2 * Virtual network driver for conversing with remote driver backends.
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation; or, when distributed
10 * separately from the Linux kernel or incorporated into other
11 * software packages, subject to the following license:
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/netdevice.h>
37 #include <linux/etherdevice.h>
38 #include <linux/skbuff.h>
39 #include <linux/ethtool.h>
40 #include <linux/if_ether.h>
42 #include <linux/udp.h>
43 #include <linux/moduleparam.h>
45 #include <linux/slab.h>
49 #include <xen/xenbus.h>
50 #include <xen/events.h>
52 #include <xen/platform_pci.h>
53 #include <xen/grant_table.h>
55 #include <xen/interface/io/netif.h>
56 #include <xen/interface/memory.h>
57 #include <xen/interface/grant_table.h>
59 /* Module parameters */
60 static unsigned int xennet_max_queues
;
61 module_param_named(max_queues
, xennet_max_queues
, uint
, 0644);
62 MODULE_PARM_DESC(max_queues
,
63 "Maximum number of queues per virtual interface");
65 static const struct ethtool_ops xennet_ethtool_ops
;
71 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
73 #define RX_COPY_THRESHOLD 256
75 #define GRANT_INVALID_REF 0
77 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
78 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
80 /* Minimum number of Rx slots (includes slot for GSO metadata). */
81 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
83 /* Queue name is interface name with "-qNNN" appended */
84 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
86 /* IRQ name is queue name with "-tx" or "-rx" appended */
87 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
89 struct netfront_stats
{
92 struct u64_stats_sync syncp
;
97 struct netfront_queue
{
98 unsigned int id
; /* Queue ID, 0-based */
99 char name
[QUEUE_NAME_SIZE
]; /* DEVNAME-qN */
100 struct netfront_info
*info
;
102 struct napi_struct napi
;
104 /* Split event channels support, tx_* == rx_* when using
105 * single event channel.
107 unsigned int tx_evtchn
, rx_evtchn
;
108 unsigned int tx_irq
, rx_irq
;
109 /* Only used when split event channels support is enabled */
110 char tx_irq_name
[IRQ_NAME_SIZE
]; /* DEVNAME-qN-tx */
111 char rx_irq_name
[IRQ_NAME_SIZE
]; /* DEVNAME-qN-rx */
114 struct xen_netif_tx_front_ring tx
;
118 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
119 * are linked from tx_skb_freelist through skb_entry.link.
121 * NB. Freelist index entries are always going to be less than
122 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
123 * greater than PAGE_OFFSET: we use this property to distinguish
129 } tx_skbs
[NET_TX_RING_SIZE
];
130 grant_ref_t gref_tx_head
;
131 grant_ref_t grant_tx_ref
[NET_TX_RING_SIZE
];
132 struct page
*grant_tx_page
[NET_TX_RING_SIZE
];
133 unsigned tx_skb_freelist
;
135 spinlock_t rx_lock ____cacheline_aligned_in_smp
;
136 struct xen_netif_rx_front_ring rx
;
139 struct timer_list rx_refill_timer
;
141 struct sk_buff
*rx_skbs
[NET_RX_RING_SIZE
];
142 grant_ref_t gref_rx_head
;
143 grant_ref_t grant_rx_ref
[NET_RX_RING_SIZE
];
146 struct netfront_info
{
147 struct list_head list
;
148 struct net_device
*netdev
;
150 struct xenbus_device
*xbdev
;
152 /* Multi-queue support */
153 struct netfront_queue
*queues
;
156 struct netfront_stats __percpu
*rx_stats
;
157 struct netfront_stats __percpu
*tx_stats
;
159 atomic_t rx_gso_checksum_fixup
;
162 struct netfront_rx_info
{
163 struct xen_netif_rx_response rx
;
164 struct xen_netif_extra_info extras
[XEN_NETIF_EXTRA_TYPE_MAX
- 1];
167 static void skb_entry_set_link(union skb_entry
*list
, unsigned short id
)
172 static int skb_entry_is_link(const union skb_entry
*list
)
174 BUILD_BUG_ON(sizeof(list
->skb
) != sizeof(list
->link
));
175 return (unsigned long)list
->skb
< PAGE_OFFSET
;
179 * Access macros for acquiring freeing slots in tx_skbs[].
182 static void add_id_to_freelist(unsigned *head
, union skb_entry
*list
,
185 skb_entry_set_link(&list
[id
], *head
);
189 static unsigned short get_id_from_freelist(unsigned *head
,
190 union skb_entry
*list
)
192 unsigned int id
= *head
;
193 *head
= list
[id
].link
;
197 static int xennet_rxidx(RING_IDX idx
)
199 return idx
& (NET_RX_RING_SIZE
- 1);
202 static struct sk_buff
*xennet_get_rx_skb(struct netfront_queue
*queue
,
205 int i
= xennet_rxidx(ri
);
206 struct sk_buff
*skb
= queue
->rx_skbs
[i
];
207 queue
->rx_skbs
[i
] = NULL
;
211 static grant_ref_t
xennet_get_rx_ref(struct netfront_queue
*queue
,
214 int i
= xennet_rxidx(ri
);
215 grant_ref_t ref
= queue
->grant_rx_ref
[i
];
216 queue
->grant_rx_ref
[i
] = GRANT_INVALID_REF
;
221 static const struct attribute_group xennet_dev_group
;
224 static bool xennet_can_sg(struct net_device
*dev
)
226 return dev
->features
& NETIF_F_SG
;
230 static void rx_refill_timeout(unsigned long data
)
232 struct netfront_queue
*queue
= (struct netfront_queue
*)data
;
233 napi_schedule(&queue
->napi
);
236 static int netfront_tx_slot_available(struct netfront_queue
*queue
)
238 return (queue
->tx
.req_prod_pvt
- queue
->tx
.rsp_cons
) <
239 (NET_TX_RING_SIZE
- MAX_SKB_FRAGS
- 2);
242 static void xennet_maybe_wake_tx(struct netfront_queue
*queue
)
244 struct net_device
*dev
= queue
->info
->netdev
;
245 struct netdev_queue
*dev_queue
= netdev_get_tx_queue(dev
, queue
->id
);
247 if (unlikely(netif_tx_queue_stopped(dev_queue
)) &&
248 netfront_tx_slot_available(queue
) &&
249 likely(netif_running(dev
)))
250 netif_tx_wake_queue(netdev_get_tx_queue(dev
, queue
->id
));
254 static struct sk_buff
*xennet_alloc_one_rx_buffer(struct netfront_queue
*queue
)
259 skb
= __netdev_alloc_skb(queue
->info
->netdev
,
260 RX_COPY_THRESHOLD
+ NET_IP_ALIGN
,
261 GFP_ATOMIC
| __GFP_NOWARN
);
265 page
= alloc_page(GFP_ATOMIC
| __GFP_NOWARN
);
270 skb_add_rx_frag(skb
, 0, page
, 0, 0, PAGE_SIZE
);
272 /* Align ip header to a 16 bytes boundary */
273 skb_reserve(skb
, NET_IP_ALIGN
);
274 skb
->dev
= queue
->info
->netdev
;
280 static void xennet_alloc_rx_buffers(struct netfront_queue
*queue
)
282 RING_IDX req_prod
= queue
->rx
.req_prod_pvt
;
286 if (unlikely(!netif_carrier_ok(queue
->info
->netdev
)))
289 for (req_prod
= queue
->rx
.req_prod_pvt
;
290 req_prod
- queue
->rx
.rsp_cons
< NET_RX_RING_SIZE
;
296 struct xen_netif_rx_request
*req
;
298 skb
= xennet_alloc_one_rx_buffer(queue
);
304 id
= xennet_rxidx(req_prod
);
306 BUG_ON(queue
->rx_skbs
[id
]);
307 queue
->rx_skbs
[id
] = skb
;
309 ref
= gnttab_claim_grant_reference(&queue
->gref_rx_head
);
310 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref
));
311 queue
->grant_rx_ref
[id
] = ref
;
313 page
= skb_frag_page(&skb_shinfo(skb
)->frags
[0]);
315 req
= RING_GET_REQUEST(&queue
->rx
, req_prod
);
316 gnttab_page_grant_foreign_access_ref_one(ref
,
317 queue
->info
->xbdev
->otherend_id
,
324 queue
->rx
.req_prod_pvt
= req_prod
;
326 /* Try again later if there are not enough requests or skb allocation
328 * Enough requests is quantified as the sum of newly created slots and
329 * the unconsumed slots at the backend.
