/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2004-2006 Kip Macy
* Copyright (c) 2015 Wei Liu <wei.liu2@citrix.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/sockio.h>
#include <sys/limits.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_media.h>
#include <net/bpf.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>
#include <netinet/tcp.h>
#include <netinet/tcp_lro.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <sys/bus.h>
#include <xen/xen-os.h>
#include <xen/hypervisor.h>
#include <xen/xen_intr.h>
#include <xen/gnttab.h>
#include <xen/interface/memory.h>
#include <xen/interface/io/netif.h>
#include <xen/xenbus/xenbusvar.h>
#include "xenbus_if.h"
/* Features supported by all backends. TSO and LRO can be negotiated */
#define XN_CSUM_FEATURES (CSUM_TCP | CSUM_UDP)
#define NET_TX_RING_SIZE __CONST_RING_SIZE(netif_tx, PAGE_SIZE)
#define NET_RX_RING_SIZE __CONST_RING_SIZE(netif_rx, PAGE_SIZE)
#define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
/*
* Should the driver do LRO on the RX end
* this can be toggled on the fly, but the
* interface must be reset (down/up) for it
* to take effect.
*/
static int xn_enable_lro = 1;
TUNABLE_INT("hw.xn.enable_lro", &xn_enable_lro);
/*
* Number of pairs of queues.
*/
static unsigned long xn_num_queues = 4;
TUNABLE_ULONG("hw.xn.num_queues", &xn_num_queues);
/**
* \brief The maximum allowed data fragments in a single transmit
* request.
*
* This limit is imposed by the backend driver. We assume here that
* we are dealing with a Linux driver domain and have set our limit
* to mirror the Linux MAX_SKB_FRAGS constant.
*/
#define MAX_TX_REQ_FRAGS (65536 / PAGE_SIZE + 2)
#define RX_COPY_THRESHOLD 256
#define net_ratelimit() 0
struct netfront_rxq;
struct netfront_txq;
struct netfront_info;
struct netfront_rx_info;
static void xn_txeof(struct netfront_txq *);
static void xn_rxeof(struct netfront_rxq *);
static void xn_alloc_rx_buffers(struct netfront_rxq *);
static void xn_alloc_rx_buffers_callout(void *arg);
static void xn_release_rx_bufs(struct netfront_rxq *);
static void xn_release_tx_bufs(struct netfront_txq *);
static void xn_rxq_intr(struct netfront_rxq *);
static void xn_txq_intr(struct netfront_txq *);
static void xn_intr(void *);
static inline int xn_count_frags(struct mbuf *m);
static int xn_assemble_tx_request(struct netfront_txq *, struct mbuf *);
static int xn_ioctl(struct ifnet *, u_long, caddr_t);
static void xn_ifinit_locked(struct netfront_info *);
static void xn_ifinit(void *);
static void xn_stop(struct netfront_info *);
static void xn_query_features(struct netfront_info *np);
static int xn_configure_features(struct netfront_info *np);
static void netif_free(struct netfront_info *info);
static int netfront_detach(device_t dev);
static int xn_txq_mq_start_locked(struct netfront_txq *, struct mbuf *);
static int xn_txq_mq_start(struct ifnet *, struct mbuf *);
static int talk_to_backend(device_t dev, struct netfront_info *info);
static int create_netdev(device_t dev);
static void netif_disconnect_backend(struct netfront_info *info);
static int setup_device(device_t dev, struct netfront_info *info,
unsigned long);
static int xn_ifmedia_upd(struct ifnet *ifp);
static void xn_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr);
static int xn_connect(struct netfront_info *);
static void xn_kick_rings(struct netfront_info *);
static int xn_get_responses(struct netfront_rxq *,
struct netfront_rx_info *, RING_IDX, RING_IDX *,
struct mbuf **);
#define virt_to_mfn(x) (vtophys(x) >> PAGE_SHIFT)
#define INVALID_P2M_ENTRY (~0UL)
#define XN_QUEUE_NAME_LEN 8 /* xn{t,r}x_%u, allow for two digits */
struct netfront_rxq {
struct netfront_info *info;
u_int id;
char name[XN_QUEUE_NAME_LEN];
struct mtx lock;
int ring_ref;
netif_rx_front_ring_t ring;
xen_intr_handle_t xen_intr_handle;
grant_ref_t gref_head;
grant_ref_t grant_ref[NET_RX_RING_SIZE + 1];
struct mbuf *mbufs[NET_RX_RING_SIZE + 1];
struct lro_ctrl lro;
struct callout rx_refill;
};
struct netfront_txq {
struct netfront_info *info;
u_int id;
char name[XN_QUEUE_NAME_LEN];
struct mtx lock;
int ring_ref;
netif_tx_front_ring_t ring;
xen_intr_handle_t xen_intr_handle;
grant_ref_t gref_head;
grant_ref_t grant_ref[NET_TX_RING_SIZE + 1];
struct mbuf *mbufs[NET_TX_RING_SIZE + 1];
int mbufs_cnt;
struct buf_ring *br;
struct taskqueue *tq;
struct task defrtask;
bool full;
};
struct netfront_info {
struct ifnet *xn_ifp;
struct mtx sc_lock;
u_int num_queues;
struct netfront_rxq *rxq;
struct netfront_txq *txq;
u_int carrier;
u_int maxfrags;
device_t xbdev;
uint8_t mac[ETHER_ADDR_LEN];
int xn_if_flags;
struct ifmedia sc_media;
bool xn_reset;
};
struct netfront_rx_info {
struct netif_rx_response rx;
struct netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
};
#define XN_RX_LOCK(_q) mtx_lock(&(_q)->lock)
#define XN_RX_UNLOCK(_q) mtx_unlock(&(_q)->lock)
#define XN_TX_LOCK(_q) mtx_lock(&(_q)->lock)
#define XN_TX_TRYLOCK(_q) mtx_trylock(&(_q)->lock)
#define XN_TX_UNLOCK(_q) mtx_unlock(&(_q)->lock)
#define XN_LOCK(_sc) mtx_lock(&(_sc)->sc_lock);
#define XN_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_lock);
#define XN_LOCK_ASSERT(_sc) mtx_assert(&(_sc)->sc_lock, MA_OWNED);
#define XN_RX_LOCK_ASSERT(_q) mtx_assert(&(_q)->lock, MA_OWNED);
#define XN_TX_LOCK_ASSERT(_q) mtx_assert(&(_q)->lock, MA_OWNED);
#define netfront_carrier_on(netif) ((netif)->carrier = 1)
#define netfront_carrier_off(netif) ((netif)->carrier = 0)
#define netfront_carrier_ok(netif) ((netif)->carrier)
/* Access macros for acquiring freeing slots in xn_free_{tx,rx}_idxs[]. */
static inline void
add_id_to_freelist(struct mbuf **list, uintptr_t id)
{
KASSERT(id != 0,
("%s: the head item (0) must always be free.", __func__));
list[id] = list[0];
list[0] = (struct mbuf *)id;
}
static inline unsigned short
get_id_from_freelist(struct mbuf **list)
{
uintptr_t id;
id = (uintptr_t)list[0];
KASSERT(id != 0,
("%s: the head item (0) must always remain free.", __func__));
list[0] = list[id];
return (id);
}
static inline int
xn_rxidx(RING_IDX idx)
{
return idx & (NET_RX_RING_SIZE - 1);
}
static inline struct mbuf *
xn_get_rx_mbuf(struct netfront_rxq *rxq, RING_IDX ri)
{
int i;
struct mbuf *m;
i = xn_rxidx(ri);
m = rxq->mbufs[i];
rxq->mbufs[i] = NULL;
return (m);
}
static inline grant_ref_t
xn_get_rx_ref(struct netfront_rxq *rxq, RING_IDX ri)
{
int i = xn_rxidx(ri);
grant_ref_t ref = rxq->grant_ref[i];
KASSERT(ref != GRANT_REF_INVALID, ("Invalid grant reference!\n"));
rxq->grant_ref[i] = GRANT_REF_INVALID;
return (ref);
}
#define IPRINTK(fmt, args...) \
printf("[XEN] " fmt, ##args)
#ifdef INVARIANTS
#define WPRINTK(fmt, args...) \
printf("[XEN] " fmt, ##args)
#else
#define WPRINTK(fmt, args...)
