static inline int tx_work_todo(struct xenvif_queue *queue);
-static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue,
- u16 id,
- s8 st,
- u16 offset,
- u16 size,
- u16 flags);
-
static inline unsigned long idx_to_pfn(struct xenvif_queue *queue,
u16 idx)
{
return i & (MAX_PENDING_REQS-1);
}
-static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
-{
- RING_IDX prod, cons;
- struct sk_buff *skb;
- int needed;
-
- skb = skb_peek(&queue->rx_queue);
- if (!skb)
- return false;
-
- needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE);
- if (skb_is_gso(skb))
- needed++;
- if (skb->sw_hash)
- needed++;
-
- do {
- prod = queue->rx.sring->req_prod;
- cons = queue->rx.req_cons;
-
- if (prod - cons >= needed)
- return true;
-
- queue->rx.sring->req_event = prod + 1;
-
- /* Make sure event is visible before we check prod
- * again.
- */
- mb();
- } while (queue->rx.sring->req_prod != prod);
-
- return false;
-}
-
-void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&queue->rx_queue.lock, flags);
-
- __skb_queue_tail(&queue->rx_queue, skb);
-
- queue->rx_queue_len += skb->len;
- if (queue->rx_queue_len > queue->rx_queue_max)
- netif_tx_stop_queue(netdev_get_tx_queue(queue->vif->dev, queue->id));
-
- spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
-}
-
-static struct sk_buff *xenvif_rx_dequeue(struct xenvif_queue *queue)
-{
- struct sk_buff *skb;
-
- spin_lock_irq(&queue->rx_queue.lock);
-
- skb = __skb_dequeue(&queue->rx_queue);
- if (skb)
- queue->rx_queue_len -= skb->len;
-
- spin_unlock_irq(&queue->rx_queue.lock);
-
- return skb;
-}
-
-static void xenvif_rx_queue_maybe_wake(struct xenvif_queue *queue)
-{
- spin_lock_irq(&queue->rx_queue.lock);
-
- if (queue->rx_queue_len < queue->rx_queue_max)
- netif_tx_wake_queue(netdev_get_tx_queue(queue->vif->dev, queue->id));
-
- spin_unlock_irq(&queue->rx_queue.lock);
-}
-
-
-static void xenvif_rx_queue_purge(struct xenvif_queue *queue)
-{
- struct sk_buff *skb;
- while ((skb = xenvif_rx_dequeue(queue)) != NULL)
- kfree_skb(skb);
-}
-
-static void xenvif_rx_queue_drop_expired(struct xenvif_queue *queue)
-{
- struct sk_buff *skb;
-
- for(;;) {
- skb = skb_peek(&queue->rx_queue);
- if (!skb)
- break;
- if (time_before(jiffies, XENVIF_RX_CB(skb)->expires))
- break;
- xenvif_rx_dequeue(queue);
- kfree_skb(skb);
- }
-}
-
-struct netrx_pending_operations {
- unsigned copy_prod, copy_cons;
- unsigned meta_prod, meta_cons;
- struct gnttab_copy *copy;
- struct xenvif_rx_meta *meta;
- int copy_off;
- grant_ref_t copy_gref;
-};
-
-static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif_queue *queue,
- struct netrx_pending_operations *npo)
-{
- struct xenvif_rx_meta *meta;
- struct xen_netif_rx_request req;
-
- RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
-
- meta = npo->meta + npo->meta_prod++;
- meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
- meta->gso_size = 0;
- meta->size = 0;
- meta->id = req.id;
-
- npo->copy_off = 0;
- npo->copy_gref = req.gref;
-
- return meta;
-}
-
-struct gop_frag_copy {
- struct xenvif_queue *queue;
- struct netrx_pending_operations *npo;
- struct xenvif_rx_meta *meta;
- int head;
- int gso_type;
- int protocol;
- int hash_present;
-
- struct page *page;
-};
-
-static void xenvif_setup_copy_gop(unsigned long gfn,
- unsigned int offset,
- unsigned int *len,
- struct gop_frag_copy *info)
-{
- struct gnttab_copy *copy_gop;
- struct xen_page_foreign *foreign;
- /* Convenient aliases */
- struct xenvif_queue *queue = info->queue;
- struct netrx_pending_operations *npo = info->npo;
- struct page *page = info->page;
-
- BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
-
- if (npo->copy_off == MAX_BUFFER_OFFSET)
- info->meta = get_next_rx_buffer(queue, npo);
-
- if (npo->copy_off + *len > MAX_BUFFER_OFFSET)
- *len = MAX_BUFFER_OFFSET - npo->copy_off;
-
- copy_gop = npo->copy + npo->copy_prod++;
- copy_gop->flags = GNTCOPY_dest_gref;
- copy_gop->len = *len;
-
- foreign = xen_page_foreign(page);
- if (foreign) {
- copy_gop->source.domid = foreign->domid;
- copy_gop->source.u.ref = foreign->gref;
- copy_gop->flags |= GNTCOPY_source_gref;
- } else {
- copy_gop->source.domid = DOMID_SELF;
- copy_gop->source.u.gmfn = gfn;
- }
- copy_gop->source.offset = offset;
-
- copy_gop->dest.domid = queue->vif->domid;
- copy_gop->dest.offset = npo->copy_off;
- copy_gop->dest.u.ref = npo->copy_gref;
-
- npo->copy_off += *len;
- info->meta->size += *len;
-
- if (!info->head)
- return;
-
- /* Leave a gap for the GSO descriptor. */
- if ((1 << info->gso_type) & queue->vif->gso_mask)
- queue->rx.req_cons++;
-
- /* Leave a gap for the hash extra segment. */
- if (info->hash_present)
- queue->rx.req_cons++;
-
- info->head = 0; /* There must be something in this buffer now */
-}
-
-static void xenvif_gop_frag_copy_grant(unsigned long gfn,
- unsigned offset,
- unsigned int len,
- void *data)
-{
- unsigned int bytes;
-
- while (len) {
- bytes = len;
- xenvif_setup_copy_gop(gfn, offset, &bytes, data);
- offset += bytes;
- len -= bytes;
- }
-}
-
-/*
- * Set up the grant operations for this fragment. If it's a flipping
- * interface, we also set up the unmap request from here.
