linux/drivers/net/xen-netback/interface.c

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xen network backend driver netback is the host side counterpart to the frontend driver in drivers/net/xen-netfront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs and even Windows. The patch is based on the driver from the xen.git pvops kernel tree but has been put through the checkpatch.pl wringer plus several manual cleanup passes and review iterations. The driver has been moved from drivers/xen/netback to drivers/net/xen-netback. One major change from xen.git is that the guest transmit path (i.e. what looks like receive to netback) has been significantly reworked to remove the dependency on the out of tree PageForeign page flag (a core kernel patch which enables a per page destructor callback on the final put_page). This page flag was used in order to implement a grant map based transmit path (where guest pages are mapped directly into SKB frags). Instead this version of netback uses grant copy operations into regular memory belonging to the backend domain. Reinstating the grant map functionality is something which I would like to revisit in the future. Note that this driver depends on 2e820f58f7ad "xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in linux next via the "xen-two" tree and is intended for the 2.6.39 merge window: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends this branch has only that single commit since 2.6.38-rc2 and is safe for cross merging into the net branch. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-15 00:06:18 +00:00
/*
* 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/ethtool.h>
#include <linux/rtnetlink.h>
#include <linux/if_vlan.h>
#include <xen/events.h>
#include <asm/xen/hypercall.h>
#define XENVIF_QUEUE_LENGTH 32
void xenvif_get(struct xenvif *vif)
{
atomic_inc(&vif->refcnt);
}
void xenvif_put(struct xenvif *vif)
{
if (atomic_dec_and_test(&vif->refcnt))
wake_up(&vif->waiting_to_free);
}
int xenvif_schedulable(struct xenvif *vif)
{
return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
}
static int xenvif_rx_schedulable(struct xenvif *vif)
{
return xenvif_schedulable(vif) && !xen_netbk_rx_ring_full(vif);
}
static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
{
struct xenvif *vif = dev_id;
if (vif->netbk == NULL)
return IRQ_NONE;
xen_netbk_schedule_xenvif(vif);
if (xenvif_rx_schedulable(vif))
netif_wake_queue(vif->dev);
return IRQ_HANDLED;
}
static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct xenvif *vif = netdev_priv(dev);
BUG_ON(skb->dev != dev);
if (vif->netbk == NULL)
goto drop;
/* Drop the packet if the target domain has no receive buffers. */
if (!xenvif_rx_schedulable(vif))
goto drop;
/* Reserve ring slots for the worst-case number of fragments. */
vif->rx_req_cons_peek += xen_netbk_count_skb_slots(vif, skb);
xenvif_get(vif);
if (vif->can_queue && xen_netbk_must_stop_queue(vif))
netif_stop_queue(dev);
xen_netbk_queue_tx_skb(vif, skb);
return NETDEV_TX_OK;
drop:
vif->dev->stats.tx_dropped++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
void xenvif_receive_skb(struct xenvif *vif, struct sk_buff *skb)
{
netif_rx_ni(skb);
}
void xenvif_notify_tx_completion(struct xenvif *vif)
{
if (netif_queue_stopped(vif->dev) && xenvif_rx_schedulable(vif))
netif_wake_queue(vif->dev);
}
static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
{
struct xenvif *vif = netdev_priv(dev);
return &vif->dev->stats;
}
static void xenvif_up(struct xenvif *vif)
{
xen_netbk_add_xenvif(vif);
enable_irq(vif->irq);
xen_netbk_check_rx_xenvif(vif);
}
static void xenvif_down(struct xenvif *vif)
{
disable_irq(vif->irq);
xen_netbk_deschedule_xenvif(vif);
xen_netbk_remove_xenvif(vif);
}
static int xenvif_open(struct net_device *dev)
{
struct xenvif *vif = netdev_priv(dev);
if (netif_carrier_ok(dev))
xenvif_up(vif);
netif_start_queue(dev);
return 0;
}
static int xenvif_close(struct net_device *dev)
{
struct xenvif *vif = netdev_priv(dev);
if (netif_carrier_ok(dev))
xenvif_down(vif);
netif_stop_queue(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)