#endif
#ifdef DEBUG
#define DPRINTK(fmt, args...) \
printf("[XEN] %s: " fmt, __func__, ##args)
#else
#define DPRINTK(fmt, args...)
#endif
/**
* Read the 'mac' node at the given device's node in the store, and parse that
* as colon-separated octets, placing result the given mac array. mac must be
* a preallocated array of length ETH_ALEN (as declared in linux/if_ether.h).
* Return 0 on success, or errno on error.
*/
static int
xen_net_read_mac(device_t dev, uint8_t mac[])
{
int error, i;
char *s, *e, *macstr;
const char *path;
path = xenbus_get_node(dev);
error = xs_read(XST_NIL, path, "mac", NULL, (void **) &macstr);
if (error == ENOENT) {
/*
* Deal with missing mac XenStore nodes on devices with
* HVM emulation (the 'ioemu' configuration attribute)
* enabled.
*
* The HVM emulator may execute in a stub device model
* domain which lacks the permission, only given to Dom0,
* to update the guest's XenStore tree. For this reason,
* the HVM emulator doesn't even attempt to write the
* front-side mac node, even when operating in Dom0.
* However, there should always be a mac listed in the
* backend tree. Fallback to this version if our query
* of the front side XenStore location doesn't find
* anything.
*/
path = xenbus_get_otherend_path(dev);
error = xs_read(XST_NIL, path, "mac", NULL, (void **) &macstr);
}
if (error != 0) {
xenbus_dev_fatal(dev, error, "parsing %s/mac", path);
return (error);
}
s = macstr;
for (i = 0; i < ETHER_ADDR_LEN; i++) {
mac[i] = strtoul(s, &e, 16);
if (s == e || (e[0] != ':' && e[0] != 0)) {
free(macstr, M_XENBUS);
return (ENOENT);
}
s = &e[1];
}
free(macstr, M_XENBUS);
return (0);
}
/**
* Entry point to this code when a new device is created. Allocate the basic
* structures and the ring buffers for communication with the backend, and
* inform the backend of the appropriate details for those. Switch to
* Connected state.
*/
static int
netfront_probe(device_t dev)
{
if (xen_hvm_domain() && xen_disable_pv_nics != 0)
return (ENXIO);
if (!strcmp(xenbus_get_type(dev), "vif")) {
device_set_desc(dev, "Virtual Network Interface");
return (0);
}
return (ENXIO);
}
static int
netfront_attach(device_t dev)
{
int err;
err = create_netdev(dev);
if (err != 0) {
xenbus_dev_fatal(dev, err, "creating netdev");
return (err);
}
SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
OID_AUTO, "enable_lro", CTLFLAG_RW,
&xn_enable_lro, 0, "Large Receive Offload");
SYSCTL_ADD_ULONG(device_get_sysctl_ctx(dev),
SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
OID_AUTO, "num_queues", CTLFLAG_RD,
&xn_num_queues, "Number of pairs of queues");
return (0);
}
static int
netfront_suspend(device_t dev)
{
struct netfront_info *np = device_get_softc(dev);
u_int i;
for (i = 0; i < np->num_queues; i++) {
XN_RX_LOCK(&np->rxq[i]);
XN_TX_LOCK(&np->txq[i]);
}
netfront_carrier_off(np);
for (i = 0; i < np->num_queues; i++) {
XN_RX_UNLOCK(&np->rxq[i]);
XN_TX_UNLOCK(&np->txq[i]);
}
return (0);
}
/**
* We are reconnecting to the backend, due to a suspend/resume, or a backend
* driver restart. We tear down our netif structure and recreate it, but
* leave the device-layer structures intact so that this is transparent to the
* rest of the kernel.
*/
static int
netfront_resume(device_t dev)
{
struct netfront_info *info = device_get_softc(dev);
u_int i;
if (xen_suspend_cancelled) {
for (i = 0; i < info->num_queues; i++) {
XN_RX_LOCK(&info->rxq[i]);
XN_TX_LOCK(&info->txq[i]);
}
netfront_carrier_on(info);
for (i = 0; i < info->num_queues; i++) {
XN_RX_UNLOCK(&info->rxq[i]);
XN_TX_UNLOCK(&info->txq[i]);
}
return (0);
}
netif_disconnect_backend(info);
return (0);
}
static int
write_queue_xenstore_keys(device_t dev,
struct netfront_rxq *rxq,
struct netfront_txq *txq,
struct xs_transaction *xst, bool hierarchy)
{
int err;
const char *message;
const char *node = xenbus_get_node(dev);
char *path;
size_t path_size;
KASSERT(rxq->id == txq->id, ("Mismatch between RX and TX queue ids"));
/* Split event channel support is not yet there. */
KASSERT(rxq->xen_intr_handle == txq->xen_intr_handle,
("Split event channels are not supported"));
if (hierarchy) {
path_size = strlen(node) + 10;
path = malloc(path_size, M_DEVBUF, M_WAITOK|M_ZERO);
snprintf(path, path_size, "%s/queue-%u", node, rxq->id);
} else {
path_size = strlen(node) + 1;
path = malloc(path_size, M_DEVBUF, M_WAITOK|M_ZERO);
snprintf(path, path_size, "%s", node);
}
err = xs_printf(*xst, path, "tx-ring-ref","%u", txq->ring_ref);
if (err != 0) {
message = "writing tx ring-ref";
goto error;
}
err = xs_printf(*xst, path, "rx-ring-ref","%u", rxq->ring_ref);
if (err != 0) {
message = "writing rx ring-ref";
goto error;
}
err = xs_printf(*xst, path, "event-channel", "%u",
xen_intr_port(rxq->xen_intr_handle));
if (err != 0) {
message = "writing event-channel";
goto error;
}
free(path, M_DEVBUF);
return (0);
error:
free(path, M_DEVBUF);
xenbus_dev_fatal(dev, err, "%s", message);
return (err);
}
/* Common code used when first setting up, and when resuming. */
static int
talk_to_backend(device_t dev, struct netfront_info *info)
{
const char *message;
struct xs_transaction xst;
const char *node = xenbus_get_node(dev);
int err;
unsigned long num_queues, max_queues = 0;
unsigned int i;
err = xen_net_read_mac(dev, info->mac);
if (err != 0) {
xenbus_dev_fatal(dev, err, "parsing %s/mac", node);
goto out;
}
err = xs_scanf(XST_NIL, xenbus_get_otherend_path(info->xbdev),
"multi-queue-max-queues", NULL, "%lu", &max_queues);
if (err != 0)
max_queues = 1;
num_queues = xn_num_queues;
if (num_queues > max_queues)
num_queues = max_queues;
err = setup_device(dev, info, num_queues);
if (err != 0)
goto out;
again:
err = xs_transaction_start(&xst);
if (err != 0) {
xenbus_dev_fatal(dev, err, "starting transaction");
goto free;
}
if (info->num_queues == 1) {
err = write_queue_xenstore_keys(dev, &info->rxq[0],
&info->txq[0], &xst, false);
if (err != 0)
goto abort_transaction_no_def_error;
} else {
err = xs_printf(xst, node, "multi-queue-num-queues",
"%u", info->num_queues);
if (err != 0) {
message = "writing multi-queue-num-queues";
goto abort_transaction;
}
for (i = 0; i < info->num_queues; i++) {
err = write_queue_xenstore_keys(dev, &info->rxq[i],
&info->txq[i], &xst, true);
if (err != 0)
goto abort_transaction_no_def_error;
}
}
err = xs_printf(xst, node, "request-rx-copy", "%u", 1);
if (err != 0) {
message = "writing request-rx-copy";
goto abort_transaction;
}
err = xs_printf(xst, node, "feature-rx-notify", "%d", 1);
if (err != 0) {
message = "writing feature-rx-notify";
goto abort_transaction;
}
err = xs_printf(xst, node, "feature-sg", "%d", 1);
if (err != 0) {
message = "writing feature-sg";
goto abort_transaction;
}
if ((info->xn_ifp->if_capenable & IFCAP_LRO) != 0) {
err = xs_printf(xst, node, "feature-gso-tcpv4", "%d", 1);
if (err != 0) {
message = "writing feature-gso-tcpv4";
goto abort_transaction;
}
}
if ((info->xn_ifp->if_capenable & IFCAP_RXCSUM) == 0) {
err = xs_printf(xst, node, "feature-no-csum-offload", "%d", 1);
if (err != 0) {
message = "writing feature-no-csum-offload";
goto abort_transaction;
}
}
err = xs_transaction_end(xst, 0);
if (err != 0) {
if (err == EAGAIN)
goto again;
xenbus_dev_fatal(dev, err, "completing transaction");
goto free;
}
return 0;
abort_transaction:
xenbus_dev_fatal(dev, err, "%s", message);
abort_transaction_no_def_error:
xs_transaction_end(xst, 1);
free:
netif_free(info);
out:
return (err);
}
static void
xn_rxq_intr(struct netfront_rxq *rxq)
{
XN_RX_LOCK(rxq);
xn_rxeof(rxq);
XN_RX_UNLOCK(rxq);
}
static void
xn_txq_start(struct netfront_txq *txq)
{
struct netfront_info *np = txq->info;
struct ifnet *ifp = np->xn_ifp;
XN_TX_LOCK_ASSERT(txq);
if (!drbr_empty(ifp, txq->br))
xn_txq_mq_start_locked(txq, NULL);
}
static void
xn_txq_intr(struct netfront_txq *txq)
{
XN_TX_LOCK(txq);
if (RING_HAS_UNCONSUMED_RESPONSES(&txq->ring))
xn_txeof(txq);
xn_txq_start(txq);
XN_TX_UNLOCK(txq);
}
static void
xn_txq_tq_deferred(void *xtxq, int pending)
{
struct netfront_txq *txq = xtxq;
XN_TX_LOCK(txq);
xn_txq_start(txq);
XN_TX_UNLOCK(txq);
}
static void
disconnect_rxq(struct netfront_rxq *rxq)
{
xn_release_rx_bufs(rxq);
gnttab_free_grant_references(rxq->gref_head);
gnttab_end_foreign_access(rxq->ring_ref, NULL);
/*
* No split event channel support at the moment, handle will
* be unbound in tx. So no need to call xen_intr_unbind here,
* but we do want to reset the handler to 0.
