--- /dev/null
+/*
+ * Xenbus code for netif backend
+ *
+ * Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>
+ * Copyright (C) 2005 XenSource Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "common.h"
+#include <linux/vmalloc.h>
+#include <linux/rtnetlink.h>
+
+struct backend_info {
+ struct xenbus_device *dev;
+ struct xenvif *vif;
+
+ /* This is the state that will be reflected in xenstore when any
+ * active hotplug script completes.
+ */
+ enum xenbus_state state;
+
+ enum xenbus_state frontend_state;
+ struct xenbus_watch hotplug_status_watch;
+ u8 have_hotplug_status_watch:1;
+
+ const char *hotplug_script;
+};
+
+static int connect_rings(struct backend_info *be, struct xenvif_queue *queue);
+static void connect(struct backend_info *be);
+static int read_xenbus_vif_flags(struct backend_info *be);
+static int backend_create_xenvif(struct backend_info *be);
+static void unregister_hotplug_status_watch(struct backend_info *be);
+static void xen_unregister_watchers(struct xenvif *vif);
+static void set_backend_state(struct backend_info *be,
+ enum xenbus_state state);
+
+#ifdef CONFIG_DEBUG_FS
+struct dentry *xen_netback_dbg_root = NULL;
+
+static int xenvif_read_io_ring(struct seq_file *m, void *v)
+{
+ struct xenvif_queue *queue = m->private;
+ struct xen_netif_tx_back_ring *tx_ring = &queue->tx;
+ struct xen_netif_rx_back_ring *rx_ring = &queue->rx;
+ struct netdev_queue *dev_queue;
+
+ if (tx_ring->sring) {
+ struct xen_netif_tx_sring *sring = tx_ring->sring;
+
+ seq_printf(m, "Queue %d\nTX: nr_ents %u\n", queue->id,
+ tx_ring->nr_ents);
+ seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
+ sring->req_prod,
+ sring->req_prod - sring->rsp_prod,
+ tx_ring->req_cons,
+ tx_ring->req_cons - sring->rsp_prod,
+ sring->req_event,
+ sring->req_event - sring->rsp_prod);
+ seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n",
+ sring->rsp_prod,
+ tx_ring->rsp_prod_pvt,
+ tx_ring->rsp_prod_pvt - sring->rsp_prod,
+ sring->rsp_event,
+ sring->rsp_event - sring->rsp_prod);
+ seq_printf(m, "pending prod %u pending cons %u nr_pending_reqs %u\n",
+ queue->pending_prod,
+ queue->pending_cons,
+ nr_pending_reqs(queue));
+ seq_printf(m, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n",
+ queue->dealloc_prod,
+ queue->dealloc_cons,
+ queue->dealloc_prod - queue->dealloc_cons);
+ }
+
+ if (rx_ring->sring) {
+ struct xen_netif_rx_sring *sring = rx_ring->sring;
+
+ seq_printf(m, "RX: nr_ents %u\n", rx_ring->nr_ents);
+ seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
+ sring->req_prod,
+ sring->req_prod - sring->rsp_prod,
+ rx_ring->req_cons,
+ rx_ring->req_cons - sring->rsp_prod,
+ sring->req_event,
+ sring->req_event - sring->rsp_prod);
+ seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n",
+ sring->rsp_prod,
+ rx_ring->rsp_prod_pvt,
+ rx_ring->rsp_prod_pvt - sring->rsp_prod,
+ sring->rsp_event,
+ sring->rsp_event - sring->rsp_prod);
+ }
+
+ seq_printf(m, "NAPI state: %lx NAPI weight: %d TX queue len %u\n"
+ "Credit timer_pending: %d, credit: %lu, usec: %lu\n"
+ "remaining: %lu, expires: %lu, now: %lu\n",
+ queue->napi.state, queue->napi.weight,
+ skb_queue_len(&queue->tx_queue),
+ timer_pending(&queue->credit_timeout),
+ queue->credit_bytes,
+ queue->credit_usec,
+ queue->remaining_credit,