xen network backend driver netback is the host side counterpart to the frontend driver in drivers/net/xen-netfront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs and even Windows. The patch is based on the driver from the xen.git pvops kernel tree but has been put through the checkpatch.pl wringer plus several manual cleanup passes and review iterations. The driver has been moved from drivers/xen/netback to drivers/net/xen-netback. One major change from xen.git is that the guest transmit path (i.e. what looks like receive to netback) has been significantly reworked to remove the dependency on the out of tree PageForeign page flag (a core kernel patch which enables a per page destructor callback on the final put_page). This page flag was used in order to implement a grant map based transmit path (where guest pages are mapped directly into SKB frags). Instead this version of netback uses grant copy operations into regular memory belonging to the backend domain. Reinstating the grant map functionality is something which I would like to revisit in the future. Note that this driver depends on 2e820f58f7ad "xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in linux next via the "xen-two" tree and is intended for the 2.6.39 merge window: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends this branch has only that single commit since 2.6.38-rc2 and is safe for cross merging into the net branch. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-15 00:06:18 +00:00
{
struct xenvif *vif = netdev_priv(dev);
if (!vif->can_sg)
features &= ~NETIF_F_SG;
if (!vif->gso && !vif->gso_prefix)
features &= ~NETIF_F_TSO;
if (!vif->csum)
features &= ~NETIF_F_IP_CSUM;
xen network backend driver netback is the host side counterpart to the frontend driver in drivers/net/xen-netfront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs and even Windows. The patch is based on the driver from the xen.git pvops kernel tree but has been put through the checkpatch.pl wringer plus several manual cleanup passes and review iterations. The driver has been moved from drivers/xen/netback to drivers/net/xen-netback. One major change from xen.git is that the guest transmit path (i.e. what looks like receive to netback) has been significantly reworked to remove the dependency on the out of tree PageForeign page flag (a core kernel patch which enables a per page destructor callback on the final put_page). This page flag was used in order to implement a grant map based transmit path (where guest pages are mapped directly into SKB frags). Instead this version of netback uses grant copy operations into regular memory belonging to the backend domain. Reinstating the grant map functionality is something which I would like to revisit in the future. Note that this driver depends on 2e820f58f7ad "xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in linux next via the "xen-two" tree and is intended for the 2.6.39 merge window: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends this branch has only that single commit since 2.6.38-rc2 and is safe for cross merging into the net branch. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-15 00:06:18 +00:00
return features;
xen network backend driver netback is the host side counterpart to the frontend driver in drivers/net/xen-netfront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs and even Windows. The patch is based on the driver from the xen.git pvops kernel tree but has been put through the checkpatch.pl wringer plus several manual cleanup passes and review iterations. The driver has been moved from drivers/xen/netback to drivers/net/xen-netback. One major change from xen.git is that the guest transmit path (i.e. what looks like receive to netback) has been significantly reworked to remove the dependency on the out of tree PageForeign page flag (a core kernel patch which enables a per page destructor callback on the final put_page). This page flag was used in order to implement a grant map based transmit path (where guest pages are mapped directly into SKB frags). Instead this version of netback uses grant copy operations into regular memory belonging to the backend domain. Reinstating the grant map functionality is something which I would like to revisit in the future. Note that this driver depends on 2e820f58f7ad "xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in linux next via the "xen-two" tree and is intended for the 2.6.39 merge window: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends this branch has only that single commit since 2.6.38-rc2 and is safe for cross merging into the net branch. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-15 00:06:18 +00:00
}
static const struct xenvif_stat {
char name[ETH_GSTRING_LEN];
u16 offset;
} xenvif_stats[] = {
{
"rx_gso_checksum_fixup",
offsetof(struct xenvif, rx_gso_checksum_fixup)
},
};
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)
{
void *vif = netdev_priv(dev);
int i;
for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
data[i] = *(unsigned long *)(vif + xenvif_stats[i].offset);
}
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 = {
