[PATCH v3 0/9] net/memif: lifecycle fixes and unit test

[PATCH v3 0/9] net/memif: lifecycle fixes and unit test

[Sriram Yagnaraman]

This series fixes a set of error-path and lifecycle bugs in the memif
PMD and adds a unit test for the driver.

The first eight patches are fixes:

 - guard eth_memif_tx() against an empty burst (nb_pkts == 0);
 - close file descriptor 0 instead of leaking it;
 - do not close the EAL-owned memseg fd in zero-copy mode;
 - free the MAC address allocated during probe on failure;
 - unwind a partially-created device on create failure;
 - refuse connections on a stopped server so it does not come up on a
   stopped port;
 - disconnect on close so a stopped server's control channel is not
   leaked, and make memif_disconnect() safe on a never-started device;
 - fix eth_memif_tx_zc() returning 65535 on an invalid interrupt fd.

The last patch adds a memif PMD unit test (app/test, memif_pmd_autotest):
a server/client vdev pair over a loopback socket covering dev_info, link
state, stats, single-segment loopback (slow and fast path), multi-segment
loopback across a ring wrap, stop/start reconnect, empty Tx burst, close
without stop, and a stopped server refusing a peer.

Verified: memif_pmd_autotest passes 11/11; each commit builds with
-Dwerror=true; check-git-log and checkpatch are clean.

Thanks to Stephen Hemminger and the ai-code-review bot for the reviews
that shaped this series.

v3:
 - Rebase on main, picking up rte_intr_fd_close() from
   d9191f684c ("interrupts: add helpers to close FD"): patch 2 keeps
   only the owned-fd ">= 0" fixes not superseded by that helper, and
   patch 7 keeps the NULL-queue guards above the rte_intr_fd_close()
   calls.
 - New patch 6: refuse connections on a stopped server. The started-
   then-stopped case is the actual trigger for the control-channel
   leak; dev_stop now sets ETH_MEMIF_FLAG_DISABLED. (v2 patch 6/7
   described this as never-started, which was wrong.)
 - Patch 7 (disconnect on close): reword to the real trigger and keep
   the close-time disconnect as a backstop.
 - Patch 3 (memseg fd): also stop closing the EAL-owned fd in
   memif_connect(), not only memif_free_regions().
 - Test: new test_memif_stopped_server_rejects_peer covering patch 6
   (fails without it); reword close-without-stop to what it actually
   covers (the NULL-queue skip); verify the full fast-path payload.

v2:
 - P1: correct Fixes tag (Tx fast path, not original driver); move the
   empty-burst check after the ring == NULL block.
 - P2: split the memseg-fd change into its own patch rather than
   widening the check to ">= 0".
 - P4 (MAC leak): document the secondary -1 -> -ENOMEM change.
 - P5 (unwind): add Fixes: multi-process support.
 - New patch: fix eth_memif_tx_zc() bogus Tx count on invalid fd.
 - Test: add to MAINTAINERS; return TEST_FAILED (not SKIPPED) on probe
   failure; add a default-bsize pair to cover the Tx fast path; set
   ring size via rsize and fix the stale comments.

Sriram Yagnaraman (9):
  net/memif: guard against empty Tx burst
  net/memif: close file descriptor zero
  net/memif: do not close EAL-owned memseg file descriptor
  net/memif: fix MAC address leak on probe failure
  net/memif: unwind partial device on create failure
  net/memif: refuse connection on stopped device
  net/memif: disconnect on device close
  net/memif: fix bogus Tx count on invalid interrupt FD
  test/memif: add memif PMD unit test

 MAINTAINERS                       |   1 +
 app/test/meson.build              |   1 +
 app/test/test_pmd_memif.c         | 751 ++++++++++++++++++++++++++++++
 drivers/net/memif/memif_socket.c  |  10 +-
 drivers/net/memif/rte_eth_memif.c |  76 ++-
 5 files changed, 812 insertions(+), 27 deletions(-)
 create mode 100644 app/test/test_pmd_memif.c

-- 
2.43.7

[PATCH v3 1/9] net/memif: guard against empty Tx burst

[Sriram Yagnaraman]

eth_memif_tx() reads bufs[0]->pool to pick the mempool for its
single-pool fast-path test, before any check on nb_pkts. A caller that
passes nb_pkts == 0 therefore dereferences bufs[0], out of bounds for an
empty burst. Return early when there is nothing to transmit, after the
ring == NULL check so a secondary process still requests regions.

Fixes: b5613c8f9d0a ("net/memif: add a Tx fast path")
Cc: stable@dpdk.org

Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
---
 drivers/net/memif/rte_eth_memif.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c
index 3ed177ffb2..36db03a268 100644
--- a/drivers/net/memif/rte_eth_memif.c
+++ b/drivers/net/memif/rte_eth_memif.c
@@ -904,6 +904,8 @@ eth_memif_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 				mq->in_port, rte_strerror(-ret));
 		return 0;
 	}
+	if (unlikely(nb_pkts == 0))
+		return 0;
 
 	ring_size = 1 << mq->log2_ring_size;
 	mask = ring_size - 1;
-- 
2.43.7

[PATCH v3 2/9] net/memif: close file descriptor zero

[Sriram Yagnaraman]

Several cleanup paths guard close() with "fd > 0", which skips a valid
file descriptor of 0 and leaks it. A descriptor of 0 is legitimate (for
example when stdin has been closed before the region or interrupt fd is
created). Use ">= 0" consistently with the -1 sentinel the code already
uses elsewhere, in the memif_free_regions() shm munmap path, the
memif_region_init_shm() error path, the control-channel teardown in
memif_disconnect(), and the SCM_RIGHTS fd check in memif_msg_send().

Fixes: 09c7e63a71f9 ("net/memif: introduce memory interface PMD")
Cc: stable@dpdk.org

Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
---
 drivers/net/memif/memif_socket.c  | 4 ++--
 drivers/net/memif/rte_eth_memif.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/memif/memif_socket.c b/drivers/net/memif/memif_socket.c
index 87b23aa8b4..550e2e468a 100644
--- a/drivers/net/memif/memif_socket.c
+++ b/drivers/net/memif/memif_socket.c
@@ -41,7 +41,7 @@ memif_msg_send(int fd, memif_msg_t *msg, int afd)
 	mh.msg_iov = iov;
 	mh.msg_iovlen = 1;
 
-	if (afd > 0) {
+	if (afd >= 0) {
 		memset(&ctl, 0, sizeof(ctl));
 		mh.msg_control = ctl;
 		mh.msg_controllen = sizeof(ctl);
@@ -623,7 +623,7 @@ memif_disconnect(struct rte_eth_dev *dev)
 		}
 
 		ih = pmd->cc->intr_handle;
-		if (rte_intr_fd_get(ih) > 0) {
+		if (rte_intr_fd_get(ih) >= 0) {
 			ret = rte_intr_callback_unregister(ih,
 							memif_intr_handler,
 							pmd->cc);
diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c
index 36db03a268..1d1d12e242 100644
--- a/drivers/net/memif/rte_eth_memif.c
+++ b/drivers/net/memif/rte_eth_memif.c
@@ -1295,7 +1295,7 @@ memif_free_regions(struct rte_eth_dev *dev)
 			}
 			if (r->addr != NULL) {
 				munmap(r->addr, r->region_size);
-				if (r->fd > 0) {
+				if (r->fd >= 0) {
 					close(r->fd);
 					r->fd = -1;
 				}
@@ -1416,7 +1416,7 @@ memif_region_init_shm(struct rte_eth_dev *dev, uint8_t has_buffers)
 	return ret;
 
 error:
-	if (r->fd > 0)
+	if (r->fd >= 0)
 		close(r->fd);
 	r->fd = -1;
 
-- 
2.43.7

[PATCH v3 3/9] net/memif: do not close EAL-owned memseg file descriptor

[Sriram Yagnaraman]

In zero-copy mode the per-memseg regions (i > 0) take their fd from
rte_memseg_get_fd(), which rte_memory.h documents as EAL-internal and
read-only. Both memif_connect() and memif_free_regions() closed that fd,
so the next connect handed the peer a stale (possibly reused)
descriptor and the PMD closed a descriptor it does not own. Stop closing
it in both paths and just clear the region fd; the fd is not ours.

