--- /dev/null
+/******************************************************************************
+ * Virtual network driver for conversing with remote driver backends.
+ *
+ * Copyright (c) 2002-2004, K A Fraser
+ *
+ * This file may be 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 <linux/config.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/inetdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <net/sock.h>
+#include <net/pkt_sched.h>
+#include <net/arp.h>
+#include <net/route.h>
+#include <asm/io.h>
+#include <asm-xen/evtchn.h>
+#include <asm-xen/ctrl_if.h>
+#include <asm-xen/xen-public/io/netif.h>
+#include <asm-xen/balloon.h>
+#include <asm/page.h>
+
+#ifndef __GFP_NOWARN
+#define __GFP_NOWARN 0
+#endif
+#define alloc_xen_skb(_l) __dev_alloc_skb((_l), GFP_ATOMIC|__GFP_NOWARN)
+
+#define init_skb_shinfo(_skb) \
+ do { \
+ atomic_set(&(skb_shinfo(_skb)->dataref), 1); \
+ skb_shinfo(_skb)->nr_frags = 0; \
+ skb_shinfo(_skb)->frag_list = NULL; \
+ } while (0)
+
+/* Allow headroom on each rx pkt for Ethernet header, alignment padding, ... */
+#define RX_HEADROOM 200
+
+/*
+ * If the backend driver is pipelining transmit requests then we can be very
+ * aggressive in avoiding new-packet notifications -- only need to send a
+ * notification if there are no outstanding unreceived responses.
+ * If the backend may be buffering our transmit buffers for any reason then we
+ * are rather more conservative.
+ */
+#ifdef CONFIG_XEN_NETDEV_FRONTEND_PIPELINED_TRANSMITTER
+#define TX_TEST_IDX resp_prod /* aggressive: any outstanding responses? */
+#else
+#define TX_TEST_IDX req_cons /* conservative: not seen all our requests? */
+#endif
+
+static void network_tx_buf_gc(struct net_device *dev);
+static void network_alloc_rx_buffers(struct net_device *dev);
+
+static unsigned long rx_pfn_array[NETIF_RX_RING_SIZE];
+static multicall_entry_t rx_mcl[NETIF_RX_RING_SIZE+1];
+static mmu_update_t rx_mmu[NETIF_RX_RING_SIZE];
+
+static struct list_head dev_list;
+
+struct net_private
+{
+ struct list_head list;
+ struct net_device *dev;
+
+ struct net_device_stats stats;
+ NETIF_RING_IDX rx_resp_cons, tx_resp_cons;
+ unsigned int tx_full;
+
+ netif_tx_interface_t *tx;
+ netif_rx_interface_t *rx;
+
+ spinlock_t tx_lock;
+ spinlock_t rx_lock;
+
+ unsigned int handle;
+ unsigned int evtchn;
+ unsigned int irq;
+
+ /* What is the status of our connection to the remote backend? */
+#define BEST_CLOSED 0
+#define BEST_DISCONNECTED 1
+#define BEST_CONNECTED 2
+ unsigned int backend_state;
+
+ /* Is this interface open or closed (down or up)? */
+#define UST_CLOSED 0
+#define UST_OPEN 1
+ unsigned int user_state;
+
+ /* Receive-ring batched refills. */
+#define RX_MIN_TARGET 8
+#define RX_MAX_TARGET NETIF_RX_RING_SIZE
+ int rx_target;
+ struct sk_buff_head rx_batch;
+
+ /*
+ * {tx,rx}_skbs store outstanding skbuffs. The first entry in each
+ * array is an index into a chain of free entries.
+ */
+ struct sk_buff *tx_skbs[NETIF_TX_RING_SIZE+1];
+ struct sk_buff *rx_skbs[NETIF_RX_RING_SIZE+1];
+};
+
+/* Access macros for acquiring freeing slots in {tx,rx}_skbs[]. */
+#define ADD_ID_TO_FREELIST(_list, _id) \
+ (_list)[(_id)] = (_list)[0]; \
+ (_list)[0] = (void *)(unsigned long)(_id);
+#define GET_ID_FROM_FREELIST(_list) \
+ ({ unsigned long _id = (unsigned long)(_list)[0]; \
+ (_list)[0] = (_list)[_id]; \
+ (unsigned short)_id; })
+
+static char *status_name[] = {
+ [NETIF_INTERFACE_STATUS_CLOSED] = "closed",
+ [NETIF_INTERFACE_STATUS_DISCONNECTED] = "disconnected",
+ [NETIF_INTERFACE_STATUS_CONNECTED] = "connected",
+ [NETIF_INTERFACE_STATUS_CHANGED] = "changed",
+};
+
+static char *be_state_name[] = {
+ [BEST_CLOSED] = "closed",
+ [BEST_DISCONNECTED] = "disconnected",
+ [BEST_CONNECTED] = "connected",
+};
+
+#if DEBUG
+#define DPRINTK(fmt, args...) \
+ printk(KERN_ALERT "xen_net (%s:%d) " fmt, __FUNCTION__, __LINE__, ##args)
+#else
+#define DPRINTK(fmt, args...) ((void)0)
+#endif
+#define IPRINTK(fmt, args...) \
+ printk(KERN_INFO "xen_net: " fmt, ##args)
+#define WPRINTK(fmt, args...) \
+ printk(KERN_WARNING "xen_net: " fmt, ##args)
+
+static struct net_device *find_dev_by_handle(unsigned int handle)
+{
+ struct list_head *ent;
+ struct net_private *np;
+ list_for_each (ent, &dev_list) {
+ np = list_entry(ent, struct net_private, list);
+ if (np->handle == handle)
+ return np->dev;
+ }
+ return NULL;
+}
+
+/** Network interface info. */
+struct netif_ctrl {
+ /** Number of interfaces. */
+ int interface_n;
+ /** Number of connected interfaces. */
+ int connected_n;
+ /** Error code. */
+ int err;
+ int up;
+};
+
+static struct netif_ctrl netctrl;
+
+static void netctrl_init(void)
+{
+ memset(&netctrl, 0, sizeof(netctrl));
+ netctrl.up = NETIF_DRIVER_STATUS_DOWN;
+}
+
+/** Get or set a network interface error.