*/
rxq->xen_intr_handle = 0;
}
static void
destroy_rxq(struct netfront_rxq *rxq)
{
callout_drain(&rxq->rx_refill);
free(rxq->ring.sring, M_DEVBUF);
}
static void
destroy_rxqs(struct netfront_info *np)
{
int i;
for (i = 0; i < np->num_queues; i++)
destroy_rxq(&np->rxq[i]);
free(np->rxq, M_DEVBUF);
np->rxq = NULL;
}
static int
setup_rxqs(device_t dev, struct netfront_info *info,
unsigned long num_queues)
{
int q, i;
int error;
netif_rx_sring_t *rxs;
struct netfront_rxq *rxq;
info->rxq = malloc(sizeof(struct netfront_rxq) * num_queues,
M_DEVBUF, M_WAITOK|M_ZERO);
for (q = 0; q < num_queues; q++) {
rxq = &info->rxq[q];
rxq->id = q;
rxq->info = info;
rxq->ring_ref = GRANT_REF_INVALID;
rxq->ring.sring = NULL;
snprintf(rxq->name, XN_QUEUE_NAME_LEN, "xnrx_%u", q);
mtx_init(&rxq->lock, rxq->name, "netfront receive lock",
MTX_DEF);
for (i = 0; i <= NET_RX_RING_SIZE; i++) {
rxq->mbufs[i] = NULL;
rxq->grant_ref[i] = GRANT_REF_INVALID;
}
/* Start resources allocation */
if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
&rxq->gref_head) != 0) {
device_printf(dev, "allocating rx gref");
error = ENOMEM;
goto fail;
}
rxs = (netif_rx_sring_t *)malloc(PAGE_SIZE, M_DEVBUF,
M_WAITOK|M_ZERO);
SHARED_RING_INIT(rxs);
FRONT_RING_INIT(&rxq->ring, rxs, PAGE_SIZE);
error = xenbus_grant_ring(dev, virt_to_mfn(rxs),
&rxq->ring_ref);
if (error != 0) {
device_printf(dev, "granting rx ring page");
goto fail_grant_ring;
}
callout_init(&rxq->rx_refill, 1);
}
return (0);
fail_grant_ring:
gnttab_free_grant_references(rxq->gref_head);
free(rxq->ring.sring, M_DEVBUF);
fail:
for (; q >= 0; q--) {
disconnect_rxq(&info->rxq[q]);
destroy_rxq(&info->rxq[q]);
}
free(info->rxq, M_DEVBUF);
return (error);
}
static void
disconnect_txq(struct netfront_txq *txq)
{
xn_release_tx_bufs(txq);
gnttab_free_grant_references(txq->gref_head);
gnttab_end_foreign_access(txq->ring_ref, NULL);
xen_intr_unbind(&txq->xen_intr_handle);
}
static void
destroy_txq(struct netfront_txq *txq)
{
free(txq->ring.sring, M_DEVBUF);
buf_ring_free(txq->br, M_DEVBUF);
taskqueue_drain_all(txq->tq);
taskqueue_free(txq->tq);
}
static void
destroy_txqs(struct netfront_info *np)
{
int i;
for (i = 0; i < np->num_queues; i++)
destroy_txq(&np->txq[i]);
free(np->txq, M_DEVBUF);
np->txq = NULL;
}
static int
setup_txqs(device_t dev, struct netfront_info *info,
unsigned long num_queues)
{
int q, i;
int error;
netif_tx_sring_t *txs;
struct netfront_txq *txq;
info->txq = malloc(sizeof(struct netfront_txq) * num_queues,
M_DEVBUF, M_WAITOK|M_ZERO);
for (q = 0; q < num_queues; q++) {
txq = &info->txq[q];
txq->id = q;
txq->info = info;
txq->ring_ref = GRANT_REF_INVALID;
txq->ring.sring = NULL;
snprintf(txq->name, XN_QUEUE_NAME_LEN, "xntx_%u", q);
mtx_init(&txq->lock, txq->name, "netfront transmit lock",
MTX_DEF);
for (i = 0; i <= NET_TX_RING_SIZE; i++) {
txq->mbufs[i] = (void *) ((u_long) i+1);
txq->grant_ref[i] = GRANT_REF_INVALID;
}
txq->mbufs[NET_TX_RING_SIZE] = (void *)0;
/* Start resources allocation. */
if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
&txq->gref_head) != 0) {
device_printf(dev, "failed to allocate tx grant refs\n");
error = ENOMEM;
goto fail;
}
txs = (netif_tx_sring_t *)malloc(PAGE_SIZE, M_DEVBUF,
M_WAITOK|M_ZERO);
SHARED_RING_INIT(txs);
FRONT_RING_INIT(&txq->ring, txs, PAGE_SIZE);
error = xenbus_grant_ring(dev, virt_to_mfn(txs),
&txq->ring_ref);
if (error != 0) {
device_printf(dev, "failed to grant tx ring\n");
goto fail_grant_ring;
}
txq->br = buf_ring_alloc(NET_TX_RING_SIZE, M_DEVBUF,
M_WAITOK, &txq->lock);
TASK_INIT(&txq->defrtask, 0, xn_txq_tq_deferred, txq);
txq->tq = taskqueue_create(txq->name, M_WAITOK,
taskqueue_thread_enqueue, &txq->tq);
error = taskqueue_start_threads(&txq->tq, 1, PI_NET,
"%s txq %d", device_get_nameunit(dev), txq->id);
if (error != 0) {
device_printf(dev, "failed to start tx taskq %d\n",
txq->id);
goto fail_start_thread;
}
error = xen_intr_alloc_and_bind_local_port(dev,
xenbus_get_otherend_id(dev), /* filter */ NULL, xn_intr,
&info->txq[q], INTR_TYPE_NET | INTR_MPSAFE | INTR_ENTROPY,
&txq->xen_intr_handle);
if (error != 0) {
device_printf(dev, "xen_intr_alloc_and_bind_local_port failed\n");
goto fail_bind_port;
}
}
return (0);
fail_bind_port:
taskqueue_drain_all(txq->tq);
fail_start_thread:
buf_ring_free(txq->br, M_DEVBUF);
taskqueue_free(txq->tq);
gnttab_end_foreign_access(txq->ring_ref, NULL);
fail_grant_ring:
gnttab_free_grant_references(txq->gref_head);
free(txq->ring.sring, M_DEVBUF);
fail:
for (; q >= 0; q--) {
disconnect_txq(&info->txq[q]);
destroy_txq(&info->txq[q]);
}
free(info->txq, M_DEVBUF);
return (error);
}
static int
setup_device(device_t dev, struct netfront_info *info,
unsigned long num_queues)
{
int error;
int q;
if (info->txq)
destroy_txqs(info);
if (info->rxq)
destroy_rxqs(info);
info->num_queues = 0;
error = setup_rxqs(dev, info, num_queues);
if (error != 0)
goto out;
error = setup_txqs(dev, info, num_queues);
if (error != 0)
goto out;
info->num_queues = num_queues;
/* No split event channel at the moment. */
for (q = 0; q < num_queues; q++)
info->rxq[q].xen_intr_handle = info->txq[q].xen_intr_handle;
return (0);
out:
KASSERT(error != 0, ("Error path taken without providing an error code"));
return (error);
}
#ifdef INET
/**
* If this interface has an ipv4 address, send an arp for it. This
* helps to get the network going again after migrating hosts.