Fixes: 43b815d88188 ("net/memif: support zero-copy slave")
Cc: stable@dpdk.org

Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
---
 drivers/net/memif/rte_eth_memif.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c
index 1d1d12e242..e753243440 100644
--- a/drivers/net/memif/rte_eth_memif.c
+++ b/drivers/net/memif/rte_eth_memif.c
@@ -1289,9 +1289,9 @@ memif_free_regions(struct rte_eth_dev *dev)
 		if (r != NULL) {
 			/* This is memzone */
 			if (i > 0 && (pmd->flags & ETH_MEMIF_FLAG_ZERO_COPY)) {
+				/* memseg fd is owned by EAL, do not close */
 				r->addr = NULL;
-				if (r->fd > 0)
-					close(r->fd);
+				r->fd = -1;
 			}
 			if (r->addr != NULL) {
 				munmap(r->addr, r->region_size);
@@ -1611,8 +1611,7 @@ memif_connect(struct rte_eth_dev *dev)
 				}
 			}
 			if (i > 0 && (pmd->flags & ETH_MEMIF_FLAG_ZERO_COPY)) {
-				/* close memseg file */
-				close(mr->fd);
+				/* memseg fd is owned by EAL, do not close */
 				mr->fd = -1;
 			}
 		}
-- 
2.43.7

[PATCH v3 4/9] net/memif: fix MAC address leak on probe failure

[Sriram Yagnaraman]

rte_pmd_memif_probe() allocates the default MAC address up front and
only hands ownership to the device in memif_create() on success. Every
argument-parsing error jumps to the exit label, which freed the kvargs
but not the MAC address, leaking it. The allocation was also dereferenced
by rte_eth_random_addr() with no check that rte_zmalloc() succeeded, and
was done even in the secondary process which never uses it.

Allocate the MAC address only in the primary process after the secondary
path has returned, check it for NULL, and free it at the exit label on
any failure (on success memif_create() owns it via data->mac_addrs).
While here, return -ENOMEM instead of -1 on the secondary-process
process-private allocation failure, matching the primary path.

Fixes: 09c7e63a71f9 ("net/memif: introduce memory interface PMD")
Cc: stable@dpdk.org

Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
---
 drivers/net/memif/rte_eth_memif.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c
index e753243440..70359554e6 100644
--- a/drivers/net/memif/rte_eth_memif.c
+++ b/drivers/net/memif/rte_eth_memif.c
@@ -2232,12 +2232,9 @@ rte_pmd_memif_probe(struct rte_vdev_device *vdev)
 	gid_t owner_gid = -1;
 	uint32_t flags = 0;
 	const char *secret = NULL;
-	struct rte_ether_addr *ether_addr = rte_zmalloc("",
-		sizeof(struct rte_ether_addr), 0);
+	struct rte_ether_addr *ether_addr = NULL;
 	struct rte_eth_dev *eth_dev;
 
-	rte_eth_random_addr(ether_addr->addr_bytes);
-
 	MIF_LOG(INFO, "Initialize MEMIF: %s.", name);
 
 	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
@@ -2264,7 +2261,7 @@ rte_pmd_memif_probe(struct rte_vdev_device *vdev)
 		if (eth_dev->process_private == NULL) {
 			MIF_LOG(ERR,
 				"Failed to alloc memory for process private");
-			return -1;
+			return -ENOMEM;
 		}
 
 		rte_eth_dev_probing_finish(eth_dev);
@@ -2272,6 +2269,13 @@ rte_pmd_memif_probe(struct rte_vdev_device *vdev)
 		return 0;
 	}
 
+	ether_addr = rte_zmalloc("", sizeof(struct rte_ether_addr), 0);
+	if (ether_addr == NULL) {
+		MIF_LOG(ERR, "Failed to alloc MAC address");
+		return -ENOMEM;
+	}
+	rte_eth_random_addr(ether_addr->addr_bytes);
+
 	ret = rte_mp_action_register(MEMIF_MP_SEND_REGION, memif_mp_send_region);
 	/*
 	 * Primary process can continue probing, but secondary process won't
@@ -2346,6 +2350,12 @@ rte_pmd_memif_probe(struct rte_vdev_device *vdev)
 			   log2_ring_size, pkt_buffer_size, secret, ether_addr);
 
 exit:
+	/*
+	 * On success memif_create() takes ownership of ether_addr
+	 * (data->mac_addrs); free it on any failure or early exit.
+	 */
+	if (ret != 0)
+		rte_free(ether_addr);
 	rte_kvargs_free(kvlist);
 	return ret;
 }
-- 
2.43.7

[PATCH v3 5/9] net/memif: unwind partial device on create failure

[Sriram Yagnaraman]

memif_create() returned -1 directly when the process-private allocation
or memif_socket_init() failed, leaving the port allocated by
rte_eth_vdev_allocate() registered and the process-private memory
leaked. Jump to an error label that frees the process-private data and
releases the port instead.

Fixes: 09c7e63a71f9 ("net/memif: introduce memory interface PMD")
Fixes: c41a04958b09 ("net/memif: support multi-process")
Cc: stable@dpdk.org

Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
---
 drivers/net/memif/rte_eth_memif.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c
index 70359554e6..e70443976d 100644
--- a/drivers/net/memif/rte_eth_memif.c
+++ b/drivers/net/memif/rte_eth_memif.c
@@ -1957,18 +1957,18 @@ memif_create(struct rte_vdev_device *vdev, enum memif_role_t role,
 	const unsigned int numa_node = vdev->device.numa_node;
 	const char *name = rte_vdev_device_name(vdev);
 
+	/* Allocate process-private data before reserving the port. */
+	process_private = rte_zmalloc(name, sizeof(struct pmd_process_private),
+				      RTE_CACHE_LINE_SIZE);
+	if (process_private == NULL) {
+		MIF_LOG(ERR, "Failed to alloc memory for process private");
+		return -ENOMEM;
+	}
+
 	eth_dev = rte_eth_vdev_allocate(vdev, sizeof(*pmd));
 	if (eth_dev == NULL) {
 		MIF_LOG(ERR, "%s: Unable to allocate device struct.", name);
-		return -1;
-	}
-
-	process_private = (struct pmd_process_private *)
-		rte_zmalloc(name, sizeof(struct pmd_process_private),
-			    RTE_CACHE_LINE_SIZE);
-
-	if (process_private == NULL) {
-		MIF_LOG(ERR, "Failed to alloc memory for process private");
+		rte_free(process_private);
 		return -1;
 	}
 	eth_dev->process_private = process_private;
@@ -1988,7 +1988,7 @@ memif_create(struct rte_vdev_device *vdev, enum memif_role_t role,
 
 	ret = memif_socket_init(eth_dev, socket_filename);
 	if (ret < 0)
-		return ret;
+		goto error;
 
 	memset(pmd->secret, 0, sizeof(char) * ETH_MEMIF_SECRET_SIZE);
 	if (secret != NULL)
@@ -2023,6 +2023,13 @@ memif_create(struct rte_vdev_device *vdev, enum memif_role_t role,
 	rte_eth_dev_probing_finish(eth_dev);
 
 	return 0;
+
+error:
+	/* rte_eth_dev_release_port() does not free process_private. */
+	rte_free(eth_dev->process_private);
+	eth_dev->process_private = NULL;
+	rte_eth_dev_release_port(eth_dev);
+	return ret;
 }
 
 static int
-- 
2.43.7

[PATCH v3 6/9] net/memif: refuse connection on stopped device

[Sriram Yagnaraman]

A memif server cleared ETH_MEMIF_FLAG_DISABLED at dev_start (in
memif_connect_server()) but dev_stop never set it again. memif_create()
sets it, so a never-started server rejects peers, but once started and
then stopped the flag stayed clear and memif_msg_receive_init() kept
accepting connections. A peer connecting to a stopped server bound
pmd->cc and, on the CONNECT message, memif_connect() set
ETH_MEMIF_FLAG_CONNECTED and reported link up on a stopped port.