xen network backend driver netback is the host side counterpart to the frontend driver in drivers/net/xen-netfront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs and even Windows. The patch is based on the driver from the xen.git pvops kernel tree but has been put through the checkpatch.pl wringer plus several manual cleanup passes and review iterations. The driver has been moved from drivers/xen/netback to drivers/net/xen-netback. One major change from xen.git is that the guest transmit path (i.e. what looks like receive to netback) has been significantly reworked to remove the dependency on the out of tree PageForeign page flag (a core kernel patch which enables a per page destructor callback on the final put_page). This page flag was used in order to implement a grant map based transmit path (where guest pages are mapped directly into SKB frags). Instead this version of netback uses grant copy operations into regular memory belonging to the backend domain. Reinstating the grant map functionality is something which I would like to revisit in the future. Note that this driver depends on 2e820f58f7ad "xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in linux next via the "xen-two" tree and is intended for the 2.6.39 merge window: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends this branch has only that single commit since 2.6.38-rc2 and is safe for cross merging into the net branch. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-15 00:06:18 +00:00
.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 = {
xen network backend driver netback is the host side counterpart to the frontend driver in drivers/net/xen-netfront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs and even Windows. The patch is based on the driver from the xen.git pvops kernel tree but has been put through the checkpatch.pl wringer plus several manual cleanup passes and review iterations. The driver has been moved from drivers/xen/netback to drivers/net/xen-netback. One major change from xen.git is that the guest transmit path (i.e. what looks like receive to netback) has been significantly reworked to remove the dependency on the out of tree PageForeign page flag (a core kernel patch which enables a per page destructor callback on the final put_page). This page flag was used in order to implement a grant map based transmit path (where guest pages are mapped directly into SKB frags). Instead this version of netback uses grant copy operations into regular memory belonging to the backend domain. Reinstating the grant map functionality is something which I would like to revisit in the future. Note that this driver depends on 2e820f58f7ad "xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in linux next via the "xen-two" tree and is intended for the 2.6.39 merge window: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends this branch has only that single commit since 2.6.38-rc2 and is safe for cross merging into the net branch. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-15 00:06:18 +00:00
.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,
xen network backend driver netback is the host side counterpart to the frontend driver in drivers/net/xen-netfront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs and even Windows. The patch is based on the driver from the xen.git pvops kernel tree but has been put through the checkpatch.pl wringer plus several manual cleanup passes and review iterations. The driver has been moved from drivers/xen/netback to drivers/net/xen-netback. One major change from xen.git is that the guest transmit path (i.e. what looks like receive to netback) has been significantly reworked to remove the dependency on the out of tree PageForeign page flag (a core kernel patch which enables a per page destructor callback on the final put_page). This page flag was used in order to implement a grant map based transmit path (where guest pages are mapped directly into SKB frags). Instead this version of netback uses grant copy operations into regular memory belonging to the backend domain. Reinstating the grant map functionality is something which I would like to revisit in the future. Note that this driver depends on 2e820f58f7ad "xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in linux next via the "xen-two" tree and is intended for the 2.6.39 merge window: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends this branch has only that single commit since 2.6.38-rc2 and is safe for cross merging into the net branch. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-15 00:06:18 +00:00
};
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);
dev = alloc_netdev(sizeof(struct xenvif), name, ether_setup);
if (dev == NULL) {
pr_warn("Could not allocate netdev\n");
return ERR_PTR(-ENOMEM);
}
SET_NETDEV_DEV(dev, parent);
vif = netdev_priv(dev);
vif->domid = domid;
vif->handle = handle;
vif->netbk = NULL;
vif->can_sg = 1;
vif->csum = 1;
atomic_set(&vif->refcnt, 1);
init_waitqueue_head(&vif->waiting_to_free);
vif->dev = dev;
INIT_LIST_HEAD(&vif->schedule_list);