+ queue->credit_timeout.expires,
+ jiffies);
+
+ dev_queue = netdev_get_tx_queue(queue->vif->dev, queue->id);
+
+ seq_printf(m, "\nRx internal queue: len %u max %u pkts %u %s\n",
+ queue->rx_queue_len, queue->rx_queue_max,
+ skb_queue_len(&queue->rx_queue),
+ netif_tx_queue_stopped(dev_queue) ? "stopped" : "running");
+
+ return 0;
+}
+
+#define XENVIF_KICK_STR "kick"
+#define BUFFER_SIZE 32
+
+static ssize_t
+xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct xenvif_queue *queue =
+ ((struct seq_file *)filp->private_data)->private;
+ int len;
+ char write[BUFFER_SIZE];
+
+ /* don't allow partial writes and check the length */
+ if (*ppos != 0)
+ return 0;
+ if (count >= sizeof(write))
+ return -ENOSPC;
+
+ len = simple_write_to_buffer(write,
+ sizeof(write) - 1,
+ ppos,
+ buf,
+ count);
+ if (len < 0)
+ return len;
+
+ write[len] = '\0';
+
+ if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1))
+ xenvif_interrupt(0, (void *)queue);
+ else {
+ pr_warn("Unknown command to io_ring_q%d. Available: kick\n",
+ queue->id);
+ count = -EINVAL;
+ }
+ return count;
+}
+
+static int xenvif_dump_open(struct inode *inode, struct file *filp)
+{
+ int ret;
+ void *queue = NULL;
+
+ if (inode->i_private)
+ queue = inode->i_private;
+ ret = single_open(filp, xenvif_read_io_ring, queue);
+ filp->f_mode |= FMODE_PWRITE;
+ return ret;
+}
+
+static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
+ .owner = THIS_MODULE,
+ .open = xenvif_dump_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+ .write = xenvif_write_io_ring,
+};
+
+static void xenvif_debugfs_addif(struct xenvif *vif)
+{
+ struct dentry *pfile;
+ int i;
+
+ if (IS_ERR_OR_NULL(xen_netback_dbg_root))
+ return;
+
+ vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
+ xen_netback_dbg_root);
+ if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
+ for (i = 0; i < vif->num_queues; ++i) {
+ char filename[sizeof("io_ring_q") + 4];
+
+ snprintf(filename, sizeof(filename), "io_ring_q%d", i);
+ pfile = debugfs_create_file(filename,
+ S_IRUSR | S_IWUSR,
+ vif->xenvif_dbg_root,
+ &vif->queues[i],
+ &xenvif_dbg_io_ring_ops_fops);
+ if (IS_ERR_OR_NULL(pfile))
+ pr_warn("Creation of io_ring file returned %ld!\n",
+ PTR_ERR(pfile));
+ }
+ } else
+ netdev_warn(vif->dev,
+ "Creation of vif debugfs dir returned %ld!\n",
+ PTR_ERR(vif->xenvif_dbg_root));
+}
+
+static void xenvif_debugfs_delif(struct xenvif *vif)
+{
+ if (IS_ERR_OR_NULL(xen_netback_dbg_root))
+ return;
+
+ if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root))
+ debugfs_remove_recursive(vif->xenvif_dbg_root);
+ vif->xenvif_dbg_root = NULL;
+}
+#endif /* CONFIG_DEBUG_FS */
+
+static int netback_remove(struct xenbus_device *dev)
+{
+ struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+ set_backend_state(be, XenbusStateClosed);
+
+ unregister_hotplug_status_watch(be);
+ if (be->vif) {
+ kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
+ xen_unregister_watchers(be->vif);
+ xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
+ xenvif_free(be->vif);
+ be->vif = NULL;
+ }
+ kfree(be->hotplug_script);
+ kfree(be);
+ dev_set_drvdata(&dev->dev, NULL);
+ return 0;
+}
+
+
+/**
+ * Entry point to this code when a new device is created. Allocate the basic
+ * structures and switch to InitWait.