*/
static void
netfront_send_fake_arp(device_t dev, struct netfront_info *info)
{
struct ifnet *ifp;
struct ifaddr *ifa;
ifp = info->xn_ifp;
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family == AF_INET) {
arp_ifinit(ifp, ifa);
}
}
}
#endif
/**
* Callback received when the backend's state changes.
*/
static void
netfront_backend_changed(device_t dev, XenbusState newstate)
{
struct netfront_info *sc = device_get_softc(dev);
DPRINTK("newstate=%d\n", newstate);
switch (newstate) {
case XenbusStateInitialising:
case XenbusStateInitialised:
case XenbusStateUnknown:
case XenbusStateReconfigured:
case XenbusStateReconfiguring:
break;
case XenbusStateInitWait:
if (xenbus_get_state(dev) != XenbusStateInitialising)
break;
if (xn_connect(sc) != 0)
break;
/* Switch to connected state before kicking the rings. */
xenbus_set_state(sc->xbdev, XenbusStateConnected);
xn_kick_rings(sc);
break;
case XenbusStateClosing:
xenbus_set_state(dev, XenbusStateClosed);
break;
case XenbusStateClosed:
if (sc->xn_reset) {
netif_disconnect_backend(sc);
xenbus_set_state(dev, XenbusStateInitialising);
sc->xn_reset = false;
}
break;
case XenbusStateConnected:
#ifdef INET
netfront_send_fake_arp(dev, sc);
#endif
break;
}
}
/**
* \brief Verify that there is sufficient space in the Tx ring
* buffer for a maximally sized request to be enqueued.
*
* A transmit request requires a transmit descriptor for each packet
* fragment, plus up to 2 entries for "options" (e.g. TSO).
*/
static inline int
xn_tx_slot_available(struct netfront_txq *txq)
{
return (RING_FREE_REQUESTS(&txq->ring) > (MAX_TX_REQ_FRAGS + 2));
}
static void
xn_release_tx_bufs(struct netfront_txq *txq)
{
int i;
for (i = 1; i <= NET_TX_RING_SIZE; i++) {
struct mbuf *m;
m = txq->mbufs[i];
/*
* We assume that no kernel addresses are
* less than NET_TX_RING_SIZE. Any entry
* in the table that is below this number
* must be an index from free-list tracking.
*/
if (((uintptr_t)m) <= NET_TX_RING_SIZE)
continue;
gnttab_end_foreign_access_ref(txq->grant_ref[i]);
gnttab_release_grant_reference(&txq->gref_head,
txq->grant_ref[i]);
txq->grant_ref[i] = GRANT_REF_INVALID;
add_id_to_freelist(txq->mbufs, i);
txq->mbufs_cnt--;
if (txq->mbufs_cnt < 0) {
panic("%s: tx_chain_cnt must be >= 0", __func__);
}
m_free(m);
}
}
static struct mbuf *
xn_alloc_one_rx_buffer(struct netfront_rxq *rxq)
{
struct mbuf *m;
m = m_getjcl(M_NOWAIT, MT_DATA, M_PKTHDR, MJUMPAGESIZE);
if (m == NULL)
return NULL;
m->m_len = m->m_pkthdr.len = MJUMPAGESIZE;
return (m);
}
static void
xn_alloc_rx_buffers(struct netfront_rxq *rxq)
{
RING_IDX req_prod;
int notify;
XN_RX_LOCK_ASSERT(rxq);
if (__predict_false(rxq->info->carrier == 0))
return;
for (req_prod = rxq->ring.req_prod_pvt;
req_prod - rxq->ring.rsp_cons < NET_RX_RING_SIZE;
req_prod++) {
struct mbuf *m;
unsigned short id;
grant_ref_t ref;
struct netif_rx_request *req;
unsigned long pfn;
m = xn_alloc_one_rx_buffer(rxq);
if (m == NULL)
break;
id = xn_rxidx(req_prod);
KASSERT(rxq->mbufs[id] == NULL, ("non-NULL xn_rx_chain"));
rxq->mbufs[id] = m;
ref = gnttab_claim_grant_reference(&rxq->gref_head);
KASSERT(ref != GNTTAB_LIST_END,
("reserved grant references exhuasted"));
rxq->grant_ref[id] = ref;
pfn = atop(vtophys(mtod(m, vm_offset_t)));
req = RING_GET_REQUEST(&rxq->ring, req_prod);
gnttab_grant_foreign_access_ref(ref,
xenbus_get_otherend_id(rxq->info->xbdev), pfn, 0);
req->id = id;
req->gref = ref;
}
rxq->ring.req_prod_pvt = req_prod;
/* Not enough requests? Try again later. */
if (req_prod - rxq->ring.rsp_cons < NET_RX_SLOTS_MIN) {
callout_reset_curcpu(&rxq->rx_refill, hz/10,
xn_alloc_rx_buffers_callout, rxq);
return;
}
wmb(); /* barrier so backend seens requests */
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&rxq->ring, notify);
if (notify)
xen_intr_signal(rxq->xen_intr_handle);
}
static void xn_alloc_rx_buffers_callout(void *arg)
{
struct netfront_rxq *rxq;
rxq = (struct netfront_rxq *)arg;
XN_RX_LOCK(rxq);
xn_alloc_rx_buffers(rxq);
XN_RX_UNLOCK(rxq);
}
static void
xn_release_rx_bufs(struct netfront_rxq *rxq)
{
int i, ref;
struct mbuf *m;
for (i = 0; i < NET_RX_RING_SIZE; i++) {
m = rxq->mbufs[i];
if (m == NULL)
continue;
ref = rxq->grant_ref[i];
if (ref == GRANT_REF_INVALID)
continue;
gnttab_end_foreign_access_ref(ref);
gnttab_release_grant_reference(&rxq->gref_head, ref);
rxq->mbufs[i] = NULL;
rxq->grant_ref[i] = GRANT_REF_INVALID;
m_freem(m);
}
}
static void
xn_rxeof(struct netfront_rxq *rxq)
{
struct ifnet *ifp;
struct netfront_info *np = rxq->info;
#if (defined(INET) || defined(INET6))
struct lro_ctrl *lro = &rxq->lro;
#endif
struct netfront_rx_info rinfo;
struct netif_rx_response *rx = &rinfo.rx;
struct netif_extra_info *extras = rinfo.extras;
RING_IDX i, rp;
struct mbuf *m;
struct mbufq mbufq_rxq, mbufq_errq;
int err, work_to_do;
XN_RX_LOCK_ASSERT(rxq);
if (!netfront_carrier_ok(np))
return;
/* XXX: there should be some sane limit. */
mbufq_init(&mbufq_errq, INT_MAX);
mbufq_init(&mbufq_rxq, INT_MAX);
ifp = np->xn_ifp;
do {
rp = rxq->ring.sring->rsp_prod;
rmb(); /* Ensure we see queued responses up to 'rp'. */
i = rxq->ring.rsp_cons;
while ((i != rp)) {
memcpy(rx, RING_GET_RESPONSE(&rxq->ring, i), sizeof(*rx));
memset(extras, 0, sizeof(rinfo.extras));
m = NULL;
err = xn_get_responses(rxq, &rinfo, rp, &i, &m);
if (__predict_false(err)) {
if (m)
(void )mbufq_enqueue(&mbufq_errq, m);
if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
continue;
}
m->m_pkthdr.rcvif = ifp;
if (rx->flags & NETRXF_data_validated) {
/*
* According to mbuf(9) the correct way to tell
* the stack that the checksum of an inbound
* packet is correct, without it actually being
* present (because the underlying interface
* doesn't provide it), is to set the
* CSUM_DATA_VALID and CSUM_PSEUDO_HDR flags,
* and the csum_data field to 0xffff.
