2 * Back-end of the driver for virtual network devices. This portion of the
3 * driver exports a 'unified' network-device interface that can be accessed
4 * by any operating system that implements a compatible front end. A
5 * reference front-end implementation can be found in:
6 * drivers/net/xen-netfront.c
8 * Copyright (c) 2002-2005, K A Fraser
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License version 2
12 * as published by the Free Software Foundation; or, when distributed
13 * separately from the Linux kernel or incorporated into other
14 * software packages, subject to the following license:
16 * Permission is hereby granted, free of charge, to any person obtaining a copy
17 * of this source file (the "Software"), to deal in the Software without
18 * restriction, including without limitation the rights to use, copy, modify,
19 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
20 * and to permit persons to whom the Software is furnished to do so, subject to
21 * the following conditions:
23 * The above copyright notice and this permission notice shall be included in
24 * all copies or substantial portions of the Software.
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
29 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
30 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
31 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
37 #include <linux/kthread.h>
38 #include <linux/if_vlan.h>
39 #include <linux/udp.h>
40 #include <linux/highmem.h>
45 #include <xen/events.h>
46 #include <xen/interface/memory.h>
49 #include <asm/xen/hypercall.h>
51 /* Provide an option to disable split event channels at load time as
52 * event channels are limited resource. Split event channels are
55 bool separate_tx_rx_irq
= true;
56 module_param(separate_tx_rx_irq
, bool, 0644);
58 /* The time that packets can stay on the guest Rx internal queue
59 * before they are dropped.
61 unsigned int rx_drain_timeout_msecs
= 10000;
62 module_param(rx_drain_timeout_msecs
, uint
, 0444);
64 /* The length of time before the frontend is considered unresponsive
65 * because it isn't providing Rx slots.
67 unsigned int rx_stall_timeout_msecs
= 60000;
68 module_param(rx_stall_timeout_msecs
, uint
, 0444);
70 unsigned int xenvif_max_queues
;
71 module_param_named(max_queues
, xenvif_max_queues
, uint
, 0644);
72 MODULE_PARM_DESC(max_queues
,
73 "Maximum number of queues per virtual interface");
76 * This is the maximum slots a skb can have. If a guest sends a skb
77 * which exceeds this limit it is considered malicious.
79 #define FATAL_SKB_SLOTS_DEFAULT 20
80 static unsigned int fatal_skb_slots
= FATAL_SKB_SLOTS_DEFAULT
;
81 module_param(fatal_skb_slots
, uint
, 0444);
83 /* The amount to copy out of the first guest Tx slot into the skb's
84 * linear area. If the first slot has more data, it will be mapped
85 * and put into the first frag.
87 * This is sized to avoid pulling headers from the frags for most
90 #define XEN_NETBACK_TX_COPY_LEN 128
93 static void xenvif_idx_release(struct xenvif_queue
*queue
, u16 pending_idx
,
96 static void make_tx_response(struct xenvif_queue
*queue
,
97 struct xen_netif_tx_request
*txp
,
98 unsigned int extra_count
,
100 static void push_tx_responses(struct xenvif_queue
*queue
);
102 static inline int tx_work_todo(struct xenvif_queue
*queue
);
104 static struct xen_netif_rx_response
*make_rx_response(struct xenvif_queue
*queue
,
111 static inline unsigned long idx_to_pfn(struct xenvif_queue
*queue
,
114 return page_to_pfn(queue
->mmap_pages
[idx
]);
117 static inline unsigned long idx_to_kaddr(struct xenvif_queue
*queue
,
120 return (unsigned long)pfn_to_kaddr(idx_to_pfn(queue
, idx
));
123 #define callback_param(vif, pending_idx) \
124 (vif->pending_tx_info[pending_idx].callback_struct)
126 /* Find the containing VIF's structure from a pointer in pending_tx_info array
128 static inline struct xenvif_queue
*ubuf_to_queue(const struct ubuf_info
*ubuf
)
130 u16 pending_idx
= ubuf
->desc
;
131 struct pending_tx_info
*temp
=
132 container_of(ubuf
, struct pending_tx_info
, callback_struct
);
133 return container_of(temp
- pending_idx
,
138 static u16
frag_get_pending_idx(skb_frag_t
*frag
)
140 return (u16
)frag
->page_offset
;
143 static void frag_set_pending_idx(skb_frag_t
*frag
, u16 pending_idx
)
145 frag
->page_offset
= pending_idx
;
148 static inline pending_ring_idx_t
pending_index(unsigned i
)
150 return i
& (MAX_PENDING_REQS
-1);
153 static bool xenvif_rx_ring_slots_available(struct xenvif_queue
*queue
)
159 skb
= skb_peek(&queue
->rx_queue
);
163 needed
= DIV_ROUND_UP(skb
->len
, XEN_PAGE_SIZE
);
168 prod
= queue
->rx
.sring
->req_prod
;
169 cons
= queue
->rx
.req_cons
;
171 if (prod
- cons
>= needed
)
174 queue
->rx
.sring
->req_event
= prod
+ 1;
176 /* Make sure event is visible before we check prod
180 } while (queue
->rx
.sring
->req_prod
!= prod
);
185 void xenvif_rx_queue_tail(struct xenvif_queue
*queue
, struct sk_buff
*skb
)
189 spin_lock_irqsave(&queue
->rx_queue
.lock
, flags
);
191 __skb_queue_tail(&queue
->rx_queue
, skb
);
193 queue
->rx_queue_len
+= skb
->len
;
194 if (queue
->rx_queue_len
> queue
->rx_queue_max
)
195 netif_tx_stop_queue(netdev_get_tx_queue(queue
->vif
->dev
, queue
->id
));
197 spin_unlock_irqrestore(&queue
->rx_queue
.lock
, flags
);
200 static struct sk_buff
*xenvif_rx_dequeue(struct xenvif_queue
*queue
)
204 spin_lock_irq(&queue
->rx_queue
.lock
);
206 skb
= __skb_dequeue(&queue
->rx_queue
);
208 queue
->rx_queue_len
-= skb
->len
;
210 spin_unlock_irq(&queue
->rx_queue
.lock
);
215 static void xenvif_rx_queue_maybe_wake(struct xenvif_queue
*queue
)
217 spin_lock_irq(&queue
->rx_queue
.lock
);
219 if (queue
->rx_queue_len
< queue
->rx_queue_max
)
220 netif_tx_wake_queue(netdev_get_tx_queue(queue
->vif
->dev
, queue
->id
));
222 spin_unlock_irq(&queue
->rx_queue
.lock
);
226 static void xenvif_rx_queue_purge(struct xenvif_queue
*queue
)
229 while ((skb
= xenvif_rx_dequeue(queue
)) != NULL
)
233 static void xenvif_rx_queue_drop_expired(struct xenvif_queue
*queue
)
238 skb
= skb_peek(&queue
->rx_queue
);
241 if (time_before(jiffies
, XENVIF_RX_CB(skb
)->expires
))
243 xenvif_rx_dequeue(queue
);
248 struct netrx_pending_operations
{
249 unsigned copy_prod
, copy_cons
;
250 unsigned meta_prod
, meta_cons
;
251 struct gnttab_copy
*copy
;
252 struct xenvif_rx_meta
*meta
;
254 grant_ref_t copy_gref
;
257 static struct xenvif_rx_meta
*get_next_rx_buffer(struct xenvif_queue
*queue
,
258 struct netrx_pending_operations
*npo
)
260 struct xenvif_rx_meta
*meta
;
261 struct xen_netif_rx_request req
;
263 RING_COPY_REQUEST(&queue
->rx
, queue
->rx
.req_cons
++, &req
);
265 meta
= npo
->meta
+ npo
->meta_prod
++;
266 meta
->gso_type
= XEN_NETIF_GSO_TYPE_NONE
;
272 npo
->copy_gref
= req
.gref
;
277 struct gop_frag_copy
{
278 struct xenvif_queue
*queue
;
279 struct netrx_pending_operations
*npo
;
280 struct xenvif_rx_meta
*meta
;
287 static void xenvif_setup_copy_gop(unsigned long gfn
,
290 struct gop_frag_copy
*info
)
292 struct gnttab_copy
*copy_gop
;
293 struct xen_page_foreign
*foreign
;
294 /* Convenient aliases */
295 struct xenvif_queue
*queue
= info
->queue
;
296 struct netrx_pending_operations
*npo
= info
->npo
;
297 struct page
*page
= info
->page
;
299 BUG_ON(npo
->copy_off
> MAX_BUFFER_OFFSET
);
301 if (npo
->copy_off
== MAX_BUFFER_OFFSET
)
302 info
->meta
= get_next_rx_buffer(queue
, npo
);
304 if (npo
->copy_off
+ *len
> MAX_BUFFER_OFFSET
)
305 *len
= MAX_BUFFER_OFFSET
- npo
->copy_off
;
307 copy_gop
= npo
->copy
+ npo
->copy_prod
++;
308 copy_gop
->flags
= GNTCOPY_dest_gref
;
309 copy_gop
->len
= *len
;
311 foreign
= xen_page_foreign(page
);
313 copy_gop
->source
.domid
= foreign
->domid
;
314 copy_gop
->source
.u
.ref
= foreign
->gref
;
315 copy_gop
->flags
|= GNTCOPY_source_gref
;
317 copy_gop
->source
.domid
= DOMID_SELF
;
318 copy_gop
->source
.u
.gmfn
= gfn
;
320 copy_gop
->source
.offset
= offset
;
322 copy_gop
->dest
.domid
= queue
->vif
->domid
;
323 copy_gop
->dest
.offset
= npo
->copy_off
;
324 copy_gop
->dest
.u
.ref
= npo
->copy_gref
;
326 npo
->copy_off
+= *len
;
327 info
->meta
->size
+= *len
;
329 /* Leave a gap for the GSO descriptor. */
330 if (info
->head
&& ((1 << info
->gso_type
) & queue
->vif
->gso_mask
))
331 queue
->rx
.req_cons
++;
333 info
->head
= 0; /* There must be something in this buffer now */
336 static void xenvif_gop_frag_copy_grant(unsigned long gfn
,
345 xenvif_setup_copy_gop(gfn
, offset
, &bytes
, data
);
352 * Set up the grant operations for this fragment. If it's a flipping
353 * interface, we also set up the unmap request from here.