+ */
+static int netback_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ const char *message;
+ struct xenbus_transaction xbt;
+ int err;
+ int sg;
+ const char *script;
+ struct backend_info *be = kzalloc(sizeof(struct backend_info),
+ GFP_KERNEL);
+ if (!be) {
+ xenbus_dev_fatal(dev, -ENOMEM,
+ "allocating backend structure");
+ return -ENOMEM;
+ }
+
+ be->dev = dev;
+ dev_set_drvdata(&dev->dev, be);
+
+ sg = 1;
+
+ do {
+ err = xenbus_transaction_start(&xbt);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "starting transaction");
+ goto fail;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
+ if (err) {
+ message = "writing feature-sg";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
+ "%d", sg);
+ if (err) {
+ message = "writing feature-gso-tcpv4";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
+ "%d", sg);
+ if (err) {
+ message = "writing feature-gso-tcpv6";
+ goto abort_transaction;
+ }
+
+ /* We support partial checksum setup for IPv6 packets */
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-ipv6-csum-offload",
+ "%d", 1);
+ if (err) {
+ message = "writing feature-ipv6-csum-offload";
+ goto abort_transaction;
+ }
+
+ /* We support rx-copy path. */
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-rx-copy", "%d", 1);
+ if (err) {
+ message = "writing feature-rx-copy";
+ goto abort_transaction;
+ }
+
+ /*
+ * We don't support rx-flip path (except old guests who don't
+ * grok this feature flag).
+ */
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-rx-flip", "%d", 0);
+ if (err) {
+ message = "writing feature-rx-flip";
+ goto abort_transaction;
+ }
+
+ err = xenbus_transaction_end(xbt, 0);
+ } while (err == -EAGAIN);
+
+ if (err) {
+ xenbus_dev_fatal(dev, err, "completing transaction");
+ goto fail;
+ }
+
+ /*
+ * Split event channels support, this is optional so it is not
+ * put inside the above loop.
+ */
+ err = xenbus_printf(XBT_NIL, dev->nodename,
+ "feature-split-event-channels",
+ "%u", separate_tx_rx_irq);
+ if (err)
+ pr_debug("Error writing feature-split-event-channels\n");
+
+ /* Multi-queue support: This is an optional feature. */
+ err = xenbus_printf(XBT_NIL, dev->nodename,
+ "multi-queue-max-queues", "%u", xenvif_max_queues);
+ if (err)
+ pr_debug("Error writing multi-queue-max-queues\n");
+
+ script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
+ if (IS_ERR(script)) {
+ err = PTR_ERR(script);
+ xenbus_dev_fatal(dev, err, "reading script");
+ goto fail;
+ }
+
+ be->hotplug_script = script;
+
+ err = xenbus_switch_state(dev, XenbusStateInitWait);
+ if (err)
+ goto fail;
+
+ be->state = XenbusStateInitWait;
+
+ /* This kicks hotplug scripts, so do it immediately. */
+ err = backend_create_xenvif(be);
+ if (err)
+ goto fail;
+
+ return 0;
+
+abort_transaction:
+ xenbus_transaction_end(xbt, 1);
+ xenbus_dev_fatal(dev, err, "%s", message);
+fail:
+ pr_debug("failed\n");
+ netback_remove(dev);
+ return err;
+}
+
+
+/*
+ * Handle the creation of the hotplug script environment. We add the script
+ * and vif variables to the environment, for the benefit of the vif-* hotplug
+ * scripts.
+ */
+static int netback_uevent(struct xenbus_device *xdev,
+ struct kobj_uevent_env *env)
+{
+ struct backend_info *be = dev_get_drvdata(&xdev->dev);
+
+ if (!be)
+ return 0;
+
+ if (add_uevent_var(env, "script=%s", be->hotplug_script))
+ return -ENOMEM;
+
+ if (!be->vif)
+ return 0;
+
+ return add_uevent_var(env, "vif=%s", be->vif->dev->name);
+}
+
+
+static int backend_create_xenvif(struct backend_info *be)
+{
+ int err;
+ long handle;
+ struct xenbus_device *dev = be->dev;
+ struct xenvif *vif;
+
+ if (be->vif != NULL)
+ return 0;
+
+ err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
+ if (err != 1) {
+ xenbus_dev_fatal(dev, err, "reading handle");
+ return (err < 0) ? err : -EINVAL;
+ }
+
+ vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
+ if (IS_ERR(vif)) {
+ err = PTR_ERR(vif);
+ xenbus_dev_fatal(dev, err, "creating interface");
+ return err;
+ }
+ be->vif = vif;
+
+ kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
+ return 0;
+}
+
+static void backend_disconnect(struct backend_info *be)
+{
+ if (be->vif) {
+ xen_unregister_watchers(be->vif);
+#ifdef CONFIG_DEBUG_FS
+ xenvif_debugfs_delif(be->vif);
+#endif /* CONFIG_DEBUG_FS */
+ xenvif_disconnect(be->vif);
+ }
+}
+
+static void backend_connect(struct backend_info *be)
+{
+ if (be->vif)
+ connect(be);
+}
+
+static inline void backend_switch_state(struct backend_info *be,
+ enum xenbus_state state)
+{
+ struct xenbus_device *dev = be->dev;
+
+ pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
+ be->state = state;
+
+ /* If we are waiting for a hotplug script then defer the
+ * actual xenbus state change.
