vfio: Fix memory leak of hostwin

hostwin is allocated and added to hostwin_list in vfio_host_win_add, but
it is only deleted from hostwin_list in vfio_host_win_del, which causes
a memory leak.  Also, freeing all elements in hostwin_list is missing in
vfio_disconnect_container.

Fix: 2e4109de ("vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2)")
CC: qemu-stable@nongnu.org
Signed-off-by: Peng Liang <liangpeng10@huawei.com>
Link: https://lore.kernel.org/r/20211117014739.1839263-1-liangpeng10@huawei.com


Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

hw/vfio/common.c

@@ -551,6 +551,7 @@ static int vfio_host_win_del(VFIOContainer *container, hwaddr min_iova,
     QLIST_FOREACH(hostwin, &container->hostwin_list, hostwin_next) {
         if (hostwin->min_iova == min_iova && hostwin->max_iova == max_iova) {
             QLIST_REMOVE(hostwin, hostwin_next);
+            g_free(hostwin);
             return 0;
         }
     }
@@ -2239,6 +2240,7 @@ static void vfio_disconnect_container(VFIOGroup *group)
     if (QLIST_EMPTY(&container->group_list)) {
         VFIOAddressSpace *space = container->space;
         VFIOGuestIOMMU *giommu, *tmp;
+        VFIOHostDMAWindow *hostwin, *next;
 
         QLIST_REMOVE(container, next);
 
@@ -2249,6 +2251,12 @@ static void vfio_disconnect_container(VFIOGroup *group)
             g_free(giommu);
         }
 
+        QLIST_FOREACH_SAFE(hostwin, &container->hostwin_list, hostwin_next,
+                           next) {
+            QLIST_REMOVE(hostwin, hostwin_next);
+            g_free(hostwin);
+        }
+
         trace_vfio_disconnect_container(container->fd);
         close(container->fd);
         g_free(container);