| /* |
| * Back-end of the driver for virtual network devices. This portion of the |
| * driver exports a 'unified' network-device interface that can be accessed |
| * by any operating system that implements a compatible front end. A |
| * reference front-end implementation can be found in: |
| * drivers/net/xen-netfront.c |
| * |
| * 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 <linux/if_vlan.h> |
| #include <linux/udp.h> |
| #include <linux/highmem.h> |
| |
| #include <net/tcp.h> |
| |
| #include <xen/xen.h> |
| #include <xen/events.h> |
| #include <xen/interface/memory.h> |
| |
| #include <asm/xen/hypercall.h> |
| #include <asm/xen/page.h> |
| |
| /* Provide an option to disable split event channels at load time as |
| * event channels are limited resource. Split event channels are |
| * enabled by default. |
| */ |
| bool separate_tx_rx_irq = 1; |
| module_param(separate_tx_rx_irq, bool, 0644); |
| |
| /* The time that packets can stay on the guest Rx internal queue |
| * before they are dropped. |
| */ |
| unsigned int rx_drain_timeout_msecs = 10000; |
| module_param(rx_drain_timeout_msecs, uint, 0444); |
| |
| /* The length of time before the frontend is considered unresponsive |
| * because it isn't providing Rx slots. |
| */ |
| unsigned int rx_stall_timeout_msecs = 60000; |
| module_param(rx_stall_timeout_msecs, uint, 0444); |
| |
| 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. |
| */ |
| #define FATAL_SKB_SLOTS_DEFAULT 20 |
| static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT; |
| module_param(fatal_skb_slots, uint, 0444); |
| |
| /* The amount to copy out of the first guest Tx slot into the skb's |
| * linear area. If the first slot has more data, it will be mapped |
| * and put into the first frag. |
| * |
| * This is sized to avoid pulling headers from the frags for most |
| * TCP/IP packets. |
| */ |
| #define XEN_NETBACK_TX_COPY_LEN 128 |
| |
| |
| static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx, |
| u8 status); |
| |
| 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_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 page_to_pfn(queue->mmap_pages[idx]); |
| } |
| |
| static inline unsigned long idx_to_kaddr(struct xenvif_queue *queue, |
| u16 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]); |
| } |
| |
| static u16 frag_get_pending_idx(skb_frag_t *frag) |
| { |
| return (u16)frag->page_offset; |
| } |
| |
| static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx) |
| { |
| frag->page_offset = pending_idx; |
| } |
| |
| static inline pending_ring_idx_t pending_index(unsigned i) |
| { |
| return i & (MAX_PENDING_REQS-1); |
| } |
| |
| bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue, int needed) |
| { |
| RING_IDX prod, cons; |
| |
| 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); |
| } |
| } |
| |
| /* |
| * Returns true if we should start a new receive buffer instead of |
| * adding 'size' bytes to a buffer which currently contains 'offset' |
| * bytes. |
| */ |
| 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) |
| return true; |
| |
| /* |
| * complex case: start a fresh buffer if the current frag |
| * would overflow the current buffer but only if: |
| * (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 |
| * unless the frag is too large for a single buffer. |
| * - (ii) stops us from leaving a buffer pointlessly empty. |
| * - (iii) stops us leaving the first buffer |
| * empty. Strictly speaking this is already covered |
| * 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. |
| */ |
| BUG_ON(size > MAX_BUFFER_OFFSET); |
| if ((offset + size > MAX_BUFFER_OFFSET) && offset && !head && |
| !full_coalesce) |
| return true; |
| |
| return false; |
| } |
| |
| 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; |
| |
| req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++); |
| |
| 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; |
| } |
| |
| /* |
| * 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 xenvif_queue *foreign_queue, |
| grant_ref_t foreign_gref) |
| { |
| struct gnttab_copy *copy_gop; |
| struct xenvif_rx_meta *meta; |
| unsigned long bytes; |
| int gso_type = XEN_NETIF_GSO_TYPE_NONE; |
| |
| /* Data must not cross a page boundary. */ |
| BUG_ON(size + offset > PAGE_SIZE<<compound_order(page)); |
| |
| 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); |
| BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET); |
