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-rw-r--r--kernel/drivers/net/xen-netback/Makefile3
-rw-r--r--kernel/drivers/net/xen-netback/common.h347
-rw-r--r--kernel/drivers/net/xen-netback/interface.c689
-rw-r--r--kernel/drivers/net/xen-netback/netback.c2049
-rw-r--r--kernel/drivers/net/xen-netback/xenbus.c1043
5 files changed, 4131 insertions, 0 deletions
diff --git a/kernel/drivers/net/xen-netback/Makefile b/kernel/drivers/net/xen-netback/Makefile
new file mode 100644
index 000000000..e346e8125
--- /dev/null
+++ b/kernel/drivers/net/xen-netback/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_XEN_NETDEV_BACKEND) := xen-netback.o
+
+xen-netback-y := netback.o xenbus.o interface.o
diff --git a/kernel/drivers/net/xen-netback/common.h b/kernel/drivers/net/xen-netback/common.h
new file mode 100644
index 000000000..8a495b318
--- /dev/null
+++ b/kernel/drivers/net/xen-netback/common.h
@@ -0,0 +1,347 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef __XEN_NETBACK__COMMON_H__
+#define __XEN_NETBACK__COMMON_H__
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/io.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+
+#include <xen/interface/io/netif.h>
+#include <xen/interface/grant_table.h>
+#include <xen/grant_table.h>
+#include <xen/xenbus.h>
+#include <linux/debugfs.h>
+
+typedef unsigned int pending_ring_idx_t;
+#define INVALID_PENDING_RING_IDX (~0U)
+
+struct pending_tx_info {
+ struct xen_netif_tx_request req; /* tx request */
+ /* Callback data for released SKBs. The callback is always
+ * xenvif_zerocopy_callback, desc contains the pending_idx, which is
+ * also an index in pending_tx_info array. It is initialized in
+ * xenvif_alloc and it never changes.
+ * skb_shinfo(skb)->destructor_arg points to the first mapped slot's
+ * callback_struct in this array of struct pending_tx_info's, then ctx
+ * to the next, or NULL if there is no more slot for this skb.
+ * ubuf_to_vif is a helper which finds the struct xenvif from a pointer
+ * to this field.
+ */
+ struct ubuf_info callback_struct;
+};
+
+#define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
+#define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
+
+struct xenvif_rx_meta {
+ int id;
+ int size;
+ int gso_type;
+ int gso_size;
+};
+
+#define GSO_BIT(type) \
+ (1 << XEN_NETIF_GSO_TYPE_ ## type)
+
+/* Discriminate from any valid pending_idx value. */
+#define INVALID_PENDING_IDX 0xFFFF
+
+#define MAX_BUFFER_OFFSET PAGE_SIZE
+
+#define MAX_PENDING_REQS XEN_NETIF_TX_RING_SIZE
+
+/* It's possible for an skb to have a maximal number of frags
+ * but still be less than MAX_BUFFER_OFFSET in size. Thus the
+ * worst-case number of copy operations is MAX_SKB_FRAGS per
+ * ring slot.
+ */
+#define MAX_GRANT_COPY_OPS (MAX_SKB_FRAGS * XEN_NETIF_RX_RING_SIZE)
+
+#define NETBACK_INVALID_HANDLE -1
+
+/* To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating
+ * the maximum slots a valid packet can use. Now this value is defined
+ * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by
+ * all backend.
+ */
+#define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
+
+/* Queue name is interface name with "-qNNN" appended */
+#define QUEUE_NAME_SIZE (IFNAMSIZ + 5)
+
+/* IRQ name is queue name with "-tx" or "-rx" appended */
+#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
+
+struct xenvif;
+
+struct xenvif_stats {
+ /* Stats fields to be updated per-queue.
+ * A subset of struct net_device_stats that contains only the
+ * fields that are updated in netback.c for each queue.
+ */
+ unsigned int rx_bytes;
+ unsigned int rx_packets;
+ unsigned int tx_bytes;
+ unsigned int tx_packets;
+
+ /* Additional stats used by xenvif */
+ unsigned long rx_gso_checksum_fixup;
+ unsigned long tx_zerocopy_sent;
+ unsigned long tx_zerocopy_success;
+ unsigned long tx_zerocopy_fail;
+ unsigned long tx_frag_overflow;
+};
+
+struct xenvif_queue { /* Per-queue data for xenvif */
+ unsigned int id; /* Queue ID, 0-based */
+ char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
+ struct xenvif *vif; /* Parent VIF */
+
+ /* Use NAPI for guest TX */
+ struct napi_struct napi;
+ /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
+ unsigned int tx_irq;
+ /* Only used when feature-split-event-channels = 1 */
+ char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
+ struct xen_netif_tx_back_ring tx;
+ struct sk_buff_head tx_queue;
+ struct page *mmap_pages[MAX_PENDING_REQS];
+ pending_ring_idx_t pending_prod;
+ pending_ring_idx_t pending_cons;
+ u16 pending_ring[MAX_PENDING_REQS];
+ struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
+ grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
+
+ struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS];
+ struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS];
+ struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS];
+ /* passed to gnttab_[un]map_refs with pages under (un)mapping */
+ struct page *pages_to_map[MAX_PENDING_REQS];
+ struct page *pages_to_unmap[MAX_PENDING_REQS];
+
+ /* This prevents zerocopy callbacks to race over dealloc_ring */
+ spinlock_t callback_lock;
+ /* This prevents dealloc thread and NAPI instance to race over response
+ * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err
+ * it only protect response creation
+ */
+ spinlock_t response_lock;
+ pending_ring_idx_t dealloc_prod;
+ pending_ring_idx_t dealloc_cons;
+ u16 dealloc_ring[MAX_PENDING_REQS];
+ struct task_struct *dealloc_task;
+ wait_queue_head_t dealloc_wq;
+ atomic_t inflight_packets;
+
+ /* Use kthread for guest RX */
+ struct task_struct *task;
+ wait_queue_head_t wq;
+ /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
+ unsigned int rx_irq;
+ /* Only used when feature-split-event-channels = 1 */
+ char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
+ struct xen_netif_rx_back_ring rx;
+ struct sk_buff_head rx_queue;
+
+ unsigned int rx_queue_max;
+ unsigned int rx_queue_len;
+ unsigned long last_rx_time;
+ bool stalled;
+
+ struct gnttab_copy grant_copy_op[MAX_GRANT_COPY_OPS];
+
+ /* We create one meta structure per ring request we consume, so
+ * the maximum number is the same as the ring size.
+ */
+ struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE];
+
+ /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
+ unsigned long credit_bytes;
+ unsigned long credit_usec;
+ unsigned long remaining_credit;
+ struct timer_list credit_timeout;
+ u64 credit_window_start;
+
+ /* Statistics */
+ struct xenvif_stats stats;
+};
+
+/* Maximum number of Rx slots a to-guest packet may use, including the
+ * slot needed for GSO meta-data.
+ */
+#define XEN_NETBK_RX_SLOTS_MAX (MAX_SKB_FRAGS + 1)
+
+enum state_bit_shift {
+ /* This bit marks that the vif is connected */
+ VIF_STATUS_CONNECTED,
+};
+
+struct xenvif {
+ /* Unique identifier for this interface. */
+ domid_t domid;
+ unsigned int handle;
+
+ u8 fe_dev_addr[6];
+
+ /* Frontend feature information. */
+ int gso_mask;
+ int gso_prefix_mask;
+
+ u8 can_sg:1;
+ u8 ip_csum:1;
+ u8 ipv6_csum:1;
+
+ /* Is this interface disabled? True when backend discovers
+ * frontend is rogue.
+ */
+ bool disabled;
+ unsigned long status;
+ unsigned long drain_timeout;
+ unsigned long stall_timeout;
+
+ /* Queues */
+ struct xenvif_queue *queues;
+ unsigned int num_queues; /* active queues, resource allocated */
+ unsigned int stalled_queues;
+
+ struct xenbus_watch credit_watch;
+
+ spinlock_t lock;
+
+#ifdef CONFIG_DEBUG_FS
+ struct dentry *xenvif_dbg_root;
+#endif
+
+ /* Miscellaneous private stuff. */
+ struct net_device *dev;
+};
+
+struct xenvif_rx_cb {
+ unsigned long expires;
+ int meta_slots_used;
+};
+
+#define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb)
+
+static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
+{
+ return to_xenbus_device(vif->dev->dev.parent);
+}
+
+void xenvif_tx_credit_callback(unsigned long data);
+
+struct xenvif *xenvif_alloc(struct device *parent,
+ domid_t domid,
+ unsigned int handle);
+
+int xenvif_init_queue(struct xenvif_queue *queue);
+void xenvif_deinit_queue(struct xenvif_queue *queue);
+
+int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
+ unsigned long rx_ring_ref, unsigned int tx_evtchn,
+ unsigned int rx_evtchn);
+void xenvif_disconnect(struct xenvif *vif);
+void xenvif_free(struct xenvif *vif);
+
+int xenvif_xenbus_init(void);
+void xenvif_xenbus_fini(void);
+
+int xenvif_schedulable(struct xenvif *vif);
+
+int xenvif_queue_stopped(struct xenvif_queue *queue);
+void xenvif_wake_queue(struct xenvif_queue *queue);
+
+/* (Un)Map communication rings. */
+void xenvif_unmap_frontend_rings(struct xenvif_queue *queue);
+int xenvif_map_frontend_rings(struct xenvif_queue *queue,
+ grant_ref_t tx_ring_ref,
+ grant_ref_t rx_ring_ref);
+
+/* Check for SKBs from frontend and schedule backend processing */
+void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
+
+/* Prevent the device from generating any further traffic. */
+void xenvif_carrier_off(struct xenvif *vif);
+
+int xenvif_tx_action(struct xenvif_queue *queue, int budget);
+
+int xenvif_kthread_guest_rx(void *data);
+void xenvif_kick_thread(struct xenvif_queue *queue);
+
+int xenvif_dealloc_kthread(void *data);
+
+void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
+
+/* Determine whether the needed number of slots (req) are available,
+ * and set req_event if not.
+ */
+bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue, int needed);
+
+void xenvif_carrier_on(struct xenvif *vif);
+
+/* Callback from stack when TX packet can be released */
+void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
+
+/* Unmap a pending page and release it back to the guest */
+void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
+
+static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
+{
+ return MAX_PENDING_REQS -
+ queue->pending_prod + queue->pending_cons;
+}
+
+/* Callback from stack when TX packet can be released */
+void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
+
+irqreturn_t xenvif_interrupt(int irq, void *dev_id);
+
+extern bool separate_tx_rx_irq;
+
+extern unsigned int rx_drain_timeout_msecs;
+extern unsigned int rx_stall_timeout_msecs;
+extern unsigned int xenvif_max_queues;
+
+#ifdef CONFIG_DEBUG_FS
+extern struct dentry *xen_netback_dbg_root;
+#endif
+
+void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
+ struct sk_buff *skb);
+void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue);
+
+#endif /* __XEN_NETBACK__COMMON_H__ */
diff --git a/kernel/drivers/net/xen-netback/interface.c b/kernel/drivers/net/xen-netback/interface.c
new file mode 100644
index 000000000..1a83e190f
--- /dev/null
+++ b/kernel/drivers/net/xen-netback/interface.c
@@ -0,0 +1,689 @@
+/*
+ * Network-device interface management.
+ *
+ * Copyright (c) 2004-2005, Keir Fraser
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "common.h"
+
+#include <linux/kthread.h>
+#include <linux/ethtool.h>
+#include <linux/rtnetlink.h>
+#include <linux/if_vlan.h>
+#include <linux/vmalloc.h>
+
+#include <xen/events.h>
+#include <asm/xen/hypercall.h>
+#include <xen/balloon.h>
+
+#define XENVIF_QUEUE_LENGTH 32
+#define XENVIF_NAPI_WEIGHT 64
+
+/* Number of bytes allowed on the internal guest Rx queue. */
+#define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
+
+/* This function is used to set SKBTX_DEV_ZEROCOPY as well as
+ * increasing the inflight counter. We need to increase the inflight
+ * counter because core driver calls into xenvif_zerocopy_callback
+ * which calls xenvif_skb_zerocopy_complete.
