diff options
Diffstat (limited to 'drivers/net/xen-netback/netback.c')
| -rw-r--r-- | drivers/net/xen-netback/netback.c | 1485 |
1 files changed, 1003 insertions, 482 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 438d0c09b7e6..aa2093325be1 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -37,6 +37,7 @@ #include <linux/kthread.h> #include <linux/if_vlan.h> #include <linux/udp.h> +#include <linux/highmem.h> #include <net/tcp.h> @@ -54,6 +55,18 @@ bool separate_tx_rx_irq = 1; module_param(separate_tx_rx_irq, bool, 0644); +/* When guest ring is filled up, qdisc queues the packets for us, but we have + * to timeout them, otherwise other guests' packets can get stuck there + */ +unsigned int rx_drain_timeout_msecs = 10000; +module_param(rx_drain_timeout_msecs, uint, 0444); +unsigned int rx_drain_timeout_jiffies; + +unsigned int xenvif_max_queues; +module_param_named(max_queues, xenvif_max_queues, uint, 0644); +MODULE_PARM_DESC(max_queues, + "Maximum number of queues per virtual interface"); + /* * This is the maximum slots a skb can have. If a guest sends a skb * which exceeds this limit it is considered malicious. @@ -62,51 +75,48 @@ module_param(separate_tx_rx_irq, bool, 0644); static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT; module_param(fatal_skb_slots, uint, 0444); -/* - * To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating - * the maximum slots a valid packet can use. Now this value is defined - * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by - * all backend. - */ -#define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN - -/* - * If head != INVALID_PENDING_RING_IDX, it means this tx request is head of - * one or more merged tx requests, otherwise it is the continuation of - * previous tx request. - */ -static inline int pending_tx_is_head(struct xenvif *vif, RING_IDX idx) -{ - return vif->pending_tx_info[idx].head != INVALID_PENDING_RING_IDX; -} - -static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx, +static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx, u8 status); -static void make_tx_response(struct xenvif *vif, +static void make_tx_response(struct xenvif_queue *queue, struct xen_netif_tx_request *txp, s8 st); -static inline int tx_work_todo(struct xenvif *vif); -static inline int rx_work_todo(struct xenvif *vif); +static inline int tx_work_todo(struct xenvif_queue *queue); +static inline int rx_work_todo(struct xenvif_queue *queue); -static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif, +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 *vif, +static inline unsigned long idx_to_pfn(struct xenvif_queue *queue, u16 idx) { - return page_to_pfn(vif->mmap_pages[idx]); + return page_to_pfn(queue->mmap_pages[idx]); } -static inline unsigned long idx_to_kaddr(struct xenvif *vif, +static inline unsigned long idx_to_kaddr(struct xenvif_queue *queue, u16 idx) { - return (unsigned long)pfn_to_kaddr(idx_to_pfn(vif, idx)); + return (unsigned long)pfn_to_kaddr(idx_to_pfn(queue, idx)); +} + +#define callback_param(vif, pending_idx) \ + (vif->pending_tx_info[pending_idx].callback_struct) + +/* Find the containing VIF's structure from a pointer in pending_tx_info array + */ +static inline struct xenvif_queue *ubuf_to_queue(const struct ubuf_info *ubuf) +{ + u16 pending_idx = ubuf->desc; + struct pending_tx_info *temp = + container_of(ubuf, struct pending_tx_info, callback_struct); + return container_of(temp - pending_idx, + struct xenvif_queue, + pending_tx_info[0]); } /* This is a miniumum size for the linear area to avoid lots of @@ -131,30 +141,24 @@ static inline pending_ring_idx_t pending_index(unsigned i) return i & (MAX_PENDING_REQS-1); } -static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif) -{ - return MAX_PENDING_REQS - - vif->pending_prod + vif->pending_cons; -} - -bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed) +bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue, int needed) { RING_IDX prod, cons; do { - prod = vif->rx.sring->req_prod; - cons = vif->rx.req_cons; + prod = queue->rx.sring->req_prod; + cons = queue->rx.req_cons; if (prod - cons >= needed) return true; - vif->rx.sring->req_event = prod + 1; + queue->rx.sring->req_event = prod + 1; /* Make sure event is visible before we check prod * again. */ mb(); - } while (vif->rx.sring->req_prod != prod); + } while (queue->rx.sring->req_prod != prod); return false; } @@ -164,7 +168,8 @@ bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed) * adding 'size' bytes to a buffer which currently contains 'offset' * bytes. */ -static bool start_new_rx_buffer(int offset, unsigned long size, int head) +static bool start_new_rx_buffer(int offset, unsigned long size, int head, + bool full_coalesce) { /* simple case: we have completely filled the current buffer. */ if (offset == MAX_BUFFER_OFFSET) @@ -176,6 +181,7 @@ static bool start_new_rx_buffer(int offset, unsigned long size, int head) * (i) this frag would fit completely in the next buffer * and (ii) there is already some data in the current buffer * and (iii) this is not the head buffer. + * and (iv) there is no need to fully utilize the buffers * * Where: * - (i) stops us splitting a frag into two copies @@ -186,14 +192,17 @@ static bool start_new_rx_buffer(int offset, unsigned long size, int head) * by (ii) but is explicitly checked because * netfront relies on the first buffer being * non-empty and can crash otherwise. + * - (iv) is needed for skbs which can use up more than MAX_SKB_FRAGS + * slot * * This means we will effectively linearise small * frags but do not needlessly split large buffers * into multiple copies tend to give large frags their * own buffers as before. */ - if ((offset + size > MAX_BUFFER_OFFSET) && - (size <= MAX_BUFFER_OFFSET) && offset && !head) + BUG_ON(size > MAX_BUFFER_OFFSET); + if ((offset + size > MAX_BUFFER_OFFSET) && offset && !head && + !full_coalesce) return true; return false; @@ -208,13 +217,13 @@ struct netrx_pending_operations { grant_ref_t copy_gref; }; -static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif *vif, +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; - req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++); + req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++); meta = npo->meta + npo->meta_prod++; meta->gso_type = XEN_NETIF_GSO_TYPE_NONE; @@ -228,14 +237,23 @@ static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif *vif, return meta; } +struct xenvif_rx_cb { + int meta_slots_used; + bool full_coalesce; +}; + +#define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb) + /* * 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 *vif, struct sk_buff *skb, +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) + unsigned long offset, int *head, + struct xenvif_queue *foreign_queue, + grant_ref_t foreign_gref) { struct gnttab_copy *copy_gop; struct xenvif_rx_meta *meta; @@ -260,14 +278,17 @@ static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb, if (bytes > size) bytes = size; - if (start_new_rx_buffer(npo->copy_off, bytes, *head)) { + if (start_new_rx_buffer(npo->copy_off, + bytes, + *head, + XENVIF_RX_CB(skb)->full_coalesce)) { /* * Netfront requires there to be some data in the head * buffer. */ BUG_ON(*head); - meta = get_next_rx_buffer(vif, npo); + meta = get_next_rx_buffer(queue, npo); } if (npo->copy_off + bytes > MAX_BUFFER_OFFSET) @@ -277,11 +298,18 @@ static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb, copy_gop->flags = GNTCOPY_dest_gref; copy_gop->len = bytes; - copy_gop->source.domid = DOMID_SELF; - copy_gop->source.u.gmfn = virt_to_mfn(page_address(page)); + if (foreign_queue) { + copy_gop->source.domid = foreign_queue->vif->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 = + virt_to_mfn(page_address(page)); + } copy_gop->source.offset = offset; - copy_gop->dest.domid = vif->domid; + copy_gop->dest.domid = queue->vif->domid; copy_gop->dest.offset = npo->copy_off; copy_gop->dest.u.ref = npo->copy_gref; @@ -306,8 +334,8 @@ static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb, gso_type = XEN_NETIF_GSO_TYPE_TCPV6; } - if (*head && ((1 << gso_type) & vif->gso_mask)) - vif->rx.req_cons++; + if (*head && ((1 << gso_type) & queue->vif->gso_mask)) + queue->rx.req_cons++; *head = 0; /* There must be something in this buffer now. */ @@ -315,6 +343,35 @@ static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb, } /* + * Find the grant ref for a