- */
-static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb,
- struct netrx_pending_operations *npo,
- struct page *page, unsigned long size,
- unsigned long offset, int *head)
-{
- struct gop_frag_copy info = {
- .queue = queue,
- .npo = npo,
- .head = *head,
- .gso_type = XEN_NETIF_GSO_TYPE_NONE,
- /* xenvif_set_skb_hash() will have either set a s/w
- * hash or cleared the hash depending on
- * whether the the frontend wants a hash for this skb.
- */
- .hash_present = skb->sw_hash,
- };
- unsigned long bytes;
-
- if (skb_is_gso(skb)) {
- if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
- info.gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
- else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
- info.gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
- }
-
- /* Data must not cross a page boundary. */
- BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
-
- info.meta = npo->meta + npo->meta_prod - 1;
-
- /* Skip unused frames from start of page */
- page += offset >> PAGE_SHIFT;
- offset &= ~PAGE_MASK;
-
- while (size > 0) {
- BUG_ON(offset >= PAGE_SIZE);
-
- bytes = PAGE_SIZE - offset;
- if (bytes > size)
- bytes = size;
-
- info.page = page;
- gnttab_foreach_grant_in_range(page, offset, bytes,
- xenvif_gop_frag_copy_grant,
- &info);
- size -= bytes;
- offset = 0;
-
- /* Next page */
- if (size) {
- BUG_ON(!PageCompound(page));
- page++;
- }
- }
-
- *head = info.head;
-}
-
-/*
- * Prepare an SKB to be transmitted to the frontend.
- *
- * This function is responsible for allocating grant operations, meta
- * structures, etc.
- *
- * It returns the number of meta structures consumed. The number of
- * ring slots used is always equal to the number of meta slots used
- * plus the number of GSO descriptors used. Currently, we use either
- * zero GSO descriptors (for non-GSO packets) or one descriptor (for
- * frontend-side LRO).
- */
-static int xenvif_gop_skb(struct sk_buff *skb,
- struct netrx_pending_operations *npo,
- struct xenvif_queue *queue)
-{
- struct xenvif *vif = netdev_priv(skb->dev);
- int nr_frags = skb_shinfo(skb)->nr_frags;
- int i;
- struct xen_netif_rx_request req;
- struct xenvif_rx_meta *meta;
- unsigned char *data;
- int head = 1;
- int old_meta_prod;
- int gso_type;
-
- old_meta_prod = npo->meta_prod;
-
- gso_type = XEN_NETIF_GSO_TYPE_NONE;
- if (skb_is_gso(skb)) {
- if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
- gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
- else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
- gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
- }
-
- /* Set up a GSO prefix descriptor, if necessary */
- if ((1 << gso_type) & vif->gso_prefix_mask) {
- RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
- meta = npo->meta + npo->meta_prod++;
- meta->gso_type = gso_type;
- meta->gso_size = skb_shinfo(skb)->gso_size;
- meta->size = 0;
- meta->id = req.id;
- }
-
- RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
- meta = npo->meta + npo->meta_prod++;
-
- if ((1 << gso_type) & vif->gso_mask) {
- meta->gso_type = gso_type;
- meta->gso_size = skb_shinfo(skb)->gso_size;
- } else {
- meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
- meta->gso_size = 0;
- }
-
- meta->size = 0;
- meta->id = req.id;
- npo->copy_off = 0;
- npo->copy_gref = req.gref;
-
- data = skb->data;
- while (data < skb_tail_pointer(skb)) {
- unsigned int offset = offset_in_page(data);
- unsigned int len = PAGE_SIZE - offset;
-
- if (data + len > skb_tail_pointer(skb))
- len = skb_tail_pointer(skb) - data;
-
- xenvif_gop_frag_copy(queue, skb, npo,
- virt_to_page(data), len, offset, &head);
- data += len;
- }
-
- for (i = 0; i < nr_frags; i++) {
- xenvif_gop_frag_copy(queue, skb, npo,
- skb_frag_page(&skb_shinfo(skb)->frags[i]),
- skb_frag_size(&skb_shinfo(skb)->frags[i]),
- skb_shinfo(skb)->frags[i].page_offset,
- &head);
- }
-
- return npo->meta_prod - old_meta_prod;
-}
-
-/*
- * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was
- * used to set up the operations on the top of
- * netrx_pending_operations, which have since been done. Check that
- * they didn't give any errors and advance over them.
