svn commit: r304081 - stable/10/sys/dev/virtio/network

[Steven Hartland]

Author: smh
Date: Sun Aug 14 15:27:59 2016
New Revision: 304081
URL: https://svnweb.freebsd.org/changeset/base/304081

Log:
  MFC r303971:
  
  Fix vtnet hang with max_virtqueue_pairs > VTNET_MAX_QUEUE_PAIRS
  
  Sponsored by:	Multiplay

Modified:
  stable/10/sys/dev/virtio/network/if_vtnet.c
  stable/10/sys/dev/virtio/network/if_vtnetvar.h
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/virtio/network/if_vtnet.c
==============================================================================
--- stable/10/sys/dev/virtio/network/if_vtnet.c	Sun Aug 14 15:26:40 2016	(r304080)
+++ stable/10/sys/dev/virtio/network/if_vtnet.c	Sun Aug 14 15:27:59 2016	(r304081)
@@ -230,18 +230,32 @@ static void	vtnet_disable_interrupts(str
 static int	vtnet_tunable_int(struct vtnet_softc *, const char *, int);
 
 /* Tunables. */
+static SYSCTL_NODE(_hw, OID_AUTO, vtnet, CTLFLAG_RD, 0, "VNET driver parameters");
 static int vtnet_csum_disable = 0;
 TUNABLE_INT("hw.vtnet.csum_disable", &vtnet_csum_disable);
+SYSCTL_INT(_hw_vtnet, OID_AUTO, csum_disable, CTLFLAG_RDTUN,
+    &vtnet_csum_disable, 0, "Disables receive and send checksum offload");
 static int vtnet_tso_disable = 0;
 TUNABLE_INT("hw.vtnet.tso_disable", &vtnet_tso_disable);
+SYSCTL_INT(_hw_vtnet, OID_AUTO, tso_disable, CTLFLAG_RDTUN, &vtnet_tso_disable,
+    0, "Disables TCP Segmentation Offload");
 static int vtnet_lro_disable = 0;
 TUNABLE_INT("hw.vtnet.lro_disable", &vtnet_lro_disable);
+SYSCTL_INT(_hw_vtnet, OID_AUTO, lro_disable, CTLFLAG_RDTUN, &vtnet_lro_disable,
+    0, "Disables TCP Large Receive Offload");
 static int vtnet_mq_disable = 0;
 TUNABLE_INT("hw.vtnet.mq_disable", &vtnet_mq_disable);
-static int vtnet_mq_max_pairs = 0;
+SYSCTL_INT(_hw_vtnet, OID_AUTO, mq_disable, CTLFLAG_RDTUN, &vtnet_mq_disable,
+    0, "Disables Multi Queue support");
+static int vtnet_mq_max_pairs = VTNET_MAX_QUEUE_PAIRS;
 TUNABLE_INT("hw.vtnet.mq_max_pairs", &vtnet_mq_max_pairs);
+SYSCTL_INT(_hw_vtnet, OID_AUTO, mq_max_pairs, CTLFLAG_RDTUN,
+    &vtnet_mq_max_pairs, 0, "Sets the maximum number of Multi Queue pairs");
 static int vtnet_rx_process_limit = 512;
 TUNABLE_INT("hw.vtnet.rx_process_limit", &vtnet_rx_process_limit);
+SYSCTL_INT(_hw_vtnet, OID_AUTO, rx_process_limit, CTLFLAG_RDTUN,
+    &vtnet_rx_process_limit, 0,
+    "Limits the number RX segments processed in a single pass");
 
 static uma_zone_t vtnet_tx_header_zone;
 
@@ -591,7 +605,6 @@ static void
 vtnet_setup_features(struct vtnet_softc *sc)
 {
 	device_t dev;
-	int max_pairs, max;
 
 	dev = sc->vtnet_dev;
 