+ */
+void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
+ struct sk_buff *skb)
+{
+ skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
+ atomic_inc(&queue->inflight_packets);
+}
+
+void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
+{
+ atomic_dec(&queue->inflight_packets);
+}
+
+int xenvif_schedulable(struct xenvif *vif)
+{
+ return netif_running(vif->dev) &&
+ test_bit(VIF_STATUS_CONNECTED, &vif->status) &&
+ !vif->disabled;
+}
+
+static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
+{
+ struct xenvif_queue *queue = dev_id;
+
+ if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))
+ napi_schedule(&queue->napi);
+
+ return IRQ_HANDLED;
+}
+
+static int xenvif_poll(struct napi_struct *napi, int budget)
+{
+ struct xenvif_queue *queue =
+ container_of(napi, struct xenvif_queue, napi);
+ int work_done;
+
+ /* This vif is rogue, we pretend we've there is nothing to do
+ * for this vif to deschedule it from NAPI. But this interface
+ * will be turned off in thread context later.
+ */
+ if (unlikely(queue->vif->disabled)) {
+ napi_complete(napi);
+ return 0;
+ }
+
+ work_done = xenvif_tx_action(queue, budget);
+
+ if (work_done < budget) {
+ napi_complete(napi);
+ xenvif_napi_schedule_or_enable_events(queue);
+ }
+
+ return work_done;
+}
+
+static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
+{
+ struct xenvif_queue *queue = dev_id;
+
+ xenvif_kick_thread(queue);
+
+ return IRQ_HANDLED;
+}
+
+irqreturn_t xenvif_interrupt(int irq, void *dev_id)
+{
+ xenvif_tx_interrupt(irq, dev_id);
+ xenvif_rx_interrupt(irq, dev_id);
+
+ return IRQ_HANDLED;
+}
+
+int xenvif_queue_stopped(struct xenvif_queue *queue)
+{
+ struct net_device *dev = queue->vif->dev;
+ unsigned int id = queue->id;
+ return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id));
+}
+
+void xenvif_wake_queue(struct xenvif_queue *queue)
+{
+ struct net_device *dev = queue->vif->dev;
+ unsigned int id = queue->id;
+ netif_tx_wake_queue(netdev_get_tx_queue(dev, id));
+}
+
+static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct xenvif *vif = netdev_priv(dev);
+ struct xenvif_queue *queue = NULL;
+ unsigned int num_queues = vif->num_queues;
+ u16 index;
+ struct xenvif_rx_cb *cb;
+
+ BUG_ON(skb->dev != dev);
+
+ /* Drop the packet if queues are not set up */
+ if (num_queues < 1)
+ goto drop;
+
+ /* Obtain the queue to be used to transmit this packet */
+ index = skb_get_queue_mapping(skb);
+ if (index >= num_queues) {
+ pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n.",
+ index, vif->dev->name);
+ index %= num_queues;
+ }
+ queue = &vif->queues[index];
+
+ /* Drop the packet if queue is not ready */
+ if (queue->task == NULL ||
+ queue->dealloc_task == NULL ||
+ !xenvif_schedulable(vif))
+ goto drop;
+
+ cb = XENVIF_RX_CB(skb);
+ cb->expires = jiffies + vif->drain_timeout;
+
+ xenvif_rx_queue_tail(queue, skb);
+ xenvif_kick_thread(queue);
+
+ return NETDEV_TX_OK;
+
+ drop:
+ vif->dev->stats.tx_dropped++;
+ dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+}
+
+static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
+{
+ struct xenvif *vif = netdev_priv(dev);
+ struct xenvif_queue *queue = NULL;
+ unsigned int num_queues = vif->num_queues;
+ unsigned long rx_bytes = 0;
+ unsigned long rx_packets = 0;
+ unsigned long tx_bytes = 0;
+ unsigned long tx_packets = 0;
+ unsigned int index;
+
+ if (vif->queues == NULL)
+ goto out;
+
+ /* Aggregate tx and rx stats from each queue */
+ for (index = 0; index < num_queues; ++index) {
+ queue = &vif->queues[index];
+ rx_bytes += queue->stats.rx_bytes;
+ rx_packets += queue->stats.rx_packets;
+ tx_bytes += queue->stats.tx_bytes;
+ tx_packets += queue->stats.tx_packets;
+ }
+
+out:
+ vif->dev->stats.rx_bytes = rx_bytes;
+ vif->dev->stats.rx_packets = rx_packets;
+ vif->dev->stats.tx_bytes = tx_bytes;
+ vif->dev->stats.tx_packets = tx_packets;
+
+ return &vif->dev->stats;
+}
+
+static void xenvif_up(struct xenvif *vif)
+{
+ struct xenvif_queue *queue = NULL;
+ unsigned int num_queues = vif->num_queues;
+ unsigned int queue_index;
+
+ for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+ queue = &vif->queues[queue_index];
+ napi_enable(&queue->napi);
+ enable_irq(queue->tx_irq);
+ if (queue->tx_irq != queue->rx_irq)
+ enable_irq(queue->rx_irq);
+ xenvif_napi_schedule_or_enable_events(queue);
+ }
+}
+
+static void xenvif_down(struct xenvif *vif)
+{
+ struct xenvif_queue *queue = NULL;
+ unsigned int num_queues = vif->num_queues;
+ unsigned int queue_index;
+
+ for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+ queue = &vif->queues[queue_index];
+ disable_irq(queue->tx_irq);
+ if (queue->tx_irq != queue->rx_irq)
+ disable_irq(queue->rx_irq);
+ napi_disable(&queue->napi);
+ del_timer_sync(&queue->credit_timeout);
+ }
+}
+
+static int xenvif_open(struct net_device *dev)
+{
+ struct xenvif *vif = netdev_priv(dev);
+ if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
+ xenvif_up(vif);
+ netif_tx_start_all_queues(dev);
+ return 0;
+}
+
+static int xenvif_close(struct net_device *dev)
+{
+ struct xenvif *vif = netdev_priv(dev);
+ if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
+ xenvif_down(vif);
+ netif_tx_stop_all_queues(dev);
+ return 0;
+}
+
+static int xenvif_change_mtu(struct net_device *dev, int mtu)
+{
+ struct xenvif *vif = netdev_priv(dev);
+ int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
+
+ if (mtu > max)
+ return -EINVAL;
+ dev->mtu = mtu;
+ return 0;
+}
+
+static netdev_features_t xenvif_fix_features(struct net_device *dev,
+ netdev_features_t features)
+{
+ struct xenvif *vif = netdev_priv(dev);
+
+ if (!vif->can_sg)
+ features &= ~NETIF_F_SG;
+ if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4))
+ features &= ~NETIF_F_TSO;
+ if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6))
+ features &= ~NETIF_F_TSO6;
+ if (!vif->ip_csum)
+ features &= ~NETIF_F_IP_CSUM;
+ if (!vif->ipv6_csum)
+ features &= ~NETIF_F_IPV6_CSUM;
+
+ return features;
+}
+
+static const struct xenvif_stat {
+ char name[ETH_GSTRING_LEN];
+ u16 offset;
+} xenvif_stats[] = {
+ {
+ "rx_gso_checksum_fixup",
+ offsetof(struct xenvif_stats, rx_gso_checksum_fixup)
+ },
+ /* If (sent != success + fail), there are probably packets never
+ * freed up properly!
+ */
+ {
+ "tx_zerocopy_sent",
+ offsetof(struct xenvif_stats, tx_zerocopy_sent),
+ },
+ {
+ "tx_zerocopy_success",
+ offsetof(struct xenvif_stats, tx_zerocopy_success),
+ },
+ {
+ "tx_zerocopy_fail",
+ offsetof(struct xenvif_stats, tx_zerocopy_fail)
+ },
+ /* Number of packets exceeding MAX_SKB_FRAG slots. You should use
+ * a guest with the same MAX_SKB_FRAG
+ */
+ {
+ "tx_frag_overflow",
+ offsetof(struct xenvif_stats, tx_frag_overflow)
+ },
+};
+
+static int xenvif_get_sset_count(struct net_device *dev, int string_set)
+{
+ switch (string_set) {
+ case ETH_SS_STATS:
+ return ARRAY_SIZE(xenvif_stats);
+ default:
+ return -EINVAL;
+ }
+}
+
+static void xenvif_get_ethtool_stats(struct net_device *dev,
+ struct ethtool_stats *stats, u64 * data)
+{
+ struct xenvif *vif = netdev_priv(dev);
+ unsigned int num_queues = vif->num_queues;
+ int i;
+ unsigned int queue_index;
+
+ for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
+ unsigned long accum = 0;
+ for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+ void *vif_stats = &vif->queues[queue_index].stats;
+ accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset);
+ }
+ data[i] = accum;
+ }
+}
+
+static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
+{
+ int i;
+
+ switch (stringset) {
+ case ETH_SS_STATS:
+ for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
+ memcpy(data + i * ETH_GSTRING_LEN,
+ xenvif_stats[i].name, ETH_GSTRING_LEN);
+ break;
+ }
+}
+
+static const struct ethtool_ops xenvif_ethtool_ops = {
+ .get_link = ethtool_op_get_link,
+
+ .get_sset_count = xenvif_get_sset_count,
+ .get_ethtool_stats = xenvif_get_ethtool_stats,
+ .get_strings = xenvif_get_strings,
+};
+
+static const struct net_device_ops xenvif_netdev_ops = {
+ .ndo_start_xmit = xenvif_start_xmit,
+ .ndo_get_stats = xenvif_get_stats,
+ .ndo_open = xenvif_open,
+ .ndo_stop = xenvif_close,
+ .ndo_change_mtu = xenvif_change_mtu,
+ .ndo_fix_features = xenvif_fix_features,
+ .ndo_set_mac_address = eth_mac_addr,
+ .ndo_validate_addr = eth_validate_addr,
+};
+
+struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
+ unsigned int handle)
+{
+ int err;
+ struct net_device *dev;
+ struct xenvif *vif;
+ char name[IFNAMSIZ] = {};
+
+ snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
+ /* Allocate a netdev with the max. supported number of queues.
+ * When the guest selects the desired number, it will be updated
+ * via netif_set_real_num_*_queues().
+ */
+ dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN,
+ ether_setup, xenvif_max_queues);
+ if (dev == NULL) {
+ pr_warn("Could not allocate netdev for %s\n", name);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ SET_NETDEV_DEV(dev, parent);
+
+ vif = netdev_priv(dev);
+
+ vif->domid = domid;
+ vif->handle = handle;
+ vif->can_sg = 1;
+ vif->ip_csum = 1;
+ vif->dev = dev;
+ vif->disabled = false;
+ vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs);
+ vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs);
+
+ /* Start out with no queues. */
+ vif->queues = NULL;
+ vif->num_queues = 0;
+
+ spin_lock_init(&vif->lock);
+
+ dev->netdev_ops = &xenvif_netdev_ops;
+ dev->hw_features = NETIF_F_SG |
+ NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
+ NETIF_F_TSO | NETIF_F_TSO6;
+ dev->features = dev->hw_features | NETIF_F_RXCSUM;
+ dev->ethtool_ops = &xenvif_ethtool_ops;
+
+ dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
+
+ /*
+ * Initialise a dummy MAC address. We choose the numerically
+ * largest non-broadcast address to prevent the address getting
+ * stolen by an Ethernet bridge for STP purposes.