331 if (req_prod
- queue
->rx
.rsp_cons
< NET_RX_SLOTS_MIN
||
333 mod_timer(&queue
->rx_refill_timer
, jiffies
+ (HZ
/10));
337 wmb(); /* barrier so backend seens requests */
339 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue
->rx
, notify
);
341 notify_remote_via_irq(queue
->rx_irq
);
344 static int xennet_open(struct net_device
*dev
)
346 struct netfront_info
*np
= netdev_priv(dev
);
347 unsigned int num_queues
= dev
->real_num_tx_queues
;
349 struct netfront_queue
*queue
= NULL
;
351 for (i
= 0; i
< num_queues
; ++i
) {
352 queue
= &np
->queues
[i
];
353 napi_enable(&queue
->napi
);
355 spin_lock_bh(&queue
->rx_lock
);
356 if (netif_carrier_ok(dev
)) {
357 xennet_alloc_rx_buffers(queue
);
358 queue
->rx
.sring
->rsp_event
= queue
->rx
.rsp_cons
+ 1;
359 if (RING_HAS_UNCONSUMED_RESPONSES(&queue
->rx
))
360 napi_schedule(&queue
->napi
);
362 spin_unlock_bh(&queue
->rx_lock
);
365 netif_tx_start_all_queues(dev
);
370 static void xennet_tx_buf_gc(struct netfront_queue
*queue
)
377 BUG_ON(!netif_carrier_ok(queue
->info
->netdev
));
380 prod
= queue
->tx
.sring
->rsp_prod
;
381 rmb(); /* Ensure we see responses up to 'rp'. */
383 for (cons
= queue
->tx
.rsp_cons
; cons
!= prod
; cons
++) {
384 struct xen_netif_tx_response
*txrsp
;
386 txrsp
= RING_GET_RESPONSE(&queue
->tx
, cons
);
387 if (txrsp
->status
== XEN_NETIF_RSP_NULL
)
391 skb
= queue
->tx_skbs
[id
].skb
;
392 if (unlikely(gnttab_query_foreign_access(
393 queue
->grant_tx_ref
[id
]) != 0)) {
394 pr_alert("%s: warning -- grant still in use by backend domain\n",
398 gnttab_end_foreign_access_ref(
399 queue
->grant_tx_ref
[id
], GNTMAP_readonly
);
400 gnttab_release_grant_reference(
401 &queue
->gref_tx_head
, queue
->grant_tx_ref
[id
]);
402 queue
->grant_tx_ref
[id
] = GRANT_INVALID_REF
;
403 queue
->grant_tx_page
[id
] = NULL
;
404 add_id_to_freelist(&queue
->tx_skb_freelist
, queue
->tx_skbs
, id
);
405 dev_kfree_skb_irq(skb
);
408 queue
->tx
.rsp_cons
= prod
;
410 RING_FINAL_CHECK_FOR_RESPONSES(&queue
->tx
, more_to_do
);
411 } while (more_to_do
);
413 xennet_maybe_wake_tx(queue
);
416 struct xennet_gnttab_make_txreq
{
417 struct netfront_queue
*queue
;
420 struct xen_netif_tx_request
*tx
; /* Last request */
424 static void xennet_tx_setup_grant(unsigned long gfn
, unsigned int offset
,
425 unsigned int len
, void *data
)
427 struct xennet_gnttab_make_txreq
*info
= data
;
429 struct xen_netif_tx_request
*tx
;
431 /* convenient aliases */
432 struct page
*page
= info
->page
;
433 struct netfront_queue
*queue
= info
->queue
;
434 struct sk_buff
*skb
= info
->skb
;
436 id
= get_id_from_freelist(&queue
->tx_skb_freelist
, queue
->tx_skbs
);
437 tx
= RING_GET_REQUEST(&queue
->tx
, queue
->tx
.req_prod_pvt
++);
438 ref
= gnttab_claim_grant_reference(&queue
->gref_tx_head
);
439 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref
));
441 gnttab_grant_foreign_access_ref(ref
, queue
->info
->xbdev
->otherend_id
,
442 gfn
, GNTMAP_readonly
);
444 queue
->tx_skbs
[id
].skb
= skb
;
445 queue
->grant_tx_page
[id
] = page
;
446 queue
->grant_tx_ref
[id
] = ref
;
455 info
->size
+= tx
->size
;
458 static struct xen_netif_tx_request
*xennet_make_first_txreq(
459 struct netfront_queue
*queue
, struct sk_buff
*skb
,
460 struct page
*page
, unsigned int offset
, unsigned int len
)
462 struct xennet_gnttab_make_txreq info
= {
469 gnttab_for_one_grant(page
, offset
, len
, xennet_tx_setup_grant
, &info
);
474 static void xennet_make_one_txreq(unsigned long gfn
, unsigned int offset
,
475 unsigned int len
, void *data
)
477 struct xennet_gnttab_make_txreq
*info
= data
;
479 info
->tx
->flags
|= XEN_NETTXF_more_data
;
481 xennet_tx_setup_grant(gfn
, offset
, len
, data
);
484 static struct xen_netif_tx_request
*xennet_make_txreqs(
485 struct netfront_queue
*queue
, struct xen_netif_tx_request
*tx
,
486 struct sk_buff
*skb
, struct page
*page
,
487 unsigned int offset
, unsigned int len
)
489 struct xennet_gnttab_make_txreq info
= {
495 /* Skip unused frames from start of page */
496 page
+= offset
>> PAGE_SHIFT
;
497 offset
&= ~PAGE_MASK
;
503 gnttab_foreach_grant_in_range(page
, offset
, len
,
504 xennet_make_one_txreq
,
516 * Count how many ring slots are required to send this skb. Each frag
517 * might be a compound page.
519 static int xennet_count_skb_slots(struct sk_buff
*skb
)
521 int i
, frags
= skb_shinfo(skb
)->nr_frags
;
524 slots
= gnttab_count_grant(offset_in_page(skb
->data
),
527 for (i
= 0; i
< frags
; i
++) {
528 skb_frag_t
*frag
= skb_shinfo(skb
)->frags
+ i
;
529 unsigned long size
= skb_frag_size(frag
);
530 unsigned long offset
= frag
->page_offset
;
532 /* Skip unused frames from start of page */
533 offset
&= ~PAGE_MASK
;
535 slots
+= gnttab_count_grant(offset
, size
);
541 static u16
xennet_select_queue(struct net_device
*dev
, struct sk_buff
*skb
,
542 void *accel_priv
, select_queue_fallback_t fallback
)
544 unsigned int num_queues
= dev
->real_num_tx_queues
;
548 /* First, check if there is only one queue */
549 if (num_queues
== 1) {
552 hash
= skb_get_hash(skb
);
553 queue_idx
= hash
% num_queues
;
559 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
561 static int xennet_start_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
563 struct netfront_info
*np
= netdev_priv(dev
);
564 struct netfront_stats
*tx_stats
= this_cpu_ptr(np
->tx_stats
);
565 struct xen_netif_tx_request
*tx
, *first_tx
;
573 struct netfront_queue
*queue
= NULL
;
574 unsigned int num_queues
= dev
->real_num_tx_queues
;
576 struct sk_buff
*nskb
;
578 /* Drop the packet if no queues are set up */
581 /* Determine which queue to transmit this SKB on */
582 queue_index
= skb_get_queue_mapping(skb
);
583 queue
= &np
->queues
[queue_index
];
585 /* If skb->len is too big for wire format, drop skb and alert
586 * user about misconfiguration.
588 if (unlikely(skb
->len
> XEN_NETIF_MAX_TX_SIZE
)) {
589 net_alert_ratelimited(
590 "xennet: skb->len = %u, too big for wire format\n",
595 slots
= xennet_count_skb_slots(skb
);
596 if (unlikely(slots
> MAX_XEN_SKB_FRAGS
+ 1)) {
597 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
599 if (skb_linearize(skb
))
603 page
= virt_to_page(skb
->data
);
604 offset
= offset_in_page(skb
->data
);
606 /* The first req should be at least ETH_HLEN size or the packet will be
607 * dropped by netback.