+ */
+ if (!be->have_hotplug_status_watch)
+ xenbus_switch_state(dev, state);
+}
+
+/* Handle backend state transitions:
+ *
+ * The backend state starts in InitWait and the following transitions are
+ * allowed.
+ *
+ * InitWait -> Connected
+ *
+ * ^ \ |
+ * | \ |
+ * | \ |
+ * | \ |
+ * | \ |
+ * | \ |
+ * | V V
+ *
+ * Closed <-> Closing
+ *
+ * The state argument specifies the eventual state of the backend and the
+ * function transitions to that state via the shortest path.
+ */
+static void set_backend_state(struct backend_info *be,
+ enum xenbus_state state)
+{
+ while (be->state != state) {
+ switch (be->state) {
+ case XenbusStateClosed:
+ switch (state) {
+ case XenbusStateInitWait:
+ case XenbusStateConnected:
+ pr_info("%s: prepare for reconnect\n",
+ be->dev->nodename);
+ backend_switch_state(be, XenbusStateInitWait);
+ break;
+ case XenbusStateClosing:
+ backend_switch_state(be, XenbusStateClosing);
+ break;
+ default:
+ BUG();
+ }
+ break;
+ case XenbusStateInitWait:
+ switch (state) {
+ case XenbusStateConnected:
+ backend_connect(be);
+ backend_switch_state(be, XenbusStateConnected);
+ break;
+ case XenbusStateClosing:
+ case XenbusStateClosed:
+ backend_switch_state(be, XenbusStateClosing);
+ break;
+ default:
+ BUG();
+ }
+ break;
+ case XenbusStateConnected:
+ switch (state) {
+ case XenbusStateInitWait:
+ case XenbusStateClosing:
+ case XenbusStateClosed:
+ backend_disconnect(be);
+ backend_switch_state(be, XenbusStateClosing);
+ break;
+ default:
+ BUG();
+ }
+ break;
+ case XenbusStateClosing:
+ switch (state) {
+ case XenbusStateInitWait:
+ case XenbusStateConnected:
+ case XenbusStateClosed:
+ backend_switch_state(be, XenbusStateClosed);
+ break;
+ default:
+ BUG();
+ }
+ break;
+ default:
+ BUG();
+ }
+ }
+}
+
+/**
+ * Callback received when the frontend's state changes.
+ */
+static void frontend_changed(struct xenbus_device *dev,
+ enum xenbus_state frontend_state)
+{
+ struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+ pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
+
+ be->frontend_state = frontend_state;
+
+ switch (frontend_state) {
+ case XenbusStateInitialising:
+ set_backend_state(be, XenbusStateInitWait);
+ break;
+
+ case XenbusStateInitialised:
+ break;
+
+ case XenbusStateConnected:
+ set_backend_state(be, XenbusStateConnected);
+ break;
+
+ case XenbusStateClosing:
+ set_backend_state(be, XenbusStateClosing);
+ break;
+
+ case XenbusStateClosed:
+ set_backend_state(be, XenbusStateClosed);
+ if (xenbus_dev_is_online(dev))
+ break;
+ /* fall through if not online */
+ case XenbusStateUnknown:
+ set_backend_state(be, XenbusStateClosed);
+ device_unregister(&dev->dev);
+ break;
+
+ default:
+ xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
+ frontend_state);
+ break;
+ }
+}
+
+
+static void xen_net_read_rate(struct xenbus_device *dev,
+ unsigned long *bytes, unsigned long *usec)
+{
+ char *s, *e;
+ unsigned long b, u;
+ char *ratestr;
+
+ /* Default to unlimited bandwidth. */
+ *bytes = ~0UL;
+ *usec = 0;
+
+ ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
+ if (IS_ERR(ratestr))
+ return;
+
+ s = ratestr;
+ b = simple_strtoul(s, &e, 10);
+ if ((s == e) || (*e != ','))
+ goto fail;
+
+ s = e + 1;
+ u = simple_strtoul(s, &e, 10);
+ if ((s == e) || (*e != '\0'))
+ goto fail;
+
+ *bytes = b;
+ *usec = u;
+
+ kfree(ratestr);
