[PATCH v5 07/10] KVM: arm/arm64: vgic-its: New helper functions to free the caches

Eric Auger
2017-10-23T14:09:16Z

From: wanghaibin <wanghaibin.wang@huawei.com>

We create two new functions that free the device and
collection lists. They are currently called by vgic_its_destroy()
and other callers will be added in subsequent patches.

We also remove the check on its->device_list.next.
Lists are initialized in vgic_create_its() and the device
is added to the device list only if this latter succeeds.

vgic_its_destroy is the device destroy ops. This latter is called
by kvm_destroy_devices() which loops on all created devices. So
at this point the list is initialized.

Signed-off-by: wanghaibin <wanghaibin.wang@huawei.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v4 -> v5:
- add mutex_lock in vgic_its_free_collection_list
- use list_for_each_entry_safe
- reword commit message
---
virt/kvm/arm/vgic/vgic-its.c | 51 ++++++++++++++++++++++----------------------
1 file changed, 26 insertions(+), 25 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 2f3c3a1..8098f91 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -910,6 +910,30 @@ static void vgic_its_free_device(struct kvm *kvm, struct its_device *device)
kfree(device);
}

+static void vgic_its_free_device_list(struct kvm *kvm, struct vgic_its *its)
+{
+ struct its_device *cur, *temp;
+
+ mutex_lock(&its->its_lock);
+
+ list_for_each_entry_safe(cur, temp, &its->device_list, dev_list)
+ vgic_its_free_device(kvm, cur);
+
+ mutex_unlock(&its->its_lock);
+}
+
+static void vgic_its_free_collection_list(struct kvm *kvm, struct vgic_its *its)
+{
+ struct its_collection *cur, *temp;
+
+ mutex_lock(&its->its_lock);
+
+ list_for_each_entry_safe(cur, temp, &its->collection_list, coll_list)
+ vgic_its_free_collection(its, cur->collection_id);
+
+ mutex_unlock(&its->its_lock);
+}
+
/* Must be called with its_lock mutex held */
static struct its_device *vgic_its_alloc_device(struct vgic_its *its,
u32 device_id, gpa_t itt_addr,
@@ -1627,32 +1651,9 @@ static void vgic_its_destroy(struct kvm_device *kvm_dev)
{
struct kvm *kvm = kvm_dev->kvm;
struct vgic_its *its = kvm_dev->private;
- struct list_head *cur, *temp;
-
- /*
- * We may end up here without the lists ever having been initialized.
- * Check this and bail out early to avoid dereferencing a NULL pointer.
- */
- if (!its->device_list.next)
- return;
-
- mutex_lock(&its->its_lock);
- list_for_each_safe(cur, temp, &its->device_list) {
- struct its_device *dev;
-
- dev = list_entry(cur, struct its_device, dev_list);
- vgic_its_free_device(kvm, dev);
- }
-
- list_for_each_safe(cur, temp, &its->collection_list) {
- struct its_collection *coll;
-
- coll = list_entry(cur, struct its_collection, coll_list);
- list_del(cur);
- kfree(coll);
- }
- mutex_unlock(&its->its_lock);

+ vgic_its_free_device_list(kvm, its);
+ vgic_its_free_collection_list(kvm, its);
kfree(its);
}

--
2.5.5