| |
| bytes = PAGE_SIZE - offset; |
| |
| if (bytes > size) |
| bytes = size; |
| |
| 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(queue, npo); |
| } |
| |
| if (npo->copy_off + bytes > MAX_BUFFER_OFFSET) |
| bytes = MAX_BUFFER_OFFSET - npo->copy_off; |
| |
| copy_gop = npo->copy + npo->copy_prod++; |
| copy_gop->flags = GNTCOPY_dest_gref; |
| copy_gop->len = bytes; |
| |
| 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 = queue->vif->domid; |
| copy_gop->dest.offset = npo->copy_off; |
| copy_gop->dest.u.ref = npo->copy_gref; |
| |
| npo->copy_off += bytes; |
| meta->size += bytes; |
| |
| offset += bytes; |
| size -= bytes; |
| |
| /* Next frame */ |
| if (offset == PAGE_SIZE && size) { |
| BUG_ON(!PageCompound(page)); |
| page++; |
| offset = 0; |
| } |
| |
| /* Leave a gap for the GSO descriptor. */ |
| 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; |
| } |
| |
| if (*head && ((1 << gso_type) & queue->vif->gso_mask)) |
| queue->rx.req_cons++; |
| |
| *head = 0; /* There must be something in this buffer now. */ |
| |
| } |
| } |
| |
| /* |
| * 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 |
| * 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; |
| const struct ubuf_info *ubuf = skb_shinfo(skb)->destructor_arg; |
| const struct ubuf_info *const head_ubuf = ubuf; |
| |
| 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) { |
| 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; |
| meta->size = 0; |
| meta->id = req->id; |
| } |
| |
| req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++); |
| 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, |
| NULL, |
| 0); |
| data += len; |
| } |
| |
| for (i = 0; i < nr_frags; i++) { |
| /* 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, |
| foreign_queue, |
| foreign_queue ? foreign_gref : UINT_MAX); |
| } |
| |
| 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) |
| { |
| 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, XEN_NETBK_RX_SLOTS_MAX) |
| && (skb = xenvif_rx_dequeue(queue)) != NULL) { |
| RING_IDX max_slots_needed; |
| RING_IDX old_req_cons; |
| RING_IDX ring_slots_used; |
| int i; |
| |
| queue->last_rx_time = jiffies; |
| |
| /* We need a cheap worse case estimate for the number of |
| * slots we'll use. |
| */ |
| |
| max_slots_needed = DIV_ROUND_UP(offset_in_page(skb->data) + |
| skb_headlen(skb), |
| 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]); |
| 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++; |
| |
| 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; |
| |
| BUG_ON(ring_slots_used > max_slots_needed); |
| |
| __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) { |
| |
| 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 = 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(queue->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) & |
| queue->vif->gso_mask) { |
| struct xen_netif_extra_info *gso = |
| (struct xen_netif_extra_info *) |
| RING_GET_RESPONSE(&queue->rx, |
| queue->rx.rsp_prod_pvt++); |
| |
| resp->flags |= XEN_NETRXF_extra_info; |
| |
| 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; |
| |
| gso->type = XEN_NETIF_EXTRA_TYPE_GSO; |
| gso->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; |
| |
| RING_FINAL_CHECK_FOR_REQUESTS(&queue->tx, more_to_do); |
| |
| if (more_to_do) |
| napi_schedule(&queue->napi); |
| } |
| |
| static void tx_add_credit(struct xenvif_queue *queue) |
| { |
| unsigned long max_burst, max_credit; |
| |
| /* |
| * 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(&queue->tx, queue->tx.req_cons)->size; |
| max_burst = min(max_burst, 131072UL); |
| max_burst = max(max_burst, queue->credit_bytes); |
| |
| /* Take care that adding a new chunk of credit doesn't wrap to zero. */ |
| max_credit = queue->remaining_credit + queue->credit_bytes; |
| if (max_credit < queue->remaining_credit) |
| max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */ |
| |
| queue->remaining_credit = min(max_credit, max_burst); |
| } |
| |
| static void tx_credit_callback(unsigned long data) |
| { |
| 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_queue *queue, |
| struct xen_netif_tx_request *txp, RING_IDX end) |
| { |
| RING_IDX cons = queue->tx.req_cons; |
| unsigned long flags; |
| |
| do { |
| 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(&queue->tx, cons++); |
| } while (1); |
| queue->tx.req_cons = cons; |
| } |
| |