+ return;
+
+ fail:
+ pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
+ kfree(ratestr);
+}
+
+static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
+{
+ char *s, *e, *macstr;
+ int i;
+
+ macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
+ if (IS_ERR(macstr))
+ return PTR_ERR(macstr);
+
+ for (i = 0; i < ETH_ALEN; i++) {
+ mac[i] = simple_strtoul(s, &e, 16);
+ if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
+ kfree(macstr);
+ return -ENOENT;
+ }
+ s = e+1;
+ }
+
+ kfree(macstr);
+ return 0;
+}
+
+static void xen_net_rate_changed(struct xenbus_watch *watch,
+ const char **vec, unsigned int len)
+{
+ struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);
+ struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
+ unsigned long credit_bytes;
+ unsigned long credit_usec;
+ unsigned int queue_index;
+
+ xen_net_read_rate(dev, &credit_bytes, &credit_usec);
+ for (queue_index = 0; queue_index < vif->num_queues; queue_index++) {
+ struct xenvif_queue *queue = &vif->queues[queue_index];
+
+ queue->credit_bytes = credit_bytes;
+ queue->credit_usec = credit_usec;
+ if (!mod_timer_pending(&queue->credit_timeout, jiffies) &&
+ queue->remaining_credit > queue->credit_bytes) {
+ queue->remaining_credit = queue->credit_bytes;
+ }
+ }
+}
+
+static int xen_register_watchers(struct xenbus_device *dev, struct xenvif *vif)
+{
+ int err = 0;
+ char *node;
+ unsigned maxlen = strlen(dev->nodename) + sizeof("/rate");
+
+ if (vif->credit_watch.node)
+ return -EADDRINUSE;
+
+ node = kmalloc(maxlen, GFP_KERNEL);
+ if (!node)
+ return -ENOMEM;
+ snprintf(node, maxlen, "%s/rate", dev->nodename);
+ vif->credit_watch.node = node;
+ vif->credit_watch.callback = xen_net_rate_changed;
+ err = register_xenbus_watch(&vif->credit_watch);
+ if (err) {
+ pr_err("Failed to set watcher %s\n", vif->credit_watch.node);
+ kfree(node);
+ vif->credit_watch.node = NULL;
+ vif->credit_watch.callback = NULL;
+ }
+ return err;
+}
+
+static void xen_unregister_watchers(struct xenvif *vif)
+{
+ if (vif->credit_watch.node) {
+ unregister_xenbus_watch(&vif->credit_watch);
+ kfree(vif->credit_watch.node);
+ vif->credit_watch.node = NULL;
+ }
+}
+
+static void unregister_hotplug_status_watch(struct backend_info *be)
+{
+ if (be->have_hotplug_status_watch) {
+ unregister_xenbus_watch(&be->hotplug_status_watch);
+ kfree(be->hotplug_status_watch.node);
+ }
+ be->have_hotplug_status_watch = 0;
+}
+
+static void hotplug_status_changed(struct xenbus_watch *watch,
+ const char **vec,
+ unsigned int vec_size)
+{
+ struct backend_info *be = container_of(watch,
+ struct backend_info,
+ hotplug_status_watch);
+ char *str;
+ unsigned int len;
+
+ str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
+ if (IS_ERR(str))
+ return;
+ if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
+ /* Complete any pending state change */
+ xenbus_switch_state(be->dev, be->state);
+
+ /* Not interested in this watch anymore. */
+ unregister_hotplug_status_watch(be);
+ }
+ kfree(str);
+}
+
+static void connect(struct backend_info *be)
+{
+ int err;
+ struct xenbus_device *dev = be->dev;
+ unsigned long credit_bytes, credit_usec;
+ unsigned int queue_index;
+ unsigned int requested_num_queues;
+ struct xenvif_queue *queue;
+
+ /* Check whether the frontend requested multiple queues
+ * and read the number requested.