*/
m->m_pkthdr.csum_flags |= (CSUM_DATA_VALID
| CSUM_PSEUDO_HDR);
m->m_pkthdr.csum_data = 0xffff;
}
if ((rx->flags & NETRXF_extra_info) != 0 &&
(extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type ==
XEN_NETIF_EXTRA_TYPE_GSO)) {
m->m_pkthdr.tso_segsz =
extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].u.gso.size;
m->m_pkthdr.csum_flags |= CSUM_TSO;
}
(void )mbufq_enqueue(&mbufq_rxq, m);
}
rxq->ring.rsp_cons = i;
xn_alloc_rx_buffers(rxq);
RING_FINAL_CHECK_FOR_RESPONSES(&rxq->ring, work_to_do);
} while (work_to_do);
mbufq_drain(&mbufq_errq);
/*
* Process all the mbufs after the remapping is complete.
* Break the mbuf chain first though.
*/
while ((m = mbufq_dequeue(&mbufq_rxq)) != NULL) {
if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
#if (defined(INET) || defined(INET6))
/* Use LRO if possible */
if ((ifp->if_capenable & IFCAP_LRO) == 0 ||
lro->lro_cnt == 0 || tcp_lro_rx(lro, m, 0)) {
/*
* If LRO fails, pass up to the stack
* directly.
*/
(*ifp->if_input)(ifp, m);
}
#else
(*ifp->if_input)(ifp, m);
#endif
}
#if (defined(INET) || defined(INET6))
/*
* Flush any outstanding LRO work
*/
tcp_lro_flush_all(lro);
#endif
}
static void
xn_txeof(struct netfront_txq *txq)
{
RING_IDX i, prod;
unsigned short id;
struct ifnet *ifp;
netif_tx_response_t *txr;
struct mbuf *m;
struct netfront_info *np = txq->info;
XN_TX_LOCK_ASSERT(txq);
if (!netfront_carrier_ok(np))
return;
ifp = np->xn_ifp;
do {
prod = txq->ring.sring->rsp_prod;
rmb(); /* Ensure we see responses up to 'rp'. */
for (i = txq->ring.rsp_cons; i != prod; i++) {
txr = RING_GET_RESPONSE(&txq->ring, i);
if (txr->status == NETIF_RSP_NULL)
continue;
if (txr->status != NETIF_RSP_OKAY) {
printf("%s: WARNING: response is %d!\n",
__func__, txr->status);
}
id = txr->id;
m = txq->mbufs[id];
KASSERT(m != NULL, ("mbuf not found in chain"));
KASSERT((uintptr_t)m > NET_TX_RING_SIZE,
("mbuf already on the free list, but we're "
"trying to free it again!"));
M_ASSERTVALID(m);
if (__predict_false(gnttab_query_foreign_access(
txq->grant_ref[id]) != 0)) {
panic("%s: grant id %u still in use by the "
"backend", __func__, id);
}
gnttab_end_foreign_access_ref(txq->grant_ref[id]);
gnttab_release_grant_reference(
&txq->gref_head, txq->grant_ref[id]);
txq->grant_ref[id] = GRANT_REF_INVALID;
txq->mbufs[id] = NULL;
add_id_to_freelist(txq->mbufs, id);
txq->mbufs_cnt--;
m_free(m);
/* Only mark the txq active if we've freed up at least one slot to try */
ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
}
txq->ring.rsp_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.
*/
txq->ring.sring->rsp_event =
prod + ((txq->ring.sring->req_prod - prod) >> 1) + 1;
mb();
} while (prod != txq->ring.sring->rsp_prod);
if (txq->full &&
((txq->ring.sring->req_prod - prod) < NET_TX_RING_SIZE)) {
txq->full = false;
xn_txq_start(txq);
}
}
static void
xn_intr(void *xsc)
{
struct netfront_txq *txq = xsc;
struct netfront_info *np = txq->info;
struct netfront_rxq *rxq = &np->rxq[txq->id];
/* kick both tx and rx */
xn_rxq_intr(rxq);
xn_txq_intr(txq);
}
static void
xn_move_rx_slot(struct netfront_rxq *rxq, struct mbuf *m,
grant_ref_t ref)
{
int new = xn_rxidx(rxq->ring.req_prod_pvt);
KASSERT(rxq->mbufs[new] == NULL, ("mbufs != NULL"));
rxq->mbufs[new] = m;
rxq->grant_ref[new] = ref;
RING_GET_REQUEST(&rxq->ring, rxq->ring.req_prod_pvt)->id = new;
RING_GET_REQUEST(&rxq->ring, rxq->ring.req_prod_pvt)->gref = ref;
rxq->ring.req_prod_pvt++;
}
static int
xn_get_extras(struct netfront_rxq *rxq,
struct netif_extra_info *extras, RING_IDX rp, RING_IDX *cons)
{
struct netif_extra_info *extra;
int err = 0;
do {
struct mbuf *m;
grant_ref_t ref;
if (__predict_false(*cons + 1 == rp)) {
err = EINVAL;
break;
}
extra = (struct netif_extra_info *)
RING_GET_RESPONSE(&rxq->ring, ++(*cons));
if (__predict_false(!extra->type ||
extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
err = EINVAL;
} else {
memcpy(&extras[extra->type - 1], extra, sizeof(*extra));
}
m = xn_get_rx_mbuf(rxq, *cons);
ref = xn_get_rx_ref(rxq, *cons);
xn_move_rx_slot(rxq, m, ref);
} while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
return err;
}
static int
xn_get_responses(struct netfront_rxq *rxq,
struct netfront_rx_info *rinfo, RING_IDX rp, RING_IDX *cons,
struct mbuf **list)
{
struct netif_rx_response *rx = &rinfo->rx;
struct netif_extra_info *extras = rinfo->extras;
struct mbuf *m, *m0, *m_prev;
grant_ref_t ref = xn_get_rx_ref(rxq, *cons);
RING_IDX ref_cons = *cons;
int frags = 1;
int err = 0;
u_long ret;
m0 = m = m_prev = xn_get_rx_mbuf(rxq, *cons);
if (rx->flags & NETRXF_extra_info) {
err = xn_get_extras(rxq, extras, rp, cons);
}
if (m0 != NULL) {
m0->m_pkthdr.len = 0;
m0->m_next = NULL;
}
for (;;) {
#if 0
DPRINTK("rx->status=%hd rx->offset=%hu frags=%u\n",
rx->status, rx->offset, frags);
#endif
if (__predict_false(rx->status < 0 ||
rx->offset + rx->status > PAGE_SIZE)) {
xn_move_rx_slot(rxq, m, ref);
if (m0 == m)
m0 = NULL;
m = NULL;
err = EINVAL;
goto next_skip_queue;
}
/*
* This definitely indicates a bug, either in this driver or in
* the backend driver. In future this should flag the bad
* situation to the system controller to reboot the backed.