Set ETH_MEMIF_FLAG_DISABLED in memif_dev_stop() before disconnecting so
a stopped server refuses peers.

Fixes: 09c7e63a71f9 ("net/memif: introduce memory interface PMD")
Cc: stable@dpdk.org

Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
---
 drivers/net/memif/rte_eth_memif.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c
index e70443976d..852a7e2e8e 100644
--- a/drivers/net/memif/rte_eth_memif.c
+++ b/drivers/net/memif/rte_eth_memif.c
@@ -1699,6 +1699,12 @@ memif_dev_stop(struct rte_eth_dev *dev)
 	rte_eal_alarm_cancel(memif_bad_desc_disconnect, dev);
 	rte_atomic_store_explicit(&pmd->bad_desc, false, rte_memory_order_relaxed);
 
+	/* Refuse peers while stopped: a server must not accept a connection
+	 * after dev_stop, which would leave a live control channel on a
+	 * stopped port.
+	 */
+	pmd->flags |= ETH_MEMIF_FLAG_DISABLED;
+
 	memif_disconnect(dev);
 
 	for (i = 0; i < dev->data->nb_rx_queues; i++)
-- 
2.43.7

[PATCH v3 7/9] net/memif: disconnect on device close

[Sriram Yagnaraman]

memif_dev_close() enqueued a disconnect message but never flushed it and
never tore down the control channel, leaking the control-channel
interrupt callback, its file descriptor and the pmd->cc allocation.

The leak is reachable on a server that was started and then stopped.
memif_create() sets ETH_MEMIF_FLAG_DISABLED and memif_connect_server()
clears it at dev_start, but dev_stop does not set it again, so after a
stop memif_msg_receive_init() still accepts a peer: pmd->cc is bound and
the port is left with a live control channel at close. (A never-started
server keeps the flag set and rejects the peer, so pmd->cc stays NULL.)
Call memif_disconnect() from close to flush the queued disconnect and
release the control channel; it is guarded on pmd->cc and clears it, so
it is safe when dev_stop already ran. The companion dev_stop fix that
refuses peers while stopped is a separate patch; this call remains as a
backstop for an init racing with stop.

memif_disconnect() also walked the per-queue interrupt handles indexed
by the configured ring count without checking that the queue pointer was
set. Closing a device that was configured but never started (so queues
were never allocated) then dereferenced a NULL queue; skip NULL queue
entries.

Fixes: 09c7e63a71f9 ("net/memif: introduce memory interface PMD")
Cc: stable@dpdk.org

Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
---
 drivers/net/memif/memif_socket.c  | 6 ++++++
 drivers/net/memif/rte_eth_memif.c | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/net/memif/memif_socket.c b/drivers/net/memif/memif_socket.c
index 550e2e468a..cdf85e09a1 100644
--- a/drivers/net/memif/memif_socket.c
+++ b/drivers/net/memif/memif_socket.c
@@ -663,6 +663,9 @@ memif_disconnect(struct rte_eth_dev *dev)
 				continue;
 		}
 
+		if (mq == NULL)
+			continue;
+
 		rte_intr_fd_close(mq->intr_handle);
 	}
 	for (i = 0; i < pmd->cfg.num_s2c_rings; i++) {
@@ -678,6 +681,9 @@ memif_disconnect(struct rte_eth_dev *dev)
 				continue;
 		}
 
+		if (mq == NULL)
+			continue;
+
 		rte_intr_fd_close(mq->intr_handle);
 	}
 
diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c
index 852a7e2e8e..cdf77d77b0 100644
--- a/drivers/net/memif/rte_eth_memif.c
+++ b/drivers/net/memif/rte_eth_memif.c
@@ -1723,6 +1723,10 @@ memif_dev_close(struct rte_eth_dev *dev)
 
 	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
 		memif_msg_enq_disconnect(pmd->cc, "Device closed", 0);
+		/* Flush the disconnect and tear down the control channel;
+		 * memif_disconnect() is idempotent if dev_stop already ran.
+		 */
+		memif_disconnect(dev);
 
 		for (i = 0; i < dev->data->nb_rx_queues; i++)
 			memif_rx_queue_release(dev, i);
-- 
2.43.7

[PATCH v3 8/9] net/memif: fix bogus Tx count on invalid interrupt FD

[Sriram Yagnaraman]

eth_memif_tx_zc() returns uint16_t but did "return -1" when the
interrupt FD was invalid, so the caller saw 65535 packets sent after
ring->head had already been published. The FD can legitimately be -1:
memif_init_queues() only warns and continues when eventfd() fails. Skip
the kick when the FD is invalid, as eth_memif_tx() does, and return the
real count.

Fixes: aedd054c5c2a ("drivers: check interrupt file descriptor validity")
Cc: stable@dpdk.org

Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
---
 drivers/net/memif/rte_eth_memif.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c
index cdf77d77b0..0680dc3947 100644
--- a/drivers/net/memif/rte_eth_memif.c
+++ b/drivers/net/memif/rte_eth_memif.c
@@ -1254,11 +1254,9 @@ eth_memif_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 	rte_atomic_store_explicit(&ring->head, slot, rte_memory_order_release);
 
 	/* Send interrupt, if enabled. */
-	if ((ring->flags & MEMIF_RING_FLAG_MASK_INT) == 0) {
+	if ((ring->flags & MEMIF_RING_FLAG_MASK_INT) == 0 &&
+	    rte_intr_fd_get(mq->intr_handle) >= 0) {
 		uint64_t a = 1;
-		if (rte_intr_fd_get(mq->intr_handle) < 0)
-			return -1;
-
 		ssize_t size = write(rte_intr_fd_get(mq->intr_handle),
 				     &a, sizeof(a));
 		if (unlikely(size < 0)) {
-- 
2.43.7

[PATCH v3 9/9] test/memif: add memif PMD unit test

[Sriram Yagnaraman]

Add a memif_pmd_autotest unit test, modelled on the TAP PMD test. memif
differs from TAP in that a port is only usable once a peer connects, so
the test creates a server and a client memif port in the same process,
connected over an abstract-namespace socket (the loopback setup from the
memif documentation), and waits for the asynchronous control-channel
handshake to bring both ports up.

The suite checks dev_info reports the memif driver, that the pair reaches
link up, statistics get and reset, a client-to-server loopback burst with
payload verification, multi-segment loopback across a ring wrap with
payload verification (general coverage for the chained-descriptor Rx and
Tx paths), that the pair reconnects after a port restart, that a
zero-length Tx burst is handled, and that a configured-but-not-started
port can be closed without crashing. It is a fast test, runs without
hugepages and under ASan.

Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
---
 MAINTAINERS               |   1 +
 app/test/meson.build      |   1 +
 app/test/test_pmd_memif.c | 751 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 753 insertions(+)
 create mode 100644 app/test/test_pmd_memif.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 93ad53027d..ec154f3a05 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1164,6 +1164,7 @@ F: drivers/net/memif/
 F: devtools/test-memif.sh
 F: doc/guides/nics/memif.rst
 F: doc/guides/nics/features/memif.ini
+F: app/test/test_pmd_memif.c
 