609 if (unlikely(PAGE_SIZE
- offset
< ETH_HLEN
)) {
610 nskb
= skb_copy(skb
, GFP_ATOMIC
);
613 dev_kfree_skb_any(skb
);
615 page
= virt_to_page(skb
->data
);
616 offset
= offset_in_page(skb
->data
);
619 len
= skb_headlen(skb
);
621 spin_lock_irqsave(&queue
->tx_lock
, flags
);
623 if (unlikely(!netif_carrier_ok(dev
) ||
624 (slots
> 1 && !xennet_can_sg(dev
)) ||
625 netif_needs_gso(skb
, netif_skb_features(skb
)))) {
626 spin_unlock_irqrestore(&queue
->tx_lock
, flags
);
630 /* First request for the linear area. */
631 first_tx
= tx
= xennet_make_first_txreq(queue
, skb
,
634 if (offset
== PAGE_SIZE
) {
640 if (skb
->ip_summed
== CHECKSUM_PARTIAL
)
642 tx
->flags
|= XEN_NETTXF_csum_blank
| XEN_NETTXF_data_validated
;
643 else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
)
644 /* remote but checksummed. */
645 tx
->flags
|= XEN_NETTXF_data_validated
;
647 /* Optional extra info after the first request. */
648 if (skb_shinfo(skb
)->gso_size
) {
649 struct xen_netif_extra_info
*gso
;
651 gso
= (struct xen_netif_extra_info
*)
652 RING_GET_REQUEST(&queue
->tx
, queue
->tx
.req_prod_pvt
++);
654 tx
->flags
|= XEN_NETTXF_extra_info
;
656 gso
->u
.gso
.size
= skb_shinfo(skb
)->gso_size
;
657 gso
->u
.gso
.type
= (skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
) ?
658 XEN_NETIF_GSO_TYPE_TCPV6
:
659 XEN_NETIF_GSO_TYPE_TCPV4
;
661 gso
->u
.gso
.features
= 0;
663 gso
->type
= XEN_NETIF_EXTRA_TYPE_GSO
;
667 /* Requests for the rest of the linear area. */
668 tx
= xennet_make_txreqs(queue
, tx
, skb
, page
, offset
, len
);
670 /* Requests for all the frags. */
671 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
672 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
673 tx
= xennet_make_txreqs(queue
, tx
, skb
,
674 skb_frag_page(frag
), frag
->page_offset
,
675 skb_frag_size(frag
));
678 /* First request has the packet length. */
679 first_tx
->size
= skb
->len
;
681 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue
->tx
, notify
);
683 notify_remote_via_irq(queue
->tx_irq
);
685 u64_stats_update_begin(&tx_stats
->syncp
);
686 tx_stats
->bytes
+= skb
->len
;
688 u64_stats_update_end(&tx_stats
->syncp
);
690 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
691 xennet_tx_buf_gc(queue
);
693 if (!netfront_tx_slot_available(queue
))
694 netif_tx_stop_queue(netdev_get_tx_queue(dev
, queue
->id
));
696 spin_unlock_irqrestore(&queue
->tx_lock
, flags
);
701 dev
->stats
.tx_dropped
++;
702 dev_kfree_skb_any(skb
);
706 static int xennet_close(struct net_device
*dev
)
708 struct netfront_info
*np
= netdev_priv(dev
);
709 unsigned int num_queues
= dev
->real_num_tx_queues
;
711 struct netfront_queue
*queue
;
712 netif_tx_stop_all_queues(np
->netdev
);
713 for (i
= 0; i
< num_queues
; ++i
) {
714 queue
= &np
->queues
[i
];
715 napi_disable(&queue
->napi
);
720 static void xennet_move_rx_slot(struct netfront_queue
*queue
, struct sk_buff
*skb
,
723 int new = xennet_rxidx(queue
->rx
.req_prod_pvt
);
725 BUG_ON(queue
->rx_skbs
[new]);
726 queue
->rx_skbs
[new] = skb
;
727 queue
->grant_rx_ref
[new] = ref
;
728 RING_GET_REQUEST(&queue
->rx
, queue
->rx
.req_prod_pvt
)->id
= new;
729 RING_GET_REQUEST(&queue
->rx
, queue
->rx
.req_prod_pvt
)->gref
= ref
;
730 queue
->rx
.req_prod_pvt
++;
733 static int xennet_get_extras(struct netfront_queue
*queue
,
734 struct xen_netif_extra_info
*extras
,
738 struct xen_netif_extra_info
*extra
;
739 struct device
*dev
= &queue
->info
->netdev
->dev
;
740 RING_IDX cons
= queue
->rx
.rsp_cons
;
747 if (unlikely(cons
+ 1 == rp
)) {
749 dev_warn(dev
, "Missing extra info\n");
754 extra
= (struct xen_netif_extra_info
*)
755 RING_GET_RESPONSE(&queue
->rx
, ++cons
);
757 if (unlikely(!extra
->type
||
758 extra
->type
>= XEN_NETIF_EXTRA_TYPE_MAX
)) {
760 dev_warn(dev
, "Invalid extra type: %d\n",
764 memcpy(&extras
[extra
->type
- 1], extra
,
768 skb
= xennet_get_rx_skb(queue
, cons
);
769 ref
= xennet_get_rx_ref(queue
, cons
);
770 xennet_move_rx_slot(queue
, skb
, ref
);
771 } while (extra
->flags
& XEN_NETIF_EXTRA_FLAG_MORE
);
773 queue
->rx
.rsp_cons
= cons
;
777 static int xennet_get_responses(struct netfront_queue
*queue
,
778 struct netfront_rx_info
*rinfo
, RING_IDX rp
,
779 struct sk_buff_head
*list
)
781 struct xen_netif_rx_response
*rx
= &rinfo
->rx
;
782 struct xen_netif_extra_info
*extras
= rinfo
->extras
;
783 struct device
*dev
= &queue
->info
->netdev
->dev
;
784 RING_IDX cons
= queue
->rx
.rsp_cons
;
785 struct sk_buff
*skb
= xennet_get_rx_skb(queue
, cons
);
786 grant_ref_t ref
= xennet_get_rx_ref(queue
, cons
);
787 int max
= MAX_SKB_FRAGS
+ (rx
->status
<= RX_COPY_THRESHOLD
);
792 if (rx
->flags
& XEN_NETRXF_extra_info
) {
793 err
= xennet_get_extras(queue
, extras
, rp
);
794 cons
= queue
->rx
.rsp_cons
;
798 if (unlikely(rx
->status
< 0 ||
799 rx
->offset
+ rx
->status
> XEN_PAGE_SIZE
)) {
801 dev_warn(dev
, "rx->offset: %u, size: %d\n",
802 rx
->offset
, rx
->status
);
803 xennet_move_rx_slot(queue
, skb
, ref
);
809 * This definitely indicates a bug, either in this driver or in
810 * the backend driver. In future this should flag the bad
811 * situation to the system controller to reboot the backend.
813 if (ref
== GRANT_INVALID_REF
) {
815 dev_warn(dev
, "Bad rx response id %d.\n",
821 ret
= gnttab_end_foreign_access_ref(ref
, 0);
824 gnttab_release_grant_reference(&queue
->gref_rx_head
, ref
);
826 __skb_queue_tail(list
, skb
);
829 if (!(rx
->flags
& XEN_NETRXF_more_data
))
832 if (cons
+ slots
== rp
) {
834 dev_warn(dev
, "Need more slots\n");
839 rx
= RING_GET_RESPONSE(&queue
->rx
, cons
+ slots
);
840 skb
= xennet_get_rx_skb(queue
, cons
+ slots
);
841 ref
= xennet_get_rx_ref(queue
, cons
+ slots
);
845 if (unlikely(slots
> max
)) {
847 dev_warn(dev
, "Too many slots\n");
852 queue
->rx
.rsp_cons
= cons
+ slots
;
857 static int xennet_set_skb_gso(struct sk_buff
*skb
,
858 struct xen_netif_extra_info
*gso
)
860 if (!gso
->u
.gso
.size
) {
862 pr_warn("GSO size must not be zero\n");
866 if (gso
->u
.gso
.type
!= XEN_NETIF_GSO_TYPE_TCPV4
&&
867 gso
->u
.gso
.type
!= XEN_NETIF_GSO_TYPE_TCPV6
) {
869 pr_warn("Bad GSO type %d\n", gso
->u
.gso
.type
);
873 skb_shinfo(skb
)->gso_size
= gso
->u
.gso
.size
;
874 skb_shinfo(skb
)->gso_type
=
875 (gso
->u
.gso
.type
== XEN_NETIF_GSO_TYPE_TCPV4
) ?