given frag in a chain of struct ubuf_info's + * skb: the skb itself + * i: the frag's number + * ubuf: a pointer to an element in the chain. It should not be NULL + * + * Returns a pointer to the element in the chain where the page were found. If + * not found, returns NULL. + * See the definition of callback_struct in common.h for more details about + * the chain. + */ +static const struct ubuf_info *xenvif_find_gref(const struct sk_buff *const skb, + const int i, + const struct ubuf_info *ubuf) +{ + struct xenvif_queue *foreign_queue = ubuf_to_queue(ubuf); + + do { + u16 pending_idx = ubuf->desc; + + if (skb_shinfo(skb)->frags[i].page.p == + foreign_queue->mmap_pages[pending_idx]) + break; + ubuf = (struct ubuf_info *) ubuf->ctx; + } while (ubuf); + + return ubuf; +} + +/* * Prepare an SKB to be transmitted to the frontend. * * This function is responsible for allocating grant operations, meta @@ -327,7 +384,8 @@ static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb, * frontend-side LRO). */ static int xenvif_gop_skb(struct sk_buff *skb, - struct netrx_pending_operations *npo) + struct netrx_pending_operations *npo, + struct xenvif_queue *queue) { struct xenvif *vif = netdev_priv(skb->dev); int nr_frags = skb_shinfo(skb)->nr_frags; @@ -338,6 +396,8 @@ static int xenvif_gop_skb(struct sk_buff *skb, int head = 1; int old_meta_prod; int gso_type; + const struct ubuf_info *ubuf = skb_shinfo(skb)->destructor_arg; + const struct ubuf_info *const head_ubuf = ubuf; old_meta_prod = npo->meta_prod; @@ -351,7 +411,7 @@ static int xenvif_gop_skb(struct sk_buff *skb, /* Set up a GSO prefix descriptor, if necessary */ if ((1 << gso_type) & vif->gso_prefix_mask) { - req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++); + req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++); meta = npo->meta + npo->meta_prod++; meta->gso_type = gso_type; meta->gso_size = skb_shinfo(skb)->gso_size; @@ -359,7 +419,7 @@ static int xenvif_gop_skb(struct sk_buff *skb, meta->id = req->id; } - req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++); + req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++); meta = npo->meta + npo->meta_prod++; if ((1 << gso_type) & vif->gso_mask) { @@ -383,17 +443,69 @@ static int xenvif_gop_skb(struct sk_buff *skb, if (data + len > skb_tail_pointer(skb)) len = skb_tail_pointer(skb) - data; - xenvif_gop_frag_copy(vif, skb, npo, - virt_to_page(data), len, offset, &head); + xenvif_gop_frag_copy(queue, skb, npo, + virt_to_page(data), len, offset, &head, + NULL, + 0); data += len; } for (i = 0; i < nr_frags; i++) { - xenvif_gop_frag_copy(vif, skb, npo, + /* This variable also signals whether foreign_gref has a real + * value or not. + */ + struct xenvif_queue *foreign_queue = NULL; + grant_ref_t foreign_gref; + + if ((skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) && + (ubuf->callback == &xenvif_zerocopy_callback)) { + const struct ubuf_info *const startpoint = ubuf; + + /* Ideally ubuf points to the chain element which + * belongs to this frag. Or if frags were removed from + * the beginning, then shortly before it. + */ + ubuf = xenvif_find_gref(skb, i, ubuf); + + /* Try again from the beginning of the list, if we + * haven't tried from there. This only makes sense in + * the unlikely event of reordering the original frags. + * For injected local pages it's an unnecessary second + * run. + */ + if (unlikely(!ubuf) && startpoint != head_ubuf) + ubuf = xenvif_find_gref(skb, i, head_ubuf); + + if (likely(ubuf)) { + u16 pending_idx = ubuf->desc; + + foreign_queue = ubuf_to_queue(ubuf); + foreign_gref = + foreign_queue->pending_tx_info[pending_idx].req.gref; + /* Just a safety measure. If this was the last + * element on the list, the for loop will + * iterate again if a local page were added to + * the end. Using head_ubuf here prevents the + * second search on the chain. Or the original + * frags changed order, but that's less likely. + * In any way, ubuf shouldn't be NULL. + */ + ubuf = ubuf->ctx ? + (struct ubuf_info *) ubuf->ctx : + head_ubuf; + } else + /* This frag was a local page, added to the + * array after the skb left netback. + */ + ubuf = head_ubuf; + } + 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); + &head, + foreign_queue, + foreign_queue ? foreign_gref : UINT_MAX); } return npo->meta_prod - old_meta_prod; @@ -425,7 +537,7 @@ static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots, return status; } -static void xenvif_add_frag_responses(struct xenvif *vif, int status, +static void xenvif_add_frag_responses(struct xenvif_queue *queue, int status, struct xenvif_rx_meta *meta, int nr_meta_slots) { @@ -446,21 +558,17 @@ static void xenvif_add_frag_responses(struct xenvif *vif, int status, flags = XEN_NETRXF_more_data; offset = 0; - make_rx_response(vif, meta[i].id, status, offset, + make_rx_response(queue, meta[i].id, status, offset, meta[i].size, flags); } } -struct skb_cb_overlay { - int meta_slots_used; -}; - -void xenvif_kick_thread(struct xenvif *vif) +void xenvif_kick_thread(struct xenvif_queue *queue) { - wake_up(&vif->wq); + wake_up(&queue->wq); } -static void xenvif_rx_action(struct xenvif *vif) +static void xenvif_rx_action(struct xenvif_queue *queue) { s8 status; u16 flags; @@ -470,18 +578,19 @@ static void xenvif_rx_action(struct xenvif *vif) LIST_HEAD(notify); int ret; unsigned long offset; - struct skb_cb_overlay *sco; bool need_to_notify = false; struct netrx_pending_operations npo = { - .copy = vif->grant_copy_op, - .meta = vif->meta, + .copy = queue->grant_copy_op, + .meta = queue->meta, }; skb_queue_head_init(&rxq); - while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) { + while ((skb = skb_dequeue(&queue->rx_queue)) != NULL) { RING_IDX max_slots_needed; + RING_IDX old_req_cons; + RING_IDX ring_slots_used; int i; /* We need a cheap worse case estimate for the number of @@ -493,63 +602,90 @@ static void xenvif_rx_action(struct xenvif *vif) PAGE_SIZE); for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { unsigned int size; + unsigned int offset; + size = skb_frag_size(&skb_shinfo(skb)->frags[i]); - max_slots_needed += DIV_ROUND_UP(size, PAGE_SIZE); + offset = skb_shinfo(skb)->frags[i].page_offset; + + /* For a worse-case estimate we need to factor in + * the fragment page offset as this will affect the + * number of times xenvif_gop_frag_copy() will + * call start_new_rx_buffer(). + */ + max_slots_needed += DIV_ROUND_UP(offset + size, + PAGE_SIZE); } + + /* To avoid the estimate becoming too pessimal for some + * frontends that limit posted rx requests, cap the estimate + * at MAX_SKB_FRAGS. In this case netback will fully coalesce + * the skb into the provided slots. + */ + if (max_slots_needed > MAX_SKB_FRAGS) { + max_slots_needed = MAX_SKB_FRAGS; + XENVIF_RX_CB(skb)->full_coalesce = true; + } else { + XENVIF_RX_CB(skb)->full_coalesce = false; + } + + /* We may need one more slot for GSO metadata */ if (skb_is_gso(skb) && (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4 || skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)) max_slots_needed++; /* If the skb may not fit then bail out now */ - if (!xenvif_rx_ring_slots_available(vif, max_slots_needed)) { - skb_queue_head(&vif->rx_queue, skb); + if (!xenvif_rx_ring_slots_available(queue, max_slots_needed)) { + skb_queue_head(&queue->rx_queue, skb); need_to_notify = true; - vif->rx_last_skb_slots = max_slots_needed; + queue->rx_last_skb_slots = max_slots_needed; break; } else - vif->rx_last_skb_slots = 0; + queue->rx_last_skb_slots = 0; + + old_req_cons = queue->rx.req_cons; + XENVIF_RX_CB(skb)->meta_slots_used = xenvif_gop_skb(skb, &npo, queue); + ring_slots_used = queue->rx.req_cons - old_req_cons; - sco = (struct skb_cb_overlay *)skb->cb; - sco->meta_slots_used = xenvif_gop_skb(skb, &npo); - BUG_ON(sco->meta_slots_used > max_slots_needed); + BUG_ON(ring_slots_used > max_slots_needed); __skb_queue_tail(&rxq, skb); } - BUG_ON(npo.meta_prod > ARRAY_SIZE(vif->meta)); + 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(vif->grant_copy_op, npo.copy_prod); + gnttab_batch_copy(queue->grant_copy_op, npo.copy_prod); while ((skb = __skb_dequeue(&rxq)) != NULL) { - sco = (struct skb_cb_overlay *)skb->cb; - if ((1 << vif->meta[npo.meta_cons].gso_type) & - vif->gso_prefix_mask) { - resp = RING_GET_RESPONSE(&vif->rx, - vif->rx.rsp_prod_pvt++); + if ((1 << queue->meta[npo.meta_cons].gso_type) & + queue->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 = vif->meta[npo.meta_cons].gso_size; - resp->id = vif->meta[npo.meta_cons].id; - resp->status = sco->meta_slots_used; + 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++; - sco->meta_slots_used--; + XENVIF_RX_CB(skb)->meta_slots_used--; } - vif->dev->stats.tx_bytes += skb->len; - vif->dev->stats.tx_packets++; + queue->stats.tx_bytes += skb->len; + queue->stats.tx_packets++; - status = xenvif_check_gop(vif, sco->meta_slots_used, &npo); + status = xenvif_check_gop(queue->vif, + XENVIF_RX_CB(skb)->meta_slots_used, + &npo); - if (sco->meta_slots_used == 1) + if (XENVIF_RX_CB(skb)->meta_slots_used == 1) flags = 0; else flags = XEN_NETRXF_more_data; @@ -561,22 +697,22 @@ static void xenvif_rx_action(struct xenvif *vif) flags |= XEN_NETRXF_data_validated; offset = 0; - resp = make_rx_response(vif, vif->meta[npo.meta_cons].id, + resp = make_rx_response(queue, queue->meta[npo.meta_cons].id, status, offset, - vif->meta[npo.meta_cons].size, + queue->meta[npo.meta_cons].size, flags); - if ((1 << vif->meta[npo.meta_cons].gso_type) & - vif->gso_mask) { + if ((1 << queue->meta[npo.meta_cons].gso_type) & + queue->vif->gso_mask) { struct xen_netif_extra_info *gso = (struct xen_netif_extra_info *) - RING_GET_RESPONSE(&vif->rx, - vif->rx.rsp_prod_pvt++); + RING_GET_RESPONSE(&queue->rx, + queue->rx.rsp_prod_pvt++); resp->flags |= XEN_NETRXF_extra_info; - gso->u.gso.type = vif->meta[npo.meta_cons].gso_type; - gso->u.gso.size = vif->meta[npo.meta_cons].gso_size; + gso->u.gso.type = queue->meta[npo.meta_cons].gso_type; + gso->u.gso.size = queue->meta[npo.meta_cons].gso_size; gso->u.gso.pad = 0; gso->u.gso.features = 0; @@ -584,34 +720,34 @@ static void xenvif_rx_action(struct xenvif *vif) gso->flags = 0; } - xenvif_add_frag_responses(vif, status, - vif->meta + npo.meta_cons + 1, - sco->meta_slots_used); + 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(&vif->rx, ret); + RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->rx, ret); need_to_notify |= !!ret; - npo.meta_cons += sco->meta_slots_used; + npo.meta_cons += XENVIF_RX_CB(skb)->meta_slots_used; dev_kfree_skb(skb); } done: if (need_to_notify) - notify_remote_via_irq(vif->rx_irq); + notify_remote_via_irq(queue->rx_irq); } -void xenvif_check_rx_xenvif(struct xenvif *vif) +void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue) { int more_to_do; - RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do); + RING_FINAL_CHECK_FOR_REQUESTS(&queue->tx, more_to_do); if (more_to_do) - napi_schedule(&vif->napi); + napi_schedule(&queue->napi); } -static void tx_add_credit(struct xenvif *vif) +static void tx_add_credit(struct xenvif_queue *queue) { unsigned long max_burst, max_credit; @@ -619,51 +755,57 @@ static void tx_add_credit(struct xenvif *vif) * Allow a burst big enough to transmit a jumbo packet of up to 128kB. * Otherwise the interface can seize up due to insufficient credit. */ - max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size; + max_burst = RING_GET_REQUEST(&queue->tx, queue->tx.req_cons)->size; max_burst = min(max_burst, 131072UL); - max_burst = max(max_burst, vif->credit_bytes); + max_burst = max(max_burst, queue->credit_bytes); /* Take care that adding a new chunk of credit doesn't wrap to zero. */ - max_credit = vif->remaining_credit + vif->credit_bytes; - if (max_credit < vif->remaining_credit) + max_credit = queue->remaining_credit + queue->credit_bytes; + if (max_credit < queue->remaining_credit) max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */ - vif->remaining_credit = min(max_credit, max_burst); + queue->remaining_credit = min(max_credit, max_burst); } static void tx_credit_callback(unsigned long data) { - struct xenvif *vif = (struct xenvif *)data; - tx_add_credit(vif); - xenvif_check_rx_xenvif(vif); + struct xenvif_queue *queue = (struct xenvif_queue *)data; + tx_add_credit(queue); + xenvif_napi_schedule_or_enable_events(queue); } -static void xenvif_tx_err(struct xenvif *vif, +static void xenvif_tx_err(struct xenvif_queue *queue, struct xen_netif_tx_request *txp, RING_IDX end) { - RING_IDX cons = vif->tx.req_cons; + RING_IDX cons = queue->tx.req_cons; + unsigned long flags; do { - make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR); + spin_lock_irqsave(&queue->response_lock, flags); + make_tx_response(queue, txp, XEN_NETIF_RSP_ERROR); + spin_unlock_irqrestore(&queue->response_lock, flags); if (cons == end) break; - txp = RING_GET_REQUEST(&vif->tx, cons++); + txp = RING_GET_REQUEST(&queue->tx, cons++); } while (1); - vif->tx.req_cons = cons; + queue->tx.req_cons = cons; } static void xenvif_fatal_tx_err(struct xenvif *vif) { netdev_err(vif->dev, "fatal error; disabling device\n"); - xenvif_carrier_off(vif); + vif->disabled = true; + /* Disable the vif from queue 0's kthread */ + if (vif->queues) + xenvif_kick_thread(&vif->queues[0]); } -static int xenvif_count_requests(struct xenvif *vif, +static int xenvif_count_requests(struct xenvif_queue *queue, struct xen_netif_tx_request *first, struct xen_netif_tx_request *txp, int work_to_do) { - RING_IDX cons = vif->tx.req_cons; + RING_IDX cons = queue->tx.req_cons; int slots = 0; int drop_err = 0; int more_data; @@ -675,10 +817,10 @@ static int xenvif_count_requests(struct xenvif *vif, struct xen_netif_tx_request dropped_tx = { 0 }; if (slots >= work_to_do) { - netdev_err(vif->dev, + netdev_err(queue->vif->dev, "Asked for %d slots but exceeds this limit\n", work_to_do); - xenvif_fatal_tx_err(vif); + xenvif_fatal_tx_err(queue->vif); return -ENODATA; } @@ -686,10 +828,10 @@ static int xenvif_count_requests(struct xenvif *vif, * considered malicious. */ if (unlikely(slots >= fatal_skb_slots)) { - netdev_err(vif->dev, + netdev_err(queue->vif->dev, "Malicious frontend using %d slots, threshold %u\n", slots, fatal_skb_slots); - xenvif_fatal_tx_err(vif); + xenvif_fatal_tx_err(queue->vif); return -E2BIG; } @@ -702,7 +844,7 @@ static int xenvif_count_requests(struct xenvif *vif, */ if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) { if (net_ratelimit()) - netdev_dbg(vif->dev, + netdev_dbg(queue->vif->dev, "Too many slots (%d) exceeding limit (%d), dropping packet\n", slots, XEN_NETBK_LEGACY_SLOTS_MAX); drop_err = -E2BIG; @@ -711,7 +853,7 @@ static int xenvif_count_requests(struct xenvif *vif, if (drop_err) txp = &dropped_tx; - memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + slots), + memcpy(txp, RING_GET_REQUEST(&queue->tx, cons + slots), sizeof(*txp)); /* If the guest submitted a frame >= 64 KiB then @@ -725,7 +867,7 @@ static int xenvif_count_requests(struct xenvif *vif, */ if (!drop_err && txp->size > first->size) { if (net_ratelimit()) - netdev_dbg(vif->dev, + netdev_dbg(queue->vif->dev, "Invalid tx request, slot size %u > remaining size %u\n", txp->size, first->size); drop_err = -EIO; @@ -735,9 +877,9 @@ static int xenvif_count_requests(struct xenvif *vif, slots++; if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) { - netdev_err(vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n", + netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n", txp->offset, txp->size); - xenvif_fatal_tx_err(vif); + xenvif_fatal_tx_err(queue->vif); return -EINVAL; } @@ -749,219 +891,269 @@ static int xenvif_count_requests(struct xenvif *vif, } while (more_data); if (drop_err) { - xenvif_tx_err(vif, first, cons + slots); + xenvif_tx_err(queue, first, cons + slots); return drop_err; } return slots; } -static struct page *xenvif_alloc_page(struct xenvif *vif, - u16 pending_idx) + +struct xenvif_tx_cb { + u16 pending_idx; +}; + +#define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb) + +static inline void xenvif_tx_create_map_op(struct xenvif_queue *queue, + u16 pending_idx, + struct xen_netif_tx_request *txp, + struct gnttab_map_grant_ref *mop) { - struct page *page; + queue->pages_to_map[mop-queue->tx_map_ops] = queue->mmap_pages[pending_idx]; + gnttab_set_map_op(mop, idx_to_kaddr(queue, pending_idx), + GNTMAP_host_map | GNTMAP_readonly, + txp->gref, queue->vif->domid); + + memcpy(&queue->pending_tx_info[pending_idx].req, txp, + sizeof(*txp)); +} - page = alloc_page(GFP_ATOMIC|__GFP_COLD); - if (!page) +static inline struct sk_buff *xenvif_alloc_skb(unsigned int size) +{ + struct sk_buff *skb = + alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN, + GFP_ATOMIC | __GFP_NOWARN); + if (unlikely(skb == NULL)) return NULL; - vif->mmap_pages[pending_idx] = page; - return page; + /* Packets passed