 
 Crypto Drivers
diff --git a/app/test/meson.build b/app/test/meson.build
index 9805cf5bee..5ef1ced7ce 100644
--- a/app/test/meson.build
+++ b/app/test/meson.build
@@ -148,6 +148,7 @@ source_file_deps = {
     'test_pflock.c': [],
     'test_pie.c': ['sched'],
     'test_pmd_af_packet.c': ['net_af_packet', 'ethdev', 'bus_vdev'],
+    'test_pmd_memif.c': ['ethdev', 'net_memif', 'bus_vdev'],
     'test_pmd_pcap.c': ['net_pcap', 'ethdev', 'bus_vdev']  + packet_burst_generator_deps,
     'test_pmd_perf.c': ['ethdev', 'net'] + packet_burst_generator_deps,
     'test_pmd_ring.c': ['net_ring', 'ethdev', 'bus_vdev'],
diff --git a/app/test/test_pmd_memif.c b/app/test/test_pmd_memif.c
new file mode 100644
index 0000000000..fa554cbb54
--- /dev/null
+++ b/app/test/test_pmd_memif.c
@@ -0,0 +1,751 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2026 Ericsson AB
+ */
+
+/*
+ * Basic test of memif PMD functionality.
+ * Based off of the TAP PMD test (test_pmd_tap.c).
+ *
+ * memif connects two endpoints over shared memory. Unlike a NIC or TAP
+ * device, a memif port is only usable once its peer connects, so the test
+ * creates a server and a client memif port in this one process, connected
+ * over an abstract-namespace socket (the loopback setup documented in
+ * doc/guides/nics/memif.rst). The control-channel handshake is asynchronous,
+ * so the test waits for both ports to report link up before exercising the
+ * data path.
+ */
+
+#include "test.h"
+
+#include <stdio.h>
+
+#ifndef RTE_EXEC_ENV_LINUX
+
+/* memif PMD is only available on Linux */
+static int
+test_pmd_memif(void)
+{
+	printf("memif PMD not supported on this platform, skipping test\n");
+	return TEST_SKIPPED;
+}
+
+#else /* RTE_EXEC_ENV_LINUX */
+
+#include <string.h>
+#include <unistd.h>
+
+#include <rte_ethdev.h>
+#include <rte_bus_vdev.h>
+#include <rte_mbuf.h>
+#include <rte_ether.h>
+
+#define SOCKET0 0
+#define RING_SIZE 256
+#define NB_MBUF 4096
+#define MAX_PKT_BURST 32
+#define PKT_LEN 64
+
+/* memif ignores nb_tx_desc; the ring size is set via the rsize arg. */
+#define MEMIF_LOG2_RING 8
+
+/*
+ * Same socket name and id on both ports makes them a connected pair.
+ * The small-bsize pair forces chained descriptors; the default-bsize pair
+ * exercises the single-pool Tx fast path.
+ */
+#define MEMIF_SRV_NAME "net_memif_test_srv"
+#define MEMIF_CLI_NAME "net_memif_test_cli"
+#define MEMIF_SRV_ARGS "role=server,id=0,bsize=512,rsize=8,socket-abstract=yes,socket=memif-autotest"
+#define MEMIF_CLI_ARGS "role=client,id=0,bsize=512,rsize=8,socket-abstract=yes,socket=memif-autotest"
+#define MEMIF_FP_SRV_NAME "net_memif_test_fsrv"
+#define MEMIF_FP_CLI_NAME "net_memif_test_fcli"
+#define MEMIF_FP_SRV_ARGS "role=server,id=2,socket-abstract=yes,socket=memif-autotest-fp"
+#define MEMIF_FP_CLI_ARGS "role=client,id=2,socket-abstract=yes,socket=memif-autotest-fp"
+
+/* Time to wait for the asynchronous control-channel handshake. */
+#define CONNECT_TRIES 50
+#define CONNECT_DELAY_US 100000
+
+static struct rte_mempool *mp;
+static int memif_srv_port = -1;
+static int memif_cli_port = -1;
+static int memif_fp_srv_port = -1;
+static int memif_fp_cli_port = -1;
+
+static int
+find_port(const char *frag)
+{
+	uint16_t port_id;
+	char name[RTE_ETH_NAME_MAX_LEN];
+
+	RTE_ETH_FOREACH_DEV(port_id) {
+		if (rte_eth_dev_get_name_by_port(port_id, name) == 0 &&
+		    strstr(name, frag) != NULL)
+			return port_id;
+	}
+	return -1;
+}
+
+static int
+configure_port(int port)
+{
+	struct rte_eth_conf port_conf;
+	int ret;
+
+	memset(&port_conf, 0, sizeof(port_conf));
+
+	ret = rte_eth_dev_configure(port, 1, 1, &port_conf);
+	if (ret < 0) {
+		printf("Configure failed for port %d: %s\n",
+		       port, rte_strerror(-ret));
+		return -1;
+	}
+
+	ret = rte_eth_tx_queue_setup(port, 0, RING_SIZE, SOCKET0, NULL);
+	if (ret < 0) {
+		printf("TX queue setup failed for port %d: %s\n",
+		       port, rte_strerror(-ret));
+		return -1;
+	}
+
+	ret = rte_eth_rx_queue_setup(port, 0, RING_SIZE, SOCKET0, NULL, mp);
+	if (ret < 0) {
+		printf("RX queue setup failed for port %d: %s\n",
+		       port, rte_strerror(-ret));
+		return -1;
+	}
+
+	ret = rte_eth_dev_start(port);
+	if (ret < 0) {
+		printf("Error starting port %d: %s\n",
+		       port, rte_strerror(-ret));
+		return -1;
+	}
+
+	return 0;
+}
+
+/* Wait until both ports report link up, i.e. the peers have connected. */
+static int
+wait_for_link_pair(int p0, int p1)
+{
+	struct rte_eth_link l0, l1;
+	int i;
+
+	for (i = 0; i < CONNECT_TRIES; i++) {
+		if (rte_eth_link_get_nowait(p0, &l0) == 0 &&
+		    rte_eth_link_get_nowait(p1, &l1) == 0 &&
+		    l0.link_status == RTE_ETH_LINK_UP &&
+		    l1.link_status == RTE_ETH_LINK_UP)
+			return 0;
+		usleep(CONNECT_DELAY_US);
+	}
+	return -1;
+}
+
+static int
+wait_for_link(void)
+{
+	return wait_for_link_pair(memif_srv_port, memif_cli_port);
+}
+
+static struct rte_mbuf *
+create_test_packet(uint16_t pkt_len, uint8_t seed)
+{
+	struct rte_mbuf *mbuf;
+	struct rte_ether_hdr *eth_hdr;
+	uint8_t *payload;
+	uint16_t i;
+
+	mbuf = rte_pktmbuf_alloc(mp);
+	if (mbuf == NULL)
+		return NULL;
+
+	if (pkt_len < RTE_ETHER_MIN_LEN)
+		pkt_len = RTE_ETHER_MIN_LEN;
+
+	eth_hdr = (struct rte_ether_hdr *)rte_pktmbuf_append(mbuf, pkt_len);
+	if (eth_hdr == NULL) {
+		rte_pktmbuf_free(mbuf);
+		return NULL;
+	}
+
+	memset(&eth_hdr->dst_addr, 0xFF, RTE_ETHER_ADDR_LEN);
+	memset(&eth_hdr->src_addr, 0x02, RTE_ETHER_ADDR_LEN);
+	eth_hdr->ether_type = rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4);
+
+	payload = (uint8_t *)(eth_hdr + 1);
+	for (i = 0; i < pkt_len - sizeof(*eth_hdr); i++)
+		payload[i] = (uint8_t)(seed + i);
+
+	return mbuf;
+}
+
+static int
+test_memif_dev_info(void)
+{
+	struct rte_eth_dev_info dev_info;
+	int ret;
+
+	ret = rte_eth_dev_info_get(memif_srv_port, &dev_info);
+	TEST_ASSERT(ret == 0, "dev_info_get failed: %s", rte_strerror(-ret));
+	TEST_ASSERT(strcmp(dev_info.driver_name, "net_memif") == 0,
+		    "unexpected driver name: %s", dev_info.driver_name);
+	return TEST_SUCCESS;
+}
+
+static int
+test_memif_link_up(void)
+{
+	/* The pair must have connected during setup. */
+	TEST_ASSERT(wait_for_link() == 0,
+		    "memif server/client did not reach link up");
+	return TEST_SUCCESS;
+}
+
+static int
+test_memif_stats_get(void)
+{
+	struct rte_eth_stats stats;
+
+	TEST_ASSERT(rte_eth_stats_get(memif_srv_port, &stats) == 0,
+		    "stats_get failed for server port");
+	TEST_ASSERT(rte_eth_stats_get(memif_cli_port, &stats) == 0,
+		    "stats_get failed for client port");
+	return TEST_SUCCESS;
+}
+
+static int
+test_memif_stats_reset(void)
+{
+	struct rte_eth_stats stats;
+
+	TEST_ASSERT(rte_eth_stats_reset(memif_srv_port) == 0,
+		    "stats_reset failed");
+	TEST_ASSERT(rte_eth_stats_get(memif_srv_port, &stats) == 0,
+		    "stats_get after reset failed");
+	TEST_ASSERT(stats.ipackets == 0 && stats.opackets == 0 &&
+		    stats.ibytes == 0 && stats.obytes == 0,
+		    "stats not zero after reset");
+	return TEST_SUCCESS;
+}
+
+/*
+ * Send a burst from the client and receive it on the server, verifying the
+ * payload is delivered intact. This exercises the Rx/Tx data path over the
+ * connected memif pair.
+ */
+static int
+test_memif_send_receive(void)
+{