355 static void xenvif_gop_frag_copy(struct xenvif_queue
*queue
, struct sk_buff
*skb
,
356 struct netrx_pending_operations
*npo
,
357 struct page
*page
, unsigned long size
,
358 unsigned long offset
, int *head
)
360 struct gop_frag_copy info
= {
364 .gso_type
= XEN_NETIF_GSO_TYPE_NONE
,
368 if (skb_is_gso(skb
)) {
369 if (skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV4
)
370 info
.gso_type
= XEN_NETIF_GSO_TYPE_TCPV4
;
371 else if (skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
)
372 info
.gso_type
= XEN_NETIF_GSO_TYPE_TCPV6
;
375 /* Data must not cross a page boundary. */
376 BUG_ON(size
+ offset
> PAGE_SIZE
<<compound_order(page
));
378 info
.meta
= npo
->meta
+ npo
->meta_prod
- 1;
380 /* Skip unused frames from start of page */
381 page
+= offset
>> PAGE_SHIFT
;
382 offset
&= ~PAGE_MASK
;
385 BUG_ON(offset
>= PAGE_SIZE
);
387 bytes
= PAGE_SIZE
- offset
;
392 gnttab_foreach_grant_in_range(page
, offset
, bytes
,
393 xenvif_gop_frag_copy_grant
,
400 BUG_ON(!PageCompound(page
));
409 * Prepare an SKB to be transmitted to the frontend.
411 * This function is responsible for allocating grant operations, meta
414 * It returns the number of meta structures consumed. The number of
415 * ring slots used is always equal to the number of meta slots used
416 * plus the number of GSO descriptors used. Currently, we use either
417 * zero GSO descriptors (for non-GSO packets) or one descriptor (for
418 * frontend-side LRO).
420 static int xenvif_gop_skb(struct sk_buff
*skb
,
421 struct netrx_pending_operations
*npo
,
422 struct xenvif_queue
*queue
)
424 struct xenvif
*vif
= netdev_priv(skb
->dev
);
425 int nr_frags
= skb_shinfo(skb
)->nr_frags
;
427 struct xen_netif_rx_request req
;
428 struct xenvif_rx_meta
*meta
;
434 old_meta_prod
= npo
->meta_prod
;
436 gso_type
= XEN_NETIF_GSO_TYPE_NONE
;
437 if (skb_is_gso(skb
)) {
438 if (skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV4
)
439 gso_type
= XEN_NETIF_GSO_TYPE_TCPV4
;
440 else if (skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
)
441 gso_type
= XEN_NETIF_GSO_TYPE_TCPV6
;
444 /* Set up a GSO prefix descriptor, if necessary */
445 if ((1 << gso_type
) & vif
->gso_prefix_mask
) {
446 RING_COPY_REQUEST(&queue
->rx
, queue
->rx
.req_cons
++, &req
);
447 meta
= npo
->meta
+ npo
->meta_prod
++;
448 meta
->gso_type
= gso_type
;
449 meta
->gso_size
= skb_shinfo(skb
)->gso_size
;
454 RING_COPY_REQUEST(&queue
->rx
, queue
->rx
.req_cons
++, &req
);
455 meta
= npo
->meta
+ npo
->meta_prod
++;
457 if ((1 << gso_type
) & vif
->gso_mask
) {
458 meta
->gso_type
= gso_type
;
459 meta
->gso_size
= skb_shinfo(skb
)->gso_size
;
461 meta
->gso_type
= XEN_NETIF_GSO_TYPE_NONE
;
468 npo
->copy_gref
= req
.gref
;
471 while (data
< skb_tail_pointer(skb
)) {
472 unsigned int offset
= offset_in_page(data
);
473 unsigned int len
= PAGE_SIZE
- offset
;
475 if (data
+ len
> skb_tail_pointer(skb
))
476 len
= skb_tail_pointer(skb
) - data
;
478 xenvif_gop_frag_copy(queue
, skb
, npo
,
479 virt_to_page(data
), len
, offset
, &head
);
483 for (i
= 0; i
< nr_frags
; i
++) {
484 xenvif_gop_frag_copy(queue
, skb
, npo
,
485 skb_frag_page(&skb_shinfo(skb
)->frags
[i
]),
486 skb_frag_size(&skb_shinfo(skb
)->frags
[i
]),
487 skb_shinfo(skb
)->frags
[i
].page_offset
,
491 return npo
->meta_prod
- old_meta_prod
;
495 * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was
496 * used to set up the operations on the top of
497 * netrx_pending_operations, which have since been done. Check that
498 * they didn't give any errors and advance over them.
500 static int xenvif_check_gop(struct xenvif
*vif
, int nr_meta_slots
,
501 struct netrx_pending_operations
*npo
)
503 struct gnttab_copy
*copy_op
;
504 int status
= XEN_NETIF_RSP_OKAY
;
507 for (i
= 0; i
< nr_meta_slots
; i
++) {
508 copy_op
= npo
->copy
+ npo
->copy_cons
++;
509 if (copy_op
->status
!= GNTST_okay
) {
511 "Bad status %d from copy to DOM%d.\n",
512 copy_op
->status
, vif
->domid
);
513 status
= XEN_NETIF_RSP_ERROR
;
520 static void xenvif_add_frag_responses(struct xenvif_queue
*queue
, int status
,
521 struct xenvif_rx_meta
*meta
,
525 unsigned long offset
;
527 /* No fragments used */
528 if (nr_meta_slots
<= 1)
533 for (i
= 0; i
< nr_meta_slots
; i
++) {
535 if (i
== nr_meta_slots
- 1)
538 flags
= XEN_NETRXF_more_data
;
541 make_rx_response(queue
, meta
[i
].id
, status
, offset
,
542 meta
[i
].size
, flags
);
546 void xenvif_kick_thread(struct xenvif_queue
*queue
)
551 static void xenvif_rx_action(struct xenvif_queue
*queue
)
555 struct xen_netif_rx_response
*resp
;
556 struct sk_buff_head rxq
;
560 unsigned long offset
;
561 bool need_to_notify
= false;
563 struct netrx_pending_operations npo
= {
564 .copy
= queue
->grant_copy_op
,
568 skb_queue_head_init(&rxq
);
570 while (xenvif_rx_ring_slots_available(queue
)
571 && (skb
= xenvif_rx_dequeue(queue
)) != NULL
) {
572 queue
->last_rx_time
= jiffies
;
574 XENVIF_RX_CB(skb
)->meta_slots_used
= xenvif_gop_skb(skb
, &npo
, queue
);
576 __skb_queue_tail(&rxq
, skb
);
579 BUG_ON(npo
.meta_prod
> ARRAY_SIZE(queue
->meta
));
584 BUG_ON(npo
.copy_prod
> MAX_GRANT_COPY_OPS
);
585 gnttab_batch_copy(queue
->grant_copy_op
, npo
.copy_prod
);
587 while ((skb
= __skb_dequeue(&rxq
)) != NULL
) {
589 if ((1 << queue
->meta
[npo
.meta_cons
].gso_type
) &
590 queue
->vif
->gso_prefix_mask
) {
591 resp
= RING_GET_RESPONSE(&queue
->rx
,
592 queue
->rx
.rsp_prod_pvt
++);
594 resp
->flags
= XEN_NETRXF_gso_prefix
| XEN_NETRXF_more_data
;
596 resp
->offset
= queue
->meta
[npo
.meta_cons
].gso_size
;
597 resp
->id
= queue
->meta
[npo
.meta_cons
].id
;
598 resp
->status
= XENVIF_RX_CB(skb
)->meta_slots_used
;
601 XENVIF_RX_CB(skb
)->meta_slots_used
--;
605 queue
->stats
.tx_bytes
+= skb
->len
;
606 queue
->stats
.tx_packets
++;
608 status
= xenvif_check_gop(queue
->vif
,
609 XENVIF_RX_CB(skb
)->meta_slots_used
,
612 if (XENVIF_RX_CB(skb
)->meta_slots_used
== 1)
615 flags
= XEN_NETRXF_more_data
;
617 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) /* local packet? */
618 flags
|= XEN_NETRXF_csum_blank
| XEN_NETRXF_data_validated
;
619 else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
)
620 /* remote but checksummed. */
621 flags
|= XEN_NETRXF_data_validated
;
624 resp
= make_rx_response(queue
, queue
->meta
[npo
.meta_cons
].id
,
626 queue
->meta
[npo
.meta_cons
].size
,
629 if ((1 << queue
->meta
[npo
.meta_cons
].gso_type
) &
630 queue
->vif
->gso_mask
) {
631 struct xen_netif_extra_info
*gso
=
632 (struct xen_netif_extra_info
*)
633 RING_GET_RESPONSE(&queue
->rx
,
634 queue
->rx
.rsp_prod_pvt
++);
636 resp
->flags
|= XEN_NETRXF_extra_info
;
638 gso
->u
.gso
.type
= queue
->meta
[npo
.meta_cons
].gso_type
;
639 gso
->u
.gso
.size
= queue
->meta
[npo
.meta_cons
].gso_size
;
641 gso
->u
.gso
.features
= 0;
643 gso
->type
= XEN_NETIF_EXTRA_TYPE_GSO
;
647 xenvif_add_frag_responses(queue
, status
,
648 queue
->meta
+ npo
.meta_cons
+ 1,
649 XENVIF_RX_CB(skb
)->meta_slots_used
);
651 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue
->rx
, ret
);
653 need_to_notify
|= !!ret
;
655 npo
.meta_cons
+= XENVIF_RX_CB(skb
)->meta_slots_used
;
661 notify_remote_via_irq(queue
->rx_irq
);
664 void xenvif_napi_schedule_or_enable_events(struct xenvif_queue
*queue
)
668 RING_FINAL_CHECK_FOR_REQUESTS(&queue
->tx
, more_to_do
);
671 napi_schedule(&queue
->napi
);
674 static void tx_add_credit(struct xenvif_queue
*queue
)
676 unsigned long max_burst
, max_credit
;
679 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
680 * Otherwise the interface can seize up due to insufficient credit.