+ * (FE:FF:FF:FF:FF:FF)
+ */
+ eth_broadcast_addr(dev->dev_addr);
+ dev->dev_addr[0] &= ~0x01;
+
+ netif_carrier_off(dev);
+
+ err = register_netdev(dev);
+ if (err) {
+ netdev_warn(dev, "Could not register device: err=%d\n", err);
+ free_netdev(dev);
+ return ERR_PTR(err);
+ }
+
+ netdev_dbg(dev, "Successfully created xenvif\n");
+
+ __module_get(THIS_MODULE);
+
+ return vif;
+}
+
+int xenvif_init_queue(struct xenvif_queue *queue)
+{
+ int err, i;
+
+ queue->credit_bytes = queue->remaining_credit = ~0UL;
+ queue->credit_usec = 0UL;
+ init_timer(&queue->credit_timeout);
+ queue->credit_timeout.function = xenvif_tx_credit_callback;
+ queue->credit_window_start = get_jiffies_64();
+
+ queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;
+
+ skb_queue_head_init(&queue->rx_queue);
+ skb_queue_head_init(&queue->tx_queue);
+
+ queue->pending_cons = 0;
+ queue->pending_prod = MAX_PENDING_REQS;
+ for (i = 0; i < MAX_PENDING_REQS; ++i)
+ queue->pending_ring[i] = i;
+
+ spin_lock_init(&queue->callback_lock);
+ spin_lock_init(&queue->response_lock);
+
+ /* If ballooning is disabled, this will consume real memory, so you
+ * better enable it. The long term solution would be to use just a
+ * bunch of valid page descriptors, without dependency on ballooning
+ */
+ err = gnttab_alloc_pages(MAX_PENDING_REQS,
+ queue->mmap_pages);
+ if (err) {
+ netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n");
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < MAX_PENDING_REQS; i++) {
+ queue->pending_tx_info[i].callback_struct = (struct ubuf_info)
+ { .callback = xenvif_zerocopy_callback,
+ .ctx = NULL,
+ .desc = i };
+ queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
+ }
+
+ return 0;
+}
+
+void xenvif_carrier_on(struct xenvif *vif)
+{
+ rtnl_lock();
+ if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
+ dev_set_mtu(vif->dev, ETH_DATA_LEN);
+ netdev_update_features(vif->dev);
+ set_bit(VIF_STATUS_CONNECTED, &vif->status);
+ if (netif_running(vif->dev))
+ xenvif_up(vif);
+ rtnl_unlock();
+}
+
+int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
+ unsigned long rx_ring_ref, unsigned int tx_evtchn,
+ unsigned int rx_evtchn)
+{
+ struct task_struct *task;
+ int err = -ENOMEM;
+
+ BUG_ON(queue->tx_irq);
+ BUG_ON(queue->task);
+ BUG_ON(queue->dealloc_task);
+
+ err = xenvif_map_frontend_rings(queue, tx_ring_ref, rx_ring_ref);
+ if (err < 0)
+ goto err;
+
+ init_waitqueue_head(&queue->wq);
+ init_waitqueue_head(&queue->dealloc_wq);
+ atomic_set(&queue->inflight_packets, 0);
+
+ netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,
+ XENVIF_NAPI_WEIGHT);
+
+ if (tx_evtchn == rx_evtchn) {
+ /* feature-split-event-channels == 0 */
+ err = bind_interdomain_evtchn_to_irqhandler(
+ queue->vif->domid, tx_evtchn, xenvif_interrupt, 0,
+ queue->name, queue);
+ if (err < 0)
+ goto err_unmap;
+ queue->tx_irq = queue->rx_irq = err;
+ disable_irq(queue->tx_irq);
+ } else {
+ /* feature-split-event-channels == 1 */
+ snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
+ "%s-tx", queue->name);
+ err = bind_interdomain_evtchn_to_irqhandler(
+ queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
+ queue->tx_irq_name, queue);
+ if (err < 0)
+ goto err_unmap;
+ queue->tx_irq = err;
+ disable_irq(queue->tx_irq);
+
+ snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
+ "%s-rx", queue->name);
+ err = bind_interdomain_evtchn_to_irqhandler(
+ queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
+ queue->rx_irq_name, queue);
+ if (err < 0)
+ goto err_tx_unbind;
+ queue->rx_irq = err;
+ disable_irq(queue->rx_irq);
+ }
+
+ queue->stalled = true;
+
+ task = kthread_create(xenvif_kthread_guest_rx,
+ (void *)queue, "%s-guest-rx", queue->name);
+ if (IS_ERR(task)) {
+ pr_warn("Could not allocate kthread for %s\n", queue->name);
+ err = PTR_ERR(task);
+ goto err_rx_unbind;
+ }
+ queue->task = task;
+ get_task_struct(task);
+
+ task = kthread_create(xenvif_dealloc_kthread,
+ (void *)queue, "%s-dealloc", queue->name);
+ if (IS_ERR(task)) {
+ pr_warn("Could not allocate kthread for %s\n", queue->name);
+ err = PTR_ERR(task);
+ goto err_rx_unbind;
+ }
+ queue->dealloc_task = task;
+
+ wake_up_process(queue->task);
+ wake_up_process(queue->dealloc_task);
+
+ return 0;
+
+err_rx_unbind:
+ unbind_from_irqhandler(queue->rx_irq, queue);
+ queue->rx_irq = 0;
+err_tx_unbind:
+ unbind_from_irqhandler(queue->tx_irq, queue);
+ queue->tx_irq = 0;
+err_unmap:
+ xenvif_unmap_frontend_rings(queue);
+err:
+ module_put(THIS_MODULE);
+ return err;
+}
+
+void xenvif_carrier_off(struct xenvif *vif)
+{
+ struct net_device *dev = vif->dev;
+
+ rtnl_lock();
+ if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
+ netif_carrier_off(dev); /* discard queued packets */
+ if (netif_running(dev))
+ xenvif_down(vif);
+ }
+ rtnl_unlock();
+}
+
+void xenvif_disconnect(struct xenvif *vif)
+{
+ struct xenvif_queue *queue = NULL;
+ unsigned int num_queues = vif->num_queues;
+ unsigned int queue_index;
+
+ xenvif_carrier_off(vif);
+
+ for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+ queue = &vif->queues[queue_index];
+
+ netif_napi_del(&queue->napi);
+
+ if (queue->task) {
+ kthread_stop(queue->task);
+ put_task_struct(queue->task);
+ queue->task = NULL;
+ }
+
+ if (queue->dealloc_task) {
+ kthread_stop(queue->dealloc_task);
+ queue->dealloc_task = NULL;
+ }
+
+ if (queue->tx_irq) {
+ if (queue->tx_irq == queue->rx_irq)
+ unbind_from_irqhandler(queue->tx_irq, queue);
+ else {
+ unbind_from_irqhandler(queue->tx_irq, queue);
+ unbind_from_irqhandler(queue->rx_irq, queue);
+ }
+ queue->tx_irq = 0;
+ }
+
+ xenvif_unmap_frontend_rings(queue);
+ }
+}
+
+/* Reverse the relevant parts of xenvif_init_queue().
+ * Used for queue teardown from xenvif_free(), and on the
+ * error handling paths in xenbus.c:connect().
+ */
+void xenvif_deinit_queue(struct xenvif_queue *queue)
+{
+ gnttab_free_pages(MAX_PENDING_REQS, queue->mmap_pages);
+}
+
+void xenvif_free(struct xenvif *vif)
+{
+ struct xenvif_queue *queue = NULL;
+ unsigned int num_queues = vif->num_queues;
+ unsigned int queue_index;
+
+ unregister_netdev(vif->dev);
+
+ for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+ queue = &vif->queues[queue_index];
+ xenvif_deinit_queue(queue);
+ }
+
+ vfree(vif->queues);
+ vif->queues = NULL;
+ vif->num_queues = 0;
+
+ free_netdev(vif->dev);
+
+ module_put(THIS_MODULE);
+}
diff --git a/kernel/drivers/net/xen-netback/netback.c b/kernel/drivers/net/xen-netback/netback.c
new file mode 100644
index 000000000..0d2594395
--- /dev/null
+++ b/kernel/drivers/net/xen-netback/netback.c
@@ -0,0 +1,2049 @@
+/*
+ * Back-end of the driver for virtual network devices. This portion of the
+ * driver exports a 'unified' network-device interface that can be accessed
+ * by any operating system that implements a compatible front end. A
+ * reference front-end implementation can be found in:
+ * drivers/net/xen-netfront.c
+ *
+ * Copyright (c) 2002-2005, K A Fraser
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "common.h"
+
+#include <linux/kthread.h>
+#include <linux/if_vlan.h>
+#include <linux/udp.h>
+#include <linux/highmem.h>
+
+#include <net/tcp.h>
+
+#include <xen/xen.h>
+#include <xen/events.h>
+#include <xen/interface/memory.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/xen/page.h>
+
+/* Provide an option to disable split event channels at load time as
+ * event channels are limited resource. Split event channels are
+ * enabled by default.
+ */
+bool separate_tx_rx_irq = 1;
+module_param(separate_tx_rx_irq, bool, 0644);
+
+/* The time that packets can stay on the guest Rx internal queue
+ * before they are dropped.
+ */
+unsigned int rx_drain_timeout_msecs = 10000;
+module_param(rx_drain_timeout_msecs, uint, 0444);
+
+/* The length of time before the frontend is considered unresponsive
+ * because it isn't providing Rx slots.
+ */
+unsigned int rx_stall_timeout_msecs = 60000;
+module_param(rx_stall_timeout_msecs, uint, 0444);
+
+unsigned int xenvif_max_queues;
+module_param_named(max_queues, xenvif_max_queues, uint, 0644);
+MODULE_PARM_DESC(max_queues,
+ "Maximum number of queues per virtual interface");
+
+/*
+ * This is the maximum slots a skb can have. If a guest sends a skb
+ * which exceeds this limit it is considered malicious.
+ */
+#define FATAL_SKB_SLOTS_DEFAULT 20
+static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT;
+module_param(fatal_skb_slots, uint, 0444);
+
+/* The amount to copy out of the first guest Tx slot into the skb's
+ * linear area. If the first slot has more data, it will be mapped
+ * and put into the first frag.
+ *
+ * This is sized to avoid pulling headers from the frags for most
+ * TCP/IP packets.
+ */
+#define XEN_NETBACK_TX_COPY_LEN 128
+
+
+static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
+ u8 status);
+
+static void make_tx_response(struct xenvif_queue *queue,
+ struct xen_netif_tx_request *txp,
+ s8 st);
+static void push_tx_responses(struct xenvif_queue *queue);
+
+static inline int tx_work_todo(struct xenvif_queue *queue);
+
+static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue,
+ u16 id,
+ s8 st,
+ u16 offset,
+ u16 size,
+ u16 flags);
+
+static inline unsigned long idx_to_pfn(struct xenvif_queue *queue,
+ u16 idx)
+{
+ return page_to_pfn(queue->mmap_pages[idx]);
+}
+
+static inline unsigned long idx_to_kaddr(struct xenvif_queue *queue,
+ u16 idx)
+{
+ return (unsigned long)pfn_to_kaddr(idx_to_pfn(queue, idx));
+}
+
+#define callback_param(vif, pending_idx) \
+ (vif->pending_tx_info[pending_idx].callback_struct)
+
+/* Find the containing VIF's structure from a pointer in pending_tx_info array
+ */
+static inline struct xenvif_queue *ubuf_to_queue(const struct ubuf_info *ubuf)
+{
+ u16 pending_idx = ubuf->desc;
+ struct pending_tx_info *temp =
+ container_of(ubuf, struct pending_tx_info, callback_struct);
+ return container_of(temp - pending_idx,
+ struct xenvif_queue,
+ pending_tx_info[0]);
+}
+
+static u16 frag_get_pending_idx(skb_frag_t *frag)
+{
+ return (u16)frag->page_offset;
+}
+
+static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
+{
+ frag->page_offset = pending_idx;
+}
+
+static inline pending_ring_idx_t pending_index(unsigned i)
+{
+ return i & (MAX_PENDING_REQS-1);
+}
+
+bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue, int needed)
+{
+ RING_IDX prod, cons;
+
+ do {
+ prod = queue->rx.sring->req_prod;
+ cons = queue->rx.req_cons;
+
+ if (prod - cons >= needed)
+ return true;
+
+ queue->rx.sring->req_event = prod + 1;
+
+ /* Make sure event is visible before we check prod
+ * again.
