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

Sasha Levin
2011-05-26T14:26:16Z

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