+	struct rte_mbuf *tx[MAX_PKT_BURST];
+	struct rte_mbuf *rx[MAX_PKT_BURST];
+	const uint16_t nb = MAX_PKT_BURST / 2;
+	uint16_t nb_tx, nb_rx, got;
+	int i, tries;
+
+	TEST_ASSERT(wait_for_link() == 0, "link not up before send/receive");
+
+	for (i = 0; i < nb; i++) {
+		tx[i] = create_test_packet(PKT_LEN, (uint8_t)i);
+		if (tx[i] == NULL) {
+			while (--i >= 0)
+				rte_pktmbuf_free(tx[i]);
+			TEST_ASSERT(0, "failed to build test packet");
+		}
+	}
+
+	nb_tx = rte_eth_tx_burst(memif_cli_port, 0, tx, nb);
+	for (i = nb_tx; i < nb; i++)
+		rte_pktmbuf_free(tx[i]);
+	TEST_ASSERT(nb_tx > 0, "client transmitted no packets");
+
+	/* Receive may take a moment; poll a few times. */
+	got = 0;
+	for (tries = 0; tries < 10 && got < nb_tx; tries++) {
+		nb_rx = rte_eth_rx_burst(memif_srv_port, 0, rx, MAX_PKT_BURST);
+		for (i = 0; i < nb_rx; i++) {
+			/* Payload must match the position-dependent pattern. */
+			uint8_t *p = rte_pktmbuf_mtod_offset(rx[i], uint8_t *,
+					sizeof(struct rte_ether_hdr));
+			uint16_t plen = PKT_LEN -
+					sizeof(struct rte_ether_hdr);
+			uint16_t k;
+			int bad = rte_pktmbuf_pkt_len(rx[i]) != PKT_LEN;
+
+			for (k = 0; !bad && k < plen; k++)
+				if (p[k] != (uint8_t)(got + k))
+					bad = 1;
+			if (bad) {
+				for (k = i; k < nb_rx; k++)
+					rte_pktmbuf_free(rx[k]);
+				TEST_ASSERT(0,
+					    "packet %u payload/length mismatch",
+					    got);
+			}
+			rte_pktmbuf_free(rx[i]);
+			got++;
+		}
+		if (got < nb_tx)
+			usleep(10000);
+	}
+
+	TEST_ASSERT(got == nb_tx,
+		    "received %u packets, expected %u", got, nb_tx);
+	return TEST_SUCCESS;
+}
+
+/*
+ * Single-segment loopback on the default-bsize pair, where bsize exceeds
+ * the mbuf data room so eth_memif_tx() takes the single-pool fast path.
+ */
+static int
+test_memif_fastpath(void)
+{
+	struct rte_mbuf *tx[MAX_PKT_BURST];
+	struct rte_mbuf *rx[MAX_PKT_BURST];
+	const uint16_t nb = MAX_PKT_BURST / 2;
+	uint16_t nb_tx, got;
+	int i, tries;
+
+	TEST_ASSERT(wait_for_link_pair(memif_fp_srv_port, memif_fp_cli_port)
+		    == 0, "fast-path pair not up");
+
+	for (i = 0; i < nb; i++) {
+		tx[i] = create_test_packet(PKT_LEN, (uint8_t)i);
+		if (tx[i] == NULL) {
+			while (--i >= 0)
+				rte_pktmbuf_free(tx[i]);
+			TEST_ASSERT(0, "failed to build test packet");
+		}
+	}
+
+	nb_tx = rte_eth_tx_burst(memif_fp_cli_port, 0, tx, nb);
+	for (i = nb_tx; i < nb; i++)
+		rte_pktmbuf_free(tx[i]);
+	TEST_ASSERT(nb_tx > 0, "fast-path client transmitted no packets");
+
+	got = 0;
+	for (tries = 0; tries < 10 && got < nb_tx; tries++) {
+		uint16_t nb_rx = rte_eth_rx_burst(memif_fp_srv_port, 0, rx,
+						  MAX_PKT_BURST);
+		for (i = 0; i < nb_rx; i++) {
+			uint8_t *p = rte_pktmbuf_mtod_offset(rx[i], uint8_t *,
+					sizeof(struct rte_ether_hdr));
+			uint16_t plen = PKT_LEN -
+					sizeof(struct rte_ether_hdr);
+			uint16_t k;
+			int bad = rte_pktmbuf_pkt_len(rx[i]) != PKT_LEN;
+
+			for (k = 0; !bad && k < plen; k++)
+				if (p[k] != (uint8_t)(got + k))
+					bad = 1;
+			if (bad) {
+				for (k = i; k < nb_rx; k++)
+					rte_pktmbuf_free(rx[k]);
+				TEST_ASSERT(0,
+					    "fast-path packet %u payload/length mismatch",
+					    got);
+			}
+			rte_pktmbuf_free(rx[i]);
+			got++;
+		}
+		if (got < nb_tx)
+			usleep(10000);
+	}
+
+	TEST_ASSERT(got == nb_tx, "fast-path received %u expected %u",
+		    got, nb_tx);
+	return TEST_SUCCESS;
+}
+
+static int
+test_memif_stop_start(void)
+{
+	TEST_ASSERT(rte_eth_dev_stop(memif_cli_port) == 0,
+		    "stop client failed");
+	TEST_ASSERT(rte_eth_dev_start(memif_cli_port) == 0,
+		    "restart client failed");
+	/* After a restart the pair must reconnect. */
+	TEST_ASSERT(wait_for_link() == 0, "link did not recover after restart");
+	return TEST_SUCCESS;
+}
+
+/*
+ * A zero-length Tx burst must be accepted and return 0 without touching
+ * the (empty) mbuf array. Regression test for the empty-burst guard in
+ * eth_memif_tx().
+ */
+static int
+test_memif_tx_empty_burst(void)
+{
+	struct rte_mbuf *dummy = NULL;
+
+	TEST_ASSERT(wait_for_link() == 0, "link not up before empty burst");
+	TEST_ASSERT(rte_eth_tx_burst(memif_cli_port, 0, &dummy, 0) == 0,
+		    "zero-length Tx burst did not return 0");
+	return TEST_SUCCESS;
+}
+
+/*
+ * Close a configured but never-started port. The queues were never
+ * allocated, so memif_disconnect() must skip the NULL queue entries
+ * rather than dereference them. Regression test for the NULL-queue guard
+ * in the disconnect-on-close fix. Uses a throwaway device so the suite
+ * pair stays intact.
+ */
+static int
+test_memif_close_without_stop(void)
+{
+	int sport, ret;
+	struct rte_eth_conf port_conf;
+
+	ret = rte_vdev_init("net_memif_test_tmps",
+			    "role=server,id=1,socket-abstract=yes,socket=memif-autotest-tmp");
+	if (ret < 0) {
+		printf("could not create throwaway server: %s\n",
+		       rte_strerror(-ret));
+		return TEST_FAILED;
+	}
+
+	sport = find_port("net_memif_test_tmps");
+	if (sport < 0) {
+		rte_vdev_uninit("net_memif_test_tmps");
+		TEST_ASSERT(0, "throwaway server port not found");
+	}
+
+	/* Configure but do not start: close is rejected on a started port. */
+	memset(&port_conf, 0, sizeof(port_conf));
+	ret = rte_eth_dev_configure(sport, 1, 1, &port_conf);
+	if (ret < 0) {
+		rte_vdev_uninit("net_memif_test_tmps");
+		TEST_ASSERT(0, "configure of throwaway server failed: %s",
+			    rte_strerror(-ret));
+	}
+
+	/* Close without ever starting; must not crash on the NULL queues. */
+	ret = rte_eth_dev_close(sport);
+	rte_vdev_uninit("net_memif_test_tmps");
+	TEST_ASSERT(ret == 0, "close without stop failed: %s",
+		    rte_strerror(-ret));
+
+	return TEST_SUCCESS;
+}
+
+/*
+ * A server that has been started and then stopped must refuse peers: a
+ * connection accepted while stopped would leave a live control channel on
+ * a stopped port. Regression test for the refuse-connection-on-stopped-
+ * device fix. Without it the stopped server reports link up here.
+ */
+static int
+test_memif_stopped_server_rejects_peer(void)
+{
+	int sport, cport, ret;
+
+	ret = rte_vdev_init("net_memif_test_tmp2s",
+			    "role=server,id=3,socket-abstract=yes,socket=memif-autotest-tmp2");
+	if (ret < 0) {
+		printf("could not create throwaway server: %s\n",
+		       rte_strerror(-ret));
+		return TEST_FAILED;
+	}
+	sport = find_port("net_memif_test_tmp2s");
+	if (sport < 0) {
+		rte_vdev_uninit("net_memif_test_tmp2s");
+		TEST_ASSERT(0, "throwaway server port not found");
+	}
+	if (configure_port(sport) < 0) {
+		rte_vdev_uninit("net_memif_test_tmp2s");
+		TEST_ASSERT(0, "throwaway server start failed");
+	}
+	if (rte_eth_dev_stop(sport) < 0) {
+		rte_eth_dev_close(sport);
+		rte_vdev_uninit("net_memif_test_tmp2s");
+		TEST_ASSERT(0, "throwaway server stop failed");
+	}
+
+	ret = rte_vdev_init("net_memif_test_tmp2c",
+			    "role=client,id=3,socket-abstract=yes,socket=memif-autotest-tmp2");
+	if (ret < 0) {
+		rte_eth_dev_close(sport);
+		rte_vdev_uninit("net_memif_test_tmp2s");
+		TEST_ASSERT(0, "could not create throwaway client: %s",
+			    rte_strerror(-ret));
+	}
+	cport = find_port("net_memif_test_tmp2c");
+	if (cport < 0 || configure_port(cport) < 0) {
+		rte_eth_dev_close(sport);
+		rte_vdev_uninit("net_memif_test_tmp2c");