879 /* Header must be checked, and gso_segs computed. */
880 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
881 skb_shinfo(skb
)->gso_segs
= 0;
886 static RING_IDX
xennet_fill_frags(struct netfront_queue
*queue
,
888 struct sk_buff_head
*list
)
890 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
891 RING_IDX cons
= queue
->rx
.rsp_cons
;
892 struct sk_buff
*nskb
;
894 while ((nskb
= __skb_dequeue(list
))) {
895 struct xen_netif_rx_response
*rx
=
896 RING_GET_RESPONSE(&queue
->rx
, ++cons
);
897 skb_frag_t
*nfrag
= &skb_shinfo(nskb
)->frags
[0];
899 if (shinfo
->nr_frags
== MAX_SKB_FRAGS
) {
900 unsigned int pull_to
= NETFRONT_SKB_CB(skb
)->pull_to
;
902 BUG_ON(pull_to
<= skb_headlen(skb
));
903 __pskb_pull_tail(skb
, pull_to
- skb_headlen(skb
));
905 BUG_ON(shinfo
->nr_frags
>= MAX_SKB_FRAGS
);
907 skb_add_rx_frag(skb
, shinfo
->nr_frags
, skb_frag_page(nfrag
),
908 rx
->offset
, rx
->status
, PAGE_SIZE
);
910 skb_shinfo(nskb
)->nr_frags
= 0;
917 static int checksum_setup(struct net_device
*dev
, struct sk_buff
*skb
)
919 bool recalculate_partial_csum
= false;
922 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
923 * peers can fail to set NETRXF_csum_blank when sending a GSO
924 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
925 * recalculate the partial checksum.
927 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
&& skb_is_gso(skb
)) {
928 struct netfront_info
*np
= netdev_priv(dev
);
929 atomic_inc(&np
->rx_gso_checksum_fixup
);
930 skb
->ip_summed
= CHECKSUM_PARTIAL
;
931 recalculate_partial_csum
= true;
934 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
935 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
)
938 return skb_checksum_setup(skb
, recalculate_partial_csum
);
941 static int handle_incoming_queue(struct netfront_queue
*queue
,
942 struct sk_buff_head
*rxq
)
944 struct netfront_stats
*rx_stats
= this_cpu_ptr(queue
->info
->rx_stats
);
945 int packets_dropped
= 0;
948 while ((skb
= __skb_dequeue(rxq
)) != NULL
) {
949 int pull_to
= NETFRONT_SKB_CB(skb
)->pull_to
;
951 if (pull_to
> skb_headlen(skb
))
952 __pskb_pull_tail(skb
, pull_to
- skb_headlen(skb
));
954 /* Ethernet work: Delayed to here as it peeks the header. */
955 skb
->protocol
= eth_type_trans(skb
, queue
->info
->netdev
);
956 skb_reset_network_header(skb
);
958 if (checksum_setup(queue
->info
->netdev
, skb
)) {
961 queue
->info
->netdev
->stats
.rx_errors
++;
965 u64_stats_update_begin(&rx_stats
->syncp
);
967 rx_stats
->bytes
+= skb
->len
;
968 u64_stats_update_end(&rx_stats
->syncp
);
971 napi_gro_receive(&queue
->napi
, skb
);
974 return packets_dropped
;
977 static int xennet_poll(struct napi_struct
*napi
, int budget
)
979 struct netfront_queue
*queue
= container_of(napi
, struct netfront_queue
, napi
);
980 struct net_device
*dev
= queue
->info
->netdev
;
982 struct netfront_rx_info rinfo
;
983 struct xen_netif_rx_response
*rx
= &rinfo
.rx
;
984 struct xen_netif_extra_info
*extras
= rinfo
.extras
;
987 struct sk_buff_head rxq
;
988 struct sk_buff_head errq
;
989 struct sk_buff_head tmpq
;
992 spin_lock(&queue
->rx_lock
);
994 skb_queue_head_init(&rxq
);
995 skb_queue_head_init(&errq
);
996 skb_queue_head_init(&tmpq
);
998 rp
= queue
->rx
.sring
->rsp_prod
;
999 rmb(); /* Ensure we see queued responses up to 'rp'. */
1001 i
= queue
->rx
.rsp_cons
;
1003 while ((i
!= rp
) && (work_done
< budget
)) {
1004 memcpy(rx
, RING_GET_RESPONSE(&queue
->rx
, i
), sizeof(*rx
));
1005 memset(extras
, 0, sizeof(rinfo
.extras
));
1007 err
= xennet_get_responses(queue
, &rinfo
, rp
, &tmpq
);
1009 if (unlikely(err
)) {
1011 while ((skb
= __skb_dequeue(&tmpq
)))
1012 __skb_queue_tail(&errq
, skb
);
1013 dev
->stats
.rx_errors
++;
1014 i
= queue
->rx
.rsp_cons
;
1018 skb
= __skb_dequeue(&tmpq
);
1020 if (extras
[XEN_NETIF_EXTRA_TYPE_GSO
- 1].type
) {
1021 struct xen_netif_extra_info
*gso
;
1022 gso
= &extras
[XEN_NETIF_EXTRA_TYPE_GSO
- 1];
1024 if (unlikely(xennet_set_skb_gso(skb
, gso
))) {
1025 __skb_queue_head(&tmpq
, skb
);
1026 queue
->rx
.rsp_cons
+= skb_queue_len(&tmpq
);
1031 NETFRONT_SKB_CB(skb
)->pull_to
= rx
->status
;
1032 if (NETFRONT_SKB_CB(skb
)->pull_to
> RX_COPY_THRESHOLD
)
1033 NETFRONT_SKB_CB(skb
)->pull_to
= RX_COPY_THRESHOLD
;
1035 skb_shinfo(skb
)->frags
[0].page_offset
= rx
->offset
;
1036 skb_frag_size_set(&skb_shinfo(skb
)->frags
[0], rx
->status
);
1037 skb
->data_len
= rx
->status
;
1038 skb
->len
+= rx
->status
;
1040 i
= xennet_fill_frags(queue
, skb
, &tmpq
);
1042 if (rx
->flags
& XEN_NETRXF_csum_blank
)
1043 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1044 else if (rx
->flags
& XEN_NETRXF_data_validated
)
1045 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
1047 __skb_queue_tail(&rxq
, skb
);
1049 queue
->rx
.rsp_cons
= ++i
;
1053 __skb_queue_purge(&errq
);
1055 work_done
-= handle_incoming_queue(queue
, &rxq
);
1057 xennet_alloc_rx_buffers(queue
);
1059 if (work_done
< budget
) {
1062 napi_complete(napi
);
1064 RING_FINAL_CHECK_FOR_RESPONSES(&queue
->rx
, more_to_do
);
1066 napi_schedule(napi
);
1069 spin_unlock(&queue
->rx_lock
);
1074 static int xennet_change_mtu(struct net_device
*dev
, int mtu
)
1076 int max
= xennet_can_sg(dev
) ? XEN_NETIF_MAX_TX_SIZE
: ETH_DATA_LEN
;
1084 static struct rtnl_link_stats64
*xennet_get_stats64(struct net_device
*dev
,
1085 struct rtnl_link_stats64
*tot
)
1087 struct netfront_info
*np
= netdev_priv(dev
);
1090 for_each_possible_cpu(cpu
) {
1091 struct netfront_stats
*rx_stats
= per_cpu_ptr(np
->rx_stats
, cpu
);
1092 struct netfront_stats
*tx_stats
= per_cpu_ptr(np
->tx_stats
, cpu
);
1093 u64 rx_packets
, rx_bytes
, tx_packets
, tx_bytes
;
1097 start
= u64_stats_fetch_begin_irq(&tx_stats
->syncp
);
1098 tx_packets
= tx_stats
->packets
;
1099 tx_bytes
= tx_stats
->bytes
;
1100 } while (u64_stats_fetch_retry_irq(&tx_stats
->syncp
, start
));
1103 start
= u64_stats_fetch_begin_irq(&rx_stats
->syncp
);
1104 rx_packets
= rx_stats
->packets
;
1105 rx_bytes
= rx_stats
->bytes
;
1106 } while (u64_stats_fetch_retry_irq(&rx_stats
->syncp
, start
));
1108 tot
->rx_packets
+= rx_packets
;
1109 tot
->tx_packets
+= tx_packets
;
1110 tot
->rx_bytes
+= rx_bytes
;
1111 tot
->tx_bytes
+= tx_bytes
;
1114 tot
->rx_errors
= dev
->stats
.rx_errors
;
1115 tot
->tx_dropped
= dev
->stats
.tx_dropped
;
1120 static void xennet_release_tx_bufs(struct netfront_queue
*queue
)
1122 struct sk_buff
*skb
;
1125 for (i
= 0; i
< NET_TX_RING_SIZE
; i
++) {
1126 /* Skip over entries which are actually freelist references */
1127 if (skb_entry_is_link(&queue
->tx_skbs
[i
]))
1130 skb
= queue
->tx_skbs
[i
].skb
;
1131 get_page(queue
->grant_tx_page
[i
]);
1132 gnttab_end_foreign_access(queue
->grant_tx_ref
[i
],
1134 (unsigned long)page_address(queue
->grant_tx_page
[i
]));
1135 queue
->grant_tx_page
[i
] = NULL
;
1136 queue
->grant_tx_ref
[i
] = GRANT_INVALID_REF
;
1137 add_id_to_freelist(&queue
->tx_skb_freelist
, queue
->tx_skbs
, i
);
1138 dev_kfree_skb_irq(skb
);
1142 static void xennet_release_rx_bufs(struct netfront_queue
*queue
)
1146 spin_lock_bh(&queue
->rx_lock
);
1148 for (id
= 0; id
< NET_RX_RING_SIZE
; id
++) {
1149 struct sk_buff
*skb
;
1152 skb
= queue
->rx_skbs
[id
];
1156 ref
= queue
->grant_rx_ref
[id
];
1157 if (ref
== GRANT_INVALID_REF
)
1160 page
= skb_frag_page(&skb_shinfo(skb
)->frags
[0]);
1162 /* gnttab_end_foreign_access() needs a page ref until
1163 * foreign access is ended (which may be deferred).