+ */
+ mb();
+ } while (queue->rx.sring->req_prod != prod);
+
+ return false;
+}
+
+void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&queue->rx_queue.lock, flags);
+
+ __skb_queue_tail(&queue->rx_queue, skb);
+
+ queue->rx_queue_len += skb->len;
+ if (queue->rx_queue_len > queue->rx_queue_max)
+ netif_tx_stop_queue(netdev_get_tx_queue(queue->vif->dev, queue->id));
+
+ spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
+}
+
+static struct sk_buff *xenvif_rx_dequeue(struct xenvif_queue *queue)
+{
+ struct sk_buff *skb;
+
+ spin_lock_irq(&queue->rx_queue.lock);
+
+ skb = __skb_dequeue(&queue->rx_queue);
+ if (skb)
+ queue->rx_queue_len -= skb->len;
+
+ spin_unlock_irq(&queue->rx_queue.lock);
+
+ return skb;
+}
+
+static void xenvif_rx_queue_maybe_wake(struct xenvif_queue *queue)
+{
+ spin_lock_irq(&queue->rx_queue.lock);
+
+ if (queue->rx_queue_len < queue->rx_queue_max)
+ netif_tx_wake_queue(netdev_get_tx_queue(queue->vif->dev, queue->id));
+
+ spin_unlock_irq(&queue->rx_queue.lock);
+}
+
+
+static void xenvif_rx_queue_purge(struct xenvif_queue *queue)
+{
+ struct sk_buff *skb;
+ while ((skb = xenvif_rx_dequeue(queue)) != NULL)
+ kfree_skb(skb);
+}
+
+static void xenvif_rx_queue_drop_expired(struct xenvif_queue *queue)
+{
+ struct sk_buff *skb;
+
+ for(;;) {
+ skb = skb_peek(&queue->rx_queue);
+ if (!skb)
+ break;
+ if (time_before(jiffies, XENVIF_RX_CB(skb)->expires))
+ break;
+ xenvif_rx_dequeue(queue);
+ kfree_skb(skb);
+ }
+}
+
+struct netrx_pending_operations {
+ unsigned copy_prod, copy_cons;
+ unsigned meta_prod, meta_cons;
+ struct gnttab_copy *copy;
+ struct xenvif_rx_meta *meta;
+ int copy_off;
+ grant_ref_t copy_gref;
+};
+
+static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif_queue *queue,
+ struct netrx_pending_operations *npo)
+{
+ struct xenvif_rx_meta *meta;
+ struct xen_netif_rx_request *req;
+
+ req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+
+ meta = npo->meta + npo->meta_prod++;
+ meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
+ meta->gso_size = 0;
+ meta->size = 0;
+ meta->id = req->id;
+
+ npo->copy_off = 0;
+ npo->copy_gref = req->gref;
+
+ return meta;
+}
+
+/*
+ * Set up the grant operations for this fragment. If it's a flipping
+ * interface, we also set up the unmap request from here.
+ */
+static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb,
+ struct netrx_pending_operations *npo,
+ struct page *page, unsigned long size,
+ unsigned long offset, int *head)
+{
+ struct gnttab_copy *copy_gop;
+ struct xenvif_rx_meta *meta;
+ unsigned long bytes;
+ int gso_type = XEN_NETIF_GSO_TYPE_NONE;
+
+ /* Data must not cross a page boundary. */
+ BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
+
+ meta = npo->meta + npo->meta_prod - 1;
+
+ /* Skip unused frames from start of page */
+ page += offset >> PAGE_SHIFT;
+ offset &= ~PAGE_MASK;
+
+ while (size > 0) {
+ struct xen_page_foreign *foreign;
+
+ BUG_ON(offset >= PAGE_SIZE);
+ BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
+
+ if (npo->copy_off == MAX_BUFFER_OFFSET)
+ meta = get_next_rx_buffer(queue, npo);
+
+ bytes = PAGE_SIZE - offset;
+ if (bytes > size)
+ bytes = size;
+
+ if (npo->copy_off + bytes > MAX_BUFFER_OFFSET)
+ bytes = MAX_BUFFER_OFFSET - npo->copy_off;
+
+ copy_gop = npo->copy + npo->copy_prod++;
+ copy_gop->flags = GNTCOPY_dest_gref;
+ copy_gop->len = bytes;
+
+ foreign = xen_page_foreign(page);
+ if (foreign) {
+ copy_gop->source.domid = foreign->domid;
+ copy_gop->source.u.ref = foreign->gref;
+ copy_gop->flags |= GNTCOPY_source_gref;
+ } else {
+ copy_gop->source.domid = DOMID_SELF;
+ copy_gop->source.u.gmfn =
+ virt_to_mfn(page_address(page));
+ }
+ copy_gop->source.offset = offset;
+
+ copy_gop->dest.domid = queue->vif->domid;
+ copy_gop->dest.offset = npo->copy_off;
+ copy_gop->dest.u.ref = npo->copy_gref;
+
+ npo->copy_off += bytes;
+ meta->size += bytes;
+
+ offset += bytes;
+ size -= bytes;
+
+ /* Next frame */
+ if (offset == PAGE_SIZE && size) {
+ BUG_ON(!PageCompound(page));
+ page++;
+ offset = 0;
+ }
+
+ /* Leave a gap for the GSO descriptor. */
+ if (skb_is_gso(skb)) {
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+ gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
+ else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+ gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
+ }
+
+ if (*head && ((1 << gso_type) & queue->vif->gso_mask))
+ queue->rx.req_cons++;
+
+ *head = 0; /* There must be something in this buffer now. */
+
+ }
+}
+
+/*
+ * Prepare an SKB to be transmitted to the frontend.
+ *
+ * This function is responsible for allocating grant operations, meta
+ * structures, etc.
+ *
+ * It returns the number of meta structures consumed. The number of
+ * ring slots used is always equal to the number of meta slots used
+ * plus the number of GSO descriptors used. Currently, we use either
+ * zero GSO descriptors (for non-GSO packets) or one descriptor (for
+ * frontend-side LRO).
+ */
+static int xenvif_gop_skb(struct sk_buff *skb,
+ struct netrx_pending_operations *npo,
+ struct xenvif_queue *queue)
+{
+ struct xenvif *vif = netdev_priv(skb->dev);
+ int nr_frags = skb_shinfo(skb)->nr_frags;
+ int i;
+ struct xen_netif_rx_request *req;
+ struct xenvif_rx_meta *meta;
+ unsigned char *data;
+ int head = 1;
+ int old_meta_prod;
+ int gso_type;
+
+ old_meta_prod = npo->meta_prod;
+
+ gso_type = XEN_NETIF_GSO_TYPE_NONE;
+ if (skb_is_gso(skb)) {
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+ gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
+ else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+ gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
+ }
+
+ /* Set up a GSO prefix descriptor, if necessary */
+ if ((1 << gso_type) & vif->gso_prefix_mask) {
+ req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+ meta = npo->meta + npo->meta_prod++;
+ meta->gso_type = gso_type;
+ meta->gso_size = skb_shinfo(skb)->gso_size;
+ meta->size = 0;
+ meta->id = req->id;
+ }
+
+ req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+ meta = npo->meta + npo->meta_prod++;
+
+ if ((1 << gso_type) & vif->gso_mask) {
+ meta->gso_type = gso_type;
+ meta->gso_size = skb_shinfo(skb)->gso_size;
+ } else {
+ meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
+ meta->gso_size = 0;
+ }
+
+ meta->size = 0;
+ meta->id = req->id;
+ npo->copy_off = 0;
+ npo->copy_gref = req->gref;
+
+ data = skb->data;
+ while (data < skb_tail_pointer(skb)) {
+ unsigned int offset = offset_in_page(data);
+ unsigned int len = PAGE_SIZE - offset;
+
+ if (data + len > skb_tail_pointer(skb))
+ len = skb_tail_pointer(skb) - data;
+
+ xenvif_gop_frag_copy(queue, skb, npo,
+ virt_to_page(data), len, offset, &head);
+ data += len;
+ }
+
+ for (i = 0; i < nr_frags; i++) {
+ xenvif_gop_frag_copy(queue, skb, npo,
+ skb_frag_page(&skb_shinfo(skb)->frags[i]),
+ skb_frag_size(&skb_shinfo(skb)->frags[i]),
+ skb_shinfo(skb)->frags[i].page_offset,
+ &head);
+ }
+
+ return npo->meta_prod - old_meta_prod;
+}
+
+/*
+ * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was
+ * used to set up the operations on the top of
+ * netrx_pending_operations, which have since been done. Check that
+ * they didn't give any errors and advance over them.
+ */
+static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots,
+ struct netrx_pending_operations *npo)
+{
+ struct gnttab_copy *copy_op;
+ int status = XEN_NETIF_RSP_OKAY;
+ int i;
+
+ for (i = 0; i < nr_meta_slots; i++) {
+ copy_op = npo->copy + npo->copy_cons++;
+ if (copy_op->status != GNTST_okay) {
+ netdev_dbg(vif->dev,
+ "Bad status %d from copy to DOM%d.\n",
+ copy_op->status, vif->domid);
+ status = XEN_NETIF_RSP_ERROR;
+ }
+ }
+
+ return status;
+}
+
+static void xenvif_add_frag_responses(struct xenvif_queue *queue, int status,
+ struct xenvif_rx_meta *meta,
+ int nr_meta_slots)
+{
+ int i;
+ unsigned long offset;
+
+ /* No fragments used */
+ if (nr_meta_slots <= 1)
+ return;
+
+ nr_meta_slots--;
+
+ for (i = 0; i < nr_meta_slots; i++) {
+ int flags;
+ if (i == nr_meta_slots - 1)
+ flags = 0;
+ else
+ flags = XEN_NETRXF_more_data;
+
+ offset = 0;
+ make_rx_response(queue, meta[i].id, status, offset,
+ meta[i].size, flags);
+ }
+}
+
+void xenvif_kick_thread(struct xenvif_queue *queue)
+{
+ wake_up(&queue->wq);
+}
+
+static void xenvif_rx_action(struct xenvif_queue *queue)
+{
+ s8 status;
+ u16 flags;
+ struct xen_netif_rx_response *resp;
+ struct sk_buff_head rxq;
+ struct sk_buff *skb;
+ LIST_HEAD(notify);
+ int ret;
+ unsigned long offset;
+ bool need_to_notify = false;
+
+ struct netrx_pending_operations npo = {
+ .copy = queue->grant_copy_op,
+ .meta = queue->meta,
+ };
+
+ skb_queue_head_init(&rxq);
+
+ while (xenvif_rx_ring_slots_available(queue, XEN_NETBK_RX_SLOTS_MAX)
+ && (skb = xenvif_rx_dequeue(queue)) != NULL) {
+ RING_IDX old_req_cons;
+ RING_IDX ring_slots_used;
+
+ queue->last_rx_time = jiffies;
+
+ old_req_cons = queue->rx.req_cons;
+ XENVIF_RX_CB(skb)->meta_slots_used = xenvif_gop_skb(skb, &npo, queue);
+ ring_slots_used = queue->rx.req_cons - old_req_cons;
+
+ __skb_queue_tail(&rxq, skb);
+ }
+
+ BUG_ON(npo.meta_prod > ARRAY_SIZE(queue->meta));
+
+ if (!npo.copy_prod)
+ goto done;
+
+ BUG_ON(npo.copy_prod > MAX_GRANT_COPY_OPS);
+ gnttab_batch_copy(queue->grant_copy_op, npo.copy_prod);
+
+ while ((skb = __skb_dequeue(&rxq)) != NULL) {
+
+ if ((1 << queue->meta[npo.meta_cons].gso_type) &
+ queue->vif->gso_prefix_mask) {
+ resp = RING_GET_RESPONSE(&queue->rx,
+ queue->rx.rsp_prod_pvt++);
+
+ resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data;
+
+ resp->offset = queue->meta[npo.meta_cons].gso_size;
+ resp->id = queue->meta[npo.meta_cons].id;
+ resp->status = XENVIF_RX_CB(skb)->meta_slots_used;
+
+ npo.meta_cons++;
+ XENVIF_RX_CB(skb)->meta_slots_used--;
+ }
+
+
+ queue->stats.tx_bytes += skb->len;
+ queue->stats.tx_packets++;
+
+ status = xenvif_check_gop(queue->vif,
+ XENVIF_RX_CB(skb)->meta_slots_used,
+ &npo);
+
+ if (XENVIF_RX_CB(skb)->meta_slots_used == 1)
+ flags = 0;
+ else
+ flags = XEN_NETRXF_more_data;
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
+ flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated;
+ else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
+ /* remote but checksummed. */
+ flags |= XEN_NETRXF_data_validated;
+
+ offset = 0;
+ resp = make_rx_response(queue, queue->meta[npo.meta_cons].id,
+ status, offset,
+ queue->meta[npo.meta_cons].size,
+ flags);
+
+ if ((1 << queue->meta[npo.meta_cons].gso_type) &
+ queue->vif->gso_mask) {
+ struct xen_netif_extra_info *gso =
+ (struct xen_netif_extra_info *)
+ RING_GET_RESPONSE(&queue->rx,
+ queue->rx.rsp_prod_pvt++);
+
+ resp->flags |= XEN_NETRXF_extra_info;
+
+ gso->u.gso.type = queue->meta[npo.meta_cons].gso_type;
+ gso->u.gso.size = queue->meta[npo.meta_cons].gso_size;
+ gso->u.gso.pad = 0;
+ gso->u.gso.features = 0;
+
+ gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
+ gso->flags = 0;
+ }
+
+ xenvif_add_frag_responses(queue, status,
+ queue->meta + npo.meta_cons + 1,
+ XENVIF_RX_CB(skb)->meta_slots_used);
+
+ RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->rx, ret);
+
+ need_to_notify |= !!ret;
+
+ npo.meta_cons += XENVIF_RX_CB(skb)->meta_slots_used;
+ dev_kfree_skb(skb);
+ }
+
+done:
+ if (need_to_notify)
+ notify_remote_via_irq(queue->rx_irq);
+}
+
+void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue)
+{
+ int more_to_do;
+
+ RING_FINAL_CHECK_FOR_REQUESTS(&queue->tx, more_to_do);
+
+ if (more_to_do)
+ napi_schedule(&queue->napi);
+}
+
+static void tx_add_credit(struct xenvif_queue *queue)
+{
+ unsigned long max_burst, max_credit;
+
+ /*
+ * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
+ * Otherwise the interface can seize up due to insufficient credit.