- */
-static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots,
- struct netrx_pending_operations *npo)
-{
- struct gnttab_copy *copy_op;
- int status = XEN_NETIF_RSP_OKAY;
- int i;
-
- for (i = 0; i < nr_meta_slots; i++) {
- copy_op = npo->copy + npo->copy_cons++;
- if (copy_op->status != GNTST_okay) {
- netdev_dbg(vif->dev,
- "Bad status %d from copy to DOM%d.\n",
- copy_op->status, vif->domid);
- status = XEN_NETIF_RSP_ERROR;
- }
- }
-
- return status;
-}
-
-static void xenvif_add_frag_responses(struct xenvif_queue *queue, int status,
- struct xenvif_rx_meta *meta,
- int nr_meta_slots)
-{
- int i;
- unsigned long offset;
-
- /* No fragments used */
- if (nr_meta_slots <= 1)
- return;
-
- nr_meta_slots--;
-
- for (i = 0; i < nr_meta_slots; i++) {
- int flags;
- if (i == nr_meta_slots - 1)
- flags = 0;
- else
- flags = XEN_NETRXF_more_data;
-
- offset = 0;
- make_rx_response(queue, meta[i].id, status, offset,
- meta[i].size, flags);
- }
-}
-
void xenvif_kick_thread(struct xenvif_queue *queue)
{
wake_up(&queue->wq);
}
-static void xenvif_rx_action(struct xenvif_queue *queue)
-{
- struct xenvif *vif = queue->vif;
- s8 status;
- u16 flags;
- struct xen_netif_rx_response *resp;
- struct sk_buff_head rxq;
- struct sk_buff *skb;
- LIST_HEAD(notify);
- int ret;
- unsigned long offset;
- bool need_to_notify = false;
-
- struct netrx_pending_operations npo = {
- .copy = queue->grant_copy_op,
- .meta = queue->meta,
- };
-
- skb_queue_head_init(&rxq);
-
- while (xenvif_rx_ring_slots_available(queue)
- && (skb = xenvif_rx_dequeue(queue)) != NULL) {
- queue->last_rx_time = jiffies;
-
- XENVIF_RX_CB(skb)->meta_slots_used = xenvif_gop_skb(skb, &npo, queue);
-
- __skb_queue_tail(&rxq, skb);
- }
-
- BUG_ON(npo.meta_prod > ARRAY_SIZE(queue->meta));
-
- if (!npo.copy_prod)
- goto done;
-
- BUG_ON(npo.copy_prod > MAX_GRANT_COPY_OPS);
- gnttab_batch_copy(queue->grant_copy_op, npo.copy_prod);
-
- while ((skb = __skb_dequeue(&rxq)) != NULL) {
- struct xen_netif_extra_info *extra = NULL;
-
- if ((1 << queue->meta[npo.meta_cons].gso_type) &
- vif->gso_prefix_mask) {
- resp = RING_GET_RESPONSE(&queue->rx,
- queue->rx.rsp_prod_pvt++);
-
- resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data;
-
- resp->offset = queue->meta[npo.meta_cons].gso_size;
- resp->id = queue->meta[npo.meta_cons].id;
- resp->status = XENVIF_RX_CB(skb)->meta_slots_used;
-
- npo.meta_cons++;
- XENVIF_RX_CB(skb)->meta_slots_used--;
- }
-
-
- queue->stats.tx_bytes += skb->len;
- queue->stats.tx_packets++;
-
- status = xenvif_check_gop(vif,
- XENVIF_RX_CB(skb)->meta_slots_used,
- &npo);
-
- if (XENVIF_RX_CB(skb)->meta_slots_used == 1)
- flags = 0;
- else
- flags = XEN_NETRXF_more_data;
-
- if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
- flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated;
- else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
- /* remote but checksummed. */
- flags |= XEN_NETRXF_data_validated;
-
- offset = 0;
- resp = make_rx_response(queue, queue->meta[npo.meta_cons].id,
- status, offset,
- queue->meta[npo.meta_cons].size,
- flags);
-
- if ((1 << queue->meta[npo.meta_cons].gso_type) &
- vif->gso_mask) {
- extra = (struct xen_netif_extra_info *)
- RING_GET_RESPONSE(&queue->rx,
- queue->rx.rsp_prod_pvt++);
-
- resp->flags |= XEN_NETRXF_extra_info;
-
- extra->u.gso.type = queue->meta[npo.meta_cons].gso_type;
- extra->u.gso.size = queue->meta[npo.meta_cons].gso_size;
- extra->u.gso.pad = 0;
- extra->u.gso.features = 0;
-
- extra->type = XEN_NETIF_EXTRA_TYPE_GSO;
- extra->flags = 0;
- }
-
- if (skb->sw_hash) {
- /* Since the skb got here via xenvif_select_queue()
- * we know that the hash has been re-calculated
- * according to a configuration set by the frontend
- * and therefore we know that it is legitimate to
- * pass it to the frontend.
- */
- if (resp->flags & XEN_NETRXF_extra_info)
- extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
- else
- resp->flags |= XEN_NETRXF_extra_info;
-
- extra = (struct xen_netif_extra_info *)
- RING_GET_RESPONSE(&queue->rx,
- queue->rx.rsp_prod_pvt++);
-
- extra->u.hash.algorithm =
- XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ;
-
- if (skb->l4_hash)
- extra->u.hash.type =
- skb->protocol == htons(ETH_P_IP) ?
- _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP :
- _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP;
- else
- extra->u.hash.type =
- skb->protocol == htons(ETH_P_IP) ?