1166 gnttab_end_foreign_access(ref
, 0,
1167 (unsigned long)page_address(page
));
1168 queue
->grant_rx_ref
[id
] = GRANT_INVALID_REF
;
1173 spin_unlock_bh(&queue
->rx_lock
);
1176 static netdev_features_t
xennet_fix_features(struct net_device
*dev
,
1177 netdev_features_t features
)
1179 struct netfront_info
*np
= netdev_priv(dev
);
1181 if (features
& NETIF_F_SG
&&
1182 !xenbus_read_unsigned(np
->xbdev
->otherend
, "feature-sg", 0))
1183 features
&= ~NETIF_F_SG
;
1185 if (features
& NETIF_F_IPV6_CSUM
&&
1186 !xenbus_read_unsigned(np
->xbdev
->otherend
,
1187 "feature-ipv6-csum-offload", 0))
1188 features
&= ~NETIF_F_IPV6_CSUM
;
1190 if (features
& NETIF_F_TSO
&&
1191 !xenbus_read_unsigned(np
->xbdev
->otherend
, "feature-gso-tcpv4", 0))
1192 features
&= ~NETIF_F_TSO
;
1194 if (features
& NETIF_F_TSO6
&&
1195 !xenbus_read_unsigned(np
->xbdev
->otherend
, "feature-gso-tcpv6", 0))
1196 features
&= ~NETIF_F_TSO6
;
1201 static int xennet_set_features(struct net_device
*dev
,
1202 netdev_features_t features
)
1204 if (!(features
& NETIF_F_SG
) && dev
->mtu
> ETH_DATA_LEN
) {
1205 netdev_info(dev
, "Reducing MTU because no SG offload");
1206 dev
->mtu
= ETH_DATA_LEN
;
1212 static irqreturn_t
xennet_tx_interrupt(int irq
, void *dev_id
)
1214 struct netfront_queue
*queue
= dev_id
;
1215 unsigned long flags
;
1217 spin_lock_irqsave(&queue
->tx_lock
, flags
);
1218 xennet_tx_buf_gc(queue
);
1219 spin_unlock_irqrestore(&queue
->tx_lock
, flags
);
1224 static irqreturn_t
xennet_rx_interrupt(int irq
, void *dev_id
)
1226 struct netfront_queue
*queue
= dev_id
;
1227 struct net_device
*dev
= queue
->info
->netdev
;
1229 if (likely(netif_carrier_ok(dev
) &&
1230 RING_HAS_UNCONSUMED_RESPONSES(&queue
->rx
)))
1231 napi_schedule(&queue
->napi
);
1236 static irqreturn_t
xennet_interrupt(int irq
, void *dev_id
)
1238 xennet_tx_interrupt(irq
, dev_id
);
1239 xennet_rx_interrupt(irq
, dev_id
);
1243 #ifdef CONFIG_NET_POLL_CONTROLLER
1244 static void xennet_poll_controller(struct net_device
*dev
)
1246 /* Poll each queue */
1247 struct netfront_info
*info
= netdev_priv(dev
);
1248 unsigned int num_queues
= dev
->real_num_tx_queues
;
1250 for (i
= 0; i
< num_queues
; ++i
)
1251 xennet_interrupt(0, &info
->queues
[i
]);
1255 static const struct net_device_ops xennet_netdev_ops
= {
1256 .ndo_open
= xennet_open
,
1257 .ndo_stop
= xennet_close
,
1258 .ndo_start_xmit
= xennet_start_xmit
,
1259 .ndo_change_mtu
= xennet_change_mtu
,
1260 .ndo_get_stats64
= xennet_get_stats64
,
1261 .ndo_set_mac_address
= eth_mac_addr
,
1262 .ndo_validate_addr
= eth_validate_addr
,
1263 .ndo_fix_features
= xennet_fix_features
,
1264 .ndo_set_features
= xennet_set_features
,
1265 .ndo_select_queue
= xennet_select_queue
,
1266 #ifdef CONFIG_NET_POLL_CONTROLLER
1267 .ndo_poll_controller
= xennet_poll_controller
,
1271 static void xennet_free_netdev(struct net_device
*netdev
)
1273 struct netfront_info
*np
= netdev_priv(netdev
);
1275 free_percpu(np
->rx_stats
);
1276 free_percpu(np
->tx_stats
);
1277 free_netdev(netdev
);
1280 static struct net_device
*xennet_create_dev(struct xenbus_device
*dev
)
1283 struct net_device
*netdev
;
1284 struct netfront_info
*np
;
1286 netdev
= alloc_etherdev_mq(sizeof(struct netfront_info
), xennet_max_queues
);
1288 return ERR_PTR(-ENOMEM
);
1290 np
= netdev_priv(netdev
);
1296 np
->rx_stats
= netdev_alloc_pcpu_stats(struct netfront_stats
);
1297 if (np
->rx_stats
== NULL
)
1299 np
->tx_stats
= netdev_alloc_pcpu_stats(struct netfront_stats
);
1300 if (np
->tx_stats
== NULL
)
1303 netdev
->netdev_ops
= &xennet_netdev_ops
;
1305 netdev
->features
= NETIF_F_IP_CSUM
| NETIF_F_RXCSUM
|
1307 netdev
->hw_features
= NETIF_F_SG
|
1309 NETIF_F_TSO
| NETIF_F_TSO6
;
1312 * Assume that all hw features are available for now. This set
1313 * will be adjusted by the call to netdev_update_features() in
1314 * xennet_connect() which is the earliest point where we can
1315 * negotiate with the backend regarding supported features.
1317 netdev
->features
|= netdev
->hw_features
;
1319 netdev
->ethtool_ops
= &xennet_ethtool_ops
;
1320 netdev
->min_mtu
= 0;
1321 netdev
->max_mtu
= XEN_NETIF_MAX_TX_SIZE
;
1322 SET_NETDEV_DEV(netdev
, &dev
->dev
);
1324 np
->netdev
= netdev
;
1326 netif_carrier_off(netdev
);
1331 xennet_free_netdev(netdev
);
1332 return ERR_PTR(err
);
1336 * Entry point to this code when a new device is created. Allocate the basic
1337 * structures and the ring buffers for communication with the backend, and
1338 * inform the backend of the appropriate details for those.