+ */
+ err = xenbus_scanf(XBT_NIL, dev->otherend,
+ "multi-queue-num-queues",
+ "%u", &requested_num_queues);
+ if (err < 0) {
+ requested_num_queues = 1; /* Fall back to single queue */
+ } else if (requested_num_queues > xenvif_max_queues) {
+ /* buggy or malicious guest */
+ xenbus_dev_fatal(dev, err,
+ "guest requested %u queues, exceeding the maximum of %u.",
+ requested_num_queues, xenvif_max_queues);
+ return;
+ }
+
+ err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
+ return;
+ }
+
+ xen_net_read_rate(dev, &credit_bytes, &credit_usec);
+ xen_unregister_watchers(be->vif);
+ xen_register_watchers(dev, be->vif);
+ read_xenbus_vif_flags(be);
+
+ /* Use the number of queues requested by the frontend */
+ be->vif->queues = vzalloc(requested_num_queues *
+ sizeof(struct xenvif_queue));
+ be->vif->num_queues = requested_num_queues;
+ be->vif->stalled_queues = requested_num_queues;
+
+ for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
+ queue = &be->vif->queues[queue_index];
+ queue->vif = be->vif;
+ queue->id = queue_index;
+ snprintf(queue->name, sizeof(queue->name), "%s-q%u",
+ be->vif->dev->name, queue->id);
+
+ err = xenvif_init_queue(queue);
+ if (err) {
+ /* xenvif_init_queue() cleans up after itself on
+ * failure, but we need to clean up any previously
+ * initialised queues. Set num_queues to i so that
+ * earlier queues can be destroyed using the regular
+ * disconnect logic.
+ */
+ be->vif->num_queues = queue_index;
+ goto err;
+ }
+
+ queue->credit_bytes = credit_bytes;
+ queue->remaining_credit = credit_bytes;
+ queue->credit_usec = credit_usec;
+
+ err = connect_rings(be, queue);
+ if (err) {
+ /* connect_rings() cleans up after itself on failure,
+ * but we need to clean up after xenvif_init_queue() here,
+ * and also clean up any previously initialised queues.
+ */
+ xenvif_deinit_queue(queue);
+ be->vif->num_queues = queue_index;
+ goto err;
+ }
+ }
+
+#ifdef CONFIG_DEBUG_FS
+ xenvif_debugfs_addif(be->vif);
+#endif /* CONFIG_DEBUG_FS */
+
+ /* Initialisation completed, tell core driver the number of
+ * active queues.
+ */
+ rtnl_lock();
+ netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
+ netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues);
+ rtnl_unlock();
+
+ xenvif_carrier_on(be->vif);
+
+ unregister_hotplug_status_watch(be);
+ err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
+ hotplug_status_changed,
+ "%s/%s", dev->nodename, "hotplug-status");
+ if (!err)
+ be->have_hotplug_status_watch = 1;
+
+ netif_tx_wake_all_queues(be->vif->dev);
+
+ return;
+
+err:
+ if (be->vif->num_queues > 0)
+ xenvif_disconnect(be->vif); /* Clean up existing queues */
+ vfree(be->vif->queues);
+ be->vif->queues = NULL;
+ be->vif->num_queues = 0;
+ return;
+}
+
+
+static int connect_rings(struct backend_info *be, struct xenvif_queue *queue)
+{
+ struct xenbus_device *dev = be->dev;
+ unsigned int num_queues = queue->vif->num_queues;
+ unsigned long tx_ring_ref, rx_ring_ref;
+ unsigned int tx_evtchn, rx_evtchn;
+ int err;
+ char *xspath;
+ size_t xspathsize;
+ const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */
+
+ /* If the frontend requested 1 queue, or we have fallen back
+ * to single queue due to lack of frontend support for multi-
+ * queue, expect the remaining XenStore keys in the toplevel
+ * directory. Otherwise, expect them in a subdirectory called
+ * queue-N.