682 max_burst
= max(131072UL, queue
->credit_bytes
);
684 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
685 max_credit
= queue
->remaining_credit
+ queue
->credit_bytes
;
686 if (max_credit
< queue
->remaining_credit
)
687 max_credit
= ULONG_MAX
; /* wrapped: clamp to ULONG_MAX */
689 queue
->remaining_credit
= min(max_credit
, max_burst
);
692 void xenvif_tx_credit_callback(unsigned long data
)
694 struct xenvif_queue
*queue
= (struct xenvif_queue
*)data
;
695 tx_add_credit(queue
);
696 xenvif_napi_schedule_or_enable_events(queue
);
699 static void xenvif_tx_err(struct xenvif_queue
*queue
,
700 struct xen_netif_tx_request
*txp
,
701 unsigned int extra_count
, RING_IDX end
)
703 RING_IDX cons
= queue
->tx
.req_cons
;
707 spin_lock_irqsave(&queue
->response_lock
, flags
);
708 make_tx_response(queue
, txp
, extra_count
, XEN_NETIF_RSP_ERROR
);
709 push_tx_responses(queue
);
710 spin_unlock_irqrestore(&queue
->response_lock
, flags
);
713 RING_COPY_REQUEST(&queue
->tx
, cons
++, txp
);
714 extra_count
= 0; /* only the first frag can have extras */
716 queue
->tx
.req_cons
= cons
;
719 static void xenvif_fatal_tx_err(struct xenvif
*vif
)
721 netdev_err(vif
->dev
, "fatal error; disabling device\n");
722 vif
->disabled
= true;
723 /* Disable the vif from queue 0's kthread */
725 xenvif_kick_thread(&vif
->queues
[0]);
728 static int xenvif_count_requests(struct xenvif_queue
*queue
,
729 struct xen_netif_tx_request
*first
,
730 unsigned int extra_count
,
731 struct xen_netif_tx_request
*txp
,
734 RING_IDX cons
= queue
->tx
.req_cons
;
739 if (!(first
->flags
& XEN_NETTXF_more_data
))
743 struct xen_netif_tx_request dropped_tx
= { 0 };
745 if (slots
>= work_to_do
) {
746 netdev_err(queue
->vif
->dev
,
747 "Asked for %d slots but exceeds this limit\n",
749 xenvif_fatal_tx_err(queue
->vif
);
753 /* This guest is really using too many slots and
754 * considered malicious.
756 if (unlikely(slots
>= fatal_skb_slots
)) {
757 netdev_err(queue
->vif
->dev
,
758 "Malicious frontend using %d slots, threshold %u\n",
759 slots
, fatal_skb_slots
);
760 xenvif_fatal_tx_err(queue
->vif
);
764 /* Xen network protocol had implicit dependency on
765 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
766 * the historical MAX_SKB_FRAGS value 18 to honor the
767 * same behavior as before. Any packet using more than
768 * 18 slots but less than fatal_skb_slots slots is
771 if (!drop_err
&& slots
>= XEN_NETBK_LEGACY_SLOTS_MAX
) {
773 netdev_dbg(queue
->vif
->dev
,
774 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
775 slots
, XEN_NETBK_LEGACY_SLOTS_MAX
);
782 RING_COPY_REQUEST(&queue
->tx
, cons
+ slots
, txp
);
784 /* If the guest submitted a frame >= 64 KiB then
785 * first->size overflowed and following slots will
786 * appear to be larger than the frame.
788 * This cannot be fatal error as there are buggy
789 * frontends that do this.
791 * Consume all slots and drop the packet.
793 if (!drop_err
&& txp
->size
> first
->size
) {
795 netdev_dbg(queue
->vif
->dev
,
796 "Invalid tx request, slot size %u > remaining size %u\n",
797 txp
->size
, first
->size
);
801 first
->size
-= txp
->size
;
804 if (unlikely((txp
->offset
+ txp
->size
) > XEN_PAGE_SIZE
)) {
805 netdev_err(queue
->vif
->dev
, "Cross page boundary, txp->offset: %u, size: %u\n",
806 txp
->offset
, txp
->size
);
807 xenvif_fatal_tx_err(queue
->vif
);
811 more_data
= txp
->flags
& XEN_NETTXF_more_data
;
819 xenvif_tx_err(queue
, first
, extra_count
, cons
+ slots
);
827 struct xenvif_tx_cb
{
831 #define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
833 static inline void xenvif_tx_create_map_op(struct xenvif_queue
*queue
,
835 struct xen_netif_tx_request
*txp
,
836 unsigned int extra_count
,
837 struct gnttab_map_grant_ref
*mop
)
839 queue
->pages_to_map
[mop
-queue
->tx_map_ops
] = queue
->mmap_pages
[pending_idx
];
840 gnttab_set_map_op(mop
, idx_to_kaddr(queue
, pending_idx
),
841 GNTMAP_host_map
| GNTMAP_readonly
,
842 txp
->gref
, queue
->vif
->domid
);
844 memcpy(&queue
->pending_tx_info
[pending_idx
].req
, txp
,
846 queue
->pending_tx_info
[pending_idx
].extra_count
= extra_count
;
849 static inline struct sk_buff
*xenvif_alloc_skb(unsigned int size
)
851 struct sk_buff
*skb
=
852 alloc_skb(size
+ NET_SKB_PAD
+ NET_IP_ALIGN
,
853 GFP_ATOMIC
| __GFP_NOWARN
);
854 if (unlikely(skb
== NULL
))
857 /* Packets passed to netif_rx() must have some headroom. */
858 skb_reserve(skb
, NET_SKB_PAD
+ NET_IP_ALIGN
);
860 /* Initialize it here to avoid later surprises */
861 skb_shinfo(skb
)->destructor_arg
= NULL
;
866 static struct gnttab_map_grant_ref
*xenvif_get_requests(struct xenvif_queue
*queue
,
868 struct xen_netif_tx_request
*txp
,
869 struct gnttab_map_grant_ref
*gop
,
870 unsigned int frag_overflow
,
871 struct sk_buff
*nskb
)
873 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
874 skb_frag_t
*frags
= shinfo
->frags
;
875 u16 pending_idx
= XENVIF_TX_CB(skb
)->pending_idx
;
877 pending_ring_idx_t index
;
878 unsigned int nr_slots
;
880 nr_slots
= shinfo
->nr_frags
;
882 /* Skip first skb fragment if it is on same page as header fragment. */
883 start
= (frag_get_pending_idx(&shinfo
->frags
[0]) == pending_idx
);
885 for (shinfo
->nr_frags
= start
; shinfo
->nr_frags
< nr_slots
;
886 shinfo
->nr_frags
++, txp
++, gop
++) {
887 index
= pending_index(queue
->pending_cons
++);
888 pending_idx
= queue
->pending_ring
[index
];
889 xenvif_tx_create_map_op(queue
, pending_idx
, txp
, 0, gop
);
890 frag_set_pending_idx(&frags
[shinfo
->nr_frags
], pending_idx
);
895 shinfo
= skb_shinfo(nskb
);
896 frags
= shinfo
->frags
;
898 for (shinfo
->nr_frags
= 0; shinfo
->nr_frags
< frag_overflow
;
899 shinfo
->nr_frags
++, txp
++, gop
++) {
900 index
= pending_index(queue
->pending_cons
++);
901 pending_idx
= queue
->pending_ring
[index
];
902 xenvif_tx_create_map_op(queue
, pending_idx
, txp
, 0,
904 frag_set_pending_idx(&frags
[shinfo
->nr_frags
],
908 skb_shinfo(skb
)->frag_list
= nskb
;
914 static inline void xenvif_grant_handle_set(struct xenvif_queue
*queue
,
916 grant_handle_t handle
)
918 if (unlikely(queue
->grant_tx_handle
[pending_idx
] !=
919 NETBACK_INVALID_HANDLE
)) {
920 netdev_err(queue
->vif
->dev
,
921 "Trying to overwrite active handle! pending_idx: 0x%x\n",
925 queue
->grant_tx_handle
[pending_idx
] = handle
;
928 static inline void xenvif_grant_handle_reset(struct xenvif_queue
*queue
,
931 if (unlikely(queue
->grant_tx_handle
[pending_idx
] ==
932 NETBACK_INVALID_HANDLE