to netif_rx() must have some headroom. */ + skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN); + + /* Initialize it here to avoid later surprises */ + skb_shinfo(skb)->destructor_arg = NULL; + + return skb; } -static struct gnttab_copy *xenvif_get_requests(struct xenvif *vif, - struct sk_buff *skb, - struct xen_netif_tx_request *txp, - struct gnttab_copy *gop) +static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif_queue *queue, + struct sk_buff *skb, + struct xen_netif_tx_request *txp, + struct gnttab_map_grant_ref *gop) { struct skb_shared_info *shinfo = skb_shinfo(skb); skb_frag_t *frags = shinfo->frags; - u16 pending_idx = *((u16 *)skb->data); - u16 head_idx = 0; - int slot, start; - struct page *page; - pending_ring_idx_t index, start_idx = 0; - uint16_t dst_offset; - unsigned int nr_slots; - struct pending_tx_info *first = NULL; + u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx; + int start; + pending_ring_idx_t index; + unsigned int nr_slots, frag_overflow = 0; /* At this point shinfo->nr_frags is in fact the number of * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX. */ + if (shinfo->nr_frags > MAX_SKB_FRAGS) { + frag_overflow = shinfo->nr_frags - MAX_SKB_FRAGS; + BUG_ON(frag_overflow > MAX_SKB_FRAGS); + shinfo->nr_frags = MAX_SKB_FRAGS; + } nr_slots = shinfo->nr_frags; /* Skip first skb fragment if it is on same page as header fragment. */ start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx); - /* Coalesce tx requests, at this point the packet passed in - * should be <= 64K. Any packets larger than 64K have been - * handled in xenvif_count_requests(). - */ - for (shinfo->nr_frags = slot = start; slot < nr_slots; - shinfo->nr_frags++) { - struct pending_tx_info *pending_tx_info = - vif->pending_tx_info; - - page = alloc_page(GFP_ATOMIC|__GFP_COLD); - if (!page) - goto err; - - dst_offset = 0; - first = NULL; - while (dst_offset < PAGE_SIZE && slot < nr_slots) { - gop->flags = GNTCOPY_source_gref; - - gop->source.u.ref = txp->gref; - gop->source.domid = vif->domid; - gop->source.offset = txp->offset; - - gop->dest.domid = DOMID_SELF; - - gop->dest.offset = dst_offset; - gop->dest.u.gmfn = virt_to_mfn(page_address(page)); - - if (dst_offset + txp->size > PAGE_SIZE) { - /* This page can only merge a portion - * of tx request. Do not increment any - * pointer / counter here. The txp - * will be dealt with in future - * rounds, eventually hitting the - * `else` branch. - */ - gop->len = PAGE_SIZE - dst_offset; - txp->offset += gop->len; - txp->size -= gop->len; - dst_offset += gop->len; /* quit loop */ - } else { - /* This tx request can be merged in the page */ - gop->len = txp->size; - dst_offset += gop->len; - - index = pending_index(vif->pending_cons++); - - pending_idx = vif->pending_ring[index]; + for (shinfo->nr_frags = start; shinfo->nr_frags < nr_slots; + shinfo->nr_frags++, txp++, gop++) { + index = pending_index(queue->pending_cons++); + pending_idx = queue->pending_ring[index]; + xenvif_tx_create_map_op(queue, pending_idx, txp, gop); + frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx); + } - memcpy(&pending_tx_info[pending_idx].req, txp, - sizeof(*txp)); + if (frag_overflow) { + struct sk_buff *nskb = xenvif_alloc_skb(0); + if (unlikely(nskb == NULL)) { + if (net_ratelimit()) + netdev_err(queue->vif->dev, + "Can't allocate the frag_list skb.\n"); + return NULL; + } - /* Poison these fields, corresponding - * fields for head tx req will be set - * to correct values after the loop. - */ - vif->mmap_pages[pending_idx] = (void *)(~0UL); - pending_tx_info[pending_idx].head = - INVALID_PENDING_RING_IDX; - - if (!first) { - first = &pending_tx_info[pending_idx]; - start_idx = index; - head_idx = pending_idx; - } - - txp++; - slot++; - } + shinfo = skb_shinfo(nskb); + frags = shinfo->frags; - gop++; + for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow; + shinfo->nr_frags++, txp++, gop++) { + index = pending_index(queue->pending_cons++); + pending_idx = queue->pending_ring[index]; + xenvif_tx_create_map_op(queue, pending_idx, txp, gop); + frag_set_pending_idx(&frags[shinfo->nr_frags], + pending_idx); } - first->req.offset = 0; - first->req.size = dst_offset; - first->head = start_idx; - vif->mmap_pages[head_idx] = page; - frag_set_pending_idx(&frags[shinfo->nr_frags], head_idx); + skb_shinfo(skb)->frag_list = nskb; } - BUG_ON(shinfo->nr_frags > MAX_SKB_FRAGS); - return gop; -err: - /* Unwind, freeing all pages and sending error responses. */ - while (shinfo->nr_frags-- > start) { - xenvif_idx_release(vif, - frag_get_pending_idx(&frags[shinfo->nr_frags]), - XEN_NETIF_RSP_ERROR); +} + +static inline void xenvif_grant_handle_set(struct xenvif_queue *queue, + u16 pending_idx, + grant_handle_t handle) +{ + if (unlikely(queue->grant_tx_handle[pending_idx] != + NETBACK_INVALID_HANDLE)) { + netdev_err(queue->vif->dev, + "Trying to overwrite active handle! pending_idx: %x\n", + pending_idx); + BUG(); } - /* The head too, if necessary. */ - if (start) - xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR); + queue->grant_tx_handle[pending_idx] = handle; +} - return NULL; +static inline void xenvif_grant_handle_reset(struct xenvif_queue *queue, + u16 pending_idx) +{ + if (unlikely(queue->grant_tx_handle[pending_idx] == + NETBACK_INVALID_HANDLE)) { + netdev_err(queue->vif->dev, + "Trying to unmap invalid handle! pending_idx: %x\n", + pending_idx); + BUG(); + } + queue->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE; } -static int xenvif_tx_check_gop(struct xenvif *vif, +static int xenvif_tx_check_gop(struct xenvif_queue *queue, struct sk_buff *skb, - struct gnttab_copy **gopp) + struct gnttab_map_grant_ref **gopp_map, + struct gnttab_copy **gopp_copy) { - struct gnttab_copy *gop = *gopp; - u16 pending_idx = *((u16 *)skb->data); + struct gnttab_map_grant_ref *gop_map = *gopp_map; + u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx; + /* This always points to the shinfo of the skb being checked, which + * could be either the first or the one on the frag_list + */ struct skb_shared_info *shinfo = skb_shinfo(skb); - struct pending_tx_info *tx_info; + /* If this is non-NULL, we are currently checking the frag_list skb, and + * this points to the shinfo of the first one + */ + struct skb_shared_info *first_shinfo = NULL; int nr_frags = shinfo->nr_frags; - int i, err, start; - u16 peek; /* peek into next tx request */ + const bool sharedslot = nr_frags && + frag_get_pending_idx(&shinfo->frags[0]) == pending_idx; + int i, err; /* Check status of header. */ - err = gop->status; - if (unlikely(err)) - xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR); - - /* Skip first skb fragment if it is on same page as header fragment. */ - start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx); + err = (*gopp_copy)->status; + if (unlikely(err)) { + if (net_ratelimit()) + netdev_dbg(queue->vif->dev, + "Grant copy of header failed! status: %d pending_idx: %u ref: %u\n", + (*gopp_copy)->status, + pending_idx, + (*gopp_copy)->source.u.ref); + /* The first frag might still have this slot mapped */ + if (!sharedslot) + xenvif_idx_release(queue, pending_idx, + XEN_NETIF_RSP_ERROR); + } + (*gopp_copy)++; - for (i = start; i < nr_frags; i++) { +check_frags: + for (i = 0; i < nr_frags; i++, gop_map++) { int j, newerr; - pending_ring_idx_t head; pending_idx = frag_get_pending_idx(&shinfo->frags[i]); - tx_info = &vif->pending_tx_info[pending_idx]; - head = tx_info->head; /* Check error status: if okay then remember grant handle. */ - do { - newerr = (++gop)->status; - if (newerr) - break; - peek = vif->pending_ring[pending_index(++head)]; - } while (!pending_tx_is_head(vif, peek)); + newerr = gop_map->status; if (likely(!newerr)) { + xenvif_grant_handle_set(queue, + pending_idx, + gop_map->handle); /* Had a previous error? Invalidate this fragment. */ - if (unlikely(err)) - xenvif_idx_release(vif, pending_idx, - XEN_NETIF_RSP_OKAY); + if (unlikely(err)) { + xenvif_idx_unmap(queue, pending_idx); + /* If the mapping of the first frag was OK, but + * the header's copy failed, and they are + * sharing a slot, send an error + */ + if (i == 0 && sharedslot) + xenvif_idx_release(queue, pending_idx, + XEN_NETIF_RSP_ERROR); + else + xenvif_idx_release(queue, pending_idx, + XEN_NETIF_RSP_OKAY); + } continue; } /* Error on this fragment: respond to client with an error. */ - xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR); + if (net_ratelimit()) + netdev_dbg(queue->vif->dev, + "Grant map of %d. frag failed! status: %d pending_idx: %u ref: %u\n", + i, + gop_map->status, + pending_idx, + gop_map->ref); + + xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR); /* Not the first error? Preceding frags already invalidated. */ if (err) continue; - /* First error: invalidate header and preceding fragments. */ - pending_idx = *((u16 *)skb->data); - xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY); - for (j = start; j < i; j++) { + /* First error: if the header haven't shared a slot with the + * first frag, release it as well. + */ + if (!sharedslot) + xenvif_idx_release(queue, + XENVIF_TX_CB(skb)->pending_idx, + XEN_NETIF_RSP_OKAY); + + /* Invalidate preceding fragments of this skb. */ + for (j = 0; j < i; j++) { pending_idx = frag_get_pending_idx(&shinfo->frags[j]); - xenvif_idx_release(vif, pending_idx, + xenvif_idx_unmap(queue, pending_idx); + xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_OKAY); } + /* And if we found the error while checking the frag_list, unmap + * the first skb's frags + */ + if (first_shinfo) { + for (j = 0; j < first_shinfo->nr_frags; j++) { + pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]); + xenvif_idx_unmap(queue, pending_idx); + xenvif_idx_release(queue, pending_idx, + XEN_NETIF_RSP_OKAY); + } + } + /* Remember the error: invalidate all subsequent fragments. */ err = newerr; } - *gopp = gop + 1; + if (skb_has_frag_list(skb) && !first_shinfo) { + first_shinfo = skb_shinfo(skb); + shinfo = skb_shinfo(skb_shinfo(skb)->frag_list); + nr_frags = shinfo->nr_frags; + + goto check_frags; + } + + *gopp_map = gop_map; return err; } -static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb) +static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb) { struct skb_shared_info *shinfo = skb_shinfo(skb); int nr_frags = shinfo->nr_frags; int i; + u16 prev_pending_idx = INVALID_PENDING_IDX; for (i = 0; i < nr_frags; i++) { skb_frag_t *frag = shinfo->frags + i; @@ -971,46 +1163,62 @@ static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb) pending_idx = frag_get_pending_idx(frag); - txp = &vif->pending_tx_info[pending_idx].req; - page = virt_to_page(idx_to_kaddr(vif, pending_idx)); + /* If this is not the first frag, chain it to the previous*/ + if (prev_pending_idx == INVALID_PENDING_IDX) + skb_shinfo(skb)->destructor_arg = + &callback_param(queue, pending_idx); + else + callback_param(queue, prev_pending_idx).ctx = + &callback_param(queue, pending_idx); + + callback_param(queue, pending_idx).ctx = NULL; + prev_pending_idx = pending_idx; + + txp = &queue->pending_tx_info[pending_idx].req; + page = virt_to_page(idx_to_kaddr(queue, pending_idx)); __skb_fill_page_desc(skb, i, page, txp->offset, txp->size); skb->len += txp->size; skb->data_len += txp->size; skb->truesize += txp->size; - /* Take an extra reference to offset xenvif_idx_release */ - get_page(vif->mmap_pages[pending_idx]); - xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY); + /* Take an extra reference to offset network stack's put_page */ + get_page(queue->mmap_pages[pending_idx]); } + /* FIXME: __skb_fill_page_desc set this to true because page->pfmemalloc + * overlaps with "index", and "mapping" is not set. I think mapping + * should be set. If delivered to local stack, it would drop this + * skb in sk_filter unless the socket has the right to use it. + */ + skb->pfmemalloc = false; } -static int xenvif_get_extras(struct xenvif *vif, +static int xenvif_get_extras(struct xenvif_queue *queue, struct xen_netif_extra_info *extras, int work_to_do) { struct xen_netif_extra_info extra; - RING_IDX cons = vif->tx.req_cons; + RING_IDX cons = queue->tx.req_cons; do { if (unlikely(work_to_do-- <= 0)) { - netdev_err(vif->dev, "Missing extra info\n"); - xenvif_fatal_tx_err(vif); + netdev_err(queue->vif->dev, "Missing extra info\n"); + xenvif_fatal_tx_err(queue->vif); return -EBADR; } - memcpy(&extra, RING_GET_REQUEST(&vif->tx, cons), + memcpy(&extra, RING_GET_REQUEST(&queue->tx, cons), sizeof(extra)); if (unlikely(!extra.type || extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) { - vif->tx.req_cons = ++cons; - netdev_err(vif->dev, + queue->tx.req_cons = ++cons; + netdev_err(queue->vif->dev, "Invalid extra type: %d\n", extra.type); - xenvif_fatal_tx_err(vif); + xenvif_fatal_tx_err(queue->vif); return -EINVAL; } memcpy(&extras[extra.type - 1], &extra, sizeof(extra)); - vif->tx.req_cons = ++cons; + queue->tx.req_cons = ++cons; } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE); return work_to_do; @@ -1045,7 +1253,7 @@ static int xenvif_set_skb_gso(struct xenvif *vif, return 0; } -static int checksum_setup(struct xenvif *vif, struct sk_buff *skb) +static int checksum_setup(struct xenvif_queue *queue, struct sk_buff *skb) { bool recalculate_partial_csum = false; @@ -1055,7 +1263,7 @@ static int checksum_setup(struct xenvif *vif, struct sk_buff *skb) * recalculate the partial checksum. */ if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { - vif->rx_gso_checksum_fixup++; + queue->stats.rx_gso_checksum_fixup++; skb->ip_summed = CHECKSUM_PARTIAL; recalculate_partial_csum = true; } @@ -1067,31 +1275,31 @@ static int checksum_setup(struct xenvif *vif, struct sk_buff *skb) return skb_checksum_setup(skb, recalculate_partial_csum); } -static bool tx_credit_exceeded(struct xenvif *vif, unsigned size) +static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size) { u64 now = get_jiffies_64(); - u64 next_credit = vif->credit_window_start + - msecs_to_jiffies(vif->credit_usec / 1000); + u64 next_credit = queue->credit_window_start + + msecs_to_jiffies(queue->credit_usec / 1000); /* Timer could already be pending in rare cases. */ - if (timer_pending(&vif->credit_timeout)) + if (timer_pending(&queue->credit_timeout)) return true; /* Passed the point where we can replenish credit? */ if (time_after_eq64(now, next_credit)) { - vif->credit_window_start = now; - tx_add_credit(vif); + queue->credit_window_start = now; + tx_add_credit(queue); } /* Still too big to send right now? Set a callback. */ - if (size > vif->remaining_credit) { - vif->credit_timeout.data = - (unsigned long)vif; - vif->credit_timeout.function = + if (size > queue->remaining_credit) { + queue->credit_timeout.data = + (unsigned long)queue; + queue->credit_timeout.function = tx_credit_callback; - mod_timer(&vif->credit_timeout, + mod_timer(&queue->credit_timeout, next_credit); - vif->credit_window_start = next_credit; + queue->credit_window_start = next_credit; return true; } @@ -1099,18 +1307,18 @@ static bool tx_credit_exceeded(struct xenvif *vif, unsigned size) return false; } -static unsigned xenvif_tx_build_gops(struct xenvif *vif, int budget) +static void xenvif_tx_build_gops(struct xenvif_queue *queue, + int budget, + unsigned *copy_ops, + unsigned *map_ops) { - struct gnttab_copy *gop = vif->tx_copy_ops, *request_gop; + struct gnttab_map_grant_ref *gop = queue->tx_map_ops, *request_gop; struct sk_buff *skb; int ret; - while ((nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX - < MAX_PENDING_REQS) && - (skb_queue_len(&vif->tx_queue) < budget)) { + while (skb_queue_len(&queue->tx_queue) < budget) { struct xen_netif_tx_request txreq; struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX]; - struct page *page; struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1]; u16 pending_idx; RING_IDX idx; @@ -1118,190 +1326,254 @@ static unsigned xenvif_tx_build_gops(struct xenvif *vif, int budget) unsigned int data_len; pending_ring_idx_t index; - if (vif->tx.sring->req_prod - vif->tx.req_cons > + if (queue->tx.sring->req_prod - queue->tx.req_cons > XEN_NETIF_TX_RING_SIZE) { - netdev_err(vif->dev, + netdev_err(queue->vif->dev, "Impossible number of requests. " "req_prod %d, req_cons %d, size %ld\n", - vif->tx.sring->req_prod, vif->tx.req_cons, + queue->tx.sring->req_prod, queue->tx.req_cons, XEN_NETIF_TX_RING_SIZE); - xenvif_fatal_tx_err(vif); - continue; + xenvif_fatal_tx_err(queue->vif); + break; } - work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&vif->tx); + work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx); if (!work_to_do) break; - idx = vif->tx.req_cons; + idx = queue->tx.req_cons; rmb(); /* Ensure that we see the request before we copy it. */ - memcpy(&txreq, RING_GET_REQUEST(&vif->tx, idx), sizeof(txreq)); + memcpy(&txreq, RING_GET_REQUEST(&queue->tx, idx), sizeof(txreq)); /* Credit-based