+ */
+ if (num_queues == 1) {
+ xspath = kzalloc(strlen(dev->otherend) + 1, GFP_KERNEL);
+ if (!xspath) {
+ xenbus_dev_fatal(dev, -ENOMEM,
+ "reading ring references");
+ return -ENOMEM;
+ }
+ strcpy(xspath, dev->otherend);
+ } else {
+ xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
+ xspath = kzalloc(xspathsize, GFP_KERNEL);
+ if (!xspath) {
+ xenbus_dev_fatal(dev, -ENOMEM,
+ "reading ring references");
+ return -ENOMEM;
+ }
+ snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
+ queue->id);
+ }
+
+ err = xenbus_gather(XBT_NIL, xspath,
+ "tx-ring-ref", "%lu", &tx_ring_ref,
+ "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
+ if (err) {
+ xenbus_dev_fatal(dev, err,
+ "reading %s/ring-ref",
+ xspath);
+ goto err;
+ }
+
+ /* Try split event channels first, then single event channel. */
+ err = xenbus_gather(XBT_NIL, xspath,
+ "event-channel-tx", "%u", &tx_evtchn,
+ "event-channel-rx", "%u", &rx_evtchn, NULL);
+ if (err < 0) {
+ err = xenbus_scanf(XBT_NIL, xspath,
+ "event-channel", "%u", &tx_evtchn);
+ if (err < 0) {
+ xenbus_dev_fatal(dev, err,
+ "reading %s/event-channel(-tx/rx)",
+ xspath);
+ goto err;
+ }
+ rx_evtchn = tx_evtchn;
+ }
+
+ /* Map the shared frame, irq etc. */
+ err = xenvif_connect(queue, tx_ring_ref, rx_ring_ref,
+ tx_evtchn, rx_evtchn);
+ if (err) {
+ xenbus_dev_fatal(dev, err,
+ "mapping shared-frames %lu/%lu port tx %u rx %u",
+ tx_ring_ref, rx_ring_ref,
+ tx_evtchn, rx_evtchn);
+ goto err;
+ }
+
+ err = 0;
+err: /* Regular return falls through with err == 0 */
+ kfree(xspath);
+ return err;
+}
+
+static int read_xenbus_vif_flags(struct backend_info *be)
+{
+ struct xenvif *vif = be->vif;
+ struct xenbus_device *dev = be->dev;
+ unsigned int rx_copy;
+ int err, val;
+
+ 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;
+ }
+ if (!rx_copy)
+ return -EOPNOTSUPP;
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend,
+ "feature-rx-notify", "%d", &val) < 0)
+ val = 0;
+ if (!val) {
+ /* - Reduce drain timeout to poll more frequently for
+ * Rx requests.
+ * - Disable Rx stall detection.
+ */
+ be->vif->drain_timeout = msecs_to_jiffies(30);
+ be->vif->stall_timeout = 0;
+ }
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",
+ "%d", &val) < 0)
+ val = 0;
+ vif->can_sg = !!val;
+
+ vif->gso_mask = 0;
+ vif->gso_prefix_mask = 0;
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
+ "%d", &val) < 0)
+ val = 0;
+ if (val)
+ vif->gso_mask |= GSO_BIT(TCPV4);
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
+ "%d", &val) < 0)
+ val = 0;
+ if (val)
+ vif->gso_prefix_mask |= GSO_BIT(TCPV4);
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6",
+ "%d", &val) < 0)
+ val = 0;
+ if (val)
+ vif->gso_mask |= GSO_BIT(TCPV6);
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6-prefix",
+ "%d", &val) < 0)
+ val = 0;
+ if (val)
+ vif->gso_prefix_mask |= GSO_BIT(TCPV6);
+
+ if (vif->gso_mask & vif->gso_prefix_mask) {
+ xenbus_dev_fatal(dev, err,
+ "%s: gso and gso prefix flags are not "
+ "mutually exclusive",
+ dev->otherend);
+ return -EOPNOTSUPP;
+ }
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
+ "%d", &val) < 0)
+ val = 0;
+ vif->ip_csum = !val;
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-ipv6-csum-offload",
+ "%d", &val) < 0)
+ val = 0;
+ vif->ipv6_csum = !!val;
+
+ return 0;
+}
+
+static const struct xenbus_device_id netback_ids[] = {
+ { "vif" },
+ { "" }
+};
+
+static struct xenbus_driver netback_driver = {
+ .ids = netback_ids,
+ .probe = netback_probe,
+ .remove = netback_remove,
+ .uevent = netback_uevent,
+ .otherend_changed = frontend_changed,
+};
+
+int xenvif_xenbus_init(void)
+{
+ return xenbus_register_backend(&netback_driver);
+}
+
+void xenvif_xenbus_fini(void)
+{
+ return xenbus_unregister_driver(&netback_driver);
+}
Code Review / kvmfornfv.git / blobdiff