)) {
933 netdev_err(queue
->vif
->dev
,
934 "Trying to unmap invalid handle! pending_idx: 0x%x\n",
938 queue
->grant_tx_handle
[pending_idx
] = NETBACK_INVALID_HANDLE
;
941 static int xenvif_tx_check_gop(struct xenvif_queue
*queue
,
943 struct gnttab_map_grant_ref
**gopp_map
,
944 struct gnttab_copy
**gopp_copy
)
946 struct gnttab_map_grant_ref
*gop_map
= *gopp_map
;
947 u16 pending_idx
= XENVIF_TX_CB(skb
)->pending_idx
;
948 /* This always points to the shinfo of the skb being checked, which
949 * could be either the first or the one on the frag_list
951 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
952 /* If this is non-NULL, we are currently checking the frag_list skb, and
953 * this points to the shinfo of the first one
955 struct skb_shared_info
*first_shinfo
= NULL
;
956 int nr_frags
= shinfo
->nr_frags
;
957 const bool sharedslot
= nr_frags
&&
958 frag_get_pending_idx(&shinfo
->frags
[0]) == pending_idx
;
961 /* Check status of header. */
962 err
= (*gopp_copy
)->status
;
965 netdev_dbg(queue
->vif
->dev
,
966 "Grant copy of header failed! status: %d pending_idx: %u ref: %u\n",
967 (*gopp_copy
)->status
,
969 (*gopp_copy
)->source
.u
.ref
);
970 /* The first frag might still have this slot mapped */
972 xenvif_idx_release(queue
, pending_idx
,
973 XEN_NETIF_RSP_ERROR
);
978 for (i
= 0; i
< nr_frags
; i
++, gop_map
++) {
981 pending_idx
= frag_get_pending_idx(&shinfo
->frags
[i
]);
983 /* Check error status: if okay then remember grant handle. */
984 newerr
= gop_map
->status
;
986 if (likely(!newerr
)) {
987 xenvif_grant_handle_set(queue
,
990 /* Had a previous error? Invalidate this fragment. */
992 xenvif_idx_unmap(queue
, pending_idx
);
993 /* If the mapping of the first frag was OK, but
994 * the header's copy failed, and they are
995 * sharing a slot, send an error
997 if (i
== 0 && sharedslot
)
998 xenvif_idx_release(queue
, pending_idx
,
999 XEN_NETIF_RSP_ERROR
);
1001 xenvif_idx_release(queue
, pending_idx
,
1002 XEN_NETIF_RSP_OKAY
);
1007 /* Error on this fragment: respond to client with an error. */
1008 if (net_ratelimit())
1009 netdev_dbg(queue
->vif
->dev
,
1010 "Grant map of %d. frag failed! status: %d pending_idx: %u ref: %u\n",
1016 xenvif_idx_release(queue
, pending_idx
, XEN_NETIF_RSP_ERROR
);
1018 /* Not the first error? Preceding frags already invalidated. */
1022 /* First error: if the header haven't shared a slot with the
1023 * first frag, release it as well.
1026 xenvif_idx_release(queue
,
1027 XENVIF_TX_CB(skb
)->pending_idx
,
1028 XEN_NETIF_RSP_OKAY
);
1030 /* Invalidate preceding fragments of this skb. */
1031 for (j
= 0; j
< i
; j
++) {
1032 pending_idx
= frag_get_pending_idx(&shinfo
->frags
[j
]);
1033 xenvif_idx_unmap(queue
, pending_idx
);
1034 xenvif_idx_release(queue
, pending_idx
,
1035 XEN_NETIF_RSP_OKAY
);
1038 /* And if we found the error while checking the frag_list, unmap
1039 * the first skb's frags
1042 for (j
= 0; j
< first_shinfo
->nr_frags
; j
++) {
1043 pending_idx
= frag_get_pending_idx(&first_shinfo
->frags
[j
]);
1044 xenvif_idx_unmap(queue
, pending_idx
);
1045 xenvif_idx_release(queue
, pending_idx
,
1046 XEN_NETIF_RSP_OKAY
);
1050 /* Remember the error: invalidate all subsequent fragments. */
1054 if (skb_has_frag_list(skb
) && !first_shinfo
) {
1055 first_shinfo
= skb_shinfo(skb
);
1056 shinfo
= skb_shinfo(skb_shinfo(skb
)->frag_list
);
1057 nr_frags
= shinfo
->nr_frags
;
1062 *gopp_map
= gop_map
;
1066 static void xenvif_fill_frags(struct xenvif_queue
*queue
, struct sk_buff
*skb
)
1068 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
1069 int nr_frags
= shinfo
->nr_frags
;
1071 u16 prev_pending_idx
= INVALID_PENDING_IDX
;
1073 for (i
= 0; i
< nr_frags
; i
++) {
1074 skb_frag_t
*frag
= shinfo
->frags
+ i
;
1075 struct xen_netif_tx_request
*txp
;
1079 pending_idx
= frag_get_pending_idx(frag
);
1081 /* If this is not the first frag, chain it to the previous*/
1082 if (prev_pending_idx
== INVALID_PENDING_IDX
)
1083 skb_shinfo(skb
)->destructor_arg
=
1084 &callback_param(queue
, pending_idx
);
1086 callback_param(queue
, prev_pending_idx
).ctx
=
1087 &callback_param(queue
, pending_idx
);
1089 callback_param(queue
, pending_idx
).ctx
= NULL
;
1090 prev_pending_idx
= pending_idx
;
1092 txp
= &queue
->pending_tx_info
[pending_idx
].req
;
1093 page
= virt_to_page(idx_to_kaddr(queue
, pending_idx
));
1094 __skb_fill_page_desc(skb
, i
, page
, txp
->offset
, txp
->size
);
1095 skb
->len
+= txp
->size
;
1096 skb
->data_len
+= txp
->size
;
1097 skb
->truesize
+= txp
->size
;
1099 /* Take an extra reference to offset network stack's put_page */
1100 get_page(queue
->mmap_pages
[pending_idx
]);
1104 static int xenvif_get_extras(struct xenvif_queue
*queue
,
1105 struct xen_netif_extra_info
*extras
,
1106 unsigned int *extra_count
,
1109 struct xen_netif_extra_info extra
;
1110 RING_IDX cons
= queue
->tx
.req_cons
;
1113 if (unlikely(work_to_do
-- <= 0)) {
1114 netdev_err(queue
->vif
->dev
, "Missing extra info\n");
1115 xenvif_fatal_tx_err(queue
->vif
);
1119 RING_COPY_REQUEST(&queue
->tx
, cons
, &extra
);
1121 queue
->tx
.req_cons
= ++cons
;
1124 if (unlikely(!extra
.type
||
1125 extra
.type
>= XEN_NETIF_EXTRA_TYPE_MAX
)) {
1126 netdev_err(queue
->vif
->dev
,
1127 "Invalid extra type: %d\n", extra
.type
);
1128 xenvif_fatal_tx_err(queue
->vif
);
1132 memcpy(&extras
[extra
.type
- 1], &extra
, sizeof(extra
));
1133 } while (extra
.flags
& XEN_NETIF_EXTRA_FLAG_MORE
);
1138 static int xenvif_set_skb_gso(struct xenvif
*vif
,
1139 struct sk_buff
*skb
,
1140 struct xen_netif_extra_info
*gso
)
1142 if (!gso
->u
.gso
.size
) {
1143 netdev_err(vif
->dev
, "GSO size must not be zero.\n");
1144 xenvif_fatal_tx_err(vif
);
1148 switch (gso
->u
.gso
.type
) {
1149 case XEN_NETIF_GSO_TYPE_TCPV4
:
1150 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV4
;
1152 case XEN_NETIF_GSO_TYPE_TCPV6
:
1153 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV6
;
1156 netdev_err(vif
->dev
, "Bad GSO type %d.\n", gso
->u
.gso
.type
);
1157 xenvif_fatal_tx_err(vif
);
1161 skb_shinfo(skb
)->gso_size
= gso
->u
.gso
.size
;
1162 /* gso_segs will be calculated later */
1167 static int checksum_setup(struct xenvif_queue
*queue
, struct sk_buff
*skb
)
1169 bool recalculate_partial_csum
= false;
1171 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1172 * peers can fail to set NETRXF_csum_blank when sending a GSO
1173 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1174 * recalculate the partial checksum.
