[RFC][PATCH 11/13] Kemari: XenbusStateAttached handler for netback

[Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>]

This patch implements XenbusStateAttached handler for netback.  The procedure
is almost the same as blkback except that it handles both tx and rx back-end
rings.

Signed-off-by: Yoshi Tamura <tamura.yoshiaki@lab.ntt.co.jp>
Signed-off-by: Yoshisato Yanagisawa <yanagisawa.yoshisato@lab.ntt.co.jp>
---
 drivers/xen/netback/common.h    |    2
 drivers/xen/netback/interface.c |   58 +++++++++++++++++++++
 drivers/xen/netback/netback.c   |    3 +
 drivers/xen/netback/xenbus.c    |  109 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 172 insertions(+)

diff -r e410857fd83c drivers/xen/netback/common.h
--- a/drivers/xen/netback/common.h	Wed Oct 22 14:55:29 2008 +0100
+++ b/drivers/xen/netback/common.h	Thu Mar 05 09:55:23 2009 +0900
@@ -182,6 +182,8 @@
 netif_t *netif_alloc(domid_t domid, unsigned int handle);
 int netif_map(netif_t *netif, unsigned long tx_ring_ref,
 	      unsigned long rx_ring_ref, unsigned int evtchn);
+int netif_attach(netif_t *netif, unsigned long tx_ring_ref,
+		 unsigned long rx_ring_ref, unsigned int evtchn);

 #define netif_get(_b) (atomic_inc(&(_b)->refcnt))
 #define netif_put(_b)						\
diff -r e410857fd83c drivers/xen/netback/interface.c
--- a/drivers/xen/netback/interface.c	Wed Oct 22 14:55:29 2008 +0100
+++ b/drivers/xen/netback/interface.c	Thu Mar 05 09:55:23 2009 +0900
@@ -303,6 +303,64 @@
 	return err;
 }

+int netif_attach(netif_t *netif, unsigned long tx_ring_ref,
+				 unsigned long rx_ring_ref, unsigned int evtchn)
+{
+	int err = -ENOMEM;
+	netif_tx_sring_t *txs;
+	netif_rx_sring_t *rxs;
+
+	/* Already connected through? */
+	if (netif->irq)
+		return 0;
+
+	netif->tx_comms_area = alloc_vm_area(PAGE_SIZE);
+	if (netif->tx_comms_area == NULL)
+		return -ENOMEM;
+	netif->rx_comms_area = alloc_vm_area(PAGE_SIZE);
+	if (netif->rx_comms_area == NULL)
+		goto err_rx;
+
+	err = map_frontend_pages(netif, tx_ring_ref, rx_ring_ref);
+	if (err)
+		goto err_map;
+
+	err = bind_interdomain_evtchn_to_irqhandler(
+		netif->domid, evtchn, netif_be_int, 0,
+		netif->dev->name, netif);
+	if (err < 0)
+		goto err_hypervisor;
+	netif->irq = err;
+	disable_irq(netif->irq);
+
+	txs = (netif_tx_sring_t *)netif->tx_comms_area->addr;
+	BACK_RING_ATTACH(&netif->tx, txs, PAGE_SIZE);
+
+	rxs = (netif_rx_sring_t *)
+		((char *)netif->rx_comms_area->addr);
+	BACK_RING_ATTACH(&netif->rx, rxs, PAGE_SIZE);
+
+	netif->rx.req_cons = netif->rx.sring->rsp_prod;
+	netif->rx_req_cons_peek = netif->rx.req_cons;
+
+	netif_get(netif);
+
+	rtnl_lock();
+	netback_carrier_on(netif);
+	if (netif_running(netif->dev))
+		__netif_up(netif);
+	rtnl_unlock();
+
+	return 0;
+err_hypervisor:
+	unmap_frontend_pages(netif);
+err_map:
+	free_vm_area(netif->rx_comms_area);
+err_rx:
+	free_vm_area(netif->tx_comms_area);
+	return err;
+}
+
 void netif_disconnect(netif_t *netif)
 {
 	if (netback_carrier_ok(netif)) {
diff -r e410857fd83c drivers/xen/netback/netback.c
--- a/drivers/xen/netback/netback.c	Wed Oct 22 14:55:29 2008 +0100
+++ b/drivers/xen/netback/netback.c	Thu Mar 05 09:55:23 2009 +0900
@@ -396,6 +396,9 @@
 		copy_gop->dest.offset = 0;
 		copy_gop->dest.u.ref = req->gref;
 		copy_gop->len = size;
+        if (req->gref == 0)
+            printk("did%d,gref%d,size%d,rc%lu,i%d\n",
+                netif->domid, req->gref, size, netif->rx.req_cons, i);
 	} else {
 		meta->copy = 0;
 		if (!xen_feature(XENFEAT_auto_translated_physmap)) {
diff -r e410857fd83c drivers/xen/netback/xenbus.c
--- a/drivers/xen/netback/xenbus.c	Wed Oct 22 14:55:29 2008 +0100
+++ b/drivers/xen/netback/xenbus.c	Thu Mar 05 09:55:23 2009 +0900
@@ -30,7 +30,9 @@


