[PATCH 6/6] kvm tools: Protect IOPORT tree by rwsem

[Sasha Levin <levinsasha928@gmail.com>]

Makes ioport thread-safe.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
---
 tools/kvm/ioport.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/tools/kvm/ioport.c b/tools/kvm/ioport.c
index 1f13960..db9ff0f 100644
--- a/tools/kvm/ioport.c
+++ b/tools/kvm/ioport.c
@@ -3,6 +3,7 @@
 #include "kvm/kvm.h"
 #include "kvm/util.h"
 #include "kvm/rbtree-interval.h"
+#include "kvm/rwsem.h"
 
 #include <linux/kvm.h>	/* for KVM_EXIT_* */
 #include <linux/types.h>
@@ -22,6 +23,7 @@ struct ioport_entry {
 
 static struct rb_root ioport_tree = RB_ROOT;
 bool ioport_debug;
+static DECLARE_RWSEM(ioport_tree_sem);
 
 static struct ioport_entry *ioport_search(struct rb_root *root, u64 addr)
 {
@@ -71,6 +73,7 @@ void ioport__register(u16 port, struct ioport_operations *ops, int count)
 {
 	struct ioport_entry *entry;
 
+	down_write(&ioport_tree_sem);
 	entry = ioport_search(&ioport_tree, port);
 	if (entry) {
 		pr_warning("ioport re-registered: %x", port);
@@ -87,6 +90,8 @@ void ioport__register(u16 port, struct ioport_operations *ops, int count)
 	};
 
 	ioport_insert(&ioport_tree, entry);
+
+	up_write(&ioport_tree_sem);
 }
 
 static const char *to_direction(int direction)
@@ -108,7 +113,9 @@ bool kvm__emulate_io(struct kvm *kvm, u16 port, void *data, int direction, int s
 	bool ret;
 	struct ioport_entry *entry;
 
+	down_read(&ioport_tree_sem);
 	entry = ioport_search(&ioport_tree, port);
+	up_read(&ioport_tree_sem);
 	if (!entry)
 		goto error;
 
-- 
1.7.5.rc3