1176 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
&& skb_is_gso(skb
)) {
1177 queue
->stats
.rx_gso_checksum_fixup
++;
1178 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1179 recalculate_partial_csum
= true;
1182 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1183 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
)
1186 return skb_checksum_setup(skb
, recalculate_partial_csum
);
1189 static bool tx_credit_exceeded(struct xenvif_queue
*queue
, unsigned size
)
1191 u64 now
= get_jiffies_64();
1192 u64 next_credit
= queue
->credit_window_start
+
1193 msecs_to_jiffies(queue
->credit_usec
/ 1000);
1195 /* Timer could already be pending in rare cases. */
1196 if (timer_pending(&queue
->credit_timeout
))
1199 /* Passed the point where we can replenish credit? */
1200 if (time_after_eq64(now
, next_credit
)) {
1201 queue
->credit_window_start
= now
;
1202 tx_add_credit(queue
);
1205 /* Still too big to send right now? Set a callback. */
1206 if (size
> queue
->remaining_credit
) {
1207 queue
->credit_timeout
.data
=
1208 (unsigned long)queue
;
1209 mod_timer(&queue
->credit_timeout
,
1211 queue
->credit_window_start
= next_credit
;
1219 /* No locking is required in xenvif_mcast_add/del() as they are
1220 * only ever invoked from NAPI poll. An RCU list is used because
1221 * xenvif_mcast_match() is called asynchronously, during start_xmit.
1224 static int xenvif_mcast_add(struct xenvif
*vif
, const u8
*addr
)
1226 struct xenvif_mcast_addr
*mcast
;
1228 if (vif
->fe_mcast_count
== XEN_NETBK_MCAST_MAX
) {
1229 if (net_ratelimit())
1230 netdev_err(vif
->dev
,
1231 "Too many multicast addresses\n");
1235 mcast
= kzalloc(sizeof(*mcast
), GFP_ATOMIC
);
1239 ether_addr_copy(mcast
->addr
, addr
);
1240 list_add_tail_rcu(&mcast
->entry
, &vif
->fe_mcast_addr
);
1241 vif
->fe_mcast_count
++;
1246 static void xenvif_mcast_del(struct xenvif
*vif
, const u8
*addr
)
1248 struct xenvif_mcast_addr
*mcast
;
1250 list_for_each_entry_rcu(mcast
, &vif
->fe_mcast_addr
, entry
) {
1251 if (ether_addr_equal(addr
, mcast
->addr
)) {
1252 --vif
->fe_mcast_count
;
1253 list_del_rcu(&mcast
->entry
);
1254 kfree_rcu(mcast
, rcu
);
1260 bool xenvif_mcast_match(struct xenvif
*vif
, const u8
*addr
)
1262 struct xenvif_mcast_addr
*mcast
;
1265 list_for_each_entry_rcu(mcast
, &vif
->fe_mcast_addr
, entry
) {
1266 if (ether_addr_equal(addr
, mcast
->addr
)) {
1276 void xenvif_mcast_addr_list_free(struct xenvif
*vif
)
1278 /* No need for locking or RCU here. NAPI poll and TX queue
1281 while (!list_empty(&vif
->fe_mcast_addr
)) {
1282 struct xenvif_mcast_addr
*mcast
;
1284 mcast
= list_first_entry(&vif
->fe_mcast_addr
,
1285 struct xenvif_mcast_addr
,
1287 --vif
->fe_mcast_count
;
1288 list_del(&mcast
->entry
);
1293 static void xenvif_tx_build_gops(struct xenvif_queue
*queue
,
1298 struct gnttab_map_grant_ref
*gop
= queue
->tx_map_ops
;
1299 struct sk_buff
*skb
, *nskb
;
1301 unsigned int frag_overflow
;
1303 while (skb_queue_len(&queue
->tx_queue
) < budget
) {
1304 struct xen_netif_tx_request txreq
;
1305 struct xen_netif_tx_request txfrags
[XEN_NETBK_LEGACY_SLOTS_MAX
];
1306 struct xen_netif_extra_info extras
[XEN_NETIF_EXTRA_TYPE_MAX
-1];
1307 unsigned int extra_count
;
1311 unsigned int data_len
;
1312 pending_ring_idx_t index
;
1314 if (queue
->tx
.sring
->req_prod
- queue
->tx
.req_cons
>
1315 XEN_NETIF_TX_RING_SIZE
) {
1316 netdev_err(queue
->vif
->dev
,
1317 "Impossible number of requests. "
1318 "req_prod %d, req_cons %d, size %ld\n",
1319 queue
->tx
.sring
->req_prod
, queue
->tx
.req_cons
,
1320 XEN_NETIF_TX_RING_SIZE
);
1321 xenvif_fatal_tx_err(queue
->vif
);
1325 work_to_do
= RING_HAS_UNCONSUMED_REQUESTS(&queue
->tx
);
1329 idx
= queue
->tx
.req_cons
;
1330 rmb(); /* Ensure that we see the request before we copy it. */
1331 RING_COPY_REQUEST(&queue
->tx
, idx
, &txreq
);
1333 /* Credit-based scheduling. */
1334 if (txreq
.size
> queue
->remaining_credit
&&
1335 tx_credit_exceeded(queue
, txreq
.size
))
1338 queue
->remaining_credit
-= txreq
.size
;
1341 queue
->tx
.req_cons
= ++idx
;
1343 memset(extras
, 0, sizeof(extras
));
1345 if (txreq
.flags
& XEN_NETTXF_extra_info
) {
1346 work_to_do
= xenvif_get_extras(queue
, extras
,
1349 idx
= queue
->tx
.req_cons
;
1350 if (unlikely(work_to_do
< 0))
1354 if (extras
[XEN_NETIF_EXTRA_TYPE_MCAST_ADD
- 1].type
) {
1355 struct xen_netif_extra_info
*extra
;
1357 extra
= &extras
[XEN_NETIF_EXTRA_TYPE_MCAST_ADD
- 1];
1358 ret
= xenvif_mcast_add(queue
->vif
, extra
->u
.mcast
.addr
);
1360 make_tx_response(queue
, &txreq
, extra_count
,
1362 XEN_NETIF_RSP_OKAY
:
1363 XEN_NETIF_RSP_ERROR
);
1364 push_tx_responses(queue
);
1368 if (extras
[XEN_NETIF_EXTRA_TYPE_MCAST_DEL
- 1].type
) {
1369 struct xen_netif_extra_info
*extra
;
1371 extra
= &extras
[XEN_NETIF_EXTRA_TYPE_MCAST_DEL
- 1];
1372 xenvif_mcast_del(queue
->vif
, extra
->u
.mcast
.addr
);
1374 make_tx_response(queue
, &txreq
, extra_count
,
1375 XEN_NETIF_RSP_OKAY
);
1376 push_tx_responses(queue
);
1380 ret
= xenvif_count_requests(queue
, &txreq
, extra_count
,
1381 txfrags
, work_to_do
);
1382 if (unlikely(ret
< 0))
1387 if (unlikely(txreq
.size
< ETH_HLEN
)) {
1388 netdev_dbg(queue
->vif
->dev
,
1389 "Bad packet size: %d\n", txreq
.size
);
1390 xenvif_tx_err(queue
, &txreq
, extra_count
, idx
);
1394 /* No crossing a page as the payload mustn't fragment. */
1395 if (unlikely((txreq
.offset
+ txreq
.size
) > XEN_PAGE_SIZE
)) {
1396 netdev_err(queue
->vif
->dev
,
1397 "txreq.offset: %u, size: %u, end: %lu\n",
1398 txreq
.offset
, txreq
.size
,
1399 (unsigned long)(txreq
.offset
&~XEN_PAGE_MASK
) + txreq
.size
);
1400 xenvif_fatal_tx_err(queue
->vif
);
1404 index
= pending_index(queue
->pending_cons
);
1405 pending_idx
= queue
->pending_ring
[index
];
1407 data_len
= (txreq
.size
> XEN_NETBACK_TX_COPY_LEN
&&
1408 ret
< XEN_NETBK_LEGACY_SLOTS_MAX
) ?