| static void xenvif_fatal_tx_err(struct xenvif *vif) |
| { |
| netdev_err(vif->dev, "fatal error; disabling device\n"); |
| 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_queue *queue, |
| struct xen_netif_tx_request *first, |
| struct xen_netif_tx_request *txp, |
| int work_to_do) |
| { |
| RING_IDX cons = queue->tx.req_cons; |
| int slots = 0; |
| int drop_err = 0; |
| int more_data; |
| |
| if (!(first->flags & XEN_NETTXF_more_data)) |
| return 0; |
| |
| do { |
| struct xen_netif_tx_request dropped_tx = { 0 }; |
| |
| if (slots >= work_to_do) { |
| netdev_err(queue->vif->dev, |
| "Asked for %d slots but exceeds this limit\n", |
| work_to_do); |
| xenvif_fatal_tx_err(queue->vif); |
| return -ENODATA; |
| } |
| |
| /* This guest is really using too many slots and |
| * considered malicious. |
| */ |
| if (unlikely(slots >= fatal_skb_slots)) { |
| netdev_err(queue->vif->dev, |
| "Malicious frontend using %d slots, threshold %u\n", |
| slots, fatal_skb_slots); |
| xenvif_fatal_tx_err(queue->vif); |
| return -E2BIG; |
| } |
| |
| /* Xen network protocol had implicit dependency on |
| * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to |
| * the historical MAX_SKB_FRAGS value 18 to honor the |
| * same behavior as before. Any packet using more than |
| * 18 slots but less than fatal_skb_slots slots is |
| * dropped |
| */ |
| if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) { |
| if (net_ratelimit()) |
| netdev_dbg(queue->vif->dev, |
| "Too many slots (%d) exceeding limit (%d), dropping packet\n", |
| slots, XEN_NETBK_LEGACY_SLOTS_MAX); |
| drop_err = -E2BIG; |
| } |
| |
| if (drop_err) |
| txp = &dropped_tx; |
| |
| memcpy(txp, RING_GET_REQUEST(&queue->tx, cons + slots), |
| sizeof(*txp)); |
| |
| /* If the guest submitted a frame >= 64 KiB then |
| * first->size overflowed and following slots will |
| * appear to be larger than the frame. |
| * |
| * This cannot be fatal error as there are buggy |
| * frontends that do this. |
| * |
| * Consume all slots and drop the packet. |
| */ |
| if (!drop_err && txp->size > first->size) { |
| if (net_ratelimit()) |
| netdev_dbg(queue->vif->dev, |
| "Invalid tx request, slot size %u > remaining size %u\n", |
| txp->size, first->size); |
| drop_err = -EIO; |
| } |
| |
| first->size -= txp->size; |
| slots++; |
| |
| if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) { |
| netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n", |
| txp->offset, txp->size); |
| xenvif_fatal_tx_err(queue->vif); |
| return -EINVAL; |
| } |
| |
| more_data = txp->flags & XEN_NETTXF_more_data; |
| |
| if (!drop_err) |
| txp++; |
| |
| } while (more_data); |
| |
| if (drop_err) { |
| xenvif_tx_err(queue, first, cons + slots); |
| return drop_err; |
| } |
| |
| return slots; |
| } |
| |
| |
| 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) |
| { |
| 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)); |
| } |
| |
| 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; |
| |
| /* 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_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 = 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); |
| |
| 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); |
| } |
| |
| 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; |
| } |
| |
| shinfo = skb_shinfo(nskb); |
| frags = shinfo->frags; |
| |
| 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); |
| } |
| |
| skb_shinfo(skb)->frag_list = nskb; |
| } |
| |
| return gop; |
| } |
| |
| 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(); |
| } |
| queue->grant_tx_handle[pending_idx] = handle; |
| } |
| |
| 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_queue *queue, |
| struct sk_buff *skb, |
| struct gnttab_map_grant_ref **gopp_map, |
| struct gnttab_copy **gopp_copy) |
| { |
| 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); |
| /* 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; |
| const bool sharedslot = nr_frags && |
| frag_get_pending_idx(&shinfo->frags[0]) == pending_idx; |
| int i, err; |
| |
| /* Check status of header. */ |
| 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)++; |
| |
| check_frags: |
| for (i = 0; i < nr_frags; i++, gop_map++) { |
| int j, newerr; |
| |
| pending_idx = frag_get_pending_idx(&shinfo->frags[i]); |
| |
| /* Check error status: if okay then remember grant handle. */ |
| 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_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. */ |