+ */
+static int netctrl_err(int err)
+{
+ if ((err < 0) && !netctrl.err)
+ netctrl.err = err;
+ return netctrl.err;
+}
+
+/** Test if all network interfaces are connected.
+ *
+ * @return 1 if all connected, 0 if not, negative error code otherwise
+ */
+static int netctrl_connected(void)
+{
+ int ok;
+
+ if (netctrl.err)
+ ok = netctrl.err;
+ else if (netctrl.up == NETIF_DRIVER_STATUS_UP)
+ ok = (netctrl.connected_n == netctrl.interface_n);
+ else
+ ok = 0;
+
+ return ok;
+}
+
+/** Count the connected network interfaces.
+ *
+ * @return connected count
+ */
+static int netctrl_connected_count(void)
+{
+
+ struct list_head *ent;
+ struct net_private *np;
+ unsigned int connected;
+
+ connected = 0;
+
+ list_for_each(ent, &dev_list) {
+ np = list_entry(ent, struct net_private, list);
+ if (np->backend_state == BEST_CONNECTED)
+ connected++;
+ }
+
+ netctrl.connected_n = connected;
+ DPRINTK("> connected_n=%d interface_n=%d\n",
+ netctrl.connected_n, netctrl.interface_n);
+ return connected;
+}
+
+/** Send a packet on a net device to encourage switches to learn the
+ * MAC. We send a fake ARP request.
+ *
+ * @param dev device
+ * @return 0 on success, error code otherwise
+ */
+static int send_fake_arp(struct net_device *dev)
+{
+ struct sk_buff *skb;
+ u32 src_ip, dst_ip;
+
+ dst_ip = INADDR_BROADCAST;
+ src_ip = inet_select_addr(dev, dst_ip, RT_SCOPE_LINK);
+
+ /* No IP? Then nothing to do. */
+ if (src_ip == 0)
+ return 0;
+
+ skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
+ dst_ip, dev, src_ip,
+ /*dst_hw*/ NULL, /*src_hw*/ NULL,
+ /*target_hw*/ dev->dev_addr);
+ if (skb == NULL)
+ return -ENOMEM;
+
+ return dev_queue_xmit(skb);
+}
+
+static int network_open(struct net_device *dev)
+{
+ struct net_private *np = netdev_priv(dev);
+
+ memset(&np->stats, 0, sizeof(np->stats));
+
+ np->user_state = UST_OPEN;
+
+ network_alloc_rx_buffers(dev);
+ np->rx->event = np->rx_resp_cons + 1;
+
+ netif_start_queue(dev);
+
+ return 0;
+}
+
+static void network_tx_buf_gc(struct net_device *dev)
+{
+ NETIF_RING_IDX i, prod;
+ unsigned short id;
+ struct net_private *np = netdev_priv(dev);
+ struct sk_buff *skb;
+
+ if (np->backend_state != BEST_CONNECTED)
+ return;
+
+ do {
+ prod = np->tx->resp_prod;
+ rmb(); /* Ensure we see responses up to 'rp'. */
+
+ for (i = np->tx_resp_cons; i != prod; i++) {
+ id = np->tx->ring[MASK_NETIF_TX_IDX(i)].resp.id;
+ skb = np->tx_skbs[id];
+ ADD_ID_TO_FREELIST(np->tx_skbs, id);
+ dev_kfree_skb_irq(skb);
+ }
+
+ np->tx_resp_cons = prod;
+
+ /*
+ * Set a new event, then check for race with update of tx_cons. Note
+ * that it is essential to schedule a callback, no matter how few
+ * buffers are pending. Even if there is space in the transmit ring,
+ * higher layers may be blocked because too much data is outstanding:
+ * in such cases notification from Xen is likely to be the only kick
+ * that we'll get.
+ */
+ np->tx->event =
+ prod + ((np->tx->req_prod - prod) >> 1) + 1;
+ mb();
+ } while (prod != np->tx->resp_prod);
+
+ if (np->tx_full && ((np->tx->req_prod - prod) < NETIF_TX_RING_SIZE)) {
+ np->tx_full = 0;
+ if (np->user_state == UST_OPEN)
+ netif_wake_queue(dev);
+ }
+}
+
+
+static void network_alloc_rx_buffers(struct net_device *dev)
+{
+ unsigned short id;
+ struct net_private *np = netdev_priv(dev);
+ struct sk_buff *skb;
+ int i, batch_target;
+ NETIF_RING_IDX req_prod = np->rx->req_prod;
+
+ if (unlikely(np->backend_state != BEST_CONNECTED))
+ return;
+
+ /*
+ * Allocate skbuffs greedily, even though we batch updates to the
+ * receive ring. This creates a less bursty demand on the memory allocator,
+ * so should reduce the chance of failed allocation requests both for
+ * ourself and for other kernel subsystems.