1409 XEN_NETBACK_TX_COPY_LEN
: txreq
.size
;
1411 skb
= xenvif_alloc_skb(data_len
);
1412 if (unlikely(skb
== NULL
)) {
1413 netdev_dbg(queue
->vif
->dev
,
1414 "Can't allocate a skb in start_xmit.\n");
1415 xenvif_tx_err(queue
, &txreq
, extra_count
, idx
);
1419 skb_shinfo(skb
)->nr_frags
= ret
;
1420 if (data_len
< txreq
.size
)
1421 skb_shinfo(skb
)->nr_frags
++;
1422 /* At this point shinfo->nr_frags is in fact the number of
1423 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
1427 if (skb_shinfo(skb
)->nr_frags
> MAX_SKB_FRAGS
) {
1428 frag_overflow
= skb_shinfo(skb
)->nr_frags
- MAX_SKB_FRAGS
;
1429 BUG_ON(frag_overflow
> MAX_SKB_FRAGS
);
1430 skb_shinfo(skb
)->nr_frags
= MAX_SKB_FRAGS
;
1431 nskb
= xenvif_alloc_skb(0);
1432 if (unlikely(nskb
== NULL
)) {
1434 xenvif_tx_err(queue
, &txreq
, extra_count
, idx
);
1435 if (net_ratelimit())
1436 netdev_err(queue
->vif
->dev
,
1437 "Can't allocate the frag_list skb.\n");
1442 if (extras
[XEN_NETIF_EXTRA_TYPE_GSO
- 1].type
) {
1443 struct xen_netif_extra_info
*gso
;
1444 gso
= &extras
[XEN_NETIF_EXTRA_TYPE_GSO
- 1];
1446 if (xenvif_set_skb_gso(queue
->vif
, skb
, gso
)) {
1447 /* Failure in xenvif_set_skb_gso is fatal. */
1454 XENVIF_TX_CB(skb
)->pending_idx
= pending_idx
;
1456 __skb_put(skb
, data_len
);
1457 queue
->tx_copy_ops
[*copy_ops
].source
.u
.ref
= txreq
.gref
;
1458 queue
->tx_copy_ops
[*copy_ops
].source
.domid
= queue
->vif
->domid
;
1459 queue
->tx_copy_ops
[*copy_ops
].source
.offset
= txreq
.offset
;
1461 queue
->tx_copy_ops
[*copy_ops
].dest
.u
.gmfn
=
1462 virt_to_gfn(skb
->data
);
1463 queue
->tx_copy_ops
[*copy_ops
].dest
.domid
= DOMID_SELF
;
1464 queue
->tx_copy_ops
[*copy_ops
].dest
.offset
=
1465 offset_in_page(skb
->data
) & ~XEN_PAGE_MASK
;
1467 queue
->tx_copy_ops
[*copy_ops
].len
= data_len
;
1468 queue
->tx_copy_ops
[*copy_ops
].flags
= GNTCOPY_source_gref
;
1472 if (data_len
< txreq
.size
) {
1473 frag_set_pending_idx(&skb_shinfo(skb
)->frags
[0],
1475 xenvif_tx_create_map_op(queue
, pending_idx
, &txreq
,
1479 frag_set_pending_idx(&skb_shinfo(skb
)->frags
[0],
1480 INVALID_PENDING_IDX
);
1481 memcpy(&queue
->pending_tx_info
[pending_idx
].req
,
1482 &txreq
, sizeof(txreq
));
1483 queue
->pending_tx_info
[pending_idx
].extra_count
=
1487 queue
->pending_cons
++;
1489 gop
= xenvif_get_requests(queue
, skb
, txfrags
, gop
,
1490 frag_overflow
, nskb
);
1492 __skb_queue_tail(&queue
->tx_queue
, skb
);
1494 queue
->tx
.req_cons
= idx
;
1496 if (((gop
-queue
->tx_map_ops
) >= ARRAY_SIZE(queue
->tx_map_ops
)) ||
1497 (*copy_ops
>= ARRAY_SIZE(queue
->tx_copy_ops
)))
1501 (*map_ops
) = gop
- queue
->tx_map_ops
;
1505 /* Consolidate skb with a frag_list into a brand new one with local pages on
1506 * frags. Returns 0 or -ENOMEM if can't allocate new pages.
1508 static int xenvif_handle_frag_list(struct xenvif_queue
*queue
, struct sk_buff
*skb
)
1510 unsigned int offset
= skb_headlen(skb
);
1511 skb_frag_t frags
[MAX_SKB_FRAGS
];
1513 struct ubuf_info
*uarg
;
1514 struct sk_buff
*nskb
= skb_shinfo(skb
)->frag_list
;
1516 queue
->stats
.tx_zerocopy_sent
+= 2;
1517 queue
->stats
.tx_frag_overflow
++;
1519 xenvif_fill_frags(queue
, nskb
);
1520 /* Subtract frags size, we will correct it later */
1521 skb
->truesize
-= skb
->data_len
;
1522 skb
->len
+= nskb
->len
;
1523 skb
->data_len
+= nskb
->len
;
1525 /* create a brand new frags array and coalesce there */
1526 for (i
= 0; offset
< skb
->len
; i
++) {
1530 BUG_ON(i
>= MAX_SKB_FRAGS
);
1531 page
= alloc_page(GFP_ATOMIC
);
1534 skb
->truesize
+= skb
->data_len
;
1535 for (j
= 0; j
< i
; j
++)
1536 put_page(frags
[j
].page
.p
);
1540 if (offset
+ PAGE_SIZE
< skb
->len
)
1543 len
= skb
->len
- offset
;
1544 if (skb_copy_bits(skb
, offset
, page_address(page
), len
))
1548 frags
[i
].page
.p
= page
;
1549 frags
[i
].page_offset
= 0;
1550 skb_frag_size_set(&frags
[i
], len
);
1553 /* Copied all the bits from the frag list -- free it. */
1554 skb_frag_list_init(skb
);
1555 xenvif_skb_zerocopy_prepare(queue
, nskb
);
1558 /* Release all the original (foreign) frags. */
1559 for (f
= 0; f
< skb_shinfo(skb
)->nr_frags
; f
++)
1560 skb_frag_unref(skb
, f
);
1561 uarg
= skb_shinfo(skb
)->destructor_arg
;
1562 /* increase inflight counter to offset decrement in callback */
1563 atomic_inc(&queue
->inflight_packets
);
1564 uarg
->callback(uarg
, true);
1565 skb_shinfo(skb
)->destructor_arg
= NULL
;
1567 /* Fill the skb with the new (local) frags. */
1568 memcpy(skb_shinfo(skb
)->frags
, frags
, i
* sizeof(skb_frag_t
));
1569 skb_shinfo(skb
)->nr_frags
= i
;
1570 skb
->truesize
+= i
* PAGE_SIZE
;
1575 static int xenvif_tx_submit(struct xenvif_queue
*queue
)
1577 struct gnttab_map_grant_ref
*gop_map
= queue
->tx_map_ops
;
1578 struct gnttab_copy
*gop_copy
= queue
->tx_copy_ops
;
1579 struct sk_buff
*skb
;
1582 while ((skb
= __skb_dequeue(&queue
->tx_queue
)) != NULL
) {
1583 struct xen_netif_tx_request
*txp
;
1587 pending_idx
= XENVIF_TX_CB(skb
)->pending_idx
;
1588 txp
= &queue
->pending_tx_info
[pending_idx
].req
;
1590 /* Check the remap error code. */
1591 if (unlikely(xenvif_tx_check_gop(queue
, skb
, &gop_map
, &gop_copy
))) {
1592 /* If there was an error, xenvif_tx_check_gop is
1593 * expected to release all the frags which were mapped,
1594 * so kfree_skb shouldn't do it again
1596 skb_shinfo(skb
)->nr_frags
= 0;
1597 if (skb_has_frag_list(skb
)) {
1598 struct sk_buff
*nskb
=
1599 skb_shinfo(skb
)->frag_list
;
1600 skb_shinfo(nskb
)->nr_frags
= 0;
1606 data_len
= skb
->len
;
1607 callback_param(queue
, pending_idx
).ctx
= NULL
;
1608 if (data_len
< txp
->size
) {
1609 /* Append the packet payload as a fragment. */
1610 txp
->offset
+= data_len
;
1611 txp
->size
-= data_len
;
1613 /* Schedule a response immediately. */
1614 xenvif_idx_release(queue
, pending_idx
,
1615 XEN_NETIF_RSP_OKAY
);
1618 if (txp
->flags
& XEN_NETTXF_csum_blank
)
1619 skb
->ip_summed
= CHECKSUM_PARTIAL
;
1620 else if (txp
->flags
& XEN_NETTXF_data_validated
)
1621 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
1623 xenvif_fill_frags(queue
, skb
);
1625 if (unlikely(skb_has_frag_list(skb
))) {
1626 if (xenvif_handle_frag_list(queue
, skb
)) {
1627 if (net_ratelimit())
1628 netdev_err(queue
->vif
->dev
,
1629 "Not enough memory to consolidate frag_list!\n");
1630 xenvif_skb_zerocopy_prepare(queue
, skb
);
1636 skb
->dev
= queue
->vif
->dev
;
1637 skb
->protocol
= eth_type_trans(skb
, skb
->dev
);
1638 skb_reset_network_header(skb
);
1640 if (checksum_setup(queue
, skb
)) {
1641 netdev_dbg(queue
->vif
->dev
,
1642 "Can't setup checksum in net_tx_action\n");
1643 /* We have to set this flag to trigger the callback */
1644 if (skb_shinfo(skb
)->destructor_arg
)
1645 xenvif_skb_zerocopy_prepare(queue
, skb
);
1650 skb_probe_transport_header(skb
, 0);
1652 /* If the packet is GSO then we will have just set up the
1653 * transport header offset in checksum_setup so it's now
1654 * straightforward to calculate gso_segs.