1340 static int netfront_probe(struct xenbus_device
*dev
,
1341 const struct xenbus_device_id
*id
)
1344 struct net_device
*netdev
;
1345 struct netfront_info
*info
;
1347 netdev
= xennet_create_dev(dev
);
1348 if (IS_ERR(netdev
)) {
1349 err
= PTR_ERR(netdev
);
1350 xenbus_dev_fatal(dev
, err
, "creating netdev");
1354 info
= netdev_priv(netdev
);
1355 dev_set_drvdata(&dev
->dev
, info
);
1357 info
->netdev
->sysfs_groups
[0] = &xennet_dev_group
;
1359 err
= register_netdev(info
->netdev
);
1361 pr_warn("%s: register_netdev err=%d\n", __func__
, err
);
1368 xennet_free_netdev(netdev
);
1369 dev_set_drvdata(&dev
->dev
, NULL
);
1373 static void xennet_end_access(int ref
, void *page
)
1375 /* This frees the page as a side-effect */
1376 if (ref
!= GRANT_INVALID_REF
)
1377 gnttab_end_foreign_access(ref
, 0, (unsigned long)page
);
1380 static void xennet_disconnect_backend(struct netfront_info
*info
)
1383 unsigned int num_queues
= info
->netdev
->real_num_tx_queues
;
1385 netif_carrier_off(info
->netdev
);
1387 for (i
= 0; i
< num_queues
&& info
->queues
; ++i
) {
1388 struct netfront_queue
*queue
= &info
->queues
[i
];
1390 del_timer_sync(&queue
->rx_refill_timer
);
1392 if (queue
->tx_irq
&& (queue
->tx_irq
== queue
->rx_irq
))
1393 unbind_from_irqhandler(queue
->tx_irq
, queue
);
1394 if (queue
->tx_irq
&& (queue
->tx_irq
!= queue
->rx_irq
)) {
1395 unbind_from_irqhandler(queue
->tx_irq
, queue
);
1396 unbind_from_irqhandler(queue
->rx_irq
, queue
);
1398 queue
->tx_evtchn
= queue
->rx_evtchn
= 0;
1399 queue
->tx_irq
= queue
->rx_irq
= 0;
1401 if (netif_running(info
->netdev
))
1402 napi_synchronize(&queue
->napi
);
1404 xennet_release_tx_bufs(queue
);
1405 xennet_release_rx_bufs(queue
);
1406 gnttab_free_grant_references(queue
->gref_tx_head
);
1407 gnttab_free_grant_references(queue
->gref_rx_head
);
1409 /* End access and free the pages */
1410 xennet_end_access(queue
->tx_ring_ref
, queue
->tx
.sring
);
1411 xennet_end_access(queue
->rx_ring_ref
, queue
->rx
.sring
);
1413 queue
->tx_ring_ref
= GRANT_INVALID_REF
;
1414 queue
->rx_ring_ref
= GRANT_INVALID_REF
;
1415 queue
->tx
.sring
= NULL
;
1416 queue
->rx
.sring
= NULL
;
1421 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1422 * driver restart. We tear down our netif structure and recreate it, but
1423 * leave the device-layer structures intact so that this is transparent to the
1424 * rest of the kernel.
1426 static int netfront_resume(struct xenbus_device
*dev
)
1428 struct netfront_info
*info
= dev_get_drvdata(&dev
->dev
);
1430 dev_dbg(&dev
->dev
, "%s\n", dev
->nodename
);
1432 xennet_disconnect_backend(info
);
1436 static int xen_net_read_mac(struct xenbus_device
*dev
, u8 mac
[])
1438 char *s
, *e
, *macstr
;
1441 macstr
= s
= xenbus_read(XBT_NIL
, dev
->nodename
, "mac", NULL
);
1443 return PTR_ERR(macstr
);
1445 for (i
= 0; i
< ETH_ALEN
; i
++) {
1446 mac
[i
] = simple_strtoul(s
, &e
, 16);
1447 if ((s
== e
) || (*e
!= ((i
== ETH_ALEN
-1) ? '\0' : ':'))) {
1458 static int setup_netfront_single(struct netfront_queue
*queue
)
1462 err
= xenbus_alloc_evtchn(queue
->info
->xbdev
, &queue
->tx_evtchn
);
1466 err
= bind_evtchn_to_irqhandler(queue
->tx_evtchn
,
1468 0, queue
->info
->netdev
->name
, queue
);
1471 queue
->rx_evtchn
= queue
->tx_evtchn
;
1472 queue
->rx_irq
= queue
->tx_irq
= err
;
1477 xenbus_free_evtchn(queue
->info
->xbdev
, queue
->tx_evtchn
);
1478 queue
->tx_evtchn
= 0;
1483 static int setup_netfront_split(struct netfront_queue
*queue
)
1487 err
= xenbus_alloc_evtchn(queue
->info
->xbdev
, &queue
->tx_evtchn
);
1490 err
= xenbus_alloc_evtchn(queue
->info
->xbdev
, &queue
->rx_evtchn
);
1492 goto alloc_rx_evtchn_fail
;
1494 snprintf(queue
->tx_irq_name
, sizeof(queue
->tx_irq_name
),
1495 "%s-tx", queue
->name
);
1496 err
= bind_evtchn_to_irqhandler(queue
->tx_evtchn
,
1497 xennet_tx_interrupt
,
1498 0, queue
->tx_irq_name
, queue
);
1501 queue
->tx_irq
= err
;
1503 snprintf(queue
->rx_irq_name
, sizeof(queue
->rx_irq_name
),
1504 "%s-rx", queue
->name
);
1505 err
= bind_evtchn_to_irqhandler(queue
->rx_evtchn
,
1506 xennet_rx_interrupt
,
1507 0, queue
->rx_irq_name
, queue
);
1510 queue
->rx_irq
= err
;
1515 unbind_from_irqhandler(queue
->tx_irq
, queue
);
1518 xenbus_free_evtchn(queue
->info
->xbdev
, queue
->rx_evtchn
);
1519 queue
->rx_evtchn
= 0;
1520 alloc_rx_evtchn_fail
:
1521 xenbus_free_evtchn(queue
->info
->xbdev
, queue
->tx_evtchn
);
1522 queue
->tx_evtchn
= 0;
1527 static int setup_netfront(struct xenbus_device
*dev
,
1528 struct netfront_queue
*queue
, unsigned int feature_split_evtchn
)
1530 struct xen_netif_tx_sring
*txs
;
1531 struct xen_netif_rx_sring
*rxs
;
1535 queue
->tx_ring_ref
= GRANT_INVALID_REF
;
1536 queue
->rx_ring_ref
= GRANT_INVALID_REF
;
1537 queue
->rx
.sring
= NULL
;
1538 queue
->tx
.sring
= NULL
;
1540 txs
= (struct xen_netif_tx_sring
*)get_zeroed_page(GFP_NOIO
| __GFP_HIGH
);
1543 xenbus_dev_fatal(dev
, err
, "allocating tx ring page");
1546 SHARED_RING_INIT(txs
);
1547 FRONT_RING_INIT(&queue
->tx
, txs
, XEN_PAGE_SIZE
);
1549 err
= xenbus_grant_ring(dev
, txs
, 1, &gref
);
1551 goto grant_tx_ring_fail
;
1552 queue
->tx_ring_ref
= gref
;
1554 rxs
= (struct xen_netif_rx_sring
*)get_zeroed_page(GFP_NOIO
| __GFP_HIGH
);
1557 xenbus_dev_fatal(dev
, err
, "allocating rx ring page");
1558 goto alloc_rx_ring_fail
;
1560 SHARED_RING_INIT(rxs
);
1561 FRONT_RING_INIT(&queue
->rx
, rxs
, XEN_PAGE_SIZE
);
1563 err
= xenbus_grant_ring(dev
, rxs
, 1, &gref
);
1565 goto grant_rx_ring_fail
;
1566 queue
->rx_ring_ref
= gref
;
1568 if (feature_split_evtchn
)
1569 err
= setup_netfront_split(queue
);
1570 /* setup single event channel if
1571 * a) feature-split-event-channels == 0
1572 * b) feature-split-event-channels == 1 but failed to setup
1574 if (!feature_split_evtchn
|| (feature_split_evtchn
&& err
))
1575 err
= setup_netfront_single(queue
);
1578 goto alloc_evtchn_fail
;
1582 /* If we fail to setup netfront, it is safe to just revoke access to
1583 * granted pages because backend is not accessing it at this point.