- _XEN_NETIF_CTRL_HASH_TYPE_IPV4 :
- _XEN_NETIF_CTRL_HASH_TYPE_IPV6;
-
- *(uint32_t *)extra->u.hash.value =
- skb_get_hash_raw(skb);
-
- extra->type = XEN_NETIF_EXTRA_TYPE_HASH;
- extra->flags = 0;
- }
-
- xenvif_add_frag_responses(queue, status,
- queue->meta + npo.meta_cons + 1,
- XENVIF_RX_CB(skb)->meta_slots_used);
-
- RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->rx, ret);
-
- need_to_notify |= !!ret;
-
- npo.meta_cons += XENVIF_RX_CB(skb)->meta_slots_used;
- dev_kfree_skb(skb);
- }
-
-done:
- if (need_to_notify)
- notify_remote_via_irq(queue->rx_irq);
-}
-
void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue)
{
int more_to_do;
notify_remote_via_irq(queue->tx_irq);
}
-static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue,
- u16 id,
- s8 st,
- u16 offset,
- u16 size,
- u16 flags)
-{
- RING_IDX i = queue->rx.rsp_prod_pvt;
- struct xen_netif_rx_response *resp;
-
- resp = RING_GET_RESPONSE(&queue->rx, i);
- resp->offset = offset;
- resp->flags = flags;
- resp->id = id;
- resp->status = (s16)size;
- if (st < 0)
- resp->status = (s16)st;
-
- queue->rx.rsp_prod_pvt = ++i;
-
- return resp;
-}
-
void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
{
int ret;
return err;
}
-static void xenvif_queue_carrier_off(struct xenvif_queue *queue)
-{
- struct xenvif *vif = queue->vif;
-
- queue->stalled = true;
-
- /* At least one queue has stalled? Disable the carrier. */
- spin_lock(&vif->lock);
- if (vif->stalled_queues++ == 0) {
- netdev_info(vif->dev, "Guest Rx stalled");
- netif_carrier_off(vif->dev);
- }
- spin_unlock(&vif->lock);
-}
-
-static void xenvif_queue_carrier_on(struct xenvif_queue *queue)
-{
- struct xenvif *vif = queue->vif;
-
- queue->last_rx_time = jiffies; /* Reset Rx stall detection. */
- queue->stalled = false;
-
- /* All queues are ready? Enable the carrier. */
- spin_lock(&vif->lock);
- if (--vif->stalled_queues == 0) {
- netdev_info(vif->dev, "Guest Rx ready");
- netif_carrier_on(vif->dev);
- }
- spin_unlock(&vif->lock);
-}
-
-static bool xenvif_rx_queue_stalled(struct xenvif_queue *queue)
-{
- RING_IDX prod, cons;
-
- prod = queue->rx.sring->req_prod;
- cons = queue->rx.req_cons;
-
- return !queue->stalled && prod - cons < 1
- && time_after(jiffies,
- queue->last_rx_time + queue->vif->stall_timeout);
-}
-
-static bool xenvif_rx_queue_ready(struct xenvif_queue *queue)
-{
- RING_IDX prod, cons;
-
- prod = queue->rx.sring->req_prod;
- cons = queue->rx.req_cons;
-
- return queue->stalled && prod - cons >= 1;
-}
-
-static bool xenvif_have_rx_work(struct xenvif_queue *queue)
-{
- return xenvif_rx_ring_slots_available(queue)
- || (queue->vif->stall_timeout &&
- (xenvif_rx_queue_stalled(queue)
- || xenvif_rx_queue_ready(queue)))
- || kthread_should_stop()
- || queue->vif->disabled;
-}
-
-static long xenvif_rx_queue_timeout(struct xenvif_queue *queue)
-{
- struct sk_buff *skb;
- long timeout;
-
- skb = skb_peek(&queue->rx_queue);
- if (!skb)
- return MAX_SCHEDULE_TIMEOUT;
-
- timeout = XENVIF_RX_CB(skb)->expires - jiffies;
- return timeout < 0 ? 0 : timeout;
-}
-
-/* Wait until the guest Rx thread has work.
- *
- * The timeout needs to be adjusted based on the current head of the
- * queue (and not just the head at the beginning). In particular, if
- * the queue is initially empty an infinite timeout is used and this
- * needs to be reduced when a skb is queued.
- *
- * This cannot be done with wait_event_timeout() because it only
- * calculates the timeout once.
- */
-static void xenvif_wait_for_rx_work(struct xenvif_queue *queue)
-{
- DEFINE_WAIT(wait);
-
- if (xenvif_have_rx_work(queue))
- return;
-
- for (;;) {
- long ret;
-
- prepare_to_wait(&queue->wq, &wait, TASK_INTERRUPTIBLE);
- if (xenvif_have_rx_work(queue))
- break;
- ret = schedule_timeout(xenvif_rx_queue_timeout(queue));
- if (!ret)
- break;
- }
- finish_wait(&queue->wq, &wait);
-}
-
-int xenvif_kthread_guest_rx(void *data)
-{
- struct xenvif_queue *queue = data;
- struct xenvif *vif = queue->vif;
-
- if (!vif->stall_timeout)
- xenvif_queue_carrier_on(queue);
-
- for (;;) {
- xenvif_wait_for_rx_work(queue);
-
- if (kthread_should_stop())
- break;
-
- /* This frontend is found to be rogue, disable it in
- * kthread context. Currently this is only set when
- * netback finds out frontend sends malformed packet,
- * but we cannot disable the interface in softirq
- * context so we defer it here, if this thread is
- * associated with queue 0.
- */
- if (unlikely(vif->disabled && queue->id == 0)) {
- xenvif_carrier_off(vif);
- break;
- }
-
- if (!skb_queue_empty(&queue->rx_queue))
- xenvif_rx_action(queue);
-
- /* If the guest hasn't provided any Rx slots for a
- * while it's probably not responsive, drop the
- * carrier so packets are dropped earlier.
- */
- if (vif->stall_timeout) {
- if (xenvif_rx_queue_stalled(queue))
- xenvif_queue_carrier_off(queue);
- else if (xenvif_rx_queue_ready(queue))
- xenvif_queue_carrier_on(queue);
- }
-
- /* Queued packets may have foreign pages from other
- * domains. These cannot be queued indefinitely as
- * this would starve guests of grant refs and transmit
- * slots.
- */
- xenvif_rx_queue_drop_expired(queue);
-
- xenvif_rx_queue_maybe_wake(queue);
-
- cond_resched();
- }
-
- /* Bin any remaining skbs */
- xenvif_rx_queue_purge(queue);
-
- return 0;
-}
-
static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue)
{
/* Dealloc thread must remain running until all inflight
--- /dev/null
+/*
+ * Copyright (c) 2016 Citrix Systems Inc.
+ * Copyright (c) 2002-2005, K A Fraser
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "common.h"
+
+#include <linux/kthread.h>
+
+#include <xen/xen.h>
+#include <xen/events.h>
+
+static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
+{
+ RING_IDX prod, cons;
+ struct sk_buff *skb;
+ int needed;
+
+ skb = skb_peek(&queue->rx_queue);
+ if (!skb)
+ return false;
+
+ needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE);
+ if (skb_is_gso(skb))
+ needed++;
+ if (skb->sw_hash)
+ needed++;
+
+ do {
+ prod = queue->rx.sring->req_prod;
+ cons = queue->rx.req_cons;
+
+ if (prod - cons >= needed)
+ return true;
+
+ queue->rx.sring->req_event = prod + 1;
+
+ /* Make sure event is visible before we check prod
+ * again.