*/
if (ref == GRANT_REF_INVALID) {
printf("%s: Bad rx response id %d.\n", __func__, rx->id);
err = EINVAL;
goto next;
}
ret = gnttab_end_foreign_access_ref(ref);
KASSERT(ret, ("Unable to end access to grant references"));
gnttab_release_grant_reference(&rxq->gref_head, ref);
next:
if (m == NULL)
break;
m->m_len = rx->status;
m->m_data += rx->offset;
m0->m_pkthdr.len += rx->status;
next_skip_queue:
if (!(rx->flags & NETRXF_more_data))
break;
if (*cons + frags == rp) {
if (net_ratelimit())
WPRINTK("Need more frags\n");
err = ENOENT;
printf("%s: cons %u frags %u rp %u, not enough frags\n",
__func__, *cons, frags, rp);
break;
}
/*
* Note that m can be NULL, if rx->status < 0 or if
* rx->offset + rx->status > PAGE_SIZE above.
*/
m_prev = m;
rx = RING_GET_RESPONSE(&rxq->ring, *cons + frags);
m = xn_get_rx_mbuf(rxq, *cons + frags);
/*
* m_prev == NULL can happen if rx->status < 0 or if
* rx->offset + * rx->status > PAGE_SIZE above.
*/
if (m_prev != NULL)
m_prev->m_next = m;
/*
* m0 can be NULL if rx->status < 0 or if * rx->offset +
* rx->status > PAGE_SIZE above.
*/
if (m0 == NULL)
m0 = m;
m->m_next = NULL;
ref = xn_get_rx_ref(rxq, *cons + frags);
ref_cons = *cons + frags;
frags++;
}
*list = m0;
*cons += frags;
return (err);
}
/**
* \brief Count the number of fragments in an mbuf chain.
*
* Surprisingly, there isn't an M* macro for this.
*/
static inline int
xn_count_frags(struct mbuf *m)
{
int nfrags;
for (nfrags = 0; m != NULL; m = m->m_next)
nfrags++;
return (nfrags);
}
/**
* Given an mbuf chain, make sure we have enough room and then push
* it onto the transmit ring.
*/
static int
xn_assemble_tx_request(struct netfront_txq *txq, struct mbuf *m_head)
{
struct mbuf *m;
struct netfront_info *np = txq->info;
struct ifnet *ifp = np->xn_ifp;
u_int nfrags;
int otherend_id;
/**
* Defragment the mbuf if necessary.
*/
nfrags = xn_count_frags(m_head);
/*
* Check to see whether this request is longer than netback
* can handle, and try to defrag it.
*/
/**
* It is a bit lame, but the netback driver in Linux can't
* deal with nfrags > MAX_TX_REQ_FRAGS, which is a quirk of
* the Linux network stack.
*/
if (nfrags > np->maxfrags) {
m = m_defrag(m_head, M_NOWAIT);
if (!m) {
/*
* Defrag failed, so free the mbuf and
* therefore drop the packet.
*/
m_freem(m_head);
return (EMSGSIZE);
}
m_head = m;
}
/* Determine how many fragments now exist */
nfrags = xn_count_frags(m_head);
/*
* Check to see whether the defragmented packet has too many
* segments for the Linux netback driver.
*/
/**
* The FreeBSD TCP stack, with TSO enabled, can produce a chain
* of mbufs longer than Linux can handle. Make sure we don't
* pass a too-long chain over to the other side by dropping the
* packet. It doesn't look like there is currently a way to
* tell the TCP stack to generate a shorter chain of packets.
*/
if (nfrags > MAX_TX_REQ_FRAGS) {
#ifdef DEBUG
printf("%s: nfrags %d > MAX_TX_REQ_FRAGS %d, netback "
"won't be able to handle it, dropping\n",
__func__, nfrags, MAX_TX_REQ_FRAGS);
#endif
m_freem(m_head);
return (EMSGSIZE);
}
/*
* This check should be redundant. We've already verified that we
* have enough slots in the ring to handle a packet of maximum
* size, and that our packet is less than the maximum size. Keep
* it in here as an assert for now just to make certain that
* chain_cnt is accurate.
*/
KASSERT((txq->mbufs_cnt + nfrags) <= NET_TX_RING_SIZE,
("%s: chain_cnt (%d) + nfrags (%d) > NET_TX_RING_SIZE "
"(%d)!", __func__, (int) txq->mbufs_cnt,
(int) nfrags, (int) NET_TX_RING_SIZE));
/*
* Start packing the mbufs in this chain into
* the fragment pointers. Stop when we run out
* of fragments or hit the end of the mbuf chain.
*/
m = m_head;
otherend_id = xenbus_get_otherend_id(np->xbdev);
for (m = m_head; m; m = m->m_next) {
netif_tx_request_t *tx;
uintptr_t id;
grant_ref_t ref;
u_long mfn; /* XXX Wrong type? */
tx = RING_GET_REQUEST(&txq->ring, txq->ring.req_prod_pvt);
id = get_id_from_freelist(txq->mbufs);
if (id == 0)
panic("%s: was allocated the freelist head!\n",
__func__);
txq->mbufs_cnt++;
if (txq->mbufs_cnt > NET_TX_RING_SIZE)
panic("%s: tx_chain_cnt must be <= NET_TX_RING_SIZE\n",
__func__);
txq->mbufs[id] = m;
tx->id = id;
ref = gnttab_claim_grant_reference(&txq->gref_head);
KASSERT((short)ref >= 0, ("Negative ref"));
mfn = virt_to_mfn(mtod(m, vm_offset_t));
gnttab_grant_foreign_access_ref(ref, otherend_id,
mfn, GNTMAP_readonly);
tx->gref = txq->grant_ref[id] = ref;
tx->offset = mtod(m, vm_offset_t) & (PAGE_SIZE - 1);
tx->flags = 0;
if (m == m_head) {
/*
* The first fragment has the entire packet
* size, subsequent fragments have just the
* fragment size. The backend works out the
* true size of the first fragment by
* subtracting the sizes of the other
* fragments.
*/
tx->size = m->m_pkthdr.len;
/*
* The first fragment contains the checksum flags
* and is optionally followed by extra data for
* TSO etc.
*/
/**
* CSUM_TSO requires checksum offloading.
* Some versions of FreeBSD fail to
* set CSUM_TCP in the CSUM_TSO case,
* so we have to test for CSUM_TSO
* explicitly.
*/
if (m->m_pkthdr.csum_flags
& (CSUM_DELAY_DATA | CSUM_TSO)) {
tx->flags |= (NETTXF_csum_blank
| NETTXF_data_validated);
}
if (m->m_pkthdr.csum_flags & CSUM_TSO) {
struct netif_extra_info *gso =
(struct netif_extra_info *)
RING_GET_REQUEST(&txq->ring,
++txq->ring.req_prod_pvt);
tx->flags |= NETTXF_extra_info;
gso->u.gso.size = m->m_pkthdr.tso_segsz;
gso->u.gso.type =
XEN_NETIF_GSO_TYPE_TCPV4;
gso->u.gso.pad = 0;
gso->u.gso.features = 0;
gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
gso->flags = 0;
}
} else {
tx->size = m->m_len;
}
if (m->m_next)
tx->flags |= NETTXF_more_data;
txq->ring.req_prod_pvt++;
}
BPF_MTAP(ifp, m_head);
if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
if_inc_counter(ifp, IFCOUNTER_OBYTES, m_head->m_pkthdr.len);
if (m_head->m_flags & M_MCAST)
if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
xn_txeof(txq);
return (0);
}
/* equivalent of network_open() in Linux */
static void
xn_ifinit_locked(struct netfront_info *np)
{
struct ifnet *ifp;
int i;
struct netfront_rxq *rxq;
XN_LOCK_ASSERT(np);
ifp = np->xn_ifp;
if (ifp->if_drv_flags & IFF_DRV_RUNNING || !netfront_carrier_ok(np))
return;
xn_stop(np);
for (i = 0; i < np->num_queues; i++) {
rxq = &np->rxq[i];
XN_RX_LOCK(rxq);
xn_alloc_rx_buffers(rxq);
rxq->ring.sring->rsp_event = rxq->ring.rsp_cons + 1;
if (RING_HAS_UNCONSUMED_RESPONSES(&rxq->ring))
xn_rxeof(rxq);
XN_RX_UNLOCK(rxq);
}
ifp->if_drv_flags |= IFF_DRV_RUNNING;
ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
if_link_state_change(ifp, LINK_STATE_UP);
}
static void
xn_ifinit(void *xsc)
{
struct netfront_info *sc = xsc;
XN_LOCK(sc);
xn_ifinit_locked(sc);
XN_UNLOCK(sc);
}
static int
xn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
struct netfront_info *sc = ifp->if_softc;
struct ifreq *ifr = (struct ifreq *) data;
device_t dev;
#ifdef INET
struct ifaddr *ifa = (struct ifaddr *)data;
#endif
int mask, error = 0, reinit;
dev = sc->xbdev;
switch(cmd) {
case SIOCSIFADDR:
#ifdef INET
XN_LOCK(sc);
if (ifa->ifa_addr->sa_family == AF_INET) {
ifp->if_flags |= IFF_UP;
if (!(ifp->if_drv_flags & IFF_DRV_RUNNING))
xn_ifinit_locked(sc);
arp_ifinit(ifp, ifa);
XN_UNLOCK(sc);
} else {
XN_UNLOCK(sc);
#endif
error = ether_ioctl(ifp, cmd, data);
#ifdef INET
}
#endif
break;
case SIOCSIFMTU:
if (ifp->if_mtu == ifr->ifr_mtu)
break;
ifp->if_mtu = ifr->ifr_mtu;
ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
xn_ifinit(sc);
break;
case SIOCSIFFLAGS:
XN_LOCK(sc);
if (ifp->if_flags & IFF_UP) {
/*
* If only the state of the PROMISC flag changed,
* then just use the 'set promisc mode' command
* instead of reinitializing the entire NIC. Doing
* a full re-init means reloading the firmware and
* waiting for it to start up, which may take a
* second or two.
