[Xen-devel] [PATCH 5/8] evtchn: dynamically allocate d->evtchn

[David Vrabel <david.vrabel@xxxxxxxxxx>]

From: Wei Liu <wei.liu2@xxxxxxxxxx>

As we move to extended evtchn ABI we need bigger d->evtchn, as a result
this will bloat struct domain. So move this array out of struct domain
and allocate a dedicated array for it.

Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
---
 xen/common/event_channel.c |   13 +++++++++++++
 xen/include/xen/sched.h    |    2 +-
 2 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 1a1636e..126cf84 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -1163,15 +1163,26 @@ int evtchn_init(struct domain *d)
     /* Default to N-level ABI. */
     evtchn_2l_init(d);
 
+    BUILD_BUG_ON(sizeof(struct evtchn *) * NR_EVTCHN_BUCKETS > PAGE_SIZE);
+    d->evtchn = xzalloc_array(struct evtchn *, NR_EVTCHN_BUCKETS);
+    if ( d->evtchn == NULL )
+        return -ENOMEM;
+
     spin_lock_init(&d->event_lock);
     if ( get_free_port(d) != 0 )
+    {
+        xfree(d->evtchn);
         return -EINVAL;
+    }
     evtchn_from_port(d, 0)->state = ECS_RESERVED;
 
 #if MAX_VIRT_CPUS > BITS_PER_LONG
     d->poll_mask = xmalloc_array(unsigned long, BITS_TO_LONGS(MAX_VIRT_CPUS));
     if ( !d->poll_mask )
+    {
+        xfree(d->evtchn);
         return -ENOMEM;
+    }
     bitmap_zero(d->poll_mask, MAX_VIRT_CPUS);
 #endif
 
@@ -1205,6 +1216,8 @@ void evtchn_destroy(struct domain *d)
     spin_unlock(&d->event_lock);
 
     clear_global_virq_handlers(d);
+
+    xfree(d->evtchn);
 }
 
 
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 0ca984d..3070555 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -272,7 +272,7 @@ struct domain
     spinlock_t       rangesets_lock;
 
     /* Event channel information. */
-    struct evtchn   *evtchn[NR_EVTCHN_BUCKETS];
+    struct evtchn  **evtchn;
     unsigned         max_evtchns;
     spinlock_t       event_lock;
     const struct evtchn_port_ops *evtchn_port_ops;
-- 
1.7.2.5


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