When commit 96b7af4388b3 intoduced a .instance_finalize() handler,
it did not take into account that the container was not necessarily
inserted into the container list of the address space. Hence, if
the container object is destroyed, by calling object_unref() for
example, before vfio_address_space_insert() is called, QEMU may
crash when removing the container from the list as done in
vfio_container_instance_finalize(). This was seen with an SEV-SNP
guest for which discarding of RAM fails.
To resolve this issue, use the safe version of QLIST_REMOVE().
Cc: Zhenzhong Duan <zhenzhong.duan@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Fixes: 96b7af4388b3 ("vfio/container: Move vfio_container_destroy() to an
instance_finalize() handler")
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>