+		rte_vdev_uninit("net_memif_test_tmp2s");
+		TEST_ASSERT(0, "throwaway client setup failed");
+	}
+
+	/* The stopped server must not come up. */
+	ret = wait_for_link_pair(sport, cport);
+
+	rte_eth_dev_stop(cport);
+	rte_eth_dev_close(cport);
+	rte_eth_dev_close(sport);
+	rte_vdev_uninit("net_memif_test_tmp2c");
+	rte_vdev_uninit("net_memif_test_tmp2s");
+
+	TEST_ASSERT(ret != 0, "stopped server accepted a peer");
+	return TEST_SUCCESS;
+}
+
+#define BIG_PKT_LEN 4000	/* > bsize (512) => chained descriptors */
+#define BIG_SEG_LEN 1000	/* each mbuf segment carries this many bytes */
+/* ~8 descriptors per packet; enough to wrap the 2^MEMIF_LOG2_RING ring */
+#define WRAP_PKTS ((1 << MEMIF_LOG2_RING) / 8 + 8)
+
+/*
+ * Build a multi-segment mbuf of pkt_len bytes, chaining as many pool mbufs
+ * as needed (BIG_SEG_LEN bytes each) with a position-dependent pattern.
+ */
+static struct rte_mbuf *
+create_big_packet(uint16_t pkt_len, uint8_t seed)
+{
+	struct rte_mbuf *head = NULL, *tail = NULL;
+	uint16_t done = 0;
+
+	while (done < pkt_len) {
+		struct rte_mbuf *seg = rte_pktmbuf_alloc(mp);
+		uint16_t seg_len = RTE_MIN((uint16_t)BIG_SEG_LEN,
+					   (uint16_t)(pkt_len - done));
+		uint8_t *data;
+		uint16_t i;
+
+		if (seg == NULL) {
+			rte_pktmbuf_free(head);
+			return NULL;
+		}
+		data = (uint8_t *)rte_pktmbuf_append(seg, seg_len);
+		for (i = 0; i < seg_len; i++)
+			data[i] = (uint8_t)(seed + done + i);
+
+		if (head == NULL) {
+			head = seg;
+			tail = seg;
+		} else {
+			tail->next = seg;
+			tail = seg;
+			head->nb_segs++;
+			head->pkt_len += seg_len;
+		}
+		done += seg_len;
+	}
+	return head;
+}
+
+/* Verify a received packet's payload, walking its segment chain. */
+static int
+check_big_packet(struct rte_mbuf *m, uint16_t pkt_len, uint8_t seed)
+{
+	uint16_t off = 0;
+	struct rte_mbuf *seg;
+
+	if (rte_pktmbuf_pkt_len(m) != pkt_len)
+		return -1;
+	for (seg = m; seg != NULL; seg = seg->next) {
+		const uint8_t *data = rte_pktmbuf_mtod(seg, const uint8_t *);
+		uint16_t i;
+
+		for (i = 0; i < rte_pktmbuf_data_len(seg); i++, off++)
+			if (data[i] != (uint8_t)(seed + off))
+				return -1;
+	}
+	return off == pkt_len ? 0 : -1;
+}
+
+/*
+ * Send multi-segment packets larger than the memif buffer size, repeated
+ * enough to wrap the ring, and verify each is delivered intact. Exercises
+ * the chained-descriptor Rx and Tx paths across a ring wrap.
+ */
+static int
+test_memif_multiseg(void)
+{
+	unsigned int sent = 0, recv = 0;
+	unsigned int iter;
+
+	TEST_ASSERT(wait_for_link() == 0, "link not up before multiseg test");
+
+	for (iter = 0; iter < WRAP_PKTS; iter++) {
+		struct rte_mbuf *tx, *rx[MAX_PKT_BURST];
+		uint16_t n, j;
+		int tries;
+
+		tx = create_big_packet(BIG_PKT_LEN, (uint8_t)iter);
+		TEST_ASSERT(tx != NULL, "failed to build big packet %u", iter);
+		if (tx->nb_segs <= 1) {
+			rte_pktmbuf_free(tx);
+			TEST_ASSERT(0, "test packet is not multi-segment");
+		}
+
+		if (rte_eth_tx_burst(memif_cli_port, 0, &tx, 1) != 1) {
+			rte_pktmbuf_free(tx);
+			continue;
+		}
+		sent++;
+
+		for (tries = 0; tries < 10; tries++) {
+			n = rte_eth_rx_burst(memif_srv_port, 0, rx,
+					     MAX_PKT_BURST);
+			for (j = 0; j < n; j++) {
+				if (check_big_packet(rx[j], BIG_PKT_LEN,
+						(uint8_t)recv) != 0) {
+					uint16_t k;
+					for (k = j; k < n; k++)
+						rte_pktmbuf_free(rx[k]);
+					TEST_ASSERT(0,
+						"multi-seg payload corrupted at pkt %u",
+						recv);
+				}
+				rte_pktmbuf_free(rx[j]);
+				recv++;
+			}
+			if (recv >= sent)
+				break;
+			usleep(2000);
+		}
+	}
+
+	TEST_ASSERT(recv == sent,
+		    "multi-seg: sent %u received %u", sent, recv);
+	return TEST_SUCCESS;
+}
+
+static void
+test_memif_cleanup(void)
+{
+	if (memif_srv_port >= 0) {
+		rte_eth_dev_stop(memif_srv_port);
+		rte_eth_dev_close(memif_srv_port);
+	}
+	if (memif_cli_port >= 0) {
+		rte_eth_dev_stop(memif_cli_port);
+		rte_eth_dev_close(memif_cli_port);
+	}
+	if (memif_fp_srv_port >= 0) {
+		rte_eth_dev_stop(memif_fp_srv_port);
+		rte_eth_dev_close(memif_fp_srv_port);
+	}
+	if (memif_fp_cli_port >= 0) {
+		rte_eth_dev_stop(memif_fp_cli_port);
+		rte_eth_dev_close(memif_fp_cli_port);
+	}
+	rte_vdev_uninit(MEMIF_SRV_NAME);
+	rte_vdev_uninit(MEMIF_CLI_NAME);
+	rte_vdev_uninit(MEMIF_FP_SRV_NAME);
+	rte_vdev_uninit(MEMIF_FP_CLI_NAME);
+	if (mp != NULL) {
+		rte_mempool_free(mp);
+		mp = NULL;
+	}
+	memif_srv_port = -1;
+	memif_cli_port = -1;
+	memif_fp_srv_port = -1;
+	memif_fp_cli_port = -1;
+}
+
+static int
+test_memif_setup(void)
+{
+	int ret;
+
+	mp = rte_pktmbuf_pool_create("memif_test_pool", NB_MBUF, 32, 0,
+				     RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
+	if (mp == NULL) {
+		printf("Error: failed to create mempool: %s\n",
+		       rte_strerror(rte_errno));
+		return -1;
+	}
+
+	ret = rte_vdev_init(MEMIF_SRV_NAME, MEMIF_SRV_ARGS);
+	if (ret < 0) {
+		printf("Error: failed to create memif server: %s\n",
+		       rte_strerror(-ret));
+		rte_mempool_free(mp);
+		mp = NULL;
+		return TEST_FAILED;
+	}
+
+	ret = rte_vdev_init(MEMIF_CLI_NAME, MEMIF_CLI_ARGS);
+	if (ret < 0) {
+		printf("Error: failed to create memif client: %s\n",
+		       rte_strerror(-ret));
+		rte_vdev_uninit(MEMIF_SRV_NAME);
+		rte_mempool_free(mp);
+		mp = NULL;
+		return -1;
+	}
+
+	memif_srv_port = find_port(MEMIF_SRV_NAME);
+	memif_cli_port = find_port(MEMIF_CLI_NAME);
+	if (memif_srv_port < 0 || memif_cli_port < 0) {
+		printf("Error: failed to find memif ports\n");
+		test_memif_cleanup();
+		return -1;
+	}
+
+	if (configure_port(memif_srv_port) < 0 ||
+	    configure_port(memif_cli_port) < 0) {
+		test_memif_cleanup();
+		return -1;
+	}
+
+	/* Second pair with default bsize to exercise the Tx fast path. */
+	if (rte_vdev_init(MEMIF_FP_SRV_NAME, MEMIF_FP_SRV_ARGS) < 0 ||
+	    rte_vdev_init(MEMIF_FP_CLI_NAME, MEMIF_FP_CLI_ARGS) < 0) {
+		printf("Error: failed to create fast-path memif pair\n");
+		test_memif_cleanup();
+		return TEST_FAILED;
+	}
+
+	memif_fp_srv_port = find_port(MEMIF_FP_SRV_NAME);
+	memif_fp_cli_port = find_port(MEMIF_FP_CLI_NAME);
+	if (memif_fp_srv_port < 0 || memif_fp_cli_port < 0) {
+		printf("Error: failed to find fast-path memif ports\n");
+		test_memif_cleanup();
+		return TEST_FAILED;
+	}
+
+	if (configure_port(memif_fp_srv_port) < 0 ||
+	    configure_port(memif_fp_cli_port) < 0) {
+		test_memif_cleanup();
+		return -1;
+	}
+
+	return 0;
+}
+
+static struct unit_test_suite test_pmd_memif_suite = {
+	.setup = test_memif_setup,
+	.teardown = test_memif_cleanup,
+	.suite_name = "memif PMD Unit Test Suite",
+	.unit_test_cases = {
+		TEST_CASE(test_memif_dev_info),
+		TEST_CASE(test_memif_link_up),
+		TEST_CASE(test_memif_stats_get),
+		TEST_CASE(test_memif_send_receive),
+		TEST_CASE(test_memif_fastpath),
+		TEST_CASE(test_memif_multiseg),
+		TEST_CASE(test_memif_stats_reset),
+		TEST_CASE(test_memif_stop_start),
+		TEST_CASE(test_memif_tx_empty_burst),
+		TEST_CASE(test_memif_close_without_stop),
+		TEST_CASE(test_memif_stopped_server_rejects_peer),
+		TEST_CASES_END()
+	}
+};
+
+static int
+test_pmd_memif(void)
+{
+	return unit_test_suite_runner(&test_pmd_memif_suite);
+}
+
+#endif /* RTE_EXEC_ENV_LINUX */
+
+REGISTER_FAST_TEST(memif_pmd_autotest, NOHUGE_OK, ASAN_OK, test_pmd_memif);
-- 
2.43.7