+ */
+ mb();
+ } while (queue->rx.sring->req_prod != prod);
+
+ return false;
+}
+
+void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&queue->rx_queue.lock, flags);
+
+ __skb_queue_tail(&queue->rx_queue, skb);
+
+ queue->rx_queue_len += skb->len;
+ if (queue->rx_queue_len > queue->rx_queue_max) {
+ struct net_device *dev = queue->vif->dev;
+
+ netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
+ }
+
+ spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
+}
+
+static struct sk_buff *xenvif_rx_dequeue(struct xenvif_queue *queue)
+{
+ struct sk_buff *skb;
+
+ spin_lock_irq(&queue->rx_queue.lock);
+
+ skb = __skb_dequeue(&queue->rx_queue);
+ if (skb)
+ queue->rx_queue_len -= skb->len;
+
+ spin_unlock_irq(&queue->rx_queue.lock);
+
+ return skb;
+}
+
+static void xenvif_rx_queue_maybe_wake(struct xenvif_queue *queue)
+{
+ spin_lock_irq(&queue->rx_queue.lock);
+
+ if (queue->rx_queue_len < queue->rx_queue_max) {
+ struct net_device *dev = queue->vif->dev;
+
+ netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
+ }
+
+ spin_unlock_irq(&queue->rx_queue.lock);
+}
+
+static void xenvif_rx_queue_purge(struct xenvif_queue *queue)
+{
+ struct sk_buff *skb;
+
+ while ((skb = xenvif_rx_dequeue(queue)) != NULL)
+ kfree_skb(skb);
+}
+
+static void xenvif_rx_queue_drop_expired(struct xenvif_queue *queue)
+{
+ struct sk_buff *skb;
+
+ for (;;) {
+ skb = skb_peek(&queue->rx_queue);
+ if (!skb)
+ break;
+ if (time_before(jiffies, XENVIF_RX_CB(skb)->expires))
+ break;
+ xenvif_rx_dequeue(queue);
+ kfree_skb(skb);
+ }
+}
+
+struct netrx_pending_operations {
+ unsigned int copy_prod, copy_cons;
+ unsigned int meta_prod, meta_cons;
+ struct gnttab_copy *copy;
+ struct xenvif_rx_meta *meta;
+ int copy_off;
+ grant_ref_t copy_gref;
+};
+
+static struct xenvif_rx_meta *get_next_rx_buffer(
+ struct xenvif_queue *queue,
+ struct netrx_pending_operations *npo)
+{
+ struct xenvif_rx_meta *meta;
+ struct xen_netif_rx_request req;
+
+ RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
+
+ meta = npo->meta + npo->meta_prod++;
+ meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
+ meta->gso_size = 0;
+ meta->size = 0;
+ meta->id = req.id;
+
+ npo->copy_off = 0;
+ npo->copy_gref = req.gref;
+
+ return meta;
+}
+
+struct gop_frag_copy {
+ struct xenvif_queue *queue;
+ struct netrx_pending_operations *npo;
+ struct xenvif_rx_meta *meta;
+ int head;
+ int gso_type;
+ int protocol;
+ int hash_present;
+
+ struct page *page;
+};
+
+static void xenvif_setup_copy_gop(unsigned long gfn,
+ unsigned int offset,
+ unsigned int *len,
+ struct gop_frag_copy *info)
+{
+ struct gnttab_copy *copy_gop;
+ struct xen_page_foreign *foreign;
+ /* Convenient aliases */
+ struct xenvif_queue *queue = info->queue;
+ struct netrx_pending_operations *npo = info->npo;
+ struct page *page = info->page;
+
+ WARN_ON(npo->copy_off > MAX_BUFFER_OFFSET);
+
+ if (npo->copy_off == MAX_BUFFER_OFFSET)
+ info->meta = get_next_rx_buffer(queue, npo);
+
+ if (npo->copy_off + *len > MAX_BUFFER_OFFSET)
+ *len = MAX_BUFFER_OFFSET - npo->copy_off;
+
+ copy_gop = npo->copy + npo->copy_prod++;
+ copy_gop->flags = GNTCOPY_dest_gref;
+ copy_gop->len = *len;
+
+ foreign = xen_page_foreign(page);
+ if (foreign) {
+ copy_gop->source.domid = foreign->domid;
+ copy_gop->source.u.ref = foreign->gref;
+ copy_gop->flags |= GNTCOPY_source_gref;
+ } else {
+ copy_gop->source.domid = DOMID_SELF;
+ copy_gop->source.u.gmfn = gfn;
+ }
+ copy_gop->source.offset = offset;
+
+ copy_gop->dest.domid = queue->vif->domid;
+ copy_gop->dest.offset = npo->copy_off;
+ copy_gop->dest.u.ref = npo->copy_gref;
+
+ npo->copy_off += *len;
+ info->meta->size += *len;
+
+ if (!info->head)
+ return;
+
+ /* Leave a gap for the GSO descriptor. */
+ if ((1 << info->gso_type) & queue->vif->gso_mask)
+ queue->rx.req_cons++;
+
+ /* Leave a gap for the hash extra segment. */
+ if (info->hash_present)
+ queue->rx.req_cons++;
+
+ info->head = 0; /* There must be something in this buffer now */
+}
+
+static void xenvif_gop_frag_copy_grant(unsigned long gfn,
+ unsigned int offset,
+ unsigned int len,
+ void *data)
+{
+ unsigned int bytes;
+
+ while (len) {
+ bytes = len;
+ xenvif_setup_copy_gop(gfn, offset, &bytes, data);
+ offset += bytes;
+ len -= bytes;
+ }
+}
+
+/* Set up the grant operations for this fragment. If it's a flipping
+ * interface, we also set up the unmap request from here.