scheduling. */ - if (txreq.size > vif->remaining_credit && - tx_credit_exceeded(vif, txreq.size)) + if (txreq.size > queue->remaining_credit && + tx_credit_exceeded(queue, txreq.size)) break; - vif->remaining_credit -= txreq.size; + queue->remaining_credit -= txreq.size; work_to_do--; - vif->tx.req_cons = ++idx; + queue->tx.req_cons = ++idx; memset(extras, 0, sizeof(extras)); if (txreq.flags & XEN_NETTXF_extra_info) { - work_to_do = xenvif_get_extras(vif, extras, + work_to_do = xenvif_get_extras(queue, extras, work_to_do); - idx = vif->tx.req_cons; + idx = queue->tx.req_cons; if (unlikely(work_to_do < 0)) break; } - ret = xenvif_count_requests(vif, &txreq, txfrags, work_to_do); + ret = xenvif_count_requests(queue, &txreq, txfrags, work_to_do); if (unlikely(ret < 0)) break; idx += ret; if (unlikely(txreq.size < ETH_HLEN)) { - netdev_dbg(vif->dev, + netdev_dbg(queue->vif->dev, "Bad packet size: %d\n", txreq.size); - xenvif_tx_err(vif, &txreq, idx); + xenvif_tx_err(queue, &txreq, idx); break; } /* No crossing a page as the payload mustn't fragment. */ if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) { - netdev_err(vif->dev, + netdev_err(queue->vif->dev, "txreq.offset: %x, size: %u, end: %lu\n", txreq.offset, txreq.size, (txreq.offset&~PAGE_MASK) + txreq.size); - xenvif_fatal_tx_err(vif); + xenvif_fatal_tx_err(queue->vif); break; } - index = pending_index(vif->pending_cons); - pending_idx = vif->pending_ring[index]; + index = pending_index(queue->pending_cons); + pending_idx = queue->pending_ring[index]; data_len = (txreq.size > PKT_PROT_LEN && ret < XEN_NETBK_LEGACY_SLOTS_MAX) ? PKT_PROT_LEN : txreq.size; - skb = alloc_skb(data_len + NET_SKB_PAD + NET_IP_ALIGN, - GFP_ATOMIC | __GFP_NOWARN); + skb = xenvif_alloc_skb(data_len); if (unlikely(skb == NULL)) { - netdev_dbg(vif->dev, + netdev_dbg(queue->vif->dev, "Can't allocate a skb in start_xmit.\n"); - xenvif_tx_err(vif, &txreq, idx); + xenvif_tx_err(queue, &txreq, idx); break; } - /* Packets passed to netif_rx() must have some headroom. */ - skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN); - if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { struct xen_netif_extra_info *gso; gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; - if (xenvif_set_skb_gso(vif, skb, gso)) { + if (xenvif_set_skb_gso(queue->vif, skb, gso)) { /* Failure in xenvif_set_skb_gso is fatal. */ kfree_skb(skb); break; } } - /* XXX could copy straight to head */ - page = xenvif_alloc_page(vif, pending_idx); - if (!page) { - kfree_skb(skb); - xenvif_tx_err(vif, &txreq, idx); - break; - } - - gop->source.u.ref = txreq.gref; - gop->source.domid = vif->domid; - gop->source.offset = txreq.offset; + XENVIF_TX_CB(skb)->pending_idx = pending_idx; - gop->dest.u.gmfn = virt_to_mfn(page_address(page)); - gop->dest.domid = DOMID_SELF; - gop->dest.offset = txreq.offset; + __skb_put(skb, data_len); + queue->tx_copy_ops[*copy_ops].source.u.ref = txreq.gref; + queue->tx_copy_ops[*copy_ops].source.domid = queue->vif->domid; + queue->tx_copy_ops[*copy_ops].source.offset = txreq.offset; - gop->len = txreq.size; - gop->flags = GNTCOPY_source_gref; + queue->tx_copy_ops[*copy_ops].dest.u.gmfn = + virt_to_mfn(skb->data); + queue->tx_copy_ops[*copy_ops].dest.domid = DOMID_SELF; + queue->tx_copy_ops[*copy_ops].dest.offset = + offset_in_page(skb->data); - gop++; + queue->tx_copy_ops[*copy_ops].len = data_len; + queue->tx_copy_ops[*copy_ops].flags = GNTCOPY_source_gref; - memcpy(&vif->pending_tx_info[pending_idx].req, - &txreq, sizeof(txreq)); - vif->pending_tx_info[pending_idx].head = index; - *((u16 *)skb->data) = pending_idx; - - __skb_put(skb, data_len); + (*copy_ops)++; skb_shinfo(skb)->nr_frags = ret; if (data_len < txreq.size) { skb_shinfo(skb)->nr_frags++; frag_set_pending_idx(&skb_shinfo(skb)->frags[0], pending_idx); + xenvif_tx_create_map_op(queue, pending_idx, &txreq, gop); + gop++; } else { frag_set_pending_idx(&skb_shinfo(skb)->frags[0], INVALID_PENDING_IDX); + memcpy(&queue->pending_tx_info[pending_idx].req, &txreq, + sizeof(txreq)); } - vif->pending_cons++; + queue->pending_cons++; - request_gop = xenvif_get_requests(vif, skb, txfrags, gop); + request_gop = xenvif_get_requests(queue, skb, txfrags, gop); if (request_gop == NULL) { kfree_skb(skb); - xenvif_tx_err(vif, &txreq, idx); + xenvif_tx_err(queue, &txreq, idx); break; } gop = request_gop; - __skb_queue_tail(&vif->tx_queue, skb); + __skb_queue_tail(&queue->tx_queue, skb); - vif->tx.req_cons = idx; + queue->tx.req_cons = idx; - if ((gop-vif->tx_copy_ops) >= ARRAY_SIZE(vif->tx_copy_ops)) + if (((gop-queue->tx_map_ops) >= ARRAY_SIZE(queue->tx_map_ops)) || + (*copy_ops >= ARRAY_SIZE(queue->tx_copy_ops))) break; } - return gop - vif->tx_copy_ops; + (*map_ops) = gop - queue->tx_map_ops; + return; } +/* Consolidate skb with a frag_list into a brand new one with local pages on + * frags. Returns 0 or -ENOMEM if can't allocate new pages. + */ +static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *skb) +{ + unsigned int offset = skb_headlen(skb); + skb_frag_t frags[MAX_SKB_FRAGS]; + int i; + struct ubuf_info *uarg; + struct sk_buff *nskb = skb_shinfo(skb)->frag_list; + + queue->stats.tx_zerocopy_sent += 2; + queue->stats.tx_frag_overflow++; + + xenvif_fill_frags(queue, nskb); + /* Subtract frags size, we will correct it later */ + skb->truesize -= skb->data_len; + skb->len += nskb->len; + skb->data_len += nskb->len; -static int xenvif_tx_submit(struct xenvif *vif) + /* create a brand new frags array and coalesce there */ + for (i = 0; offset < skb->len; i++) { + struct page *page; + unsigned int len; + + BUG_ON(i >= MAX_SKB_FRAGS); + page = alloc_page(GFP_ATOMIC|__GFP_COLD); + if (!page) { + int j; + skb->truesize += skb->data_len; + for (j = 0; j < i; j++) + put_page(frags[j].page.p); + return -ENOMEM; + } + + if (offset + PAGE_SIZE < skb->len) + len = PAGE_SIZE; + else + len = skb->len - offset; + if (skb_copy_bits(skb, offset, page_address(page), len)) + BUG(); + + offset += len; + frags[i].page.p = page; + frags[i].page_offset = 0; + skb_frag_size_set(&frags[i], len); + } + /* swap out with old one */ + memcpy(skb_shinfo(skb)->frags, + frags, + i * sizeof(skb_frag_t)); + skb_shinfo(skb)->nr_frags = i; + skb->truesize += i * PAGE_SIZE; + + /* remove traces of mapped pages and frag_list */ + skb_frag_list_init(skb); + uarg = skb_shinfo(skb)->destructor_arg; + uarg->callback(uarg, true); + skb_shinfo(skb)->destructor_arg = NULL; + + skb_shinfo(nskb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + kfree_skb(nskb); + + return 0; +} + +static int xenvif_tx_submit(struct xenvif_queue *queue) { - struct gnttab_copy *gop = vif->tx_copy_ops; + struct gnttab_map_grant_ref *gop_map = queue->tx_map_ops; + struct gnttab_copy *gop_copy = queue->tx_copy_ops; struct sk_buff *skb; int work_done = 0; - while ((skb = __skb_dequeue(&vif->tx_queue)) != NULL) { + while ((skb = __skb_dequeue(&queue->tx_queue)) != NULL) { struct xen_netif_tx_request *txp; u16 pending_idx; unsigned data_len; - pending_idx = *((u16 *)skb->data); - txp = &vif->pending_tx_info[pending_idx].req; + pending_idx = XENVIF_TX_CB(skb)->pending_idx; + txp = &queue->pending_tx_info[pending_idx].req; /* Check the remap error code. */ - if (unlikely(xenvif_tx_check_gop(vif, skb, &gop))) { - netdev_dbg(vif->dev, "netback grant failed.\n"); + if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) { + /* If there was an error, xenvif_tx_check_gop is + * expected to release all the frags which were mapped, + * so kfree_skb shouldn't do it again + */ skb_shinfo(skb)->nr_frags = 0; + if (skb_has_frag_list(skb)) { + struct sk_buff *nskb = + skb_shinfo(skb)->frag_list; + skb_shinfo(nskb)->nr_frags = 0; + } kfree_skb(skb); continue; } data_len = skb->len; - memcpy(skb->data, - (void *)(idx_to_kaddr(vif, pending_idx)|txp->offset), - data_len); + callback_param(queue, pending_idx).ctx = NULL; if (data_len < txp->size) { /* Append the packet payload as a fragment. */ txp->offset += data_len; txp->size -= data_len; } else { /* Schedule a response immediately. */ - xenvif_idx_release(vif, pending_idx, + xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_OKAY); } @@ -1310,20 +1582,34 @@ static int xenvif_tx_submit(struct xenvif *vif) else if (txp->flags & XEN_NETTXF_data_validated) skb->ip_summed = CHECKSUM_UNNECESSARY; - xenvif_fill_frags(vif, skb); + xenvif_fill_frags(queue, skb); + + if (unlikely(skb_has_frag_list(skb))) { + if (xenvif_handle_frag_list(queue, skb)) { + if (net_ratelimit()) + netdev_err(queue->vif->dev, + "Not enough memory to consolidate frag_list!