| 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: 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_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; |
| } |
| |
| 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_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; |
| struct xen_netif_tx_request *txp; |
| struct page *page; |
| u16 pending_idx; |
| |
| pending_idx = frag_get_pending_idx(frag); |
| |
| /* 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 network stack's put_page */ |
| get_page(queue->mmap_pages[pending_idx]); |
| } |
| } |
| |
| 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 = queue->tx.req_cons; |
| |
| do { |
| if (unlikely(work_to_do-- <= 0)) { |
| netdev_err(queue->vif->dev, "Missing extra info\n"); |
| xenvif_fatal_tx_err(queue->vif); |
| return -EBADR; |
| } |
| |
| memcpy(&extra, RING_GET_REQUEST(&queue->tx, cons), |
| sizeof(extra)); |
| if (unlikely(!extra.type || |
| extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) { |
| queue->tx.req_cons = ++cons; |
| netdev_err(queue->vif->dev, |
| "Invalid extra type: %d\n", extra.type); |
| xenvif_fatal_tx_err(queue->vif); |
| return -EINVAL; |
| } |
| |
| memcpy(&extras[extra.type - 1], &extra, sizeof(extra)); |
| queue->tx.req_cons = ++cons; |
| } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE); |
| |
| return work_to_do; |
| } |
| |
| static int xenvif_set_skb_gso(struct xenvif *vif, |
| struct sk_buff *skb, |
| struct xen_netif_extra_info *gso) |
| { |
| if (!gso->u.gso.size) { |
| netdev_err(vif->dev, "GSO size must not be zero.\n"); |
| xenvif_fatal_tx_err(vif); |
| return -EINVAL; |
| } |
| |
| switch (gso->u.gso.type) { |
| case XEN_NETIF_GSO_TYPE_TCPV4: |
| skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; |
| break; |
| case XEN_NETIF_GSO_TYPE_TCPV6: |
| skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; |
| break; |
| default: |
| netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type); |
| xenvif_fatal_tx_err(vif); |
| return -EINVAL; |
| } |
| |
| skb_shinfo(skb)->gso_size = gso->u.gso.size; |
| /* gso_segs will be calculated later */ |
| |
| return 0; |
| } |
| |
| static int checksum_setup(struct xenvif_queue *queue, struct sk_buff *skb) |
| { |
| bool recalculate_partial_csum = false; |
| |
| /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy |
| * peers can fail to set NETRXF_csum_blank when sending a GSO |
| * frame. In this case force the SKB to CHECKSUM_PARTIAL and |
| * recalculate the partial checksum. |
| */ |
| if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { |
| queue->stats.rx_gso_checksum_fixup++; |
| skb->ip_summed = CHECKSUM_PARTIAL; |
| recalculate_partial_csum = true; |
| } |
| |
| /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ |
| if (skb->ip_summed != CHECKSUM_PARTIAL) |
| return 0; |
| |
| return skb_checksum_setup(skb, recalculate_partial_csum); |
| } |
| |
| static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size) |
| { |
| u64 now = get_jiffies_64(); |
| 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(&queue->credit_timeout)) |
| return true; |
| |
| /* Passed the point where we can replenish credit? */ |
| if (time_after_eq64(now, next_credit)) { |
| queue->credit_window_start = now; |
| tx_add_credit(queue); |
| } |
| |
| /* Still too big to send right now? Set a callback. */ |
| if (size > queue->remaining_credit) { |
| queue->credit_timeout.data = |
| (unsigned long)queue; |
| queue->credit_timeout.function = |
| tx_credit_callback; |
| mod_timer(&queue->credit_timeout, |
| next_credit); |
| queue->credit_window_start = next_credit; |
| |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static void xenvif_tx_build_gops(struct xenvif_queue *queue, |
| int budget, |
| unsigned *copy_ops, |
| unsigned *map_ops) |
| { |
| struct gnttab_map_grant_ref *gop = queue->tx_map_ops, *request_gop; |
| struct sk_buff *skb; |
| int ret; |
| |
| 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 xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1]; |
| u16 pending_idx; |
| RING_IDX idx; |
| int work_to_do; |
| unsigned int data_len; |
| pending_ring_idx_t index; |
| |
| if (queue->tx.sring->req_prod - queue->tx.req_cons > |
| XEN_NETIF_TX_RING_SIZE) { |
| netdev_err(queue->vif->dev, |
| "Impossible number of requests. " |
| "req_prod %d, req_cons %d, size %ld\n", |