+ */
+ max_burst = RING_GET_REQUEST(&queue->tx, queue->tx.req_cons)->size;
+ max_burst = min(max_burst, 131072UL);
+ max_burst = max(max_burst, queue->credit_bytes);
+
+ /* Take care that adding a new chunk of credit doesn't wrap to zero. */
+ max_credit = queue->remaining_credit + queue->credit_bytes;
+ if (max_credit < queue->remaining_credit)
+ max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
+
+ queue->remaining_credit = min(max_credit, max_burst);
+}
+
+void xenvif_tx_credit_callback(unsigned long data)
+{
+ struct xenvif_queue *queue = (struct xenvif_queue *)data;
+ tx_add_credit(queue);
+ xenvif_napi_schedule_or_enable_events(queue);
+}
+
+static void xenvif_tx_err(struct xenvif_queue *queue,
+ struct xen_netif_tx_request *txp, RING_IDX end)
+{
+ RING_IDX cons = queue->tx.req_cons;
+ unsigned long flags;
+
+ do {
+ spin_lock_irqsave(&queue->response_lock, flags);
+ make_tx_response(queue, txp, XEN_NETIF_RSP_ERROR);
+ push_tx_responses(queue);
+ spin_unlock_irqrestore(&queue->response_lock, flags);
+ if (cons == end)
+ break;
+ txp = RING_GET_REQUEST(&queue->tx, cons++);
+ } while (1);
+ queue->tx.req_cons = cons;
+}
+
+static void xenvif_fatal_tx_err(struct xenvif *vif)
+{
+ netdev_err(vif->dev, "fatal error; disabling device\n");
+ vif->disabled = true;
+ /* Disable the vif from queue 0's kthread */
+ if (vif->queues)
+ xenvif_kick_thread(&vif->queues[0]);
+}
+
+static int xenvif_count_requests(struct xenvif_queue *queue,
+ struct xen_netif_tx_request *first,
+ struct xen_netif_tx_request *txp,
+ int work_to_do)
+{
+ RING_IDX cons = queue->tx.req_cons;
+ int slots = 0;
+ int drop_err = 0;
+ int more_data;
+
+ if (!(first->flags & XEN_NETTXF_more_data))
+ return 0;
+
+ do {
+ struct xen_netif_tx_request dropped_tx = { 0 };
+
+ if (slots >= work_to_do) {
+ netdev_err(queue->vif->dev,
+ "Asked for %d slots but exceeds this limit\n",
+ work_to_do);
+ xenvif_fatal_tx_err(queue->vif);
+ return -ENODATA;
+ }
+
+ /* This guest is really using too many slots and
+ * considered malicious.
+ */
+ if (unlikely(slots >= fatal_skb_slots)) {
+ netdev_err(queue->vif->dev,
+ "Malicious frontend using %d slots, threshold %u\n",
+ slots, fatal_skb_slots);
+ xenvif_fatal_tx_err(queue->vif);
+ return -E2BIG;
+ }
+
+ /* Xen network protocol had implicit dependency on
+ * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
+ * the historical MAX_SKB_FRAGS value 18 to honor the
+ * same behavior as before. Any packet using more than
+ * 18 slots but less than fatal_skb_slots slots is
+ * dropped
+ */
+ if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
+ if (net_ratelimit())
+ netdev_dbg(queue->vif->dev,
+ "Too many slots (%d) exceeding limit (%d), dropping packet\n",
+ slots, XEN_NETBK_LEGACY_SLOTS_MAX);
+ drop_err = -E2BIG;
+ }
+
+ if (drop_err)
+ txp = &dropped_tx;
+
+ memcpy(txp, RING_GET_REQUEST(&queue->tx, cons + slots),
+ sizeof(*txp));
+
+ /* If the guest submitted a frame >= 64 KiB then
+ * first->size overflowed and following slots will
+ * appear to be larger than the frame.
+ *
+ * This cannot be fatal error as there are buggy
+ * frontends that do this.
+ *
+ * Consume all slots and drop the packet.
+ */
+ if (!drop_err && txp->size > first->size) {
+ if (net_ratelimit())
+ netdev_dbg(queue->vif->dev,
+ "Invalid tx request, slot size %u > remaining size %u\n",
+ txp->size, first->size);
+ drop_err = -EIO;
+ }
+
+ first->size -= txp->size;
+ slots++;
+
+ if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) {
+ netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n",
+ txp->offset, txp->size);
+ xenvif_fatal_tx_err(queue->vif);
+ return -EINVAL;
+ }
+
+ more_data = txp->flags & XEN_NETTXF_more_data;
+
+ if (!drop_err)
+ txp++;
+
+ } while (more_data);
+
+ if (drop_err) {
+ xenvif_tx_err(queue, first, cons + slots);
+ return drop_err;
+ }
+
+ return slots;
+}
+
+
+struct xenvif_tx_cb {
+ u16 pending_idx;
+};
+
+#define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
+
+static inline void xenvif_tx_create_map_op(struct xenvif_queue *queue,
+ u16 pending_idx,
+ struct xen_netif_tx_request *txp,
+ struct gnttab_map_grant_ref *mop)
+{
+ queue->pages_to_map[mop-queue->tx_map_ops] = queue->mmap_pages[pending_idx];
+ gnttab_set_map_op(mop, idx_to_kaddr(queue, pending_idx),
+ GNTMAP_host_map | GNTMAP_readonly,
+ txp->gref, queue->vif->domid);
+
+ memcpy(&queue->pending_tx_info[pending_idx].req, txp,
+ sizeof(*txp));
+}
+
+static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
+{
+ struct sk_buff *skb =
+ alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN,
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (unlikely(skb == NULL))
+ return NULL;
+
+ /* Packets passed to netif_rx() must have some headroom. */
+ skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
+
+ /* Initialize it here to avoid later surprises */
+ skb_shinfo(skb)->destructor_arg = NULL;
+
+ return skb;
+}
+
+static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif_queue *queue,
+ struct sk_buff *skb,
+ struct xen_netif_tx_request *txp,
+ struct gnttab_map_grant_ref *gop)
+{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ skb_frag_t *frags = shinfo->frags;
+ u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
+ int start;
+ pending_ring_idx_t index;
+ unsigned int nr_slots, frag_overflow = 0;
+
+ /* At this point shinfo->nr_frags is in fact the number of
+ * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
+ */
+ if (shinfo->nr_frags > MAX_SKB_FRAGS) {
+ frag_overflow = shinfo->nr_frags - MAX_SKB_FRAGS;
+ BUG_ON(frag_overflow > MAX_SKB_FRAGS);
+ shinfo->nr_frags = MAX_SKB_FRAGS;
+ }
+ nr_slots = shinfo->nr_frags;
+
+ /* Skip first skb fragment if it is on same page as header fragment. */
+ start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
+
+ for (shinfo->nr_frags = start; shinfo->nr_frags < nr_slots;
+ shinfo->nr_frags++, txp++, gop++) {
+ index = pending_index(queue->pending_cons++);
+ pending_idx = queue->pending_ring[index];
+ xenvif_tx_create_map_op(queue, pending_idx, txp, gop);
+ frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
+ }
+
+ if (frag_overflow) {
+ struct sk_buff *nskb = xenvif_alloc_skb(0);
+ if (unlikely(nskb == NULL)) {
+ if (net_ratelimit())
+ netdev_err(queue->vif->dev,
+ "Can't allocate the frag_list skb.\n");
+ return NULL;
+ }
+
+ shinfo = skb_shinfo(nskb);
+ frags = shinfo->frags;
+
+ for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow;
+ shinfo->nr_frags++, txp++, gop++) {
+ index = pending_index(queue->pending_cons++);
+ pending_idx = queue->pending_ring[index];
+ xenvif_tx_create_map_op(queue, pending_idx, txp, gop);
+ frag_set_pending_idx(&frags[shinfo->nr_frags],
+ pending_idx);
+ }
+
+ skb_shinfo(skb)->frag_list = nskb;
+ }
+
+ return gop;
+}
+
+static inline void xenvif_grant_handle_set(struct xenvif_queue *queue,
+ u16 pending_idx,
+ grant_handle_t handle)
+{
+ if (unlikely(queue->grant_tx_handle[pending_idx] !=
+ NETBACK_INVALID_HANDLE)) {
+ netdev_err(queue->vif->dev,
+ "Trying to overwrite active handle! pending_idx: %x\n",
+ pending_idx);
+ BUG();
+ }
+ queue->grant_tx_handle[pending_idx] = handle;
+}
+
+static inline void xenvif_grant_handle_reset(struct xenvif_queue *queue,
+ u16 pending_idx)
+{
+ if (unlikely(queue->grant_tx_handle[pending_idx] ==
+ NETBACK_INVALID_HANDLE)) {
+ netdev_err(queue->vif->dev,
+ "Trying to unmap invalid handle! pending_idx: %x\n",
+ pending_idx);
+ BUG();
+ }
+ queue->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE;
+}
+
+static int xenvif_tx_check_gop(struct xenvif_queue *queue,
+ struct sk_buff *skb,
+ struct gnttab_map_grant_ref **gopp_map,
+ struct gnttab_copy **gopp_copy)
+{
+ struct gnttab_map_grant_ref *gop_map = *gopp_map;
+ u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
+ /* This always points to the shinfo of the skb being checked, which
+ * could be either the first or the one on the frag_list
+ */
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ /* If this is non-NULL, we are currently checking the frag_list skb, and
+ * this points to the shinfo of the first one
+ */
+ struct skb_shared_info *first_shinfo = NULL;
+ int nr_frags = shinfo->nr_frags;
+ const bool sharedslot = nr_frags &&
+ frag_get_pending_idx(&shinfo->frags[0]) == pending_idx;
+ int i, err;
+
+ /* Check status of header. */
+ err = (*gopp_copy)->status;
+ if (unlikely(err)) {
+ if (net_ratelimit())
+ netdev_dbg(queue->vif->dev,
+ "Grant copy of header failed! status: %d pending_idx: %u ref: %u\n",
+ (*gopp_copy)->status,
+ pending_idx,
+ (*gopp_copy)->source.u.ref);
+ /* The first frag might still have this slot mapped */
+ if (!sharedslot)
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_ERROR);
+ }
+ (*gopp_copy)++;
+
+check_frags:
+ for (i = 0; i < nr_frags; i++, gop_map++) {
+ int j, newerr;
+
+ pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
+
+ /* Check error status: if okay then remember grant handle. */
+ newerr = gop_map->status;
+
+ if (likely(!newerr)) {
+ xenvif_grant_handle_set(queue,
+ pending_idx,
+ gop_map->handle);
+ /* Had a previous error? Invalidate this fragment. */
+ if (unlikely(err)) {
+ xenvif_idx_unmap(queue, pending_idx);
+ /* If the mapping of the first frag was OK, but
+ * the header's copy failed, and they are
+ * sharing a slot, send an error
+ */
+ if (i == 0 && sharedslot)
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_ERROR);
+ else
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_OKAY);
+ }
+ continue;
+ }
+
+ /* Error on this fragment: respond to client with an error. */
+ if (net_ratelimit())
+ netdev_dbg(queue->vif->dev,
+ "Grant map of %d. frag failed! status: %d pending_idx: %u ref: %u\n",
+ i,
+ gop_map->status,
+ pending_idx,
+ gop_map->ref);
+
+ xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
+
+ /* Not the first error? Preceding frags already invalidated. */
+ if (err)
+ continue;
+
+ /* First error: if the header haven't shared a slot with the
+ * first frag, release it as well.
