linux/drivers/net/xen-netback/interface.c
Paul Durrant 210c34dcd8 xen-netback: add support for multicast control
Xen's PV network protocol includes messages to add/remove ethernet
multicast addresses to/from a filter list in the backend. This allows
the frontend to request the backend only forward multicast packets
which are of interest thus preventing unnecessary noise on the shared
ring.

The canonical netif header in git://xenbits.xen.org/xen.git specifies
the message format (two more XEN_NETIF_EXTRA_TYPEs) so the minimal
necessary changes have been pulled into include/xen/interface/io/netif.h.

To prevent the frontend from extending the multicast filter list
arbitrarily a limit (XEN_NETBK_MCAST_MAX) has been set to 64 entries.
This limit is not specified by the protocol and so may change in future.
If the limit is reached then the next XEN_NETIF_EXTRA_TYPE_MCAST_ADD
sent by the frontend will be failed with NETIF_RSP_ERROR.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-02 11:45:00 -07:00

706 lines
18 KiB
C

/*
* 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);
/* Wake the dealloc thread _after_ decrementing inflight_packets so
* that if kthread_stop() has already been called, the dealloc thread
* does not wait forever with nothing to wake it.
*/
wake_up(&queue->dealloc_wq);
}
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;
if (vif->multicast_control && skb->pkt_type == PACKET_MULTICAST) {
struct ethhdr *eth = (struct ethhdr *)skb->data;
if (!xenvif_mcast_match(vif, eth->h_dest))
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);
INIT_LIST_HEAD(&vif->fe_mcast_addr);
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);
}
xenvif_mcast_addr_list_free(vif);
}
/* 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);
}