+ */
+ batch_target = np->rx_target - (req_prod - np->rx_resp_cons);
+ for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
+ if (unlikely((skb = alloc_xen_skb(dev->mtu + RX_HEADROOM)) == NULL))
+ break;
+ __skb_queue_tail(&np->rx_batch, skb);
+ }
+
+ /* Is the batch large enough to be worthwhile? */
+ if (i < (np->rx_target/2))
+ return;
+
+ for (i = 0; ; i++) {
+ if ((skb = __skb_dequeue(&np->rx_batch)) == NULL)
+ break;
+
+ skb->dev = dev;
+
+ id = GET_ID_FROM_FREELIST(np->rx_skbs);
+
+ np->rx_skbs[id] = skb;
+
+ np->rx->ring[MASK_NETIF_RX_IDX(req_prod + i)].req.id = id;
+
+ rx_pfn_array[i] = virt_to_machine(skb->head) >> PAGE_SHIFT;
+
+ /* Remove this page from pseudo phys map before passing back to Xen. */
+ phys_to_machine_mapping[__pa(skb->head) >> PAGE_SHIFT]
+ = INVALID_P2M_ENTRY;
+
+ rx_mcl[i].op = __HYPERVISOR_update_va_mapping;
+ rx_mcl[i].args[0] = (unsigned long)skb->head;
+ rx_mcl[i].args[1] = 0;
+ rx_mcl[i].args[2] = 0;
+ }
+
+ /* After all PTEs have been zapped we blow away stale TLB entries. */
+ rx_mcl[i-1].args[2] = UVMF_TLB_FLUSH|UVMF_ALL;
+
+ /* Give away a batch of pages. */
+ rx_mcl[i].op = __HYPERVISOR_dom_mem_op;
+ rx_mcl[i].args[0] = MEMOP_decrease_reservation;
+ rx_mcl[i].args[1] = (unsigned long)rx_pfn_array;
+ rx_mcl[i].args[2] = (unsigned long)i;
+ rx_mcl[i].args[3] = 0;
+ rx_mcl[i].args[4] = DOMID_SELF;
+
+ /* Tell the ballon driver what is going on. */
+ balloon_update_driver_allowance(i);
+
+ /* Zap PTEs and give away pages in one big multicall. */
+ (void)HYPERVISOR_multicall(rx_mcl, i+1);
+
+ /* Check return status of HYPERVISOR_dom_mem_op(). */
+ if (unlikely(rx_mcl[i].args[5] != i))
+ panic("Unable to reduce memory reservation\n");
+
+ /* Above is a suitable barrier to ensure backend will see requests. */
+ np->rx->req_prod = req_prod + i;
+
+ /* Adjust our floating fill target if we risked running out of buffers. */
+ if (((req_prod - np->rx->resp_prod) < (np->rx_target / 4)) &&
+ ((np->rx_target *= 2) > RX_MAX_TARGET))
+ np->rx_target = RX_MAX_TARGET;
+}
+
+
+static int network_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ unsigned short id;
+ struct net_private *np = netdev_priv(dev);
+ netif_tx_request_t *tx;
+ NETIF_RING_IDX i;
+
+ if (unlikely(np->tx_full)) {
+ printk(KERN_ALERT "%s: full queue wasn't stopped!\n", dev->name);
+ netif_stop_queue(dev);
+ goto drop;
+ }
+
+ if (unlikely((((unsigned long)skb->data & ~PAGE_MASK) + skb->len) >=
+ PAGE_SIZE)) {
+ struct sk_buff *nskb;
+ if (unlikely((nskb = alloc_xen_skb(skb->len)) == NULL))
+ goto drop;
+ skb_put(nskb, skb->len);
+ memcpy(nskb->data, skb->data, skb->len);
+ nskb->dev = skb->dev;
+ dev_kfree_skb(skb);
+ skb = nskb;
+ }
+
+ spin_lock_irq(&np->tx_lock);
+
+ if (np->backend_state != BEST_CONNECTED) {
+ spin_unlock_irq(&np->tx_lock);
+ goto drop;
+ }
+
+ i = np->tx->req_prod;
+
+ id = GET_ID_FROM_FREELIST(np->tx_skbs);
+ np->tx_skbs[id] = skb;
+
+ tx = &np->tx->ring[MASK_NETIF_TX_IDX(i)].req;
+
+ tx->id = id;
+ tx->addr = virt_to_machine(skb->data);
+ tx->size = skb->len;
+
+ wmb(); /* Ensure that backend will see the request. */
+ np->tx->req_prod = i + 1;
+
+ network_tx_buf_gc(dev);
+
+ if ((i - np->tx_resp_cons) == (NETIF_TX_RING_SIZE - 1)) {
+ np->tx_full = 1;
+ netif_stop_queue(dev);
+ }
+
+ spin_unlock_irq(&np->tx_lock);
+
+ np->stats.tx_bytes += skb->len;
+ np->stats.tx_packets++;
+
+ /* Only notify Xen if we really have to. */
+ mb();
+ if (np->tx->TX_TEST_IDX == i)
+ notify_via_evtchn(np->evtchn);
+
+ return 0;
+
+ drop:
+ np->stats.tx_dropped++;
+ dev_kfree_skb(skb);
+ return 0;
+}
+
+static irqreturn_t netif_int(int irq, void *dev_id, struct pt_regs *ptregs)
+{
+ struct net_device *dev = dev_id;
+ struct net_private *np = netdev_priv(dev);
+ unsigned long flags;
+
+ spin_lock_irqsave(&np->tx_lock, flags);
+ network_tx_buf_gc(dev);
+ spin_unlock_irqrestore(&np->tx_lock, flags);
+
+ if ((np->rx_resp_cons != np->rx->resp_prod) && (np->user_state == UST_OPEN))
+ netif_rx_schedule(dev);
+
+ return IRQ_HANDLED;
+}
+
+
+static int netif_poll(struct net_device *dev, int *pbudget)
+{
+ struct net_private *np = netdev_priv(dev);
+ struct sk_buff *skb, *nskb;
+ netif_rx_response_t *rx;
+ NETIF_RING_IDX i, rp;
+ mmu_update_t *mmu = rx_mmu;
+ multicall_entry_t *mcl = rx_mcl;
+ int work_done, budget, more_to_do = 1;
+ struct sk_buff_head rxq;
+ unsigned long flags;
+
+ spin_lock(&np->rx_lock);
+
+ if (np->backend_state != BEST_CONNECTED) {
+ spin_unlock(&np->rx_lock);
+ return 0;
+ }
+
+ skb_queue_head_init(&rxq);
+
+ if ((budget = *pbudget) > dev->quota)
+ budget = dev->quota;
+
+ rp = np->rx->resp_prod;
+ rmb(); /* Ensure we see queued responses up to 'rp'. */
+
+ for (i = np->rx_resp_cons, work_done = 0;
+ (i != rp) && (work_done < budget);
+ i++, work_done++) {
+ rx = &np->rx->ring[MASK_NETIF_RX_IDX(i)].resp;
+
+ /*
+ * An error here is very odd. Usually indicates a backend bug,
+ * low-memory condition, or that we didn't have reservation headroom.