1656 if (skb_is_gso(skb
)) {
1657 int mss
= skb_shinfo(skb
)->gso_size
;
1658 int hdrlen
= skb_transport_header(skb
) -
1659 skb_mac_header(skb
) +
1662 skb_shinfo(skb
)->gso_segs
=
1663 DIV_ROUND_UP(skb
->len
- hdrlen
, mss
);
1666 queue
->stats
.rx_bytes
+= skb
->len
;
1667 queue
->stats
.rx_packets
++;
1671 /* Set this flag right before netif_receive_skb, otherwise
1672 * someone might think this packet already left netback, and
1673 * do a skb_copy_ubufs while we are still in control of the
1674 * skb. E.g. the __pskb_pull_tail earlier can do such thing.
1676 if (skb_shinfo(skb
)->destructor_arg
) {
1677 xenvif_skb_zerocopy_prepare(queue
, skb
);
1678 queue
->stats
.tx_zerocopy_sent
++;
1681 netif_receive_skb(skb
);
1687 void xenvif_zerocopy_callback(struct ubuf_info
*ubuf
, bool zerocopy_success
)
1689 unsigned long flags
;
1690 pending_ring_idx_t index
;
1691 struct xenvif_queue
*queue
= ubuf_to_queue(ubuf
);
1693 /* This is the only place where we grab this lock, to protect callbacks
1696 spin_lock_irqsave(&queue
->callback_lock
, flags
);
1698 u16 pending_idx
= ubuf
->desc
;
1699 ubuf
= (struct ubuf_info
*) ubuf
->ctx
;
1700 BUG_ON(queue
->dealloc_prod
- queue
->dealloc_cons
>=
1702 index
= pending_index(queue
->dealloc_prod
);
1703 queue
->dealloc_ring
[index
] = pending_idx
;
1704 /* Sync with xenvif_tx_dealloc_action:
1705 * insert idx then incr producer.
1708 queue
->dealloc_prod
++;
1710 spin_unlock_irqrestore(&queue
->callback_lock
, flags
);
1712 if (likely(zerocopy_success
))
1713 queue
->stats
.tx_zerocopy_success
++;
1715 queue
->stats
.tx_zerocopy_fail
++;
1716 xenvif_skb_zerocopy_complete(queue
);
1719 static inline void xenvif_tx_dealloc_action(struct xenvif_queue
*queue
)
1721 struct gnttab_unmap_grant_ref
*gop
;
1722 pending_ring_idx_t dc
, dp
;
1723 u16 pending_idx
, pending_idx_release
[MAX_PENDING_REQS
];
1726 dc
= queue
->dealloc_cons
;
1727 gop
= queue
->tx_unmap_ops
;
1729 /* Free up any grants we have finished using */
1731 dp
= queue
->dealloc_prod
;
1733 /* Ensure we see all indices enqueued by all
1734 * xenvif_zerocopy_callback().
1739 BUG_ON(gop
- queue
->tx_unmap_ops
>= MAX_PENDING_REQS
);
1741 queue
->dealloc_ring
[pending_index(dc
++)];
1743 pending_idx_release
[gop
- queue
->tx_unmap_ops
] =
1745 queue
->pages_to_unmap
[gop
- queue
->tx_unmap_ops
] =
1746 queue
->mmap_pages
[pending_idx
];
1747 gnttab_set_unmap_op(gop
,
1748 idx_to_kaddr(queue
, pending_idx
),
1750 queue
->grant_tx_handle
[pending_idx
]);
1751 xenvif_grant_handle_reset(queue
, pending_idx
);
1755 } while (dp
!= queue
->dealloc_prod
);
1757 queue
->dealloc_cons
= dc
;
1759 if (gop
- queue
->tx_unmap_ops
> 0) {
1761 ret
= gnttab_unmap_refs(queue
->tx_unmap_ops
,
1763 queue
->pages_to_unmap
,
1764 gop
- queue
->tx_unmap_ops
);
1766 netdev_err(queue
->vif
->dev
, "Unmap fail: nr_ops %tu ret %d\n",
1767 gop
- queue
->tx_unmap_ops
, ret
);
1768 for (i
= 0; i
< gop
- queue
->tx_unmap_ops
; ++i
) {
1769 if (gop
[i
].status
!= GNTST_okay
)
1770 netdev_err(queue
->vif
->dev
,
1771 " host_addr: 0x%llx handle: 0x%x status: %d\n",
1780 for (i
= 0; i
< gop
- queue
->tx_unmap_ops
; ++i
)
1781 xenvif_idx_release(queue
, pending_idx_release
[i
],
1782 XEN_NETIF_RSP_OKAY
);
1786 /* Called after netfront has transmitted */
1787 int xenvif_tx_action(struct xenvif_queue
*queue
, int budget
)
1789 unsigned nr_mops
, nr_cops
= 0;
1792 if (unlikely(!tx_work_todo(queue
)))
1795 xenvif_tx_build_gops(queue
, budget
, &nr_cops
, &nr_mops
);
1800 gnttab_batch_copy(queue
->tx_copy_ops
, nr_cops
);
1802 ret
= gnttab_map_refs(queue
->tx_map_ops
,
1804 queue
->pages_to_map
,
1809 work_done
= xenvif_tx_submit(queue
);
1814 static void xenvif_idx_release(struct xenvif_queue
*queue
, u16 pending_idx
,
1817 struct pending_tx_info
*pending_tx_info
;
1818 pending_ring_idx_t index
;
1819 unsigned long flags
;
1821 pending_tx_info
= &queue
->pending_tx_info
[pending_idx
];
1823 spin_lock_irqsave(&queue
->response_lock
, flags
);
1825 make_tx_response(queue
, &pending_tx_info
->req
,
1826 pending_tx_info
->extra_count
, status
);
1828 /* Release the pending index before pusing the Tx response so
1829 * its available before a new Tx request is pushed by the
1832 index
= pending_index(queue
->pending_prod
++);
1833 queue
->pending_ring
[index
] = pending_idx
;
1835 push_tx_responses(queue
);
1837 spin_unlock_irqrestore(&queue
->response_lock
, flags
);
1841 static void make_tx_response(struct xenvif_queue
*queue
,
1842 struct xen_netif_tx_request
*txp
,
1843 unsigned int extra_count
,
1846 RING_IDX i
= queue
->tx
.rsp_prod_pvt
;
1847 struct xen_netif_tx_response
*resp
;
1849 resp
= RING_GET_RESPONSE(&queue
->tx
, i
);
1853 while (extra_count
-- != 0)
1854 RING_GET_RESPONSE(&queue
->tx
, ++i
)->status
= XEN_NETIF_RSP_NULL
;
1856 queue
->tx
.rsp_prod_pvt
= ++i
;
1859 static void push_tx_responses(struct xenvif_queue
*queue
)
1863 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue
->tx
, notify
);
1865 notify_remote_via_irq(queue
->tx_irq
);
1868 static struct xen_netif_rx_response
*make_rx_response(struct xenvif_queue
*queue
,
1875 RING_IDX i
= queue
->rx
.rsp_prod_pvt
;
1876 struct xen_netif_rx_response
*resp
;
1878 resp
= RING_GET_RESPONSE(&queue
->rx
, i
);
1879 resp
->offset
= offset
;
1880 resp
->flags
= flags
;
1882 resp
->status
= (s16
)size
;
1884 resp
->status
= (s16
)st
;
1886 queue
->rx
.rsp_prod_pvt
= ++i
;
1891 void xenvif_idx_unmap(struct xenvif_queue
*queue
, u16 pending_idx
)
1894 struct gnttab_unmap_grant_ref tx_unmap_op
;
1896 gnttab_set_unmap_op(&tx_unmap_op
,
1897 idx_to_kaddr(queue
, pending_idx
),
1899 queue
->grant_tx_handle
[pending_idx
]);
1900 xenvif_grant_handle_reset(queue
, pending_idx
);
1902 ret
= gnttab_unmap_refs(&tx_unmap_op
, NULL
,
1903 &queue
->mmap_pages
[pending_idx
], 1);
1905 netdev_err(queue
->vif
->dev
,
1906 "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: 0x%x status: %d\n",
1909 tx_unmap_op
.host_addr
,
1911 tx_unmap_op
.status
);
1916 static inline int tx_work_todo(struct xenvif_queue
*queue
)
1918 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue
->tx
)))
1924 static inline bool tx_dealloc_work_todo(struct xenvif_queue
*queue
)
1926 return queue
->dealloc_cons
!= queue
->dealloc_prod
;
1929 void xenvif_unmap_frontend_rings(struct xenvif_queue
*queue
)
1931 if (queue
->tx
.sring
)
1932 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue
->vif
),
1934 if (queue
->rx
.sring
)
1935 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue
->vif
),