@@ -640,32 +653,31 @@ vtnet_setup_features(struct vtnet_softc 
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_MQ) &&
 	    sc->vtnet_flags & VTNET_FLAG_CTRL_VQ) {
-		max_pairs = virtio_read_dev_config_2(dev,
+		sc->vtnet_max_vq_pairs = virtio_read_dev_config_2(dev,
 		    offsetof(struct virtio_net_config, max_virtqueue_pairs));
-		if (max_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
-		    max_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX)
-			max_pairs = 1;
 	} else
-		max_pairs = 1;
+		sc->vtnet_max_vq_pairs = 1;
 
-	if (max_pairs > 1) {
+	if (sc->vtnet_max_vq_pairs > 1) {
 		/*
-		 * Limit the maximum number of queue pairs to the number of
-		 * CPUs or the configured maximum. The actual number of
-		 * queues that get used may be less.
+		 * Limit the maximum number of queue pairs to the lower of
+		 * the number of CPUs and the configured maximum.
+		 * The actual number of queues that get used may be less.
 		 */
+		int max;
+
 		max = vtnet_tunable_int(sc, "mq_max_pairs", vtnet_mq_max_pairs);
-		if (max > 0 && max_pairs > max)
-			max_pairs = max;
-		if (max_pairs > mp_ncpus)
-			max_pairs = mp_ncpus;
-		if (max_pairs > VTNET_MAX_QUEUE_PAIRS)
-			max_pairs = VTNET_MAX_QUEUE_PAIRS;
-		if (max_pairs > 1)
-			sc->vtnet_flags |= VTNET_FLAG_MULTIQ;
+		if (max > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN) {
+			if (max > mp_ncpus)
+				max = mp_ncpus;
+			if (max > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX)
+				max = VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX;
+			if (max > 1) {
+				sc->vtnet_requested_vq_pairs = max;
+				sc->vtnet_flags |= VTNET_FLAG_MULTIQ;
+			}
+		}
 	}
-
-	sc->vtnet_max_vq_pairs = max_pairs;
 }
 
 static int
@@ -2991,13 +3003,11 @@ vtnet_set_active_vq_pairs(struct vtnet_s
 	dev = sc->vtnet_dev;
 
 	if ((sc->vtnet_flags & VTNET_FLAG_MULTIQ) == 0) {
-		MPASS(sc->vtnet_max_vq_pairs == 1);
 		sc->vtnet_act_vq_pairs = 1;
 		return;
 	}
 
-	/* BMV: Just use the maximum configured for now. */
-	npairs = sc->vtnet_max_vq_pairs;
+	npairs = sc->vtnet_requested_vq_pairs;
 
 	if (vtnet_ctrl_mq_cmd(sc, npairs) != 0) {
 		device_printf(dev,
@@ -3853,6 +3863,9 @@ vtnet_setup_sysctl(struct vtnet_softc *s
 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "max_vq_pairs",
 	    CTLFLAG_RD, &sc->vtnet_max_vq_pairs, 0,
 	    "Maximum number of supported virtqueue pairs");
+	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "requested_vq_pairs",
+	    CTLFLAG_RD, &sc->vtnet_requested_vq_pairs, 0,
+	    "Requested number of virtqueue pairs");
 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "act_vq_pairs",
 	    CTLFLAG_RD, &sc->vtnet_act_vq_pairs, 0,
 	    "Number of active virtqueue pairs");

Modified: stable/10/sys/dev/virtio/network/if_vtnetvar.h
==============================================================================
--- stable/10/sys/dev/virtio/network/if_vtnetvar.h	Sun Aug 14 15:26:40 2016	(r304080)
+++ stable/10/sys/dev/virtio/network/if_vtnetvar.h	Sun Aug 14 15:27:59 2016	(r304081)
@@ -155,6 +155,7 @@ struct vtnet_softc {
 	int			 vtnet_if_flags;
 	int			 vtnet_act_vq_pairs;
 	int			 vtnet_max_vq_pairs;
+	int			 vtnet_requested_vq_pairs;
 
 	struct virtqueue	*vtnet_ctrl_vq;
 	struct vtnet_mac_filter	*vtnet_mac_filter;