+ */
+ if (unlikely(rx->status <= 0)) {
+ if (net_ratelimit())
+ printk(KERN_WARNING "Bad rx buffer (memory squeeze?).\n");
+ np->rx->ring[MASK_NETIF_RX_IDX(np->rx->req_prod)].req.id = rx->id;
+ wmb();
+ np->rx->req_prod++;
+ work_done--;
+ continue;
+ }
+
+ skb = np->rx_skbs[rx->id];
+ ADD_ID_TO_FREELIST(np->rx_skbs, rx->id);
+
+ /* NB. We handle skb overflow later. */
+ skb->data = skb->head + (rx->addr & ~PAGE_MASK);
+ skb->len = rx->status;
+ skb->tail = skb->data + skb->len;
+
+ np->stats.rx_packets++;
+ np->stats.rx_bytes += rx->status;
+
+ /* Remap the page. */
+ mmu->ptr = (rx->addr & PAGE_MASK) | MMU_MACHPHYS_UPDATE;
+ mmu->val = __pa(skb->head) >> PAGE_SHIFT;
+ mmu++;
+ mcl->op = __HYPERVISOR_update_va_mapping;
+ mcl->args[0] = (unsigned long)skb->head;
+ mcl->args[1] = (rx->addr & PAGE_MASK) | __PAGE_KERNEL;
+ mcl->args[2] = 0;
+ mcl++;
+
+ phys_to_machine_mapping[__pa(skb->head) >> PAGE_SHIFT] =
+ rx->addr >> PAGE_SHIFT;
+
+ __skb_queue_tail(&rxq, skb);
+ }
+
+ /* Some pages are no longer absent... */
+ balloon_update_driver_allowance(-work_done);
+
+ /* Do all the remapping work, and M->P updates, in one big hypercall. */
+ if (likely((mcl - rx_mcl) != 0)) {
+ mcl->op = __HYPERVISOR_mmu_update;
+ mcl->args[0] = (unsigned long)rx_mmu;
+ mcl->args[1] = mmu - rx_mmu;
+ mcl->args[2] = 0;
+ mcl->args[3] = DOMID_SELF;
+ mcl++;
+ (void)HYPERVISOR_multicall(rx_mcl, mcl - rx_mcl);
+ }
+
+ while ((skb = __skb_dequeue(&rxq)) != NULL) {
+ /*
+ * Enough room in skbuff for the data we were passed? Also, Linux
+ * expects at least 16 bytes headroom in each receive buffer.
