[PATCH v2 04/10] udp_vu: Make virtqueue buffers stack-local for thread safety

[Laurent Vivier <lvivier@redhat.com>]

The function-local static buffers elem[] and iov_vu[] in
udp_vu_sock_to_tap() are shared across all threads. When multiple
worker threads process UDP vhost-user data concurrently, they would
stomp on each other's buffers.

Remove the static qualifier so each call gets its own stack-allocated
arrays, eliminating cross-thread sharing.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 udp_vu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/udp_vu.c b/udp_vu.c
index 21fa891b3b51..c045e421001c 100644
--- a/udp_vu.c
+++ b/udp_vu.c
@@ -151,9 +151,9 @@ void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx,
 {
 	const struct flowside *toside = flowside_at_sidx(tosidx);
 	bool v6 = !(inany_v4(&toside->eaddr) && inany_v4(&toside->oaddr));
-	static struct vu_virtq_element elem[VIRTQUEUE_MAX_SIZE];
+	struct vu_virtq_element elem[VIRTQUEUE_MAX_SIZE];
+	struct iovec iov_vu[VIRTQUEUE_MAX_SIZE];
 	int toguest = QPAIR_TOGUEST_QUEUE(qpair);
-	static struct iovec iov_vu[VIRTQUEUE_MAX_SIZE];
 	struct vu_dev *vdev = c->vdev;
 	struct vu_virtq *vq = &vdev->vq[toguest];
 	size_t hdrlen = udp_vu_hdrlen(v6);
-- 
2.54.0