Re: [PATCH v3 0/9] net/memif: lifecycle fixes and unit test

[Stephen Hemminger]

On Fri, 16 Oct 2026 16:15:48 +0200
Sriram Yagnaraman <sriram.yagnaraman@ericsson.com> wrote:

> This series fixes a set of error-path and lifecycle bugs in the memif
> PMD and adds a unit test for the driver.
> 
> The first eight patches are fixes:
> 
>  - guard eth_memif_tx() against an empty burst (nb_pkts == 0);
>  - close file descriptor 0 instead of leaking it;
>  - do not close the EAL-owned memseg fd in zero-copy mode;
>  - free the MAC address allocated during probe on failure;
>  - unwind a partially-created device on create failure;
>  - refuse connections on a stopped server so it does not come up on a
>    stopped port;
>  - disconnect on close so a stopped server's control channel is not
>    leaked, and make memif_disconnect() safe on a never-started device;
>  - fix eth_memif_tx_zc() returning 65535 on an invalid interrupt fd.
> 
> The last patch adds a memif PMD unit test (app/test, memif_pmd_autotest):
> a server/client vdev pair over a loopback socket covering dev_info, link
> state, stats, single-segment loopback (slow and fast path), multi-segment
> loopback across a ring wrap, stop/start reconnect, empty Tx burst, close
> without stop, and a stopped server refusing a peer.
> 
> Verified: memif_pmd_autotest passes 11/11; each commit builds with
> -Dwerror=true; check-git-log and checkpatch are clean.
> 
> Thanks to Stephen Hemminger and the ai-code-review bot for the reviews
> that shaped this series.
> 
> v3:
>  - Rebase on main, picking up rte_intr_fd_close() from
>    d9191f684c ("interrupts: add helpers to close FD"): patch 2 keeps
>    only the owned-fd ">= 0" fixes not superseded by that helper, and
>    patch 7 keeps the NULL-queue guards above the rte_intr_fd_close()
>    calls.
>  - New patch 6: refuse connections on a stopped server. The started-
>    then-stopped case is the actual trigger for the control-channel
>    leak; dev_stop now sets ETH_MEMIF_FLAG_DISABLED. (v2 patch 6/7
>    described this as never-started, which was wrong.)
>  - Patch 7 (disconnect on close): reword to the real trigger and keep
>    the close-time disconnect as a backstop.
>  - Patch 3 (memseg fd): also stop closing the EAL-owned fd in
>    memif_connect(), not only memif_free_regions().
>  - Test: new test_memif_stopped_server_rejects_peer covering patch 6
>    (fails without it); reword close-without-stop to what it actually
>    covers (the NULL-queue skip); verify the full fast-path payload.
> 
> v2:
>  - P1: correct Fixes tag (Tx fast path, not original driver); move the
>    empty-burst check after the ring == NULL block.
>  - P2: split the memseg-fd change into its own patch rather than
>    widening the check to ">= 0".
>  - P4 (MAC leak): document the secondary -1 -> -ENOMEM change.
>  - P5 (unwind): add Fixes: multi-process support.
>  - New patch: fix eth_memif_tx_zc() bogus Tx count on invalid fd.
>  - Test: add to MAINTAINERS; return TEST_FAILED (not SKIPPED) on probe
>    failure; add a default-bsize pair to cover the Tx fast path; set
>    ring size via rsize and fix the stale comments.
> 
> Sriram Yagnaraman (9):
>   net/memif: guard against empty Tx burst
>   net/memif: close file descriptor zero
>   net/memif: do not close EAL-owned memseg file descriptor
>   net/memif: fix MAC address leak on probe failure
>   net/memif: unwind partial device on create failure
>   net/memif: refuse connection on stopped device
>   net/memif: disconnect on device close
>   net/memif: fix bogus Tx count on invalid interrupt FD
>   test/memif: add memif PMD unit test
> 
>  MAINTAINERS                       |   1 +
>  app/test/meson.build              |   1 +
>  app/test/test_pmd_memif.c         | 751 ++++++++++++++++++++++++++++++
>  drivers/net/memif/memif_socket.c  |  10 +-
>  drivers/net/memif/rte_eth_memif.c |  76 ++-
>  5 files changed, 812 insertions(+), 27 deletions(-)
>  create mode 100644 app/test/test_pmd_memif.c
> 


