[PATCH v4 09/12] libvduse: Fix assignment in vring_set_avail_event

[Marcel Holtmann]

Since the assignment is causing a compiler warning, fix it by using
memcpy instead.

  CC       libvduse.o
libvduse.c: In function ‘vring_set_avail_event’:
libvduse.c:603:7: error: dereferencing type-punned pointer will break 
strict-aliasing rules [-Werror=strict-aliasin]
  603 |     *((uint16_t *)&vq->vring.used->ring[vq->vring.num]) = htole16(val);
      |      ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Suggested-by: Xie Yongji <xieyongji@bytedance.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
---
 subprojects/libvduse/libvduse.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/subprojects/libvduse/libvduse.c b/subprojects/libvduse/libvduse.c
index 338ad5e352e7..377959a0b4fb 100644
--- a/subprojects/libvduse/libvduse.c
+++ b/subprojects/libvduse/libvduse.c
@@ -582,7 +582,8 @@ void vduse_queue_notify(VduseVirtq *vq)
 
 static inline void vring_set_avail_event(VduseVirtq *vq, uint16_t val)
 {
-    *((uint16_t *)&vq->vring.used->ring[vq->vring.num]) = htole16(val);
+    uint16_t val_le = htole16(val);
+    memcpy(&vq->vring.used->ring[vq->vring.num], &val_le, sizeof(uint16_t));
 }
 
 static bool vduse_queue_map_single_desc(VduseVirtq *vq, unsigned int *p_num_sg,
-- 
2.38.1