1586 gnttab_end_foreign_access_ref(queue
->rx_ring_ref
, 0);
1588 free_page((unsigned long)rxs
);
1590 gnttab_end_foreign_access_ref(queue
->tx_ring_ref
, 0);
1592 free_page((unsigned long)txs
);
1597 /* Queue-specific initialisation
1598 * This used to be done in xennet_create_dev() but must now
1601 static int xennet_init_queue(struct netfront_queue
*queue
)
1606 spin_lock_init(&queue
->tx_lock
);
1607 spin_lock_init(&queue
->rx_lock
);
1609 setup_timer(&queue
->rx_refill_timer
, rx_refill_timeout
,
1610 (unsigned long)queue
);
1612 snprintf(queue
->name
, sizeof(queue
->name
), "%s-q%u",
1613 queue
->info
->netdev
->name
, queue
->id
);
1615 /* Initialise tx_skbs as a free chain containing every entry. */
1616 queue
->tx_skb_freelist
= 0;
1617 for (i
= 0; i
< NET_TX_RING_SIZE
; i
++) {
1618 skb_entry_set_link(&queue
->tx_skbs
[i
], i
+1);
1619 queue
->grant_tx_ref
[i
] = GRANT_INVALID_REF
;
1620 queue
->grant_tx_page
[i
] = NULL
;
1623 /* Clear out rx_skbs */
1624 for (i
= 0; i
< NET_RX_RING_SIZE
; i
++) {
1625 queue
->rx_skbs
[i
] = NULL
;
1626 queue
->grant_rx_ref
[i
] = GRANT_INVALID_REF
;
1629 /* A grant for every tx ring slot */
1630 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE
,
1631 &queue
->gref_tx_head
) < 0) {
1632 pr_alert("can't alloc tx grant refs\n");
1637 /* A grant for every rx ring slot */
1638 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE
,
1639 &queue
->gref_rx_head
) < 0) {
1640 pr_alert("can't alloc rx grant refs\n");
1648 gnttab_free_grant_references(queue
->gref_tx_head
);
1653 static int write_queue_xenstore_keys(struct netfront_queue
*queue
,
1654 struct xenbus_transaction
*xbt
, int write_hierarchical
)
1656 /* Write the queue-specific keys into XenStore in the traditional
1657 * way for a single queue, or in a queue subkeys for multiple
1660 struct xenbus_device
*dev
= queue
->info
->xbdev
;
1662 const char *message
;
1666 /* Choose the correct place to write the keys */
1667 if (write_hierarchical
) {
1668 pathsize
= strlen(dev
->nodename
) + 10;
1669 path
= kzalloc(pathsize
, GFP_KERNEL
);
1672 message
= "out of memory while writing ring references";
1675 snprintf(path
, pathsize
, "%s/queue-%u",
1676 dev
->nodename
, queue
->id
);
1678 path
= (char *)dev
->nodename
;
1681 /* Write ring references */
1682 err
= xenbus_printf(*xbt
, path
, "tx-ring-ref", "%u",
1683 queue
->tx_ring_ref
);
1685 message
= "writing tx-ring-ref";
1689 err
= xenbus_printf(*xbt
, path
, "rx-ring-ref", "%u",
1690 queue
->rx_ring_ref
);
1692 message
= "writing rx-ring-ref";
1696 /* Write event channels; taking into account both shared
1697 * and split event channel scenarios.
1699 if (queue
->tx_evtchn
== queue
->rx_evtchn
) {
1700 /* Shared event channel */
1701 err
= xenbus_printf(*xbt
, path
,
1702 "event-channel", "%u", queue
->tx_evtchn
);
1704 message
= "writing event-channel";
1708 /* Split event channels */
1709 err
= xenbus_printf(*xbt
, path
,
1710 "event-channel-tx", "%u", queue
->tx_evtchn
);
1712 message
= "writing event-channel-tx";
1716 err
= xenbus_printf(*xbt
, path
,
1717 "event-channel-rx", "%u", queue
->rx_evtchn
);
1719 message
= "writing event-channel-rx";
1724 if (write_hierarchical
)
1729 if (write_hierarchical
)
1731 xenbus_dev_fatal(dev
, err
, "%s", message
);
1735 static void xennet_destroy_queues(struct netfront_info
*info
)
1741 for (i
= 0; i
< info
->netdev
->real_num_tx_queues
; i
++) {
1742 struct netfront_queue
*queue
= &info
->queues
[i
];
1744 if (netif_running(info
->netdev
))
1745 napi_disable(&queue
->napi
);
1746 netif_napi_del(&queue
->napi
);
1751 kfree(info
->queues
);
1752 info
->queues
= NULL
;
1755 static int xennet_create_queues(struct netfront_info
*info
,
1756 unsigned int *num_queues
)
1761 info
->queues
= kcalloc(*num_queues
, sizeof(struct netfront_queue
),
1768 for (i
= 0; i
< *num_queues
; i
++) {
1769 struct netfront_queue
*queue
= &info
->queues
[i
];
1774 ret
= xennet_init_queue(queue
);
1776 dev_warn(&info
->netdev
->dev
,
1777 "only created %d queues\n", i
);
1782 netif_napi_add(queue
->info
->netdev
, &queue
->napi
,
1784 if (netif_running(info
->netdev
))
1785 napi_enable(&queue
->napi
);
1788 netif_set_real_num_tx_queues(info
->netdev
, *num_queues
);
1792 if (*num_queues
== 0) {
1793 dev_err(&info
->netdev
->dev
, "no queues\n");
1799 /* Common code used when first setting up, and when resuming. */
1800 static int talk_to_netback(struct xenbus_device
*dev
,
1801 struct netfront_info
*info
)
1803 const char *message
;
1804 struct xenbus_transaction xbt
;
1806 unsigned int feature_split_evtchn
;
1808 unsigned int max_queues
= 0;
1809 struct netfront_queue
*queue
= NULL
;
1810 unsigned int num_queues
= 1;
1812 info
->netdev
->irq
= 0;
1814 /* Check if backend supports multiple queues */
1815 max_queues
= xenbus_read_unsigned(info
->xbdev
->otherend
,
1816 "multi-queue-max-queues", 1);
1817 num_queues
= min(max_queues
, xennet_max_queues
);
1819 /* Check feature-split-event-channels */
1820 feature_split_evtchn
= xenbus_read_unsigned(info
->xbdev
->otherend
,
1821 "feature-split-event-channels", 0);
1823 /* Read mac addr. */
1824 err
= xen_net_read_mac(dev
, info
->netdev
->dev_addr
);
1826 xenbus_dev_fatal(dev
, err
, "parsing %s/mac", dev
->nodename
);
1831 xennet_destroy_queues(info
);
1833 err
= xennet_create_queues(info
, &num_queues
);
1835 xenbus_dev_fatal(dev
, err
, "creating queues");
1836 kfree(info
->queues
);
1837 info
->queues
= NULL
;
1841 /* Create shared ring, alloc event channel -- for each queue */
1842 for (i
= 0; i
< num_queues
; ++i
) {
1843 queue
= &info
->queues
[i
];
1844 err
= setup_netfront(dev
, queue
, feature_split_evtchn
);
1850 err
= xenbus_transaction_start(&xbt
);
1852 xenbus_dev_fatal(dev
, err
, "starting transaction");
1856 if (xenbus_exists(XBT_NIL
,
1857 info
->xbdev
->otherend
, "multi-queue-max-queues")) {
1858 /* Write the number of queues */
1859 err
= xenbus_printf(xbt
, dev
->nodename
,
1860 "multi-queue-num-queues", "%u", num_queues
);
1862 message
= "writing multi-queue-num-queues";
1863 goto abort_transaction_no_dev_fatal
;
1867 if (num_queues
== 1) {
1868 err
= write_queue_xenstore_keys(&info
->queues
[0], &xbt
, 0); /* flat */
1870 goto abort_transaction_no_dev_fatal
;
1872 /* Write the keys for each queue */
1873 for (i
= 0; i
< num_queues
; ++i
) {
1874 queue
= &info
->queues
[i
];
1875 err
= write_queue_xenstore_keys(queue
, &xbt
, 1); /* hierarchical */
1877 goto abort_transaction_no_dev_fatal
;
1881 /* The remaining keys are not queue-specific */
1882 err
= xenbus_printf(xbt
, dev
->nodename
, "request-rx-copy", "%u",
1885 message
= "writing request-rx-copy";
1886 goto abort_transaction
;