+ */
+ if (unlikely(skb->tail > skb->end) ||
+ unlikely((skb->data - skb->head) < 16)) {
+ nskb = NULL;
+
+ /* Only copy the packet if it fits in the current MTU. */
+ if (skb->len <= (dev->mtu + ETH_HLEN)) {
+ if ((skb->tail > skb->end) && net_ratelimit())
+ printk(KERN_INFO "Received packet needs %d bytes more "
+ "headroom.\n", skb->tail - skb->end);
+
+ if ((nskb = alloc_xen_skb(skb->len + 2)) != NULL) {
+ skb_reserve(nskb, 2);
+ skb_put(nskb, skb->len);
+ memcpy(nskb->data, skb->data, skb->len);
+ nskb->dev = skb->dev;
+ }
+ }
+ else if (net_ratelimit())
+ printk(KERN_INFO "Received packet too big for MTU "
+ "(%d > %d)\n", skb->len - ETH_HLEN, dev->mtu);
+
+ /* Reinitialise and then destroy the old skbuff. */
+ skb->len = 0;
+ skb->tail = skb->data;
+ init_skb_shinfo(skb);
+ dev_kfree_skb(skb);
+
+ /* Switch old for new, if we copied the buffer. */
+ if ((skb = nskb) == NULL)
+ continue;
+ }
+
+ /* Set the shared-info area, which is hidden behind the real data. */
+ init_skb_shinfo(skb);
+
+ /* Ethernet-specific work. Delayed to here as it peeks the header. */
+ skb->protocol = eth_type_trans(skb, dev);
+
+ /* Pass it up. */
+ netif_receive_skb(skb);
+ dev->last_rx = jiffies;
+ }
+
+ np->rx_resp_cons = i;
+
+ /* If we get a callback with very few responses, reduce fill target. */
+ /* NB. Note exponential increase, linear decrease. */
+ if (((np->rx->req_prod - np->rx->resp_prod) > ((3*np->rx_target) / 4)) &&
+ (--np->rx_target < RX_MIN_TARGET))
+ np->rx_target = RX_MIN_TARGET;
+
+ network_alloc_rx_buffers(dev);
+
+ *pbudget -= work_done;
+ dev->quota -= work_done;
+
+ if (work_done < budget) {
+ local_irq_save(flags);
+
+ np->rx->event = i + 1;
+
+ /* Deal with hypervisor racing our resetting of rx_event. */
+ mb();
+ if (np->rx->resp_prod == i) {
+ __netif_rx_complete(dev);
+ more_to_do = 0;
+ }
+
+ local_irq_restore(flags);
+ }
+
+ spin_unlock(&np->rx_lock);
+
+ return more_to_do;
+}
+
+
+static int network_close(struct net_device *dev)
+{
+ struct net_private *np = netdev_priv(dev);
+ np->user_state = UST_CLOSED;
+ netif_stop_queue(np->dev);
+ return 0;
+}
+
+
+static struct net_device_stats *network_get_stats(struct net_device *dev)
+{
+ struct net_private *np = netdev_priv(dev);
+ return &np->stats;
+}
+
+
+static void network_connect(struct net_device *dev,
+ netif_fe_interface_status_t *status)
+{
+ struct net_private *np;
+ int i, requeue_idx;
+ netif_tx_request_t *tx;
+
+ np = netdev_priv(dev);
+ spin_lock_irq(&np->tx_lock);
+ spin_lock(&np->rx_lock);
+
+ /* Recovery procedure: */
+
+ /* Step 1: Reinitialise variables. */
+ np->rx_resp_cons = np->tx_resp_cons = np->tx_full = 0;
+ np->rx->event = np->tx->event = 1;
+
+ /* Step 2: Rebuild the RX and TX ring contents.
+ * NB. We could just free the queued TX packets now but we hope
+ * that sending them out might do some good. We have to rebuild
+ * the RX ring because some of our pages are currently flipped out
+ * so we can't just free the RX skbs.
+ * NB2. Freelist index entries are always going to be less than
+ * __PAGE_OFFSET, whereas pointers to skbs will always be equal or
+ * greater than __PAGE_OFFSET: we use this property to distinguish
+ * them.
+ */
+
+ /* Rebuild the TX buffer freelist and the TX ring itself.
+ * NB. This reorders packets. We could keep more private state
+ * to avoid this but maybe it doesn't matter so much given the
+ * interface has been down.
+ */
+ for (requeue_idx = 0, i = 1; i <= NETIF_TX_RING_SIZE; i++) {
+ if ((unsigned long)np->tx_skbs[i] >= __PAGE_OFFSET) {
+ struct sk_buff *skb = np->tx_skbs[i];
+
+ tx = &np->tx->ring[requeue_idx++].req;
+
+ tx->id = i;
+ tx->addr = virt_to_machine(skb->data);
+ tx->size = skb->len;
+
+ np->stats.tx_bytes += skb->len;
+ np->stats.tx_packets++;
+ }
+ }
+ wmb();
+ np->tx->req_prod = requeue_idx;
+
+ /* Rebuild the RX buffer freelist and the RX ring itself. */
+ for (requeue_idx = 0, i = 1; i <= NETIF_RX_RING_SIZE; i++)
+ if ((unsigned long)np->rx_skbs[i] >= __PAGE_OFFSET)
+ np->rx->ring[requeue_idx++].req.id = i;
+ wmb();
+ np->rx->req_prod = requeue_idx;
+
+ /* Step 3: All public and private state should now be sane. Get
+ * ready to start sending and receiving packets and give the driver
+ * domain a kick because we've probably just requeued some
+ * packets.
+ */
+ np->backend_state = BEST_CONNECTED;
+ wmb();
+ notify_via_evtchn(status->evtchn);
+ network_tx_buf_gc(dev);
+
+ if (np->user_state == UST_OPEN)
+ netif_start_queue(dev);
+
+ spin_unlock(&np->rx_lock);
+ spin_unlock_irq(&np->tx_lock);
+}
+
+static void vif_show(struct net_private *np)
+{
+#if DEBUG
+ if (np) {
+ IPRINTK("<vif handle=%u %s(%s) evtchn=%u irq=%u tx=%p rx=%p>\n",
+ np->handle,
+ be_state_name[np->backend_state],
+ np->user_state ? "open" : "closed",
+ np->evtchn,
+ np->irq,
+ np->tx,
+ np->rx);
+ } else {
+ IPRINTK("<vif NULL>\n");
+ }
+#endif
+}
+
+/* Send a connect message to xend to tell it to bring up the interface. */
+static void send_interface_connect(struct net_private *np)
+{
+ ctrl_msg_t cmsg = {
+ .type = CMSG_NETIF_FE,
+ .subtype = CMSG_NETIF_FE_INTERFACE_CONNECT,
+ .length = sizeof(netif_fe_interface_connect_t),
+ };
+ netif_fe_interface_connect_t *msg = (void*)cmsg.msg;
+
+ msg->handle = np->handle;
+ msg->tx_shmem_frame = (virt_to_machine(np->tx) >> PAGE_SHIFT);
+ msg->rx_shmem_frame = (virt_to_machine(np->rx) >> PAGE_SHIFT);
+
+ ctrl_if_send_message_block(&cmsg, NULL, 0, TASK_UNINTERRUPTIBLE);
+}
+
+/* Send a driver status notification to the domain controller. */
+static int send_driver_status(int ok)
+{
+ int err = 0;
+ ctrl_msg_t cmsg = {
+ .type = CMSG_NETIF_FE,
+ .subtype = CMSG_NETIF_FE_DRIVER_STATUS,
+ .length = sizeof(netif_fe_driver_status_t),
+ };
+ netif_fe_driver_status_t *msg = (void*)cmsg.msg;
+
+ msg->status = (ok ? NETIF_DRIVER_STATUS_UP : NETIF_DRIVER_STATUS_DOWN);
+ err = ctrl_if_send_message_block(&cmsg, NULL, 0, TASK_UNINTERRUPTIBLE);
+ return err;
+}
+
+/* Stop network device and free tx/rx queues and irq.
