[PATCH 1/1] add selftest for virtio-net

From: Hengjinxiao
Date: Tue Aug 26 2014 - 21:47:09 EST


Selftest is an important part of network driver, this patch adds selftest for
virtio-net, including loopback test, negotiate test and reset test. Loopback
test checks whether virtio-net can send and receive packets normally. Negotiate test
executes feature negotiation between virtio-net driver in Guest OS and virtio-net
device in Host OS. Reset test resets virtio-net.

Signed-off-by: Hengjinxiao <hjxiaohust@xxxxxxxxx>

---
drivers/net/virtio_net.c | 233 +++++++++++++++++++++++++++++++++++++++-
include/uapi/linux/virtio_net.h | 9 ++
2 files changed, 241 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 59caa06..f83f6e4 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -28,6 +28,7 @@
#include <linux/cpu.h>
#include <linux/average.h>
#include <net/busy_poll.h>
+#include <linux/pci.h>

static int napi_weight = NAPI_POLL_WEIGHT;
module_param(napi_weight, int, 0444);
@@ -51,6 +52,23 @@ module_param(gso, bool, 0444);
#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)

#define VIRTNET_DRIVER_VERSION "1.0.0"
+#define __VIRTNET_TESTING 0
+
+enum {
+ VIRTNET_LOOPBACK_TEST,
+ VIRTNET_FEATURE_NEG_TEST,
+ VIRTNET_RESET_TEST,
+};
+
+static const struct {
+ const char string[ETH_GSTRING_LEN];
+} virtnet_gstrings_test[] = {
+ [VIRTNET_LOOPBACK_TEST] = { "loopback test (offline)" },
+ [VIRTNET_FEATURE_NEG_TEST] = { "negotiate test (offline)" },
+ [VIRTNET_RESET_TEST] = { "reset test (offline)" },
+};
+
+#define VIRTNET_NUM_TEST ARRAY_SIZE(virtnet_gstrings_test)

struct virtnet_stats {
struct u64_stats_sync tx_syncp;
@@ -104,6 +122,8 @@ struct virtnet_info {
struct send_queue *sq;
struct receive_queue *rq;
unsigned int status;
+ unsigned long flags;
+ atomic_t lb_count;

/* Max # of queue pairs supported by the device */
u16 max_queue_pairs;
@@ -436,6 +456,19 @@ err_buf:
return NULL;
}

+void virtnet_check_lb_frame(struct virtnet_info *vi,
+ struct sk_buff *skb)
+{
+ unsigned int frame_size = skb->len;
+
+ if (*(skb->data + 3) == 0xFF) {
+ if ((*(skb->data + frame_size / 2 + 10) == 0xBE) &&
+ (*(skb->data + frame_size / 2 + 12) == 0xAF)) {
+ atomic_dec(&vi->lb_count);
+ }
+ }
+}
+
static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
{
struct virtnet_info *vi = rq->vq->vdev->priv;
@@ -485,7 +518,12 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
} else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
-
+ /* loopback self test for ethtool */
+ if (test_bit(__VIRTNET_TESTING, &vi->flags)) {
+ virtnet_check_lb_frame(vi, skb);
+ dev_kfree_skb_any(skb);
+ return;
+ }
skb->protocol = eth_type_trans(skb, dev);
pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
ntohs(skb->protocol), skb->len, skb->pkt_type);
@@ -813,6 +851,9 @@ static int virtnet_open(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
int i;
+ /* disallow open during test */
+ if (test_bit(__VIRTNET_TESTING, &vi->flags))
+ return -EBUSY;

for (i = 0; i < vi->max_queue_pairs; i++) {
if (i < vi->curr_queue_pairs)
@@ -1363,12 +1404,158 @@ static void virtnet_get_channels(struct net_device *dev,
channels->other_count = 0;
}