 static int connect_rings(struct backend_info *);
+static int attach_rings(struct backend_info *);
 static void connect(struct backend_info *);
+static void attach(struct backend_info *);
 static void backend_create_netif(struct backend_info *be);

 static int netback_remove(struct xenbus_device *dev)
@@ -239,6 +241,12 @@
 			connect(be);
 		break;

+	case XenbusStateAttached:
+		backend_create_netif(be);
+		if (be->netif)
+			attach(be);
+		break;
+
 	case XenbusStateClosing:
 		if (be->netif) {
 			kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
@@ -347,6 +355,29 @@
 	netif_wake_queue(be->netif->dev);
 }

+static void attach(struct backend_info *be)
+{
+	int err;
+	struct xenbus_device *dev = be->dev;
+
+	err = attach_rings(be);
+	if (err)
+		return;
+
+	err = xen_net_read_mac(dev, be->netif->fe_dev_addr);
+	if (err) {
+		xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
+		return;
+	}
+
+	xen_net_read_rate(dev, &be->netif->credit_bytes,
+			  &be->netif->credit_usec);
+	be->netif->remaining_credit = be->netif->credit_bytes;
+
+	xenbus_switch_state(dev, XenbusStateAttached);
+
+	netif_wake_queue(be->netif->dev);
+}

 static int connect_rings(struct backend_info *be)
 {
@@ -427,6 +458,84 @@
 	return 0;
 }

+static int attach_rings(struct backend_info *be)
+{
+	struct xenbus_device *dev = be->dev;
+	unsigned long tx_ring_ref, rx_ring_ref;
+	unsigned int evtchn, rx_copy;
+	int err;
+	int val;
+
+	DPRINTK("");
+
+	err = xenbus_gather(XBT_NIL, dev->otherend,
+			    "tx-ring-ref", "%lu", &tx_ring_ref,
+			    "rx-ring-ref", "%lu", &rx_ring_ref,
+			    "event-channel", "%u", &evtchn, NULL);
+	if (err) {
+		xenbus_dev_fatal(dev, err,
+				 "reading %s/ring-ref and event-channel",
+				 dev->otherend);
+		return err;
+	}
+
+	err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
+			   &rx_copy);
+	if (err == -ENOENT) {
+		err = 0;
+		rx_copy = 0;
+	}
+	if (err < 0) {
+		xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
+				 dev->otherend);
+		return err;
+	}
+	be->netif->copying_receiver = !!rx_copy;
+
+	if (be->netif->dev->tx_queue_len != 0) {
+		if (xenbus_scanf(XBT_NIL, dev->otherend,
+				 "feature-rx-notify", "%d", &val) < 0)
+			val = 0;
+		if (val)
+			be->netif->can_queue = 1;
+		else
+			/* Must be non-zero for pfifo_fast to work. */
+			be->netif->dev->tx_queue_len = 1;
+	}
+
+	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg", "%d", &val) < 0)
+		val = 0;
+	if (val) {
+		be->netif->features |= NETIF_F_SG;
+		be->netif->dev->features |= NETIF_F_SG;
+	}
+
+	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4", "%d",
+			 &val) < 0)
+		val = 0;
+	if (val) {
+		be->netif->features |= NETIF_F_TSO;
+		be->netif->dev->features |= NETIF_F_TSO;
+	}
+
+	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
+			 "%d", &val) < 0)
+		val = 0;
+	if (val) {
+		be->netif->features &= ~NETIF_F_IP_CSUM;
+		be->netif->dev->features &= ~NETIF_F_IP_CSUM;
+	}
+
+	/* Map the shared frame, irq etc. */
+	err = netif_attach(be->netif, tx_ring_ref, rx_ring_ref, evtchn);
+	if (err) {
+		xenbus_dev_fatal(dev, err,
+				 "mapping shared-frames %lu/%lu port %u",
+				 tx_ring_ref, rx_ring_ref, evtchn);
+		return err;
+	}
+	return 0;
+}

 /* ** Driver Registration ** */