+ */
+static void vif_release(struct net_private *np)
+{
+ /* Stop old i/f to prevent errors whilst we rebuild the state. */
+ spin_lock_irq(&np->tx_lock);
+ spin_lock(&np->rx_lock);
+ netif_stop_queue(np->dev);
+ /* np->backend_state = BEST_DISCONNECTED; */
+ spin_unlock(&np->rx_lock);
+ spin_unlock_irq(&np->tx_lock);
+
+ /* Free resources. */
+ if(np->tx != NULL){
+ free_irq(np->irq, np->dev);
+ unbind_evtchn_from_irq(np->evtchn);
+ free_page((unsigned long)np->tx);
+ free_page((unsigned long)np->rx);
+ np->irq = 0;
+ np->evtchn = 0;
+ np->tx = NULL;
+ np->rx = NULL;
+ }
+}
+
+/* Release vif resources and close it down completely.
+ */
+static void vif_close(struct net_private *np)
+{
+ WPRINTK("Unexpected netif-CLOSED message in state %s\n",
+ be_state_name[np->backend_state]);
+ vif_release(np);
+ np->backend_state = BEST_CLOSED;
+ /* todo: take dev down and free. */
+ vif_show(np);
+}
+
+/* Move the vif into disconnected state.
+ * Allocates tx/rx pages.
+ * Sends connect message to xend.
+ */
+static void vif_disconnect(struct net_private *np)
+{
+ if(np->tx) free_page((unsigned long)np->tx);
+ if(np->rx) free_page((unsigned long)np->rx);
+ // Before this np->tx and np->rx had better be null.
+ np->tx = (netif_tx_interface_t *)__get_free_page(GFP_KERNEL);
+ np->rx = (netif_rx_interface_t *)__get_free_page(GFP_KERNEL);
+ memset(np->tx, 0, PAGE_SIZE);
+ memset(np->rx, 0, PAGE_SIZE);
+ np->backend_state = BEST_DISCONNECTED;
+ send_interface_connect(np);
+ vif_show(np);
+}
+
+/* Begin interface recovery.
+ *
+ * NB. Whilst we're recovering, we turn the carrier state off. We
+ * take measures to ensure that this device isn't used for
+ * anything. We also stop the queue for this device. Various
+ * different approaches (e.g. continuing to buffer packets) have
+ * been tested but don't appear to improve the overall impact on
+ * TCP connections.
+ *
+ * TODO: (MAW) Change the Xend<->Guest protocol so that a recovery
+ * is initiated by a special "RESET" message - disconnect could
+ * just mean we're not allowed to use this interface any more.
+ */
+static void vif_reset(struct net_private *np)
+{
+ IPRINTK("Attempting to reconnect network interface: handle=%u\n",
+ np->handle);
+ vif_release(np);
+ vif_disconnect(np);
+ vif_show(np);
+}
+
+/* Move the vif into connected state.
+ * Sets the mac and event channel from the message.
+ * Binds the irq to the event channel.
+ */
+static void
+vif_connect(struct net_private *np, netif_fe_interface_status_t *status)
+{
+ struct net_device *dev = np->dev;
+ memcpy(dev->dev_addr, status->mac, ETH_ALEN);
+ network_connect(dev, status);
+ np->evtchn = status->evtchn;
+ np->irq = bind_evtchn_to_irq(np->evtchn);
+ (void)request_irq(np->irq, netif_int, SA_SAMPLE_RANDOM, dev->name, dev);
+ netctrl_connected_count();
+ (void)send_fake_arp(dev);
+ vif_show(np);
+}
+
+
+/** Create a network device.
