_domctl_numainfo xen_domctl_numainfo_t;
+DEFINE_XEN_GUEST_HANDLE(xen_domctl_numainfo_t);
+
+
 /* XEN_DOMCTL_scheduler_op */
 /* Scheduler types. */
 #define XEN_SCHEDULER_SEDF     4
@@ -966,6 +986,7 @@ struct xen_domctl {
 #define XEN_DOMCTL_getnodeaffinity               69
 #define XEN_DOMCTL_set_max_evtchn                70
 #define XEN_DOMCTL_cacheflush                    71
+#define XEN_DOMCTL_numainfo                      72
 #define XEN_DOMCTL_gdbsx_guestmemio            1000
 #define XEN_DOMCTL_gdbsx_pausevcpu             1001
 #define XEN_DOMCTL_gdbsx_unpausevcpu           1002
@@ -986,6 +1007,7 @@ struct xen_domctl {
         struct xen_domctl_vcpucontext       vcpucontext;
         struct xen_domctl_getvcpuinfo       getvcpuinfo;
         struct xen_domctl_max_vcpus         max_vcpus;
+        struct xen_domctl_numainfo          numainfo;
         struct xen_domctl_scheduler_op      scheduler_op;
         struct xen_domctl_setdomainhandle   setdomainhandle;
         struct xen_domctl_setdebugging      setdebugging;
diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
index 96276ac..edc1d34 100644
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -727,6 +727,9 @@ static int flask_domctl(struct domain *d, int cmd)
     case XEN_DOMCTL_cacheflush:
         return current_has_perm(d, SECCLASS_DOMAIN2, DOMAIN2__CACHEFLUSH);
 
+    case XEN_DOMCTL_numainfo:
+        return current_has_perm(d, SECCLASS_DOMAIN2, DOMAIN2__NUMAINFO);
+
     default:
         printk("flask_domctl: Unknown op %d\n", cmd);
         return -EPERM;
diff --git a/xen/xsm/flask/policy/access_vectors b/xen/xsm/flask/policy/access_vectors
index a0ed13d..e218992 100644
--- a/xen/xsm/flask/policy/access_vectors
+++ b/xen/xsm/flask/policy/access_vectors
@@ -198,6 +198,8 @@ class domain2
     set_max_evtchn
 # XEN_DOMCTL_cacheflush
     cacheflush
+# XEN_DOMCTL_numainfo
+    numainfo
 }
 
 # Similar to class domain, but primarily contains domctls related to HVM domains