1939 int xenvif_map_frontend_rings(struct xenvif_queue
*queue
,
1940 grant_ref_t tx_ring_ref
,
1941 grant_ref_t rx_ring_ref
)
1944 struct xen_netif_tx_sring
*txs
;
1945 struct xen_netif_rx_sring
*rxs
;
1949 err
= xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue
->vif
),
1950 &tx_ring_ref
, 1, &addr
);
1954 txs
= (struct xen_netif_tx_sring
*)addr
;
1955 BACK_RING_INIT(&queue
->tx
, txs
, XEN_PAGE_SIZE
);
1957 err
= xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue
->vif
),
1958 &rx_ring_ref
, 1, &addr
);
1962 rxs
= (struct xen_netif_rx_sring
*)addr
;
1963 BACK_RING_INIT(&queue
->rx
, rxs
, XEN_PAGE_SIZE
);
1968 xenvif_unmap_frontend_rings(queue
);
1972 static void xenvif_queue_carrier_off(struct xenvif_queue
*queue
)
1974 struct xenvif
*vif
= queue
->vif
;
1976 queue
->stalled
= true;
1978 /* At least one queue has stalled? Disable the carrier. */
1979 spin_lock(&vif
->lock
);
1980 if (vif
->stalled_queues
++ == 0) {
1981 netdev_info(vif
->dev
, "Guest Rx stalled");
1982 netif_carrier_off(vif
->dev
);
1984 spin_unlock(&vif
->lock
);
1987 static void xenvif_queue_carrier_on(struct xenvif_queue
*queue
)
1989 struct xenvif
*vif
= queue
->vif
;
1991 queue
->last_rx_time
= jiffies
; /* Reset Rx stall detection. */
1992 queue
->stalled
= false;
1994 /* All queues are ready? Enable the carrier. */
1995 spin_lock(&vif
->lock
);
1996 if (--vif
->stalled_queues
== 0) {
1997 netdev_info(vif
->dev
, "Guest Rx ready");
1998 netif_carrier_on(vif
->dev
);
2000 spin_unlock(&vif
->lock
);
2003 static bool xenvif_rx_queue_stalled(struct xenvif_queue
*queue
)
2005 RING_IDX prod
, cons
;
2007 prod
= queue
->rx
.sring
->req_prod
;
2008 cons
= queue
->rx
.req_cons
;
2010 return !queue
->stalled
&& prod
- cons
< 1
2011 && time_after(jiffies
,
2012 queue
->last_rx_time
+ queue
->vif
->stall_timeout
);
2015 static bool xenvif_rx_queue_ready(struct xenvif_queue
*queue
)
2017 RING_IDX prod
, cons
;
2019 prod
= queue
->rx
.sring
->req_prod
;
2020 cons
= queue
->rx
.req_cons
;
2022 return queue
->stalled
&& prod
- cons
>= 1;
2025 static bool xenvif_have_rx_work(struct xenvif_queue
*queue
)
2027 return xenvif_rx_ring_slots_available(queue
)
2028 || (queue
->vif
->stall_timeout
&&
2029 (xenvif_rx_queue_stalled(queue
)
2030 || xenvif_rx_queue_ready(queue
)))
2031 || kthread_should_stop()
2032 || queue
->vif
->disabled
;
2035 static long xenvif_rx_queue_timeout(struct xenvif_queue
*queue
)
2037 struct sk_buff
*skb
;
2040 skb
= skb_peek(&queue
->rx_queue
);
2042 return MAX_SCHEDULE_TIMEOUT
;
2044 timeout
= XENVIF_RX_CB(skb
)->expires
- jiffies
;
2045 return timeout
< 0 ? 0 : timeout
;
2048 /* Wait until the guest Rx thread has work.
2050 * The timeout needs to be adjusted based on the current head of the
2051 * queue (and not just the head at the beginning). In particular, if
2052 * the queue is initially empty an infinite timeout is used and this
2053 * needs to be reduced when a skb is queued.
2055 * This cannot be done with wait_event_timeout() because it only
2056 * calculates the timeout once.
2058 static void xenvif_wait_for_rx_work(struct xenvif_queue
*queue
)
2062 if (xenvif_have_rx_work(queue
))
2068 prepare_to_wait(&queue
->wq
, &wait
, TASK_INTERRUPTIBLE
);
2069 if (xenvif_have_rx_work(queue
))
2071 ret
= schedule_timeout(xenvif_rx_queue_timeout(queue
));
2075 finish_wait(&queue
->wq
, &wait
);
2078 int xenvif_kthread_guest_rx(void *data
)
2080 struct xenvif_queue
*queue
= data
;
2081 struct xenvif
*vif
= queue
->vif
;
2083 if (!vif
->stall_timeout
)
2084 xenvif_queue_carrier_on(queue
);
2087 xenvif_wait_for_rx_work(queue
);
2089 if (kthread_should_stop())
2092 /* This frontend is found to be rogue, disable it in
2093 * kthread context. Currently this is only set when
2094 * netback finds out frontend sends malformed packet,
2095 * but we cannot disable the interface in softirq
2096 * context so we defer it here, if this thread is
2097 * associated with queue 0.
2099 if (unlikely(vif
->disabled
&& queue
->id
== 0)) {
2100 xenvif_carrier_off(vif
);
2104 if (!skb_queue_empty(&queue
->rx_queue
))
2105 xenvif_rx_action(queue
);
2107 /* If the guest hasn't provided any Rx slots for a
2108 * while it's probably not responsive, drop the
2109 * carrier so packets are dropped earlier.
2111 if (vif
->stall_timeout
) {
2112 if (xenvif_rx_queue_stalled(queue
))
2113 xenvif_queue_carrier_off(queue
);
2114 else if (xenvif_rx_queue_ready(queue
))
2115 xenvif_queue_carrier_on(queue
);
2118 /* Queued packets may have foreign pages from other
2119 * domains. These cannot be queued indefinitely as
2120 * this would starve guests of grant refs and transmit
2123 xenvif_rx_queue_drop_expired(queue
);
2125 xenvif_rx_queue_maybe_wake(queue
);
2130 /* Bin any remaining skbs */
2131 xenvif_rx_queue_purge(queue
);
2136 static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue
*queue
)
2138 /* Dealloc thread must remain running until all inflight
2141 return kthread_should_stop() &&
2142 !atomic_read(&queue
->inflight_packets
);
2145 int xenvif_dealloc_kthread(void *data
)
2147 struct xenvif_queue
*queue
= data
;
2150 wait_event_interruptible(queue
->dealloc_wq
,
2151 tx_dealloc_work_todo(queue
) ||
2152 xenvif_dealloc_kthread_should_stop(queue
));
2153 if (xenvif_dealloc_kthread_should_stop(queue
))
2156 xenvif_tx_dealloc_action(queue
);
2160 /* Unmap anything remaining*/
2161 if (tx_dealloc_work_todo(queue
))
2162 xenvif_tx_dealloc_action(queue
);
2167 static int __init
netback_init(void)
2174 /* Allow as many queues as there are CPUs if user has not
2175 * specified a value.
2177 if (xenvif_max_queues
== 0)
2178 xenvif_max_queues
= num_online_cpus();
2180 if (fatal_skb_slots
< XEN_NETBK_LEGACY_SLOTS_MAX
) {
2181 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
2182 fatal_skb_slots
, XEN_NETBK_LEGACY_SLOTS_MAX
);
2183 fatal_skb_slots
= XEN_NETBK_LEGACY_SLOTS_MAX
;
2186 rc
= xenvif_xenbus_init();
2190 #ifdef CONFIG_DEBUG_FS
2191 xen_netback_dbg_root
= debugfs_create_dir("xen-netback", NULL
);
2192 if (IS_ERR_OR_NULL(xen_netback_dbg_root
))
2193 pr_warn("Init of debugfs returned %ld!\n",
2194 PTR_ERR(xen_netback_dbg_root
));
2195 #endif /* CONFIG_DEBUG_FS */
2203 module_init(netback_init
);
2205 static void __exit
netback_fini(void)
2207 #ifdef CONFIG_DEBUG_FS
2208 if (!IS_ERR_OR_NULL(xen_netback_dbg_root
))
2209 debugfs_remove_recursive(xen_netback_dbg_root
);
2210 #endif /* CONFIG_DEBUG_FS */
2211 xenvif_xenbus_fini();
2213 module_exit(netback_fini
);
2215 MODULE_LICENSE("Dual BSD/GPL");
2216 MODULE_ALIAS("xen-backend:vif");