+ */
+static void xenvif_gop_frag_copy(struct xenvif_queue *queue,
+ struct sk_buff *skb,
+ struct netrx_pending_operations *npo,
+ struct page *page, unsigned long size,
+ unsigned long offset, int *head)
+{
+ struct gop_frag_copy info = {
+ .queue = queue,
+ .npo = npo,
+ .head = *head,
+ .gso_type = XEN_NETIF_GSO_TYPE_NONE,
+ /* xenvif_set_skb_hash() will have either set a s/w
+ * hash or cleared the hash depending on
+ * whether the the frontend wants a hash for this skb.
+ */
+ .hash_present = skb->sw_hash,
+ };
+ unsigned long bytes;
+
+ if (skb_is_gso(skb)) {
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+ info.gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
+ else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+ info.gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
+ }
+
+ /* Data must not cross a page boundary. */
+ WARN_ON(size + offset > (PAGE_SIZE << compound_order(page)));
+
+ info.meta = npo->meta + npo->meta_prod - 1;
+
+ /* Skip unused frames from start of page */
+ page += offset >> PAGE_SHIFT;
+ offset &= ~PAGE_MASK;
+
+ while (size > 0) {
+ WARN_ON(offset >= PAGE_SIZE);
+
+ bytes = PAGE_SIZE - offset;
+ if (bytes > size)
+ bytes = size;
+
+ info.page = page;
+ gnttab_foreach_grant_in_range(page, offset, bytes,
+ xenvif_gop_frag_copy_grant,
+ &info);
+ size -= bytes;
+ offset = 0;
+
+ /* Next page */
+ if (size) {
+ WARN_ON(!PageCompound(page));
+ page++;
+ }
+ }
+
+ *head = info.head;
+}
+
+/* Prepare an SKB to be transmitted to the frontend.
+ *
+ * This function is responsible for allocating grant operations, meta
+ * structures, etc.
+ *
+ * It returns the number of meta structures consumed. The number of
+ * ring slots used is always equal to the number of meta slots used
+ * plus the number of GSO descriptors used. Currently, we use either
+ * zero GSO descriptors (for non-GSO packets) or one descriptor (for
+ * frontend-side LRO).
+ */
+static int xenvif_gop_skb(struct sk_buff *skb,
+ struct netrx_pending_operations *npo,
+ struct xenvif_queue *queue)
+{
+ struct xenvif *vif = netdev_priv(skb->dev);
+ int nr_frags = skb_shinfo(skb)->nr_frags;
+ int i;
+ struct xen_netif_rx_request req;
+ struct xenvif_rx_meta *meta;
+ unsigned char *data;
+ int head = 1;
+ int old_meta_prod;
+ int gso_type;
+
+ old_meta_prod = npo->meta_prod;
+
+ gso_type = XEN_NETIF_GSO_TYPE_NONE;
+ if (skb_is_gso(skb)) {
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+ gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
+ else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+ gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
+ }
+
+ /* Set up a GSO prefix descriptor, if necessary */
+ if ((1 << gso_type) & vif->gso_prefix_mask) {
+ RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
+ meta = npo->meta + npo->meta_prod++;
+ meta->gso_type = gso_type;
+ meta->gso_size = skb_shinfo(skb)->gso_size;
+ meta->size = 0;
+ meta->id = req.id;
+ }
+
+ RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
+ meta = npo->meta + npo->meta_prod++;
+
+ if ((1 << gso_type) & vif->gso_mask) {
+ meta->gso_type = gso_type;
+ meta->gso_size = skb_shinfo(skb)->gso_size;
+ } else {
+ meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
+ meta->gso_size = 0;
+ }
+
+ meta->size = 0;
+ meta->id = req.id;
+ npo->copy_off = 0;
+ npo->copy_gref = req.gref;
+
+ data = skb->data;
+ while (data < skb_tail_pointer(skb)) {
+ unsigned int offset = offset_in_page(data);
+ unsigned int len = PAGE_SIZE - offset;
+
+ if (data + len > skb_tail_pointer(skb))
+ len = skb_tail_pointer(skb) - data;
+
+ xenvif_gop_frag_copy(queue, skb, npo,
+ virt_to_page(data), len, offset, &head);
+ data += len;
+ }
+
+ for (i = 0; i < nr_frags; i++) {
+ xenvif_gop_frag_copy(queue, skb, npo,
+ skb_frag_page(&skb_shinfo(skb)->frags[i]),
+ skb_frag_size(&skb_shinfo(skb)->frags[i]),
+ skb_shinfo(skb)->frags[i].page_offset,
+ &head);
+ }
+
+ return npo->meta_prod - old_meta_prod;
+}
+
+/* This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was
+ * used to set up the operations on the top of
+ * netrx_pending_operations, which have since been done. Check that
+ * they didn't give any errors and advance over them.