+ * @param handle device handle
+ * @param val return parameter for created device
+ * @return 0 on success, error code otherwise
+ */
+static int create_netdev(int handle, struct net_device **val)
+{
+ int i, err = 0;
+ struct net_device *dev = NULL;
+ struct net_private *np = NULL;
+
+ if ((dev = alloc_etherdev(sizeof(struct net_private))) == NULL) {
+ printk(KERN_WARNING "%s> alloc_etherdev failed.\n", __FUNCTION__);
+ err = -ENOMEM;
+ goto exit;
+ }
+
+ np = netdev_priv(dev);
+ np->backend_state = BEST_CLOSED;
+ np->user_state = UST_CLOSED;
+ np->handle = handle;
+
+ spin_lock_init(&np->tx_lock);
+ spin_lock_init(&np->rx_lock);
+
+ skb_queue_head_init(&np->rx_batch);
+ np->rx_target = RX_MIN_TARGET;
+
+ /* Initialise {tx,rx}_skbs to be a free chain containing every entry. */
+ for (i = 0; i <= NETIF_TX_RING_SIZE; i++)
+ np->tx_skbs[i] = (void *)(i+1);
+ for (i = 0; i <= NETIF_RX_RING_SIZE; i++)
+ np->rx_skbs[i] = (void *)(i+1);
+
+ dev->open = network_open;
+ dev->hard_start_xmit = network_start_xmit;
+ dev->stop = network_close;
+ dev->get_stats = network_get_stats;
+ dev->poll = netif_poll;
+ dev->weight = 64;
+
+ if ((err = register_netdev(dev)) != 0) {
+ printk(KERN_WARNING "%s> register_netdev err=%d\n", __FUNCTION__, err);
+ goto exit;
+ }
+ np->dev = dev;
+ list_add(&np->list, &dev_list);
+
+ exit:
+ if ((err != 0) && (dev != NULL ))
+ kfree(dev);
+ else if (val != NULL)
+ *val = dev;
+ return err;
+}
+
+/* Get the target interface for a status message.
+ * Creates the interface when it makes sense.
+ * The returned interface may be null when there is no error.
+ *
+ * @param status status message
+ * @param np return parameter for interface state
+ * @return 0 on success, error code otherwise
+ */
+static int
+target_vif(netif_fe_interface_status_t *status, struct net_private **np)
+{
+ int err = 0;
+ struct net_device *dev;
+
+ DPRINTK("> handle=%d\n", status->handle);
+ if (status->handle < 0) {
+ err = -EINVAL;
+ goto exit;
+ }
+
+ if ((dev = find_dev_by_handle(status->handle)) != NULL)
+ goto exit;
+
+ if (status->status == NETIF_INTERFACE_STATUS_CLOSED)
+ goto exit;
+ if (status->status == NETIF_INTERFACE_STATUS_CHANGED)
+ goto exit;
+
+ /* It's a new interface in a good state - create it. */
+ DPRINTK("> create device...\n");
+ if ((err = create_netdev(status->handle, &dev)) != 0)
+ goto exit;
+
+ netctrl.interface_n++;
+
+ exit:
+ if (np != NULL)
+ *np = ((dev && !err) ? netdev_priv(dev) : NULL);
+ DPRINTK("< err=%d\n", err);
+ return err;
+}
+
+/* Handle an interface status message. */
+static void netif_interface_status(netif_fe_interface_status_t *status)
+{
+ int err = 0;
+ struct net_private *np = NULL;
+
+ DPRINTK("> status=%s handle=%d\n",
+ status_name[status->status], status->handle);
+
+ if ((err = target_vif(status, &np)) != 0) {
+ WPRINTK("Invalid netif: handle=%u\n", status->handle);
+ return;
+ }
+
+ if (np == NULL) {
+ DPRINTK("> no vif\n");
+ return;
+ }
+
+ switch (status->status) {
+ case NETIF_INTERFACE_STATUS_CLOSED:
+ switch (np->backend_state) {
+ case BEST_CLOSED:
+ case BEST_DISCONNECTED:
+ case BEST_CONNECTED:
+ vif_close(np);
+ break;
+ }
+ break;
+
+ case NETIF_INTERFACE_STATUS_DISCONNECTED:
+ switch (np->backend_state) {
+ case BEST_CLOSED:
+ vif_disconnect(np);
+ break;
+ case BEST_DISCONNECTED:
+ case BEST_CONNECTED:
+ vif_reset(np);
+ break;
+ }
+ break;
+
+ case NETIF_INTERFACE_STATUS_CONNECTED:
+ switch (np->backend_state) {
+ case BEST_CLOSED:
+ WPRINTK("Unexpected netif status %s in state %s\n",
+ status_name[status->status],
+ be_state_name[np->backend_state]);
+ vif_disconnect(np);
+ vif_connect(np, status);
+ break;
+ case BEST_DISCONNECTED:
+ vif_connect(np, status);
+ break;
+ }
+ break;
+
+ case NETIF_INTERFACE_STATUS_CHANGED:
+ /*
+ * The domain controller is notifying us that a device has been
+ * added or removed.
+ */
+ break;
+
+ default:
+ WPRINTK("Invalid netif status code %d\n", status->status);
+ break;
+ }
+
+ vif_show(np);
+}
+
+/*
+ * Initialize the network control interface.
+ */
+static void netif_driver_status(netif_fe_driver_status_t *status)
+{
+ netctrl.up = status->status;
+ netctrl_connected_count();
+}
+
+/* Receive handler for control messages. */
+static void netif_ctrlif_rx(ctrl_msg_t *msg, unsigned long id)
+{
+
+ switch (msg->subtype) {
+ case CMSG_NETIF_FE_INTERFACE_STATUS:
+ netif_interface_status((netif_fe_interface_status_t *) &msg->msg[0]);
+ break;
+
+ case CMSG_NETIF_FE_DRIVER_STATUS:
+ netif_driver_status((netif_fe_driver_status_t *) &msg->msg[0]);
+ break;
+
+ default:
+ msg->length = 0;
+ break;
+ }
+
+ ctrl_if_send_response(msg);
+}
+
+
+#if 1
+/* Wait for all interfaces to be connected.
+ *
+ * This works OK, but we'd like to use the probing mode (see below).