+ */
+ if (!sharedslot)
+ xenvif_idx_release(queue,
+ XENVIF_TX_CB(skb)->pending_idx,
+ XEN_NETIF_RSP_OKAY);
+
+ /* Invalidate preceding fragments of this skb. */
+ for (j = 0; j < i; j++) {
+ pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
+ xenvif_idx_unmap(queue, pending_idx);
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_OKAY);
+ }
+
+ /* And if we found the error while checking the frag_list, unmap
+ * the first skb's frags
+ */
+ if (first_shinfo) {
+ for (j = 0; j < first_shinfo->nr_frags; j++) {
+ pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]);
+ xenvif_idx_unmap(queue, pending_idx);
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_OKAY);
+ }
+ }
+
+ /* Remember the error: invalidate all subsequent fragments. */
+ err = newerr;
+ }
+
+ if (skb_has_frag_list(skb) && !first_shinfo) {
+ first_shinfo = skb_shinfo(skb);
+ shinfo = skb_shinfo(skb_shinfo(skb)->frag_list);
+ nr_frags = shinfo->nr_frags;
+
+ goto check_frags;
+ }
+
+ *gopp_map = gop_map;
+ return err;
+}
+
+static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb)
+{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ int nr_frags = shinfo->nr_frags;
+ int i;
+ u16 prev_pending_idx = INVALID_PENDING_IDX;
+
+ for (i = 0; i < nr_frags; i++) {
+ skb_frag_t *frag = shinfo->frags + i;
+ struct xen_netif_tx_request *txp;
+ struct page *page;
+ u16 pending_idx;
+
+ pending_idx = frag_get_pending_idx(frag);
+
+ /* If this is not the first frag, chain it to the previous*/
+ if (prev_pending_idx == INVALID_PENDING_IDX)
+ skb_shinfo(skb)->destructor_arg =
+ &callback_param(queue, pending_idx);
+ else
+ callback_param(queue, prev_pending_idx).ctx =
+ &callback_param(queue, pending_idx);
+
+ callback_param(queue, pending_idx).ctx = NULL;
+ prev_pending_idx = pending_idx;
+
+ txp = &queue->pending_tx_info[pending_idx].req;
+ page = virt_to_page(idx_to_kaddr(queue, pending_idx));
+ __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
+ skb->len += txp->size;
+ skb->data_len += txp->size;
+ skb->truesize += txp->size;
+
+ /* Take an extra reference to offset network stack's put_page */
+ get_page(queue->mmap_pages[pending_idx]);
+ }
+}
+
+static int xenvif_get_extras(struct xenvif_queue *queue,
+ struct xen_netif_extra_info *extras,
+ int work_to_do)
+{
+ struct xen_netif_extra_info extra;
+ RING_IDX cons = queue->tx.req_cons;
+
+ do {
+ if (unlikely(work_to_do-- <= 0)) {
+ netdev_err(queue->vif->dev, "Missing extra info\n");
+ xenvif_fatal_tx_err(queue->vif);
+ return -EBADR;
+ }
+
+ memcpy(&extra, RING_GET_REQUEST(&queue->tx, cons),
+ sizeof(extra));
+ if (unlikely(!extra.type ||
+ extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
+ queue->tx.req_cons = ++cons;
+ netdev_err(queue->vif->dev,
+ "Invalid extra type: %d\n", extra.type);
+ xenvif_fatal_tx_err(queue->vif);
+ return -EINVAL;
+ }
+
+ memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
+ queue->tx.req_cons = ++cons;
+ } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
+
+ return work_to_do;
+}
+
+static int xenvif_set_skb_gso(struct xenvif *vif,
+ struct sk_buff *skb,
+ struct xen_netif_extra_info *gso)
+{
+ if (!gso->u.gso.size) {
+ netdev_err(vif->dev, "GSO size must not be zero.\n");
+ xenvif_fatal_tx_err(vif);
+ return -EINVAL;
+ }
+
+ switch (gso->u.gso.type) {
+ case XEN_NETIF_GSO_TYPE_TCPV4:
+ skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
+ break;
+ case XEN_NETIF_GSO_TYPE_TCPV6:
+ skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
+ break;
+ default:
+ netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
+ xenvif_fatal_tx_err(vif);
+ return -EINVAL;
+ }
+
+ skb_shinfo(skb)->gso_size = gso->u.gso.size;
+ /* gso_segs will be calculated later */
+
+ return 0;
+}
+
+static int checksum_setup(struct xenvif_queue *queue, struct sk_buff *skb)
+{
+ bool recalculate_partial_csum = false;
+
+ /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
+ * peers can fail to set NETRXF_csum_blank when sending a GSO
+ * frame. In this case force the SKB to CHECKSUM_PARTIAL and
+ * recalculate the partial checksum.
+ */
+ if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
+ queue->stats.rx_gso_checksum_fixup++;
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ recalculate_partial_csum = true;
+ }
+
+ /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
+ if (skb->ip_summed != CHECKSUM_PARTIAL)
+ return 0;
+
+ return skb_checksum_setup(skb, recalculate_partial_csum);
+}
+
+static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size)
+{
+ u64 now = get_jiffies_64();
+ u64 next_credit = queue->credit_window_start +
+ msecs_to_jiffies(queue->credit_usec / 1000);
+
+ /* Timer could already be pending in rare cases. */
+ if (timer_pending(&queue->credit_timeout))
+ return true;
+
+ /* Passed the point where we can replenish credit? */
+ if (time_after_eq64(now, next_credit)) {
+ queue->credit_window_start = now;
+ tx_add_credit(queue);
+ }
+
+ /* Still too big to send right now? Set a callback. */
+ if (size > queue->remaining_credit) {
+ queue->credit_timeout.data =
+ (unsigned long)queue;
+ mod_timer(&queue->credit_timeout,
+ next_credit);
+ queue->credit_window_start = next_credit;
+
+ return true;
+ }
+
+ return false;
+}
+
+static void xenvif_tx_build_gops(struct xenvif_queue *queue,
+ int budget,
+ unsigned *copy_ops,
+ unsigned *map_ops)
+{
+ struct gnttab_map_grant_ref *gop = queue->tx_map_ops, *request_gop;
+ struct sk_buff *skb;
+ int ret;
+
+ while (skb_queue_len(&queue->tx_queue) < budget) {
+ struct xen_netif_tx_request txreq;
+ struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
+ struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
+ u16 pending_idx;
+ RING_IDX idx;
+ int work_to_do;
+ unsigned int data_len;
+ pending_ring_idx_t index;
+
+ if (queue->tx.sring->req_prod - queue->tx.req_cons >
+ XEN_NETIF_TX_RING_SIZE) {
+ netdev_err(queue->vif->dev,
+ "Impossible number of requests. "
+ "req_prod %d, req_cons %d, size %ld\n",
+ queue->tx.sring->req_prod, queue->tx.req_cons,
+ XEN_NETIF_TX_RING_SIZE);
+ xenvif_fatal_tx_err(queue->vif);
+ break;
+ }
+
+ work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx);
+ if (!work_to_do)
+ break;
+
+ idx = queue->tx.req_cons;
+ rmb(); /* Ensure that we see the request before we copy it. */
+ memcpy(&txreq, RING_GET_REQUEST(&queue->tx, idx), sizeof(txreq));
+
+ /* Credit-based scheduling. */
+ if (txreq.size > queue->remaining_credit &&
+ tx_credit_exceeded(queue, txreq.size))
+ break;
+
+ queue->remaining_credit -= txreq.size;
+
+ work_to_do--;
+ queue->tx.req_cons = ++idx;
+
+ memset(extras, 0, sizeof(extras));
+ if (txreq.flags & XEN_NETTXF_extra_info) {
+ work_to_do = xenvif_get_extras(queue, extras,
+ work_to_do);
+ idx = queue->tx.req_cons;
+ if (unlikely(work_to_do < 0))
+ break;
+ }
+
+ ret = xenvif_count_requests(queue, &txreq, txfrags, work_to_do);
+ if (unlikely(ret < 0))
+ break;
+
+ idx += ret;
+
+ if (unlikely(txreq.size < ETH_HLEN)) {
+ netdev_dbg(queue->vif->dev,
+ "Bad packet size: %d\n", txreq.size);
+ xenvif_tx_err(queue, &txreq, idx);
+ break;
+ }
+
+ /* No crossing a page as the payload mustn't fragment. */
+ if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) {
+ netdev_err(queue->vif->dev,
+ "txreq.offset: %x, size: %u, end: %lu\n",
+ txreq.offset, txreq.size,
+ (unsigned long)(txreq.offset&~PAGE_MASK) + txreq.size);
+ xenvif_fatal_tx_err(queue->vif);
+ break;
+ }
+
+ index = pending_index(queue->pending_cons);
+ pending_idx = queue->pending_ring[index];
+
+ data_len = (txreq.size > XEN_NETBACK_TX_COPY_LEN &&
+ ret < XEN_NETBK_LEGACY_SLOTS_MAX) ?