+static int virtnet_reset(struct virtnet_info *vi);
+
+static void virtnet_create_lb_frame(struct sk_buff *skb,
+ unsigned int frame_size)
+{
+ memset(skb->data, 0xFF, frame_size);
+ frame_size &= ~1;
+ memset(&skb->data[frame_size / 2], 0xAA, frame_size / 2 - 1);
+ memset(&skb->data[frame_size / 2 + 10], 0xBE, 1);
+ memset(&skb->data[frame_size / 2 + 12], 0xAF, 1);
+}
+
+static int virtnet_start_loopback(struct virtnet_info *vi)
+{
+ if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_LOOPBACK,
+ VIRTIO_NET_CTRL_LOOPBACK_SET, NULL, NULL)) {
+ dev_warn(&vi->dev->dev, "Failed to set loopback.\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int virtnet_run_loopback_test(struct virtnet_info *vi)
+{
+ int i;
+ netdev_tx_t rc;
+ struct sk_buff *skb;
+ unsigned int size = GOOD_COPY_LEN;
+
+ for (i = 0; i < 100; i++) {
+ skb = netdev_alloc_skb(vi->dev, size);
+ if (!skb)
+ return -ENOMEM;
+
+ skb->queue_mapping = 0;
+ skb_put(skb, size);
+ virtnet_create_lb_frame(skb, size);
+ rc = start_xmit(skb, vi->dev);
+ if (rc != NETDEV_TX_OK)
+ return -EPIPE;
+ atomic_inc(&vi->lb_count);
+ }
+ /* Give queue time to settle before testing results. */
+ msleep(20);
+ return atomic_read(&vi->lb_count) ? -EIO : 0;
+}
+
+static int virtnet_stop_loopback(struct virtnet_info *vi)
+{
+ if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_LOOPBACK,
+ VIRTIO_NET_CTRL_LOOPBACK_UNSET, NULL, NULL)) {
+ dev_warn(&vi->dev->dev, "Failed to unset loopback.\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int virtnet_loopback_test(struct virtnet_info *vi, u64 *data)
+{
+ *data = virtnet_start_loopback(vi);
+ if (*data)
+ goto out;
+ *data = virtnet_run_loopback_test(vi);
+ if (*data)
+ goto out;
+ *data = virtnet_stop_loopback(vi);
+out:
+ return *data;
+}
+
+static void virtnet_feature_neg_test(struct virtnet_info *vi)
+{
+ struct virtio_device *dev = vi->vdev;
+ struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+ int i;
+ u32 device_features;
+
+ /* Figure out what features the device supports. */
+ device_features = dev->config->get_features(dev);
+
+ /* Features supported by both device and driver into dev->features. */
+ memset(dev->features, 0, sizeof(dev->features));
+ for (i = 0; i < drv->feature_table_size; i++) {
+ unsigned int f = drv->feature_table[i];
+
+ BUG_ON(f >= 32);
+ if (device_features & (1 << f))
+ set_bit(f, dev->features);
+ }
+
+ /* Transport features always preserved to pass to finalize_features. */
+ for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
+ if (device_features & (1 << i))
+ set_bit(i, dev->features);
+
+ dev->config->finalize_features(dev);
+}
+
+static int virtnet_get_sset_count(struct net_device *netdev, int sset)
+{
+ switch (sset) {
+ case ETH_SS_TEST:
+ return VIRTNET_NUM_TEST;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
+{
+ switch (stringset) {
+ case ETH_SS_TEST:
+ memcpy(buf, &virtnet_gstrings_test,
+ sizeof(virtnet_gstrings_test));
+ break;
+ default:
+ break;
+ }
+}
+
+static void virtnet_self_test(struct net_device *netdev,
+ struct ethtool_test *eth_test, u64 *data)
+{
+ struct virtnet_info *vi = netdev_priv(netdev);
+ bool if_running = netif_running(netdev);
+
+ set_bit(__VIRTNET_TESTING, &vi->flags);
+ memset(data, 0, sizeof(u64) * VIRTNET_NUM_TEST);
+
+ if (eth_test->flags == ETH_TEST_FL_OFFLINE) {
+ if (!if_running) {
+ dev_warn(&vi->dev->dev, "Failed to execute self test.\n");
+ eth_test->flags |= ETH_TEST_FL_FAILED;
+ return;
+ }
+ if (virtnet_loopback_test(vi, &data[VIRTNET_LOOPBACK_TEST]))
+ eth_test->flags |= ETH_TEST_FL_FAILED;
+ virtnet_feature_neg_test(vi);
+ virtnet_reset(vi);
+ }
+ clear_bit(__VIRTNET_TESTING, &vi->flags);
+}
+
static const struct ethtool_ops virtnet_ethtool_ops = {
.get_drvinfo = virtnet_get_drvinfo,
.get_link = ethtool_op_get_link,
.get_ringparam = virtnet_get_ringparam,
.set_channels = virtnet_set_channels,
.get_channels = virtnet_get_channels,
+ .self_test = virtnet_self_test,
+ .get_strings = virtnet_get_strings,
+ .get_sset_count = virtnet_get_sset_count,
};

#define MIN_MTU 68
@@ -1957,6 +2144,50 @@ static int virtnet_restore(struct virtio_device *vdev)
}
#endif

+static int virtnet_reset(struct virtnet_info *vi)
+{
+ struct virtio_device *vdev = vi->vdev;
+ int err, i;
+ u8 status;
+
+ mutex_lock(&vi->config_lock);
+ vi->config_enable = false;
+ mutex_unlock(&vi->config_lock);
+
+ cancel_delayed_work_sync(&vi->refill);
+
+ if (netif_running(vi->dev))
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ napi_disable(&vi->rq[i].napi);
+ netif_napi_del(&vi->rq[i].napi);
+ }
+
+ remove_vq_common(vi);
+ flush_work(&vi->config_work);
+
+ virtnet_feature_neg_test(vi);
+ err = init_vqs(vi);
+ if (err)
+ return err;
+ if (netif_running(vi->dev)) {
+ for (i = 0; i < vi->curr_queue_pairs; i++)
+ if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
+ schedule_delayed_work(&vi->refill, 0);
+
+ for (i = 0; i < vi->max_queue_pairs; i++)
+ virtnet_napi_enable(&vi->rq[i]);
+ }
+
+ mutex_lock(&vi->config_lock);
+ vi->config_enable = true;
+ mutex_unlock(&vi->config_lock);
+
+ virtnet_set_queues(vi, vi->curr_queue_pairs);
+ status = vdev->config->get_status(vdev);
+ vdev->config->set_status(vdev, status | VIRTIO_CONFIG_S_DRIVER_OK);
+ return 0;
+}
+
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
{ 0 },
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 172a7f0..1f31f90 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -201,4 +201,13 @@ struct virtio_net_ctrl_mq {
#define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN 1
#define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX 0x8000

+ /*
+ * Control Loopback(5 is used by VIRTIO_NET_CTRL_GUEST_OFFLOADS in latest qemu)
+ *
+ * The command VIRTIO_NET_CTRL_LOOPBACK_SET is used to require the device come
+ * into loopback state.
+ */
+#define VIRTIO_NET_CTRL_LOOPBACK 6
+ #define VIRTIO_NET_CTRL_LOOPBACK_SET 0
+ #define VIRTIO_NET_CTRL_LOOPBACK_UNSET 1
#endif /* _LINUX_VIRTIO_NET_H */
--
1.8.3.2

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