1889 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-rx-notify", "%d", 1);
1891 message
= "writing feature-rx-notify";
1892 goto abort_transaction
;
1895 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-sg", "%d", 1);
1897 message
= "writing feature-sg";
1898 goto abort_transaction
;
1901 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-gso-tcpv4", "%d", 1);
1903 message
= "writing feature-gso-tcpv4";
1904 goto abort_transaction
;
1907 err
= xenbus_write(xbt
, dev
->nodename
, "feature-gso-tcpv6", "1");
1909 message
= "writing feature-gso-tcpv6";
1910 goto abort_transaction
;
1913 err
= xenbus_write(xbt
, dev
->nodename
, "feature-ipv6-csum-offload",
1916 message
= "writing feature-ipv6-csum-offload";
1917 goto abort_transaction
;
1920 err
= xenbus_transaction_end(xbt
, 0);
1924 xenbus_dev_fatal(dev
, err
, "completing transaction");
1931 xenbus_dev_fatal(dev
, err
, "%s", message
);
1932 abort_transaction_no_dev_fatal
:
1933 xenbus_transaction_end(xbt
, 1);
1935 xennet_disconnect_backend(info
);
1936 xennet_destroy_queues(info
);
1938 unregister_netdev(info
->netdev
);
1939 xennet_free_netdev(info
->netdev
);
1943 static int xennet_connect(struct net_device
*dev
)
1945 struct netfront_info
*np
= netdev_priv(dev
);
1946 unsigned int num_queues
= 0;
1949 struct netfront_queue
*queue
= NULL
;
1951 if (!xenbus_read_unsigned(np
->xbdev
->otherend
, "feature-rx-copy", 0)) {
1953 "backend does not support copying receive path\n");
1957 err
= talk_to_netback(np
->xbdev
, np
);
1961 /* talk_to_netback() sets the correct number of queues */
1962 num_queues
= dev
->real_num_tx_queues
;
1965 netdev_update_features(dev
);
1969 * All public and private state should now be sane. Get
1970 * ready to start sending and receiving packets and give the driver
1971 * domain a kick because we've probably just requeued some
1974 netif_carrier_on(np
->netdev
);
1975 for (j
= 0; j
< num_queues
; ++j
) {
1976 queue
= &np
->queues
[j
];
1978 notify_remote_via_irq(queue
->tx_irq
);
1979 if (queue
->tx_irq
!= queue
->rx_irq
)
1980 notify_remote_via_irq(queue
->rx_irq
);
1982 spin_lock_irq(&queue
->tx_lock
);
1983 xennet_tx_buf_gc(queue
);
1984 spin_unlock_irq(&queue
->tx_lock
);
1986 spin_lock_bh(&queue
->rx_lock
);
1987 xennet_alloc_rx_buffers(queue
);
1988 spin_unlock_bh(&queue
->rx_lock
);
1995 * Callback received when the backend's state changes.
1997 static void netback_changed(struct xenbus_device
*dev
,
1998 enum xenbus_state backend_state
)
2000 struct netfront_info
*np
= dev_get_drvdata(&dev
->dev
);
2001 struct net_device
*netdev
= np
->netdev
;
2003 dev_dbg(&dev
->dev
, "%s\n", xenbus_strstate(backend_state
));
2005 switch (backend_state
) {
2006 case XenbusStateInitialising
:
2007 case XenbusStateInitialised
:
2008 case XenbusStateReconfiguring
:
2009 case XenbusStateReconfigured
:
2010 case XenbusStateUnknown
:
2013 case XenbusStateInitWait
:
2014 if (dev
->state
!= XenbusStateInitialising
)
2016 if (xennet_connect(netdev
) != 0)
2018 xenbus_switch_state(dev
, XenbusStateConnected
);
2021 case XenbusStateConnected
:
2022 netdev_notify_peers(netdev
);
2025 case XenbusStateClosed
:
2026 if (dev
->state
== XenbusStateClosed
)
2028 /* Missed the backend's CLOSING state -- fallthrough */
2029 case XenbusStateClosing
:
2030 xenbus_frontend_closed(dev
);
2035 static const struct xennet_stat
{
2036 char name
[ETH_GSTRING_LEN
];
2038 } xennet_stats
[] = {
2040 "rx_gso_checksum_fixup",
2041 offsetof(struct netfront_info
, rx_gso_checksum_fixup
)
2045 static int xennet_get_sset_count(struct net_device
*dev
, int string_set
)
2047 switch (string_set
) {
2049 return ARRAY_SIZE(xennet_stats
);
2055 static void xennet_get_ethtool_stats(struct net_device
*dev
,
2056 struct ethtool_stats
*stats
, u64
* data
)
2058 void *np
= netdev_priv(dev
);
2061 for (i
= 0; i
< ARRAY_SIZE(xennet_stats
); i
++)
2062 data
[i
] = atomic_read((atomic_t
*)(np
+ xennet_stats
[i
].offset
));
2065 static void xennet_get_strings(struct net_device
*dev
, u32 stringset
, u8
* data
)
2069 switch (stringset
) {
2071 for (i
= 0; i
< ARRAY_SIZE(xennet_stats
); i
++)
2072 memcpy(data
+ i
* ETH_GSTRING_LEN
,
2073 xennet_stats
[i
].name
, ETH_GSTRING_LEN
);
2078 static const struct ethtool_ops xennet_ethtool_ops
=
2080 .get_link
= ethtool_op_get_link
,
2082 .get_sset_count
= xennet_get_sset_count
,
2083 .get_ethtool_stats
= xennet_get_ethtool_stats
,
2084 .get_strings
= xennet_get_strings
,
2088 static ssize_t
show_rxbuf(struct device
*dev
,
2089 struct device_attribute
*attr
, char *buf
)
2091 return sprintf(buf
, "%lu\n", NET_RX_RING_SIZE
);
2094 static ssize_t
store_rxbuf(struct device
*dev
,
2095 struct device_attribute
*attr
,
2096 const char *buf
, size_t len
)
2099 unsigned long target
;
2101 if (!capable(CAP_NET_ADMIN
))
2104 target
= simple_strtoul(buf
, &endp
, 0);
2108 /* rxbuf_min and rxbuf_max are no longer configurable. */
2113 static DEVICE_ATTR(rxbuf_min
, S_IRUGO
|S_IWUSR
, show_rxbuf
, store_rxbuf
);
2114 static DEVICE_ATTR(rxbuf_max
, S_IRUGO
|S_IWUSR
, show_rxbuf
, store_rxbuf
);
2115 static DEVICE_ATTR(rxbuf_cur
, S_IRUGO
, show_rxbuf
, NULL
);
2117 static struct attribute
*xennet_dev_attrs
[] = {
2118 &dev_attr_rxbuf_min
.attr
,
2119 &dev_attr_rxbuf_max
.attr
,
2120 &dev_attr_rxbuf_cur
.attr
,
2124 static const struct attribute_group xennet_dev_group
= {
2125 .attrs
= xennet_dev_attrs
2127 #endif /* CONFIG_SYSFS */
2129 static int xennet_remove(struct xenbus_device
*dev
)
2131 struct netfront_info
*info
= dev_get_drvdata(&dev
->dev
);
2133 dev_dbg(&dev
->dev
, "%s\n", dev
->nodename
);
2135 xennet_disconnect_backend(info
);
2137 unregister_netdev(info
->netdev
);
2140 xennet_destroy_queues(info
);
2141 xennet_free_netdev(info
->netdev
);
2146 static const struct xenbus_device_id netfront_ids
[] = {
2151 static struct xenbus_driver netfront_driver
= {
2152 .ids
= netfront_ids
,
2153 .probe
= netfront_probe
,
2154 .remove
= xennet_remove
,
2155 .resume
= netfront_resume
,
2156 .otherend_changed
= netback_changed
,
2159 static int __init
netif_init(void)
2164 if (!xen_has_pv_nic_devices())
2167 pr_info("Initialising Xen virtual ethernet driver\n");
2169 /* Allow as many queues as there are CPUs if user has not
2170 * specified a value.
2172 if (xennet_max_queues
== 0)
2173 xennet_max_queues
= num_online_cpus();
2175 return xenbus_register_frontend(&netfront_driver
);
2177 module_init(netif_init
);
2180 static void __exit
netif_exit(void)
2182 xenbus_unregister_driver(&netfront_driver
);
2184 module_exit(netif_exit
);
2186 MODULE_DESCRIPTION("Xen virtual network device frontend");
2187 MODULE_LICENSE("GPL");
2188 MODULE_ALIAS("xen:vif");
2189 MODULE_ALIAS("xennet");