Still see warnings from AI

v3 applies to main (26.11-rc1) and every commit builds with
-Dwerror=true. Not run. The v2 comments are addressed. 6/9 fixes the
stopped-server case at the source, and the close test now covers what
its comment says.


[PATCH v3 7/9] net/memif: disconnect on device close

Info: the commit message describes the tree before 6/9. With 6/9
applied first, dev_stop does set ETH_MEMIF_FLAG_DISABLED, so "dev_stop
does not set it again ... memif_msg_receive_init() still accepts a
peer" is no longer true at this commit. Suggest:

  Before the previous patch, a server that was started and then
  stopped still accepted a peer and held a live pmd->cc at close.
  Call memif_disconnect() from close as a backstop for an init that
  races with stop.


[PATCH v3 9/9] test/memif: add memif PMD unit test

Warning: test_memif_stopped_server_rejects_peer() passes only by
timing out, so it always burns the full wait_for_link_pair() window
(CONNECT_TRIES * CONNECT_DELAY_US = 5s). memif_pmd_autotest is a fast
test with a 10s meson timeout, and that budget also has to cover EAL
init and the other handshakes, under ASan too. Use a short window for
the negative check:

	static int
	wait_for_link_pair_tries(int p0, int p1, int tries)
	...

	#define REJECT_TRIES 10	/* 1s */

	ret = wait_for_link_pair_tries(sport, cport, REJECT_TRIES);

Info: the commit message does not list the fast-path loopback or the
stopped-server test.

RE: [PATCH v3 0/9] net/memif: lifecycle fixes and unit test

[Sriram Yagnaraman]

> -----Original Message-----
> From: Stephen Hemminger <stephen@networkplumber.org>
> Sent: Friday, 16 October 2026 19:05
> To: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
> Cc: dev@dpdk.org; Jakub Grajciar <jgrajcia@cisco.com>; stable@dpdk.org
> Subject: Re: [PATCH v3 0/9] net/memif: lifecycle fixes and unit test
> 
> On Fri, 16 Oct 2026 16:15:48 +0200
> Sriram Yagnaraman <sriram.yagnaraman@ericsson.com> wrote:
> 
> > This series fixes a set of error-path and lifecycle bugs in the memif
> > PMD and adds a unit test for the driver.
> >
> > The first eight patches are fixes:
> >
> >  - guard eth_memif_tx() against an empty burst (nb_pkts == 0);
> >  - close file descriptor 0 instead of leaking it;
> >  - do not close the EAL-owned memseg fd in zero-copy mode;
> >  - free the MAC address allocated during probe on failure;
> >  - unwind a partially-created device on create failure;
> >  - refuse connections on a stopped server so it does not come up on a
> >    stopped port;
> >  - disconnect on close so a stopped server's control channel is not
> >    leaked, and make memif_disconnect() safe on a never-started device;
> >  - fix eth_memif_tx_zc() returning 65535 on an invalid interrupt fd.
> >
> > The last patch adds a memif PMD unit test (app/test,
> memif_pmd_autotest):
> > a server/client vdev pair over a loopback socket covering dev_info,
> > link state, stats, single-segment loopback (slow and fast path),
> > multi-segment loopback across a ring wrap, stop/start reconnect, empty
> > Tx burst, close without stop, and a stopped server refusing a peer.
> >
> > Verified: memif_pmd_autotest passes 11/11; each commit builds with
> > -Dwerror=true; check-git-log and checkpatch are clean.
> >
> > Thanks to Stephen Hemminger and the ai-code-review bot for the reviews
> > that shaped this series.
> >
> > v3:
> >  - Rebase on main, picking up rte_intr_fd_close() from
> >    d9191f684c ("interrupts: add helpers to close FD"): patch 2 keeps
> >    only the owned-fd ">= 0" fixes not superseded by that helper, and
> >    patch 7 keeps the NULL-queue guards above the rte_intr_fd_close()
> >    calls.
> >  - New patch 6: refuse connections on a stopped server. The started-
> >    then-stopped case is the actual trigger for the control-channel
> >    leak; dev_stop now sets ETH_MEMIF_FLAG_DISABLED. (v2 patch 6/7
> >    described this as never-started, which was wrong.)
> >  - Patch 7 (disconnect on close): reword to the real trigger and keep
> >    the close-time disconnect as a backstop.
> >  - Patch 3 (memseg fd): also stop closing the EAL-owned fd in
> >    memif_connect(), not only memif_free_regions().
> >  - Test: new test_memif_stopped_server_rejects_peer covering patch 6
> >    (fails without it); reword close-without-stop to what it actually
> >    covers (the NULL-queue skip); verify the full fast-path payload.
> >
> > v2:
> >  - P1: correct Fixes tag (Tx fast path, not original driver); move the
> >    empty-burst check after the ring == NULL block.
> >  - P2: split the memseg-fd change into its own patch rather than
> >    widening the check to ">= 0".
> >  - P4 (MAC leak): document the secondary -1 -> -ENOMEM change.
> >  - P5 (unwind): add Fixes: multi-process support.
> >  - New patch: fix eth_memif_tx_zc() bogus Tx count on invalid fd.
> >  - Test: add to MAINTAINERS; return TEST_FAILED (not SKIPPED) on probe
> >    failure; add a default-bsize pair to cover the Tx fast path; set
> >    ring size via rsize and fix the stale comments.
> >
> > Sriram Yagnaraman (9):
> >   net/memif: guard against empty Tx burst
> >   net/memif: close file descriptor zero
> >   net/memif: do not close EAL-owned memseg file descriptor
> >   net/memif: fix MAC address leak on probe failure
> >   net/memif: unwind partial device on create failure
> >   net/memif: refuse connection on stopped device
> >   net/memif: disconnect on device close
> >   net/memif: fix bogus Tx count on invalid interrupt FD
> >   test/memif: add memif PMD unit test
> >
> >  MAINTAINERS                       |   1 +
> >  app/test/meson.build              |   1 +
> >  app/test/test_pmd_memif.c         | 751 ++++++++++++++++++++++++++++++
> >  drivers/net/memif/memif_socket.c  |  10 +-
> > drivers/net/memif/rte_eth_memif.c |  76 ++-
> >  5 files changed, 812 insertions(+), 27 deletions(-)  create mode
> > 100644 app/test/test_pmd_memif.c
> >
> 
> 
> Still see warnings from AI
> 

Thanks for reviewing, sent v4 with the warnings fixed now.