*/
xn_ifinit_locked(sc);
} else {
if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
xn_stop(sc);
}
}
sc->xn_if_flags = ifp->if_flags;
XN_UNLOCK(sc);
break;
case SIOCSIFCAP:
mask = ifr->ifr_reqcap ^ ifp->if_capenable;
reinit = 0;
if (mask & IFCAP_TXCSUM) {
ifp->if_capenable ^= IFCAP_TXCSUM;
ifp->if_hwassist ^= XN_CSUM_FEATURES;
}
if (mask & IFCAP_TSO4) {
ifp->if_capenable ^= IFCAP_TSO4;
ifp->if_hwassist ^= CSUM_TSO;
}
if (mask & (IFCAP_RXCSUM | IFCAP_LRO)) {
/* These Rx features require us to renegotiate. */
reinit = 1;
if (mask & IFCAP_RXCSUM)
ifp->if_capenable ^= IFCAP_RXCSUM;
if (mask & IFCAP_LRO)
ifp->if_capenable ^= IFCAP_LRO;
}
if (reinit == 0)
break;
/*
* We must reset the interface so the backend picks up the
* new features.
*/
device_printf(sc->xbdev,
"performing interface reset due to feature change\n");
XN_LOCK(sc);
netfront_carrier_off(sc);
sc->xn_reset = true;
/*
* NB: the pending packet queue is not flushed, since
* the interface should still support the old options.
*/
XN_UNLOCK(sc);
/*
* Delete the xenstore nodes that export features.
*
* NB: There's a xenbus state called
* "XenbusStateReconfiguring", which is what we should set
* here. Sadly none of the backends know how to handle it,
* and simply disconnect from the frontend, so we will just
* switch back to XenbusStateInitialising in order to force
* a reconnection.
*/
xs_rm(XST_NIL, xenbus_get_node(dev), "feature-gso-tcpv4");
xs_rm(XST_NIL, xenbus_get_node(dev), "feature-no-csum-offload");
xenbus_set_state(dev, XenbusStateClosing);
/*
* Wait for the frontend to reconnect before returning
* from the ioctl. 30s should be more than enough for any
* sane backend to reconnect.
*/
error = tsleep(sc, 0, "xn_rst", 30*hz);
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
break;
case SIOCSIFMEDIA:
case SIOCGIFMEDIA:
error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
break;
default:
error = ether_ioctl(ifp, cmd, data);
}
return (error);
}
static void
xn_stop(struct netfront_info *sc)
{
struct ifnet *ifp;
XN_LOCK_ASSERT(sc);
ifp = sc->xn_ifp;
ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
if_link_state_change(ifp, LINK_STATE_DOWN);
}
static void
xn_rebuild_rx_bufs(struct netfront_rxq *rxq)
{
int requeue_idx, i;
grant_ref_t ref;
netif_rx_request_t *req;
for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
struct mbuf *m;
u_long pfn;
if (rxq->mbufs[i] == NULL)
continue;
m = rxq->mbufs[requeue_idx] = xn_get_rx_mbuf(rxq, i);
ref = rxq->grant_ref[requeue_idx] = xn_get_rx_ref(rxq, i);
req = RING_GET_REQUEST(&rxq->ring, requeue_idx);
pfn = vtophys(mtod(m, vm_offset_t)) >> PAGE_SHIFT;
gnttab_grant_foreign_access_ref(ref,
xenbus_get_otherend_id(rxq->info->xbdev),
pfn, 0);
req->gref = ref;
req->id = requeue_idx;
requeue_idx++;
}
rxq->ring.req_prod_pvt = requeue_idx;
}
/* START of Xenolinux helper functions adapted to FreeBSD */
static int
xn_connect(struct netfront_info *np)
{
int i, error;
u_int feature_rx_copy;
struct netfront_rxq *rxq;
struct netfront_txq *txq;
error = xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
"feature-rx-copy", NULL, "%u", &feature_rx_copy);
if (error != 0)
feature_rx_copy = 0;
/* We only support rx copy. */
if (!feature_rx_copy)
return (EPROTONOSUPPORT);
/* Recovery procedure: */
error = talk_to_backend(np->xbdev, np);
if (error != 0)
return (error);
/* Step 1: Reinitialise variables. */
xn_query_features(np);
xn_configure_features(np);
/* Step 2: Release TX buffer */
for (i = 0; i < np->num_queues; i++) {
txq = &np->txq[i];
xn_release_tx_bufs(txq);
}
/* Step 3: Rebuild the RX buffer freelist and the RX ring itself. */
for (i = 0; i < np->num_queues; i++) {
rxq = &np->rxq[i];
xn_rebuild_rx_bufs(rxq);
}
/* Step 4: 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.
*/
netfront_carrier_on(np);
wakeup(np);
return (0);
}
static void
xn_kick_rings(struct netfront_info *np)
{
struct netfront_rxq *rxq;
struct netfront_txq *txq;
int i;
for (i = 0; i < np->num_queues; i++) {
txq = &np->txq[i];
rxq = &np->rxq[i];
xen_intr_signal(txq->xen_intr_handle);
XN_TX_LOCK(txq);
xn_txeof(txq);
XN_TX_UNLOCK(txq);
XN_RX_LOCK(rxq);
xn_alloc_rx_buffers(rxq);
XN_RX_UNLOCK(rxq);
}
}
static void
xn_query_features(struct netfront_info *np)
{
int val;
device_printf(np->xbdev, "backend features:");
if (xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
"feature-sg", NULL, "%d", &val) != 0)
val = 0;
np->maxfrags = 1;
if (val) {
np->maxfrags = MAX_TX_REQ_FRAGS;
printf(" feature-sg");
}
if (xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
"feature-gso-tcpv4", NULL, "%d", &val) != 0)
val = 0;
np->xn_ifp->if_capabilities &= ~(IFCAP_TSO4|IFCAP_LRO);
if (val) {
np->xn_ifp->if_capabilities |= IFCAP_TSO4|IFCAP_LRO;
printf(" feature-gso-tcp4");
}
/*
* HW CSUM offload is assumed to be available unless
* feature-no-csum-offload is set in xenstore.