+ */
+static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots,
+ struct netrx_pending_operations *npo)
+{
+ struct gnttab_copy *copy_op;
+ int status = XEN_NETIF_RSP_OKAY;
+ int i;
+
+ for (i = 0; i < nr_meta_slots; i++) {
+ copy_op = npo->copy + npo->copy_cons++;
+ if (copy_op->status != GNTST_okay) {
+ netdev_dbg(vif->dev,
+ "Bad status %d from copy to DOM%d.\n",
+ copy_op->status, vif->domid);
+ status = XEN_NETIF_RSP_ERROR;
+ }
+ }
+
+ return status;
+}
+
+static struct xen_netif_rx_response *make_rx_response(
+ struct xenvif_queue *queue, u16 id, s8 st, u16 offset, u16 size,
+ u16 flags)
+{
+ RING_IDX i = queue->rx.rsp_prod_pvt;
+ struct xen_netif_rx_response *resp;
+
+ resp = RING_GET_RESPONSE(&queue->rx, i);
+ resp->offset = offset;
+ resp->flags = flags;
+ resp->id = id;
+ resp->status = (s16)size;
+ if (st < 0)
+ resp->status = (s16)st;
+
+ queue->rx.rsp_prod_pvt = ++i;
+
+ return resp;
+}
+
+static void xenvif_add_frag_responses(struct xenvif_queue *queue,
+ int status,
+ struct xenvif_rx_meta *meta,
+ int nr_meta_slots)
+{
+ int i;
+ unsigned long offset;
+
+ /* No fragments used */
+ if (nr_meta_slots <= 1)
+ return;
+
+ nr_meta_slots--;
+
+ for (i = 0; i < nr_meta_slots; i++) {
+ int flags;
+
+ if (i == nr_meta_slots - 1)
+ flags = 0;
+ else
+ flags = XEN_NETRXF_more_data;
+
+ offset = 0;
+ make_rx_response(queue, meta[i].id, status, offset,
+ meta[i].size, flags);
+ }
+}
+
+static void xenvif_rx_action(struct xenvif_queue *queue)
+{
+ struct xenvif *vif = queue->vif;
+ s8 status;
+ u16 flags;
+ struct xen_netif_rx_response *resp;
+ struct sk_buff_head rxq;
+ struct sk_buff *skb;
+ LIST_HEAD(notify);
+ int ret;
+ unsigned long offset;
+ bool need_to_notify = false;
+
+ struct netrx_pending_operations npo = {
+ .copy = queue->grant_copy_op,
+ .meta = queue->meta,
+ };
+
+ skb_queue_head_init(&rxq);
+
+ while (xenvif_rx_ring_slots_available(queue) &&
+ (skb = xenvif_rx_dequeue(queue)) != NULL) {
+ queue->last_rx_time = jiffies;
+
+ XENVIF_RX_CB(skb)->meta_slots_used =
+ xenvif_gop_skb(skb, &npo, queue);
+
+ __skb_queue_tail(&rxq, skb);
+ }
+
+ WARN_ON(npo.meta_prod > ARRAY_SIZE(queue->meta));
+
+ if (!npo.copy_prod)
+ goto done;
+
+ WARN_ON(npo.copy_prod > MAX_GRANT_COPY_OPS);
+ gnttab_batch_copy(queue->grant_copy_op, npo.copy_prod);
+
+ while ((skb = __skb_dequeue(&rxq)) != NULL) {
+ struct xen_netif_extra_info *extra = NULL;
+
+ if ((1 << queue->meta[npo.meta_cons].gso_type) &
+ vif->gso_prefix_mask) {
+ resp = RING_GET_RESPONSE(&queue->rx,
+ queue->rx.rsp_prod_pvt++);
+
+ resp->flags = XEN_NETRXF_gso_prefix |
+ XEN_NETRXF_more_data;
+
+ resp->offset = queue->meta[npo.meta_cons].gso_size;
+ resp->id = queue->meta[npo.meta_cons].id;
+ resp->status = XENVIF_RX_CB(skb)->meta_slots_used;
+
+ npo.meta_cons++;
+ XENVIF_RX_CB(skb)->meta_slots_used--;
+ }
+
+ queue->stats.tx_bytes += skb->len;
+ queue->stats.tx_packets++;
+
+ status = xenvif_check_gop(vif,
+ XENVIF_RX_CB(skb)->meta_slots_used,
+ &npo);
+
+ if (XENVIF_RX_CB(skb)->meta_slots_used == 1)
+ flags = 0;
+ else
+ flags = XEN_NETRXF_more_data;
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
+ flags |= XEN_NETRXF_csum_blank |
+ XEN_NETRXF_data_validated;
+ else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
+ /* remote but checksummed. */
+ flags |= XEN_NETRXF_data_validated;
+
+ offset = 0;
+ resp = make_rx_response(queue, queue->meta[npo.meta_cons].id,
+ status, offset,
+ queue->meta[npo.meta_cons].size,
+ flags);
+
+ if ((1 << queue->meta[npo.meta_cons].gso_type) &
+ vif->gso_mask) {
+ extra = (struct xen_netif_extra_info *)
+ RING_GET_RESPONSE(&queue->rx,
+ queue->rx.rsp_prod_pvt++);
+
+ resp->flags |= XEN_NETRXF_extra_info;
+
+ extra->u.gso.type = queue->meta[npo.meta_cons].gso_type;
+ extra->u.gso.size = queue->meta[npo.meta_cons].gso_size;
+ extra->u.gso.pad = 0;
+ extra->u.gso.features = 0;
+
+ extra->type = XEN_NETIF_EXTRA_TYPE_GSO;
+ extra->flags = 0;
+ }
+
+ if (skb->sw_hash) {
+ /* Since the skb got here via xenvif_select_queue()
+ * we know that the hash has been re-calculated
+ * according to a configuration set by the frontend
+ * and therefore we know that it is legitimate to
+ * pass it to the frontend.
+ */
+ if (resp->flags & XEN_NETRXF_extra_info)
+ extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
+ else
+ resp->flags |= XEN_NETRXF_extra_info;
+
+ extra = (struct xen_netif_extra_info *)
+ RING_GET_RESPONSE(&queue->rx,
+ queue->rx.rsp_prod_pvt++);
+
+ extra->u.hash.algorithm =
+ XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ;
+
+ if (skb->l4_hash)
+ extra->u.hash.type =
+ skb->protocol == htons(ETH_P_IP) ?
+ _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP :
+ _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP;
+ else
+ extra->u.hash.type =
+ skb->protocol == htons(ETH_P_IP) ?