+ */
+static int probe_interfaces(void)
+{
+ int err = 0, conn = 0;
+ int wait_i, wait_n = 100;
+
+ DPRINTK(">\n");
+
+ for (wait_i = 0; wait_i < wait_n; wait_i++) {
+ DPRINTK("> wait_i=%d\n", wait_i);
+ conn = netctrl_connected();
+ if(conn) break;
+ DPRINTK("> schedule_timeout...\n");
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(10);
+ }
+
+ DPRINTK("> wait finished...\n");
+ if (conn <= 0) {
+ err = netctrl_err(-ENETDOWN);
+ WPRINTK("Failed to connect all virtual interfaces: err=%d\n", err);
+ }
+
+ DPRINTK("< err=%d\n", err);
+
+ return err;
+}
+#else
+/* Probe for interfaces until no more are found.
+ *
+ * This is the mode we'd like to use, but at the moment it panics the kernel.
+*/
+static int probe_interfaces(void)
+{
+ int err = 0;
+ int wait_i, wait_n = 100;
+ ctrl_msg_t cmsg = {
+ .type = CMSG_NETIF_FE,
+ .subtype = CMSG_NETIF_FE_INTERFACE_STATUS,
+ .length = sizeof(netif_fe_interface_status_t),
+ };
+ netif_fe_interface_status_t msg = {};
+ ctrl_msg_t rmsg = {};
+ netif_fe_interface_status_t *reply = (void*)rmsg.msg;
+ int state = TASK_UNINTERRUPTIBLE;
+ u32 query = -1;
+
+ DPRINTK(">\n");
+
+ netctrl.interface_n = 0;
+ for (wait_i = 0; wait_i < wait_n; wait_i++) {
+ DPRINTK("> wait_i=%d query=%d\n", wait_i, query);
+ msg.handle = query;
+ memcpy(cmsg.msg, &msg, sizeof(msg));
+ DPRINTK("> set_current_state...\n");
+ set_current_state(state);
+ DPRINTK("> rmsg=%p msg=%p, reply=%p\n", &rmsg, rmsg.msg, reply);
+ DPRINTK("> sending...\n");
+ err = ctrl_if_send_message_and_get_response(&cmsg, &rmsg, state);
+ DPRINTK("> err=%d\n", err);
+ if(err) goto exit;
+ DPRINTK("> rmsg=%p msg=%p, reply=%p\n", &rmsg, rmsg.msg, reply);
+ if((int)reply->handle < 0) {
+ // No more interfaces.
+ break;
+ }
+ query = -reply->handle - 2;
+ DPRINTK(">netif_interface_status ...\n");
+ netif_interface_status(reply);
+ }
+
+ exit:
+ if (err) {
+ err = netctrl_err(-ENETDOWN);
+ WPRINTK("Connecting virtual network interfaces failed: err=%d\n", err);
+ }
+
+ DPRINTK("< err=%d\n", err);
+ return err;
+}
+
+#endif
+
+/*
+ * We use this notifier to send out a fake ARP reply to reset switches and
+ * router ARP caches when an IP interface is brought up on a VIF.
+ */
+static int
+inetdev_notify(struct notifier_block *this, unsigned long event, void *ptr)
+{
+ struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
+ struct net_device *dev = ifa->ifa_dev->dev;
+ struct list_head *ent;
+ struct net_private *np;
+
+ if (event != NETDEV_UP)
+ goto out;
+
+ list_for_each (ent, &dev_list) {
+ np = list_entry(ent, struct net_private, list);
+ if (np->dev == dev)
+ (void)send_fake_arp(dev);
+ }
+
+ out:
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block notifier_inetdev = {
+ .notifier_call = inetdev_notify,
+ .next = NULL,
+ .priority = 0
+};
+
+static int __init netif_init(void)
+{
+ int err = 0;
+
+ if (xen_start_info.flags & SIF_INITDOMAIN)
+ return 0;
+
+ IPRINTK("Initialising virtual ethernet driver.\n");
+ INIT_LIST_HEAD(&dev_list);
+ (void)register_inetaddr_notifier(¬ifier_inetdev);
+ netctrl_init();
+ (void)ctrl_if_register_receiver(CMSG_NETIF_FE, netif_ctrlif_rx,
+ CALLBACK_IN_BLOCKING_CONTEXT);
+ send_driver_status(1);
+ err = probe_interfaces();
+ if (err)
+ ctrl_if_unregister_receiver(CMSG_NETIF_FE, netif_ctrlif_rx);
+
+ DPRINTK("< err=%d\n", err);
+ return err;
+}
+
+static void vif_suspend(struct net_private *np)
+{
+ /* Avoid having tx/rx stuff happen until we're ready. */
+ free_irq(np->irq, np->dev);
+ unbind_evtchn_from_irq(np->evtchn);
+}
+
+static void vif_resume(struct net_private *np)
+{
+ /*
+ * Connect regardless of whether IFF_UP flag set.
+ * Stop bad things from happening until we're back up.
+ */
+ np->backend_state = BEST_DISCONNECTED;
+ memset(np->tx, 0, PAGE_SIZE);
+ memset(np->rx, 0, PAGE_SIZE);
+
+ send_interface_connect(np);
+}
+
+void netif_suspend(void)
+{
+ struct list_head *ent;
+ struct net_private *np;
+
+ list_for_each (ent, &dev_list) {
+ np = list_entry(ent, struct net_private, list);
+ vif_suspend(np);
+ }
+}
+
+void netif_resume(void)
+{
+ struct list_head *ent;
+ struct net_private *np;
+
+ list_for_each (ent, &dev_list) {
+ np = list_entry(ent, struct net_private, list);
+ vif_resume(np);
+ }
+}
+
+
+module_init(netif_init);
+
git://git.onelab.eu / linux-2.6.git / blobdiff