\n"); + skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + kfree_skb(skb); + continue; + } + } if (skb_is_nonlinear(skb) && skb_headlen(skb) < PKT_PROT_LEN) { int target = min_t(int, skb->len, PKT_PROT_LEN); __pskb_pull_tail(skb, target - skb_headlen(skb)); } - skb->dev = vif->dev; + skb->dev = queue->vif->dev; skb->protocol = eth_type_trans(skb, skb->dev); skb_reset_network_header(skb); - if (checksum_setup(vif, skb)) { - netdev_dbg(vif->dev, + if (checksum_setup(queue, skb)) { + netdev_dbg(queue->vif->dev, "Can't setup checksum in net_tx_action\n"); + /* We have to set this flag to trigger the callback */ + if (skb_shinfo(skb)->destructor_arg) + skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; kfree_skb(skb); continue; } @@ -1344,116 +1630,205 @@ static int xenvif_tx_submit(struct xenvif *vif) DIV_ROUND_UP(skb->len - hdrlen, mss); } - vif->dev->stats.rx_bytes += skb->len; - vif->dev->stats.rx_packets++; + queue->stats.rx_bytes += skb->len; + queue->stats.rx_packets++; work_done++; + /* Set this flag right before netif_receive_skb, otherwise + * someone might think this packet already left netback, and + * do a skb_copy_ubufs while we are still in control of the + * skb. E.g. the __pskb_pull_tail earlier can do such thing. + */ + if (skb_shinfo(skb)->destructor_arg) { + skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + queue->stats.tx_zerocopy_sent++; + } + netif_receive_skb(skb); } return work_done; } -/* Called after netfront has transmitted */ -int xenvif_tx_action(struct xenvif *vif, int budget) +void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success) { - unsigned nr_gops; - int work_done; - - if (unlikely(!tx_work_todo(vif))) - return 0; - - nr_gops = xenvif_tx_build_gops(vif, budget); - - if (nr_gops == 0) - return 0; - - gnttab_batch_copy(vif->tx_copy_ops, nr_gops); - - work_done = xenvif_tx_submit(vif); + unsigned long flags; + pending_ring_idx_t index; + struct xenvif_queue *queue = ubuf_to_queue(ubuf); - return work_done; + /* This is the only place where we grab this lock, to protect callbacks + * from each other. + */ + spin_lock_irqsave(&queue->callback_lock, flags); + do { + u16 pending_idx = ubuf->desc; + ubuf = (struct ubuf_info *) ubuf->ctx; + BUG_ON(queue->dealloc_prod - queue->dealloc_cons >= + MAX_PENDING_REQS); + index = pending_index(queue->dealloc_prod); + queue->dealloc_ring[index] = pending_idx; + /* Sync with xenvif_tx_dealloc_action: + * insert idx then incr producer. + */ + smp_wmb(); + queue->dealloc_prod++; + } while (ubuf); + wake_up(&queue->dealloc_wq); + spin_unlock_irqrestore(&queue->callback_lock, flags); + + if (likely(zerocopy_success)) + queue->stats.tx_zerocopy_success++; + else + queue->stats.tx_zerocopy_fail++; } -static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx, - u8 status) +static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue) { - struct pending_tx_info *pending_tx_info; - pending_ring_idx_t head; - u16 peek; /* peek into next tx request */ + struct gnttab_unmap_grant_ref *gop; + pending_ring_idx_t dc, dp; + u16 pending_idx, pending_idx_release[MAX_PENDING_REQS]; + unsigned int i = 0; - BUG_ON(vif->mmap_pages[pending_idx] == (void *)(~0UL)); + dc = queue->dealloc_cons; + gop = queue->tx_unmap_ops; - /* Already complete? */ - if (vif->mmap_pages[pending_idx] == NULL) - return; + /* Free up any grants we have finished using */ + do { + dp = queue->dealloc_prod; + + /* Ensure we see all indices enqueued by all + * xenvif_zerocopy_callback(). + */ + smp_rmb(); + + while (dc != dp) { + BUG_ON(gop - queue->tx_unmap_ops > MAX_PENDING_REQS); + pending_idx = + queue->dealloc_ring[pending_index(dc++)]; + + pending_idx_release[gop-queue->tx_unmap_ops] = + pending_idx; + queue->pages_to_unmap[gop-queue->tx_unmap_ops] = + queue->mmap_pages[pending_idx]; + gnttab_set_unmap_op(gop, + idx_to_kaddr(queue, pending_idx), + GNTMAP_host_map, + queue->grant_tx_handle[pending_idx]); + xenvif_grant_handle_reset(queue, pending_idx); + ++gop; + } + + } while (dp != queue->dealloc_prod); + + queue->dealloc_cons = dc; + + if (gop - queue->tx_unmap_ops > 0) { + int ret; + ret = gnttab_unmap_refs(queue->tx_unmap_ops, + NULL, + queue->pages_to_unmap, + gop - queue->tx_unmap_ops); + if (ret) { + netdev_err(queue->vif->dev, "Unmap fail: nr_ops %tx ret %d\n", + gop - queue->tx_unmap_ops, ret); + for (i = 0; i < gop - queue->tx_unmap_ops; ++i) { + if (gop[i].status != GNTST_okay) + netdev_err(queue->vif->dev, + " host_addr: %llx handle: %x status: %d\n", + gop[i].host_addr, + gop[i].handle, + gop[i].status); + } + BUG(); + } + } - pending_tx_info = &vif->pending_tx_info[pending_idx]; + for (i = 0; i < gop - queue->tx_unmap_ops; ++i) + xenvif_idx_release(queue, pending_idx_release[i], + XEN_NETIF_RSP_OKAY); +} - head = pending_tx_info->head; - BUG_ON(!pending_tx_is_head(vif, head)); - BUG_ON(vif->pending_ring[pending_index(head)] != pending_idx); +/* Called after netfront has transmitted */ +int xenvif_tx_action(struct xenvif_queue *queue, int budget) +{ + unsigned nr_mops, nr_cops = 0; + int work_done, ret; - do { - pending_ring_idx_t index; - pending_ring_idx_t idx = pending_index(head); - u16 info_idx = vif->pending_ring[idx]; + if (unlikely(!tx_work_todo(queue))) + return 0; - pending_tx_info = &vif->pending_tx_info[info_idx]; - make_tx_response(vif, &pending_tx_info->req, status); + xenvif_tx_build_gops(queue, budget, &nr_cops, &nr_mops); - /* Setting any number other than - * INVALID_PENDING_RING_IDX indicates this slot is - * starting a new packet / ending a previous packet. - */ - pending_tx_info->head = 0; + if (nr_cops == 0) + return 0; - index = pending_index(vif->pending_prod++); - vif->pending_ring[index] = vif->pending_ring[info_idx]; + gnttab_batch_copy(queue->tx_copy_ops, nr_cops); + if (nr_mops != 0) { + ret = gnttab_map_refs(queue->tx_map_ops, + NULL, + queue->pages_to_map, + nr_mops); + BUG_ON(ret); + } - peek = vif->pending_ring[pending_index(++head)]; + work_done = xenvif_tx_submit(queue); - } while (!pending_tx_is_head(vif, peek)); + return work_done; +} - put_page(vif->mmap_pages[pending_idx]); - vif->mmap_pages[pending_idx] = NULL; +static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx, + u8 status) +{ + struct pending_tx_info *pending_tx_info; + pending_ring_idx_t index; + unsigned long flags; + + pending_tx_info = &queue->pending_tx_info[pending_idx]; + spin_lock_irqsave(&queue->response_lock, flags); + make_tx_response(queue, &pending_tx_info->req, status); + index = pending_index(queue->pending_prod); + queue->pending_ring[index] = pending_idx; + /* TX shouldn't use the index before we give it back here */ + mb(); + queue->pending_prod++; + spin_unlock_irqrestore(&queue->response_lock, flags); } -static void make_tx_response(struct xenvif *vif, +static void make_tx_response(struct xenvif_queue *queue, struct xen_netif_tx_request *txp, s8 st) { - RING_IDX i = vif->tx.rsp_prod_pvt; + RING_IDX i = queue->tx.rsp_prod_pvt; struct xen_netif_tx_response *resp; int notify; - resp = RING_GET_RESPONSE(&vif->tx, i); + resp = RING_GET_RESPONSE(&queue->tx, i); resp->id = txp->id; resp->status = st; if (txp->flags & XEN_NETTXF_extra_info) - RING_GET_RESPONSE(&vif->tx, ++i)->status = XEN_NETIF_RSP_NULL; + RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL; - vif->tx.rsp_prod_pvt = ++i; - RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify); + queue->tx.rsp_prod_pvt = ++i; + RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify); if (notify) - notify_remote_via_irq(vif->tx_irq); + notify_remote_via_irq(queue->tx_irq); } -static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif, +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 = vif->rx.rsp_prod_pvt; + RING_IDX i = queue->rx.rsp_prod_pvt; struct xen_netif_rx_response *resp; - resp = RING_GET_RESPONSE(&vif->rx, i); + resp = RING_GET_RESPONSE(&queue->rx, i); resp->offset = offset; resp->flags = flags; resp->id = id; @@ -1461,39 +1836,66 @@ static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif, if (st < 0) resp->status = (s16)st; - vif->rx.rsp_prod_pvt = ++i; + queue->rx.rsp_prod_pvt = ++i; return resp; } -static inline int rx_work_todo(struct xenvif *vif) +void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx) { - return !skb_queue_empty(&vif->rx_queue) && - xenvif_rx_ring_slots_available(vif, vif->rx_last_skb_slots); + int ret; + struct gnttab_unmap_grant_ref tx_unmap_op; + + gnttab_set_unmap_op(&tx_unmap_op, + idx_to_kaddr(queue, pending_idx), + GNTMAP_host_map, + queue->grant_tx_handle[pending_idx]); + xenvif_grant_handle_reset(queue, pending_idx); + + ret = gnttab_unmap_refs(&tx_unmap_op, NULL, + &queue->mmap_pages[pending_idx], 1); + if (ret) { + netdev_err(queue->vif->dev, + "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: %x status: %d\n", + ret, + pending_idx, + tx_unmap_op.host_addr, + tx_unmap_op.handle, + tx_unmap_op.status); + BUG(); + } } -static inline int tx_work_todo(struct xenvif *vif) +static inline int rx_work_todo(struct xenvif_queue *queue) { + return (!skb_queue_empty(&queue->rx_queue) && + xenvif_rx_ring_slots_available(queue, queue->rx_last_skb_slots)); +} - if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->tx)) && - (nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX - < MAX_PENDING_REQS)) +static inline int tx_work_todo(struct xenvif_queue *queue) +{ + if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))) return 1; return 0; } -void xenvif_unmap_frontend_rings(struct xenvif *vif) +static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue) { - if (vif->tx.sring) - xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif), - vif->tx.sring); - if (vif->rx.sring) - xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif), - vif->rx.sring); + return queue->dealloc_cons != queue->dealloc_prod; } -int xenvif_map_frontend_rings(struct xenvif *vif, +void xenvif_unmap_frontend_rings(struct xenvif_queue *queue) +{ + if (queue->tx.sring) + xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif), + queue->tx.sring); + if (queue->rx.sring) + xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif), + queue->rx.sring); +} + +int xenvif_map_frontend_rings(struct xenvif_queue *queue, grant_ref_t tx_ring_ref, grant_ref_t rx_ring_ref) { @@ -1503,72 +1905,175 @@ int xenvif_map_frontend_rings(struct xenvif *vif, int err = -ENOMEM; - err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif), + err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif), tx_ring_ref, &addr); if (err) goto err; txs = (struct xen_netif_tx_sring *)addr; - BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE); + BACK_RING_INIT(&queue->tx, txs, PAGE_SIZE); - err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif), + err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif), rx_ring_ref, &addr); if (err) goto err; rxs = (struct xen_netif_rx_sring *)addr; - BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE); + BACK_RING_INIT(&queue->rx, rxs, PAGE_SIZE); return 0; err: - xenvif_unmap_frontend_rings(vif); + xenvif_unmap_frontend_rings(queue); return err; } -void xenvif_stop_queue(struct xenvif *vif) +static void xenvif_start_queue(struct xenvif_queue *queue) { - if (!vif->can_queue) - return; - - netif_stop_queue(vif->dev); + if (xenvif_schedulable(queue->vif)) + xenvif_wake_queue(queue); } -static void xenvif_start_queue(struct xenvif *vif) +/* Only called from the queue's thread, it handles the situation when the guest + * doesn't post enough requests on the receiving ring. + * First xenvif_start_xmit disables QDisc and start a timer, and then either the + * timer fires, or the guest send an interrupt after posting new request. If it + * is the timer, the carrier is turned off here. + * */ +static void xenvif_rx_purge_event(struct xenvif_queue *queue) { - if (xenvif_schedulable(vif)) - netif_wake_queue(vif->dev); + /* Either the last unsuccesful skb or at least 1 slot should fit */ + int needed = queue->rx_last_skb_slots ? + queue->rx_last_skb_slots : 1; + + /* It is assumed that if the guest post new slots after this, the RX + * interrupt will set the QUEUE_STATUS_RX_PURGE_EVENT bit and wake up + * the thread again + */ + set_bit(QUEUE_STATUS_RX_STALLED, &queue->status); + if (!xenvif_rx_ring_slots_available(queue, needed)) { + rtnl_lock(); + if (netif_carrier_ok(queue->vif->dev)) { + /* Timer fired and there are still no slots. Turn off + * everything except the interrupts + */ + netif_carrier_off(queue->vif->dev); + skb_queue_purge(&queue->rx_queue); + queue->rx_last_skb_slots = 0; + if (net_ratelimit()) + netdev_err(queue->vif->dev, "Carrier off due to lack of guest response on queue %d\n", queue->id); + } else { + /* Probably an another queue already turned the carrier + * off, make sure nothing is stucked in the internal + * queue of this queue + */ + skb_queue_purge(&queue->rx_queue); + queue->rx_last_skb_slots = 0; + } + rtnl_unlock(); + } else if (!netif_carrier_ok(queue->vif->dev)) { + unsigned int num_queues = queue->vif->num_queues; + unsigned int i; + /* The carrier was down, but an interrupt kicked + * the thread again after new requests were + * posted + */ + clear_bit(QUEUE_STATUS_RX_STALLED, + &queue->status); + rtnl_lock(); + netif_carrier_on(queue->vif->dev); + netif_tx_wake_all_queues(queue->vif->dev); + rtnl_unlock(); + + for (i = 0; i < num_queues; i++) { + struct xenvif_queue *temp = &queue->vif->queues[i]; + + xenvif_napi_schedule_or_enable_events(temp); + } + if (net_ratelimit()) + netdev_err(queue->vif->dev, "Carrier on again\n"); + } else { + /* Queuing were stopped, but the guest posted + * new requests and sent an interrupt + */ + clear_bit(QUEUE_STATUS_RX_STALLED, + &queue->status); + del_timer_sync(&queue->rx_stalled); + xenvif_start_queue(queue); + } } -int xenvif_kthread(void *data) +int xenvif_kthread_guest_rx(void *data) { - struct xenvif *vif = data; + struct xenvif_queue *queue = data; struct sk_buff *skb; while (!kthread_should_stop()) { - wait_event_interruptible(vif->wq, - rx_work_todo(vif) || + wait_event_interruptible(queue->wq, + rx_work_todo(queue) || + queue->vif->disabled || + test_bit(QUEUE_STATUS_RX_PURGE_EVENT, &queue->status) || kthread_should_stop()); + if (kthread_should_stop()) break; - if (!skb_queue_empty(&vif->rx_queue)) - xenvif_rx_action(vif); + /* 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(queue->vif->disabled && queue->id == 0)) + xenvif_carrier_off(queue->vif); + else if (unlikely(test_and_clear_bit(QUEUE_STATUS_RX_PURGE_EVENT, + &queue->status))) { + xenvif_rx_purge_event(queue); + } else if (!netif_carrier_ok(queue->vif->dev)) { + /* Another queue stalled and turned the carrier off, so + * purge the internal queue of queues which were not + * blocked + */ + skb_queue_purge(&queue->rx_queue); + queue->rx_last_skb_slots = 0; + } - if (skb_queue_empty(&vif->rx_queue) && - netif_queue_stopped(vif->dev)) - xenvif_start_queue(vif); + if (!skb_queue_empty(&queue->rx_queue)) + xenvif_rx_action(queue); cond_resched(); } /* Bin any remaining skbs */ - while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) + while ((skb = skb_dequeue(&queue->rx_queue)) != NULL) dev_kfree_skb(skb); return 0; } +int xenvif_dealloc_kthread(void *data) +{ + struct xenvif_queue *queue = data; + + while (!kthread_should_stop()) { + wait_event_interruptible(queue->dealloc_wq, + tx_dealloc_work_todo(queue) || + kthread_should_stop()); + if (kthread_should_stop()) + break; + + xenvif_tx_dealloc_action(queue); + cond_resched(); + } + + /* Unmap anything remaining*/ + if (tx_dealloc_work_todo(queue)) + xenvif_tx_dealloc_action(queue); + + return 0; +} + static int __init netback_init(void) { int rc = 0; @@ -1576,6 +2081,9 @@ static int __init netback_init(void) if (!xen_domain()) return -ENODEV; + /* Allow as many queues as there are CPUs, by default */ + xenvif_max_queues = num_online_cpus(); + if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) { pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n", fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX); @@ -1586,6 +2094,15 @@ static int __init netback_init(void) if (rc) goto failed_init; + rx_drain_timeout_jiffies = msecs_to_jiffies(rx_drain_timeout_msecs); + +#ifdef CONFIG_DEBUG_FS + xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL); + if (IS_ERR_OR_NULL(xen_netback_dbg_root)) + pr_warn("Init of debugfs returned %ld!\n", + PTR_ERR(xen_netback_dbg_root)); +#endif /* CONFIG_DEBUG_FS */ + return 0; failed_init: @@ -1596,6 +2113,10 @@ module_init(netback_init); static void __exit netback_fini(void) { +#ifdef CONFIG_DEBUG_FS + if (!IS_ERR_OR_NULL(xen_netback_dbg_root)) + debugfs_remove_recursive(xen_netback_dbg_root); +#endif /* CONFIG_DEBUG_FS */ xenvif_xenbus_fini(); } module_exit(netback_fini); |