+ _XEN_NETIF_CTRL_HASH_TYPE_IPV4 :
+ _XEN_NETIF_CTRL_HASH_TYPE_IPV6;
+
+ *(uint32_t *)extra->u.hash.value =
+ skb_get_hash_raw(skb);
+
+ extra->type = XEN_NETIF_EXTRA_TYPE_HASH;
+ extra->flags = 0;
+ }
+
+ xenvif_add_frag_responses(queue, status,
+ queue->meta + npo.meta_cons + 1,
+ XENVIF_RX_CB(skb)->meta_slots_used);
+
+ RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->rx, ret);
+
+ need_to_notify |= !!ret;
+
+ npo.meta_cons += XENVIF_RX_CB(skb)->meta_slots_used;
+ dev_kfree_skb(skb);
+ }
+
+done:
+ if (need_to_notify)
+ notify_remote_via_irq(queue->rx_irq);
+}
+
+static bool xenvif_rx_queue_stalled(struct xenvif_queue *queue)
+{
+ RING_IDX prod, cons;
+
+ prod = queue->rx.sring->req_prod;
+ cons = queue->rx.req_cons;
+
+ return !queue->stalled &&
+ prod - cons < 1 &&
+ time_after(jiffies,
+ queue->last_rx_time + queue->vif->stall_timeout);
+}
+
+static bool xenvif_rx_queue_ready(struct xenvif_queue *queue)
+{
+ RING_IDX prod, cons;
+
+ prod = queue->rx.sring->req_prod;
+ cons = queue->rx.req_cons;
+
+ return queue->stalled && prod - cons >= 1;
+}
+
+static bool xenvif_have_rx_work(struct xenvif_queue *queue)
+{
+ return xenvif_rx_ring_slots_available(queue) ||
+ (queue->vif->stall_timeout &&
+ (xenvif_rx_queue_stalled(queue) ||
+ xenvif_rx_queue_ready(queue))) ||
+ kthread_should_stop() ||
+ queue->vif->disabled;
+}
+
+static long xenvif_rx_queue_timeout(struct xenvif_queue *queue)
+{
+ struct sk_buff *skb;
+ long timeout;
+
+ skb = skb_peek(&queue->rx_queue);
+ if (!skb)
+ return MAX_SCHEDULE_TIMEOUT;
+
+ timeout = XENVIF_RX_CB(skb)->expires - jiffies;
+ return timeout < 0 ? 0 : timeout;
+}
+
+/* Wait until the guest Rx thread has work.
+ *
+ * The timeout needs to be adjusted based on the current head of the
+ * queue (and not just the head at the beginning). In particular, if
+ * the queue is initially empty an infinite timeout is used and this
+ * needs to be reduced when a skb is queued.
+ *
+ * This cannot be done with wait_event_timeout() because it only
+ * calculates the timeout once.
+ */
+static void xenvif_wait_for_rx_work(struct xenvif_queue *queue)
+{
+ DEFINE_WAIT(wait);
+
+ if (xenvif_have_rx_work(queue))
+ return;
+
+ for (;;) {
+ long ret;
+
+ prepare_to_wait(&queue->wq, &wait, TASK_INTERRUPTIBLE);
+ if (xenvif_have_rx_work(queue))
+ break;
+ ret = schedule_timeout(xenvif_rx_queue_timeout(queue));
+ if (!ret)
+ break;
+ }
+ finish_wait(&queue->wq, &wait);
+}
+
+static void xenvif_queue_carrier_off(struct xenvif_queue *queue)
+{
+ struct xenvif *vif = queue->vif;
+
+ queue->stalled = true;
+
+ /* At least one queue has stalled? Disable the carrier. */
+ spin_lock(&vif->lock);
+ if (vif->stalled_queues++ == 0) {
+ netdev_info(vif->dev, "Guest Rx stalled");
+ netif_carrier_off(vif->dev);
+ }
+ spin_unlock(&vif->lock);
+}
+
+static void xenvif_queue_carrier_on(struct xenvif_queue *queue)
+{
+ struct xenvif *vif = queue->vif;
+
+ queue->last_rx_time = jiffies; /* Reset Rx stall detection. */
+ queue->stalled = false;
+
+ /* All queues are ready? Enable the carrier. */
+ spin_lock(&vif->lock);
+ if (--vif->stalled_queues == 0) {
+ netdev_info(vif->dev, "Guest Rx ready");
+ netif_carrier_on(vif->dev);
+ }
+ spin_unlock(&vif->lock);
+}
+
+int xenvif_kthread_guest_rx(void *data)
+{
+ struct xenvif_queue *queue = data;
+ struct xenvif *vif = queue->vif;
+
+ if (!vif->stall_timeout)
+ xenvif_queue_carrier_on(queue);
+
+ for (;;) {
+ xenvif_wait_for_rx_work(queue);
+
+ if (kthread_should_stop())
+ break;
+
+ /* This frontend is found to be rogue, disable it in
+ * kthread context. Currently this is only set when
+ * netback finds out frontend sends malformed packet,
+ * but we cannot disable the interface in softirq
+ * context so we defer it here, if this thread is
+ * associated with queue 0.
+ */
+ if (unlikely(vif->disabled && queue->id == 0)) {
+ xenvif_carrier_off(vif);
+ break;
+ }
+
+ if (!skb_queue_empty(&queue->rx_queue))
+ xenvif_rx_action(queue);
+
+ /* If the guest hasn't provided any Rx slots for a
+ * while it's probably not responsive, drop the
+ * carrier so packets are dropped earlier.
+ */
+ if (vif->stall_timeout) {
+ if (xenvif_rx_queue_stalled(queue))
+ xenvif_queue_carrier_off(queue);
+ else if (xenvif_rx_queue_ready(queue))
+ xenvif_queue_carrier_on(queue);
+ }
+
+ /* Queued packets may have foreign pages from other
+ * domains. These cannot be queued indefinitely as
+ * this would starve guests of grant refs and transmit
+ * slots.
+ */
+ xenvif_rx_queue_drop_expired(queue);
+
+ xenvif_rx_queue_maybe_wake(queue);
+
+ cond_resched();
+ }
+
+ /* Bin any remaining skbs */
+ xenvif_rx_queue_purge(queue);
+
+ return 0;
+}
projects / cascardo / linux.git / commitdiff