*/
if (xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
"feature-no-csum-offload", NULL, "%d", &val) != 0)
val = 0;
np->xn_ifp->if_capabilities |= IFCAP_HWCSUM;
if (val) {
np->xn_ifp->if_capabilities &= ~(IFCAP_HWCSUM);
printf(" feature-no-csum-offload");
}
printf("\n");
}
static int
xn_configure_features(struct netfront_info *np)
{
int err, cap_enabled;
#if (defined(INET) || defined(INET6))
int i;
#endif
struct ifnet *ifp;
ifp = np->xn_ifp;
err = 0;
if ((ifp->if_capenable & ifp->if_capabilities) == ifp->if_capenable) {
/* Current options are available, no need to do anything. */
return (0);
}
/* Try to preserve as many options as possible. */
cap_enabled = ifp->if_capenable;
ifp->if_capenable = ifp->if_hwassist = 0;
#if (defined(INET) || defined(INET6))
if ((cap_enabled & IFCAP_LRO) != 0)
for (i = 0; i < np->num_queues; i++)
tcp_lro_free(&np->rxq[i].lro);
if (xn_enable_lro &&
(ifp->if_capabilities & cap_enabled & IFCAP_LRO) != 0) {
ifp->if_capenable |= IFCAP_LRO;
for (i = 0; i < np->num_queues; i++) {
err = tcp_lro_init(&np->rxq[i].lro);
if (err != 0) {
device_printf(np->xbdev,
"LRO initialization failed\n");
ifp->if_capenable &= ~IFCAP_LRO;
break;
}
np->rxq[i].lro.ifp = ifp;
}
}
if ((ifp->if_capabilities & cap_enabled & IFCAP_TSO4) != 0) {
ifp->if_capenable |= IFCAP_TSO4;
ifp->if_hwassist |= CSUM_TSO;
}
#endif
if ((ifp->if_capabilities & cap_enabled & IFCAP_TXCSUM) != 0) {
ifp->if_capenable |= IFCAP_TXCSUM;
ifp->if_hwassist |= XN_CSUM_FEATURES;
}
if ((ifp->if_capabilities & cap_enabled & IFCAP_RXCSUM) != 0)
ifp->if_capenable |= IFCAP_RXCSUM;
return (err);
}
static int
xn_txq_mq_start_locked(struct netfront_txq *txq, struct mbuf *m)
{
struct netfront_info *np;
struct ifnet *ifp;
struct buf_ring *br;
int error, notify;
np = txq->info;
br = txq->br;
ifp = np->xn_ifp;
error = 0;
XN_TX_LOCK_ASSERT(txq);
if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
!netfront_carrier_ok(np)) {
if (m != NULL)
error = drbr_enqueue(ifp, br, m);
return (error);
}
if (m != NULL) {
error = drbr_enqueue(ifp, br, m);
if (error != 0)
return (error);
}
while ((m = drbr_peek(ifp, br)) != NULL) {
if (!xn_tx_slot_available(txq)) {
drbr_putback(ifp, br, m);
break;
}
error = xn_assemble_tx_request(txq, m);
/* xn_assemble_tx_request always consumes the mbuf*/
if (error != 0) {
drbr_advance(ifp, br);
break;
}
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&txq->ring, notify);
if (notify)
xen_intr_signal(txq->xen_intr_handle);
drbr_advance(ifp, br);
}
if (RING_FULL(&txq->ring))
txq->full = true;
return (0);
}
static int
xn_txq_mq_start(struct ifnet *ifp, struct mbuf *m)
{
struct netfront_info *np;
struct netfront_txq *txq;
int i, npairs, error;
np = ifp->if_softc;
npairs = np->num_queues;
if (!netfront_carrier_ok(np))
return (ENOBUFS);
KASSERT(npairs != 0, ("called with 0 available queues"));
/* check if flowid is set */
if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE)
i = m->m_pkthdr.flowid % npairs;
else
i = curcpu % npairs;
txq = &np->txq[i];
if (XN_TX_TRYLOCK(txq) != 0) {
error = xn_txq_mq_start_locked(txq, m);
XN_TX_UNLOCK(txq);
} else {
error = drbr_enqueue(ifp, txq->br, m);
taskqueue_enqueue(txq->tq, &txq->defrtask);
}
return (error);
}
static void
xn_qflush(struct ifnet *ifp)
{
struct netfront_info *np;
struct netfront_txq *txq;
struct mbuf *m;
int i;
np = ifp->if_softc;
for (i = 0; i < np->num_queues; i++) {
txq = &np->txq[i];
XN_TX_LOCK(txq);
while ((m = buf_ring_dequeue_sc(txq->br)) != NULL)
m_freem(m);
XN_TX_UNLOCK(txq);
}
if_qflush(ifp);
}
/**
* Create a network device.
* @param dev Newbus device representing this virtual NIC.
*/
int
create_netdev(device_t dev)
{
struct netfront_info *np;
int err;
struct ifnet *ifp;
np = device_get_softc(dev);
np->xbdev = dev;
mtx_init(&np->sc_lock, "xnsc", "netfront softc lock", MTX_DEF);
ifmedia_init(&np->sc_media, 0, xn_ifmedia_upd, xn_ifmedia_sts);
ifmedia_add(&np->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
ifmedia_set(&np->sc_media, IFM_ETHER|IFM_MANUAL);
err = xen_net_read_mac(dev, np->mac);
if (err != 0)
goto error;
/* Set up ifnet structure */
ifp = np->xn_ifp = if_alloc(IFT_ETHER);
ifp->if_softc = np;
if_initname(ifp, "xn", device_get_unit(dev));
ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
ifp->if_ioctl = xn_ioctl;
ifp->if_transmit = xn_txq_mq_start;
ifp->if_qflush = xn_qflush;
ifp->if_init = xn_ifinit;
ifp->if_hwassist = XN_CSUM_FEATURES;
/* Enable all supported features at device creation. */
ifp->if_capenable = ifp->if_capabilities =
IFCAP_HWCSUM|IFCAP_TSO4|IFCAP_LRO;
ifp->if_hw_tsomax = 65536 - (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN);
ifp->if_hw_tsomaxsegcount = MAX_TX_REQ_FRAGS;
ifp->if_hw_tsomaxsegsize = PAGE_SIZE;
ether_ifattach(ifp, np->mac);
netfront_carrier_off(np);
return (0);
error:
KASSERT(err != 0, ("Error path with no error code specified"));
return (err);
}
static int
netfront_detach(device_t dev)
{
struct netfront_info *info = device_get_softc(dev);
DPRINTK("%s\n", xenbus_get_node(dev));
netif_free(info);
return 0;
}
static void
netif_free(struct netfront_info *np)
{
XN_LOCK(np);
xn_stop(np);
XN_UNLOCK(np);
netif_disconnect_backend(np);
ether_ifdetach(np->xn_ifp);
free(np->rxq, M_DEVBUF);
free(np->txq, M_DEVBUF);
if_free(np->xn_ifp);
np->xn_ifp = NULL;
ifmedia_removeall(&np->sc_media);
}
static void
netif_disconnect_backend(struct netfront_info *np)
{
u_int i;
for (i = 0; i < np->num_queues; i++) {
XN_RX_LOCK(&np->rxq[i]);
XN_TX_LOCK(&np->txq[i]);
}
netfront_carrier_off(np);
for (i = 0; i < np->num_queues; i++) {
XN_RX_UNLOCK(&np->rxq[i]);
XN_TX_UNLOCK(&np->txq[i]);
}
for (i = 0; i < np->num_queues; i++) {
disconnect_rxq(&np->rxq[i]);
disconnect_txq(&np->txq[i]);
}
}
static int
xn_ifmedia_upd(struct ifnet *ifp)
{
return (0);
}
static void
xn_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
{
ifmr->ifm_status = IFM_AVALID|IFM_ACTIVE;
ifmr->ifm_active = IFM_ETHER|IFM_MANUAL;
}
/* ** Driver registration ** */
static device_method_t netfront_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, netfront_probe),
DEVMETHOD(device_attach, netfront_attach),
DEVMETHOD(device_detach, netfront_detach),
DEVMETHOD(device_shutdown, bus_generic_shutdown),
DEVMETHOD(device_suspend, netfront_suspend),
DEVMETHOD(device_resume, netfront_resume),
/* Xenbus interface */
DEVMETHOD(xenbus_otherend_changed, netfront_backend_changed),
DEVMETHOD_END
};
static driver_t netfront_driver = {
"xn",
netfront_methods,
sizeof(struct netfront_info),
};
devclass_t netfront_devclass;
DRIVER_MODULE(xe, xenbusb_front, netfront_driver, netfront_devclass, NULL,
NULL);