+ XEN_NETBACK_TX_COPY_LEN : txreq.size;
+
+ skb = xenvif_alloc_skb(data_len);
+ if (unlikely(skb == NULL)) {
+ netdev_dbg(queue->vif->dev,
+ "Can't allocate a skb in start_xmit.\n");
+ xenvif_tx_err(queue, &txreq, idx);
+ break;
+ }
+
+ if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
+ struct xen_netif_extra_info *gso;
+ gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
+
+ if (xenvif_set_skb_gso(queue->vif, skb, gso)) {
+ /* Failure in xenvif_set_skb_gso is fatal. */
+ kfree_skb(skb);
+ break;
+ }
+ }
+
+ XENVIF_TX_CB(skb)->pending_idx = pending_idx;
+
+ __skb_put(skb, data_len);
+ queue->tx_copy_ops[*copy_ops].source.u.ref = txreq.gref;
+ queue->tx_copy_ops[*copy_ops].source.domid = queue->vif->domid;
+ queue->tx_copy_ops[*copy_ops].source.offset = txreq.offset;
+
+ queue->tx_copy_ops[*copy_ops].dest.u.gmfn =
+ virt_to_mfn(skb->data);
+ queue->tx_copy_ops[*copy_ops].dest.domid = DOMID_SELF;
+ queue->tx_copy_ops[*copy_ops].dest.offset =
+ offset_in_page(skb->data);
+
+ queue->tx_copy_ops[*copy_ops].len = data_len;
+ queue->tx_copy_ops[*copy_ops].flags = GNTCOPY_source_gref;
+
+ (*copy_ops)++;
+
+ skb_shinfo(skb)->nr_frags = ret;
+ if (data_len < txreq.size) {
+ skb_shinfo(skb)->nr_frags++;
+ frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
+ pending_idx);
+ xenvif_tx_create_map_op(queue, pending_idx, &txreq, gop);
+ gop++;
+ } else {
+ frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
+ INVALID_PENDING_IDX);
+ memcpy(&queue->pending_tx_info[pending_idx].req, &txreq,
+ sizeof(txreq));
+ }
+
+ queue->pending_cons++;
+
+ request_gop = xenvif_get_requests(queue, skb, txfrags, gop);
+ if (request_gop == NULL) {
+ kfree_skb(skb);
+ xenvif_tx_err(queue, &txreq, idx);
+ break;
+ }
+ gop = request_gop;
+
+ __skb_queue_tail(&queue->tx_queue, skb);
+
+ queue->tx.req_cons = idx;
+
+ if (((gop-queue->tx_map_ops) >= ARRAY_SIZE(queue->tx_map_ops)) ||
+ (*copy_ops >= ARRAY_SIZE(queue->tx_copy_ops)))
+ break;
+ }
+
+ (*map_ops) = gop - queue->tx_map_ops;
+ return;
+}
+
+/* Consolidate skb with a frag_list into a brand new one with local pages on
+ * frags. Returns 0 or -ENOMEM if can't allocate new pages.
+ */
+static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *skb)
+{
+ unsigned int offset = skb_headlen(skb);
+ skb_frag_t frags[MAX_SKB_FRAGS];
+ int i, f;
+ struct ubuf_info *uarg;
+ struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
+
+ queue->stats.tx_zerocopy_sent += 2;
+ queue->stats.tx_frag_overflow++;
+
+ xenvif_fill_frags(queue, nskb);
+ /* Subtract frags size, we will correct it later */
+ skb->truesize -= skb->data_len;
+ skb->len += nskb->len;
+ skb->data_len += nskb->len;
+
+ /* create a brand new frags array and coalesce there */
+ for (i = 0; offset < skb->len; i++) {
+ struct page *page;
+ unsigned int len;
+
+ BUG_ON(i >= MAX_SKB_FRAGS);
+ page = alloc_page(GFP_ATOMIC);
+ if (!page) {
+ int j;
+ skb->truesize += skb->data_len;
+ for (j = 0; j < i; j++)
+ put_page(frags[j].page.p);
+ return -ENOMEM;
+ }
+
+ if (offset + PAGE_SIZE < skb->len)
+ len = PAGE_SIZE;
+ else
+ len = skb->len - offset;
+ if (skb_copy_bits(skb, offset, page_address(page), len))
+ BUG();
+
+ offset += len;
+ frags[i].page.p = page;
+ frags[i].page_offset = 0;
+ skb_frag_size_set(&frags[i], len);
+ }
+
+ /* Copied all the bits from the frag list -- free it. */
+ skb_frag_list_init(skb);
+ xenvif_skb_zerocopy_prepare(queue, nskb);
+ kfree_skb(nskb);
+
+ /* Release all the original (foreign) frags. */
+ for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
+ skb_frag_unref(skb, f);
+ uarg = skb_shinfo(skb)->destructor_arg;
+ /* increase inflight counter to offset decrement in callback */
+ atomic_inc(&queue->inflight_packets);
+ uarg->callback(uarg, true);
+ skb_shinfo(skb)->destructor_arg = NULL;
+
+ /* Fill the skb with the new (local) frags. */
+ memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t));
+ skb_shinfo(skb)->nr_frags = i;
+ skb->truesize += i * PAGE_SIZE;
+
+ return 0;
+}
+
+static int xenvif_tx_submit(struct xenvif_queue *queue)
+{
+ struct gnttab_map_grant_ref *gop_map = queue->tx_map_ops;
+ struct gnttab_copy *gop_copy = queue->tx_copy_ops;
+ struct sk_buff *skb;
+ int work_done = 0;
+
+ while ((skb = __skb_dequeue(&queue->tx_queue)) != NULL) {
+ struct xen_netif_tx_request *txp;
+ u16 pending_idx;
+ unsigned data_len;
+
+ pending_idx = XENVIF_TX_CB(skb)->pending_idx;
+ txp = &queue->pending_tx_info[pending_idx].req;
+
+ /* Check the remap error code. */
+ if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) {
+ /* If there was an error, xenvif_tx_check_gop is
+ * expected to release all the frags which were mapped,
+ * so kfree_skb shouldn't do it again
+ */
+ skb_shinfo(skb)->nr_frags = 0;
+ if (skb_has_frag_list(skb)) {
+ struct sk_buff *nskb =
+ skb_shinfo(skb)->frag_list;
+ skb_shinfo(nskb)->nr_frags = 0;
+ }
+ kfree_skb(skb);
+ continue;
+ }
+
+ data_len = skb->len;
+ callback_param(queue, pending_idx).ctx = NULL;
+ if (data_len < txp->size) {
+ /* Append the packet payload as a fragment. */
+ txp->offset += data_len;
+ txp->size -= data_len;
+ } else {
+ /* Schedule a response immediately. */
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_OKAY);
+ }
+
+ if (txp->flags & XEN_NETTXF_csum_blank)
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ else if (txp->flags & XEN_NETTXF_data_validated)
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ xenvif_fill_frags(queue, skb);
+
+ if (unlikely(skb_has_frag_list(skb))) {
+ if (xenvif_handle_frag_list(queue, skb)) {
+ if (net_ratelimit())
+ netdev_err(queue->vif->dev,
+ "Not enough memory to consolidate frag_list!\n");
+ xenvif_skb_zerocopy_prepare(queue, skb);
+ kfree_skb(skb);
+ continue;
+ }
+ }
+
+ skb->dev = queue->vif->dev;
+ skb->protocol = eth_type_trans(skb, skb->dev);
+ skb_reset_network_header(skb);
+
+ if (checksum_setup(queue, skb)) {
+ netdev_dbg(queue->vif->dev,
+ "Can't setup checksum in net_tx_action\n");
+ /* We have to set this flag to trigger the callback */
+ if (skb_shinfo(skb)->destructor_arg)
+ xenvif_skb_zerocopy_prepare(queue, skb);
+ kfree_skb(skb);
+ continue;
+ }
+
+ skb_probe_transport_header(skb, 0);
+
+ /* If the packet is GSO then we will have just set up the
+ * transport header offset in checksum_setup so it's now
+ * straightforward to calculate gso_segs.
+ */
+ if (skb_is_gso(skb)) {
+ int mss = skb_shinfo(skb)->gso_size;
+ int hdrlen = skb_transport_header(skb) -
+ skb_mac_header(skb) +
+ tcp_hdrlen(skb);
+
+ skb_shinfo(skb)->gso_segs =
+ DIV_ROUND_UP(skb->len - hdrlen, mss);
+ }
+
+ queue->stats.rx_bytes += skb->len;
+ queue->stats.rx_packets++;
+
+ work_done++;
+
+ /* Set this flag right before netif_receive_skb, otherwise
+ * someone might think this packet already left netback, and
+ * do a skb_copy_ubufs while we are still in control of the
+ * skb. E.g. the __pskb_pull_tail earlier can do such thing.
+ */
+ if (skb_shinfo(skb)->destructor_arg) {
+ xenvif_skb_zerocopy_prepare(queue, skb);
+ queue->stats.tx_zerocopy_sent++;
+ }
+
+ netif_receive_skb(skb);
+ }
+
+ return work_done;
+}
+
+void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success)
+{
+ unsigned long flags;
+ pending_ring_idx_t index;
+ struct xenvif_queue *queue = ubuf_to_queue(ubuf);
+
+ /* This is the only place where we grab this lock, to protect callbacks
+ * from each other.
+ */
+ spin_lock_irqsave(&queue->callback_lock, flags);
+ do {
+ u16 pending_idx = ubuf->desc;
+ ubuf = (struct ubuf_info *) ubuf->ctx;
+ BUG_ON(queue->dealloc_prod - queue->dealloc_cons >=
+ MAX_PENDING_REQS);
+ index = pending_index(queue->dealloc_prod);
+ queue->dealloc_ring[index] = pending_idx;
+ /* Sync with xenvif_tx_dealloc_action:
+ * insert idx then incr producer.
+ */
+ smp_wmb();
+ queue->dealloc_prod++;
+ } while (ubuf);
+ wake_up(&queue->dealloc_wq);
+ spin_unlock_irqrestore(&queue->callback_lock, flags);
+
+ if (likely(zerocopy_success))
+ queue->stats.tx_zerocopy_success++;
+ else
+ queue->stats.tx_zerocopy_fail++;
+ xenvif_skb_zerocopy_complete(queue);
+}
+
+static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
+{
+ struct gnttab_unmap_grant_ref *gop;
+ pending_ring_idx_t dc, dp;
+ u16 pending_idx, pending_idx_release[MAX_PENDING_REQS];
+ unsigned int i = 0;
+
+ dc = queue->dealloc_cons;
+ gop = queue->tx_unmap_ops;
+
+ /* Free up any grants we have finished using */
+ do {
+ dp = queue->dealloc_prod;
+
+ /* Ensure we see all indices enqueued by all
+ * xenvif_zerocopy_callback().
+ */
+ smp_rmb();
+
+ while (dc != dp) {
+ BUG_ON(gop - queue->tx_unmap_ops > MAX_PENDING_REQS);
+ pending_idx =
+ queue->dealloc_ring[pending_index(dc++)];
+
+ pending_idx_release[gop-queue->tx_unmap_ops] =
+ pending_idx;
+ queue->pages_to_unmap[gop-queue->tx_unmap_ops] =
+ queue->mmap_pages[pending_idx];
+ gnttab_set_unmap_op(gop,
+ idx_to_kaddr(queue, pending_idx),
+ GNTMAP_host_map,
+ queue->grant_tx_handle[pending_idx]);
+ xenvif_grant_handle_reset(queue, pending_idx);
+ ++gop;
+ }
+
+ } while (dp != queue->dealloc_prod);
+
+ queue->dealloc_cons = dc;
+
+ if (gop - queue->tx_unmap_ops > 0) {
+ int ret;
+ ret = gnttab_unmap_refs(queue->tx_unmap_ops,
+ NULL,
+ queue->pages_to_unmap,
+ gop - queue->tx_unmap_ops);
+ if (ret) {
+ netdev_err(queue->vif->dev, "Unmap fail: nr_ops %tx ret %d\n",
+ gop - queue->tx_unmap_ops, ret);
+ for (i = 0; i < gop - queue->tx_unmap_ops; ++i) {
+ if (gop[i].status != GNTST_okay)
+ netdev_err(queue->vif->dev,
+ " host_addr: %llx handle: %x status: %d\n",
+ gop[i].host_addr,
+ gop[i].handle,
+ gop[i].status);
+ }
+ BUG();
+ }
+ }
+
+ for (i = 0; i < gop - queue->tx_unmap_ops; ++i)
+ xenvif_idx_release(queue, pending_idx_release[i],
+ XEN_NETIF_RSP_OKAY);
+}
+
+
+/* Called after netfront has transmitted */
+int xenvif_tx_action(struct xenvif_queue *queue, int budget)
+{
+ unsigned nr_mops, nr_cops = 0;
+ int work_done, ret;
+
+ if (unlikely(!tx_work_todo(queue)))
+ return 0;
+
+ xenvif_tx_build_gops(queue, budget, &nr_cops, &nr_mops);
+
+ if (nr_cops == 0)
+ return 0;
+
+ gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
+ if (nr_mops != 0) {
+ ret = gnttab_map_refs(queue->tx_map_ops,
+ NULL,
+ queue->pages_to_map,
+ nr_mops);
+ BUG_ON(ret);
+ }
+
+ work_done = xenvif_tx_submit(queue);
+
+ return work_done;
+}
+
+static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
+ u8 status)
+{
+ struct pending_tx_info *pending_tx_info;
+ pending_ring_idx_t index;
+ unsigned long flags;
+
+ pending_tx_info = &queue->pending_tx_info[pending_idx];
+
+ spin_lock_irqsave(&queue->response_lock, flags);
+
+ make_tx_response(queue, &pending_tx_info->req, status);
+
+ /* Release the pending index before pusing the Tx response so
+ * its available before a new Tx request is pushed by the
+ * frontend.