INIT_LIST_HEAD(&vif->notify_list);
vif->credit_bytes = vif->remaining_credit = ~0UL;
vif->credit_usec = 0UL;
init_timer(&vif->credit_timeout);
/* Initialize 'expires' now: it's used to track the credit window. */
vif->credit_timeout.expires = jiffies;
dev->netdev_ops = &xenvif_netdev_ops;
dev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_TSO;
dev->features = dev->hw_features;
xen network backend driver netback is the host side counterpart to the frontend driver in drivers/net/xen-netfront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs and even Windows. The patch is based on the driver from the xen.git pvops kernel tree but has been put through the checkpatch.pl wringer plus several manual cleanup passes and review iterations. The driver has been moved from drivers/xen/netback to drivers/net/xen-netback. One major change from xen.git is that the guest transmit path (i.e. what looks like receive to netback) has been significantly reworked to remove the dependency on the out of tree PageForeign page flag (a core kernel patch which enables a per page destructor callback on the final put_page). This page flag was used in order to implement a grant map based transmit path (where guest pages are mapped directly into SKB frags). Instead this version of netback uses grant copy operations into regular memory belonging to the backend domain. Reinstating the grant map functionality is something which I would like to revisit in the future. Note that this driver depends on 2e820f58f7ad "xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in linux next via the "xen-two" tree and is intended for the 2.6.39 merge window: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends this branch has only that single commit since 2.6.38-rc2 and is safe for cross merging into the net branch. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-15 00:06:18 +00:00
SET_ETHTOOL_OPS(dev, &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)
*/
memset(dev->dev_addr, 0xFF, ETH_ALEN);
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");
return vif;
}
int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
unsigned long rx_ring_ref, unsigned int evtchn)
{
int err = -ENOMEM;
/* Already connected through? */
if (vif->irq)
return 0;
err = xen_netbk_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
if (err < 0)
goto err;
err = bind_interdomain_evtchn_to_irqhandler(
vif->domid, evtchn, xenvif_interrupt, 0,
vif->dev->name, vif);
if (err < 0)
goto err_unmap;
vif->irq = err;
disable_irq(vif->irq);
xenvif_get(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);
netif_carrier_on(vif->dev);
if (netif_running(vif->dev))
xenvif_up(vif);
xen network backend driver netback is the host side counterpart to the frontend driver in drivers/net/xen-netfront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs and even Windows. The patch is based on the driver from the xen.git pvops kernel tree but has been put through the checkpatch.pl wringer plus several manual cleanup passes and review iterations. The driver has been moved from drivers/xen/netback to drivers/net/xen-netback. One major change from xen.git is that the guest transmit path (i.e. what looks like receive to netback) has been significantly reworked to remove the dependency on the out of tree PageForeign page flag (a core kernel patch which enables a per page destructor callback on the final put_page). This page flag was used in order to implement a grant map based transmit path (where guest pages are mapped directly into SKB frags). Instead this version of netback uses grant copy operations into regular memory belonging to the backend domain. Reinstating the grant map functionality is something which I would like to revisit in the future. Note that this driver depends on 2e820f58f7ad "xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in linux next via the "xen-two" tree and is intended for the 2.6.39 merge window: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends this branch has only that single commit since 2.6.38-rc2 and is safe for cross merging into the net branch. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-15 00:06:18 +00:00
rtnl_unlock();
return 0;
err_unmap:
xen_netbk_unmap_frontend_rings(vif);
err:
return err;
}
void xenvif_disconnect(struct xenvif *vif)
{
struct net_device *dev = vif->dev;
if (netif_carrier_ok(dev)) {
rtnl_lock();
netif_carrier_off(dev); /* discard queued packets */
if (netif_running(dev))
xenvif_down(vif);
rtnl_unlock();
xenvif_put(vif);
}
atomic_dec(&vif->refcnt);
wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0);
del_timer_sync(&vif->credit_timeout);
if (vif->irq)
unbind_from_irqhandler(vif->irq, vif);
unregister_netdev(vif->dev);
xen_netbk_unmap_frontend_rings(vif);
free_netdev(vif->dev);
}