+ */
+ index = pending_index(queue->pending_prod++);
+ queue->pending_ring[index] = pending_idx;
+
+ push_tx_responses(queue);
+
+ spin_unlock_irqrestore(&queue->response_lock, flags);
+}
+
+
+static void make_tx_response(struct xenvif_queue *queue,
+ struct xen_netif_tx_request *txp,
+ s8 st)
+{
+ RING_IDX i = queue->tx.rsp_prod_pvt;
+ struct xen_netif_tx_response *resp;
+
+ resp = RING_GET_RESPONSE(&queue->tx, i);
+ resp->id = txp->id;
+ resp->status = st;
+
+ if (txp->flags & XEN_NETTXF_extra_info)
+ RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL;
+
+ queue->tx.rsp_prod_pvt = ++i;
+}
+
+static void push_tx_responses(struct xenvif_queue *queue)
+{
+ int notify;
+
+ RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify);
+ if (notify)
+ notify_remote_via_irq(queue->tx_irq);
+}
+
+static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue,
+ u16 id,
+ s8 st,
+ u16 offset,
+ u16 size,
+ u16 flags)
+{
+ RING_IDX i = queue->rx.rsp_prod_pvt;
+ struct xen_netif_rx_response *resp;
+
+ resp = RING_GET_RESPONSE(&queue->rx, i);
+ resp->offset = offset;
+ resp->flags = flags;
+ resp->id = id;
+ resp->status = (s16)size;
+ if (st < 0)
+ resp->status = (s16)st;
+
+ queue->rx.rsp_prod_pvt = ++i;
+
+ return resp;
+}
+
+void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
+{
+ int ret;
+ struct gnttab_unmap_grant_ref tx_unmap_op;
+
+ gnttab_set_unmap_op(&tx_unmap_op,
+ idx_to_kaddr(queue, pending_idx),
+ GNTMAP_host_map,
+ queue->grant_tx_handle[pending_idx]);
+ xenvif_grant_handle_reset(queue, pending_idx);
+
+ ret = gnttab_unmap_refs(&tx_unmap_op, NULL,
+ &queue->mmap_pages[pending_idx], 1);
+ if (ret) {
+ netdev_err(queue->vif->dev,
+ "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: %x status: %d\n",
+ ret,
+ pending_idx,
+ tx_unmap_op.host_addr,
+ tx_unmap_op.handle,
+ tx_unmap_op.status);
+ BUG();
+ }
+}
+
+static inline int tx_work_todo(struct xenvif_queue *queue)
+{
+ if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)))
+ return 1;
+
+ return 0;
+}
+
+static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue)
+{
+ return queue->dealloc_cons != queue->dealloc_prod;
+}
+
+void xenvif_unmap_frontend_rings(struct xenvif_queue *queue)
+{
+ if (queue->tx.sring)
+ xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
+ queue->tx.sring);
+ if (queue->rx.sring)
+ xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
+ queue->rx.sring);
+}
+
+int xenvif_map_frontend_rings(struct xenvif_queue *queue,
+ grant_ref_t tx_ring_ref,
+ grant_ref_t rx_ring_ref)
+{
+ void *addr;
+ struct xen_netif_tx_sring *txs;
+ struct xen_netif_rx_sring *rxs;
+
+ int err = -ENOMEM;
+
+ err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
+ &tx_ring_ref, 1, &addr);
+ if (err)
+ goto err;
+
+ txs = (struct xen_netif_tx_sring *)addr;
+ BACK_RING_INIT(&queue->tx, txs, PAGE_SIZE);
+
+ err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
+ &rx_ring_ref, 1, &addr);
+ if (err)
+ goto err;
+
+ rxs = (struct xen_netif_rx_sring *)addr;
+ BACK_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
+
+ return 0;
+
+err:
+ xenvif_unmap_frontend_rings(queue);
+ return err;
+}
+
+static void xenvif_queue_carrier_off(struct xenvif_queue *queue)
+{
+ struct xenvif *vif = queue->vif;
+
+ queue->stalled = true;
+
+ /* At least one queue has stalled? Disable the carrier. */
+ spin_lock(&vif->lock);
+ if (vif->stalled_queues++ == 0) {
+ netdev_info(vif->dev, "Guest Rx stalled");
+ netif_carrier_off(vif->dev);
+ }
+ spin_unlock(&vif->lock);
+}
+
+static void xenvif_queue_carrier_on(struct xenvif_queue *queue)
+{
+ struct xenvif *vif = queue->vif;
+
+ queue->last_rx_time = jiffies; /* Reset Rx stall detection. */
+ queue->stalled = false;
+
+ /* All queues are ready? Enable the carrier. */
+ spin_lock(&vif->lock);
+ if (--vif->stalled_queues == 0) {
+ netdev_info(vif->dev, "Guest Rx ready");
+ netif_carrier_on(vif->dev);
+ }
+ spin_unlock(&vif->lock);
+}
+
+static bool xenvif_rx_queue_stalled(struct xenvif_queue *queue)
+{
+ RING_IDX prod, cons;
+
+ prod = queue->rx.sring->req_prod;
+ cons = queue->rx.req_cons;
+
+ return !queue->stalled
+ && prod - cons < XEN_NETBK_RX_SLOTS_MAX
+ && time_after(jiffies,
+ queue->last_rx_time + queue->vif->stall_timeout);
+}
+
+static bool xenvif_rx_queue_ready(struct xenvif_queue *queue)
+{
+ RING_IDX prod, cons;
+
+ prod = queue->rx.sring->req_prod;
+ cons = queue->rx.req_cons;
+
+ return queue->stalled
+ && prod - cons >= XEN_NETBK_RX_SLOTS_MAX;
+}
+
+static bool xenvif_have_rx_work(struct xenvif_queue *queue)
+{
+ return (!skb_queue_empty(&queue->rx_queue)
+ && xenvif_rx_ring_slots_available(queue, XEN_NETBK_RX_SLOTS_MAX))
+ || (queue->vif->stall_timeout &&
+ (xenvif_rx_queue_stalled(queue)
+ || xenvif_rx_queue_ready(queue)))
+ || kthread_should_stop()
+ || queue->vif->disabled;
+}
+
+static long xenvif_rx_queue_timeout(struct xenvif_queue *queue)
+{
+ struct sk_buff *skb;
+ long timeout;
+
+ skb = skb_peek(&queue->rx_queue);
+ if (!skb)
+ return MAX_SCHEDULE_TIMEOUT;
+
+ timeout = XENVIF_RX_CB(skb)->expires - jiffies;
+ return timeout < 0 ? 0 : timeout;
+}
+
+/* Wait until the guest Rx thread has work.
+ *
+ * The timeout needs to be adjusted based on the current head of the
+ * queue (and not just the head at the beginning). In particular, if
+ * the queue is initially empty an infinite timeout is used and this
+ * needs to be reduced when a skb is queued.
+ *
+ * This cannot be done with wait_event_timeout() because it only
+ * calculates the timeout once.
+ */
+static void xenvif_wait_for_rx_work(struct xenvif_queue *queue)
+{
+ DEFINE_WAIT(wait);
+
+ if (xenvif_have_rx_work(queue))
+ return;
+
+ for (;;) {
+ long ret;
+
+ prepare_to_wait(&queue->wq, &wait, TASK_INTERRUPTIBLE);
+ if (xenvif_have_rx_work(queue))
+ break;
+ ret = schedule_timeout(xenvif_rx_queue_timeout(queue));
+ if (!ret)
+ break;
+ }
+ finish_wait(&queue->wq, &wait);
+}
+
+int xenvif_kthread_guest_rx(void *data)
+{
+ struct xenvif_queue *queue = data;
+ struct xenvif *vif = queue->vif;
+
+ if (!vif->stall_timeout)
+ xenvif_queue_carrier_on(queue);
+
+ for (;;) {
+ xenvif_wait_for_rx_work(queue);
+
+ if (kthread_should_stop())
+ break;
+
+ /* This frontend is found to be rogue, disable it in
+ * kthread context. Currently this is only set when
+ * netback finds out frontend sends malformed packet,
+ * but we cannot disable the interface in softirq
+ * context so we defer it here, if this thread is
+ * associated with queue 0.
+ */
+ if (unlikely(vif->disabled && queue->id == 0)) {
+ xenvif_carrier_off(vif);
+ break;
+ }
+
+ if (!skb_queue_empty(&queue->rx_queue))
+ xenvif_rx_action(queue);
+
+ /* If the guest hasn't provided any Rx slots for a
+ * while it's probably not responsive, drop the
+ * carrier so packets are dropped earlier.
+ */
+ if (vif->stall_timeout) {
+ if (xenvif_rx_queue_stalled(queue))
+ xenvif_queue_carrier_off(queue);
+ else if (xenvif_rx_queue_ready(queue))
+ xenvif_queue_carrier_on(queue);
+ }
+
+ /* Queued packets may have foreign pages from other
+ * domains. These cannot be queued indefinitely as
+ * this would starve guests of grant refs and transmit
+ * slots.
+ */
+ xenvif_rx_queue_drop_expired(queue);
+
+ xenvif_rx_queue_maybe_wake(queue);
+
+ cond_resched();
+ }
+
+ /* Bin any remaining skbs */
+ xenvif_rx_queue_purge(queue);
+
+ return 0;
+}
+
+static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue)
+{
+ /* Dealloc thread must remain running until all inflight
+ * packets complete.
+ */
+ return kthread_should_stop() &&
+ !atomic_read(&queue->inflight_packets);
+}
+
+int xenvif_dealloc_kthread(void *data)
+{
+ struct xenvif_queue *queue = data;
+
+ for (;;) {
+ wait_event_interruptible(queue->dealloc_wq,
+ tx_dealloc_work_todo(queue) ||
+ xenvif_dealloc_kthread_should_stop(queue));
+ if (xenvif_dealloc_kthread_should_stop(queue))
+ break;
+
+ xenvif_tx_dealloc_action(queue);
+ cond_resched();
+ }
+
+ /* Unmap anything remaining*/
+ if (tx_dealloc_work_todo(queue))
+ xenvif_tx_dealloc_action(queue);
+
+ return 0;
+}
+
+static int __init netback_init(void)
+{
+ int rc = 0;
+
+ if (!xen_domain())
+ return -ENODEV;
+
+ /* Allow as many queues as there are CPUs, by default */
+ xenvif_max_queues = num_online_cpus();
+
+ if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
+ pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
+ fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
+ fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
+ }
+
+ rc = xenvif_xenbus_init();
+ if (rc)
+ goto failed_init;
+
+#ifdef CONFIG_DEBUG_FS
+ xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
+ if (IS_ERR_OR_NULL(xen_netback_dbg_root))
+ pr_warn("Init of debugfs returned %ld!\n",
+ PTR_ERR(xen_netback_dbg_root));
+#endif /* CONFIG_DEBUG_FS */
+
+ return 0;
+
+failed_init:
+ return rc;
+}
+
+module_init(netback_init);
+
+static void __exit netback_fini(void)
+{
+#ifdef CONFIG_DEBUG_FS
+ if (!IS_ERR_OR_NULL(xen_netback_dbg_root))
+ debugfs_remove_recursive(xen_netback_dbg_root);
+#endif /* CONFIG_DEBUG_FS */
+ xenvif_xenbus_fini();
+}
+module_exit(netback_fini);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("xen-backend:vif");
diff --git a/kernel/drivers/net/xen-netback/xenbus.c b/kernel/drivers/net/xen-netback/xenbus.c
new file mode 100644
index 000000000..ec383b0f5
--- /dev/null
+++ b/kernel/drivers/net/xen-netback/xenbus.c
@@ -0,0 +1,1043 @@
+/*
+ * 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);
+}