| queue->tx.sring->req_prod, queue->tx.req_cons, |
| XEN_NETIF_TX_RING_SIZE); |
| xenvif_fatal_tx_err(queue->vif); |
| break; |
| } |
| |
| work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx); |
| if (!work_to_do) |
| break; |
| |
| idx = queue->tx.req_cons; |
| rmb(); /* Ensure that we see the request before we copy it. */ |
| memcpy(&txreq, RING_GET_REQUEST(&queue->tx, idx), sizeof(txreq)); |
| |
| /* Credit-based scheduling. */ |
| if (txreq.size > queue->remaining_credit && |
| tx_credit_exceeded(queue, txreq.size)) |
| break; |
| |
| queue->remaining_credit -= txreq.size; |
| |
| work_to_do--; |
| queue->tx.req_cons = ++idx; |
| |
| memset(extras, 0, sizeof(extras)); |
| if (txreq.flags & XEN_NETTXF_extra_info) { |
| work_to_do = xenvif_get_extras(queue, extras, |
| work_to_do); |
| idx = queue->tx.req_cons; |
| if (unlikely(work_to_do < 0)) |
| break; |
| } |
| |
| 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(queue->vif->dev, |
| "Bad packet size: %d\n", txreq.size); |
| 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(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(queue->vif); |
| break; |
| } |
| |
| index = pending_index(queue->pending_cons); |
| pending_idx = queue->pending_ring[index]; |
| |
| data_len = (txreq.size > XEN_NETBACK_TX_COPY_LEN && |
| ret < XEN_NETBK_LEGACY_SLOTS_MAX) ? |
| XEN_NETBACK_TX_COPY_LEN : txreq.size; |
| |
| skb = xenvif_alloc_skb(data_len); |
| if (unlikely(skb == NULL)) { |
| netdev_dbg(queue->vif->dev, |
| "Can't allocate a skb in start_xmit.\n"); |
| xenvif_tx_err(queue, &txreq, idx); |
| break; |
| } |
| |
| 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(queue->vif, skb, gso)) { |
| /* Failure in xenvif_set_skb_gso is fatal. */ |
| kfree_skb(skb); |
| break; |
| } |
| } |
| |
| XENVIF_TX_CB(skb)->pending_idx = pending_idx; |
| |
| __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; |
| |
| 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); |
| |
| queue->tx_copy_ops[*copy_ops].len = data_len; |
| queue->tx_copy_ops[*copy_ops].flags = GNTCOPY_source_gref; |
| |
| (*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)); |
| } |
| |
| queue->pending_cons++; |
| |
| request_gop = xenvif_get_requests(queue, skb, txfrags, gop); |
| if (request_gop == NULL) { |
| kfree_skb(skb); |
| xenvif_tx_err(queue, &txreq, idx); |
| break; |
| } |
| gop = request_gop; |
| |
| __skb_queue_tail(&queue->tx_queue, skb); |
| |
| queue->tx.req_cons = idx; |
| |
| if (((gop-queue->tx_map_ops) >= ARRAY_SIZE(queue->tx_map_ops)) || |
| (*copy_ops >= ARRAY_SIZE(queue->tx_copy_ops))) |
| break; |
| } |
| |
| (*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; |
| |
| /* 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); |
| 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; |
| /* increase inflight counter to offset decrement in callback */ |
| atomic_inc(&queue->inflight_packets); |
| uarg->callback(uarg, true); |
| skb_shinfo(skb)->destructor_arg = NULL; |
| |
| xenvif_skb_zerocopy_prepare(queue, nskb); |
| kfree_skb(nskb); |
| |
| return 0; |
| } |
| |
| static int xenvif_tx_submit(struct xenvif_queue *queue) |
| { |
| 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(&queue->tx_queue)) != NULL) { |
| struct xen_netif_tx_request *txp; |
| u16 pending_idx; |
| unsigned data_len; |
| |
| 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(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; |
| 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(queue, pending_idx, |
| XEN_NETIF_RSP_OKAY); |
| } |
| |
| if (txp->flags & XEN_NETTXF_csum_blank) |
| skb->ip_summed = CHECKSUM_PARTIAL; |
| else if (txp->flags & XEN_NETTXF_data_validated) |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| |
| 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"); |
| xenvif_skb_zerocopy_prepare(queue, skb); |
| kfree_skb(skb); |
| continue; |
| } |
| } |
| |
| skb->dev = queue->vif->dev; |
| skb->protocol = eth_type_trans(skb, skb->dev); |
| skb_reset_network_header(skb); |
| |
| 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) |
| xenvif_skb_zerocopy_prepare(queue, skb); |
| kfree_skb(skb); |
| continue; |
| } |
| |
| skb_probe_transport_header(skb, 0); |
| |
| /* If the packet is GSO then we will have just set up the |
| * transport header offset in checksum_setup so it's now |
| * straightforward to calculate gso_segs. |
| */ |
| if (skb_is_gso(skb)) { |
| int mss = skb_shinfo(skb)->gso_size; |
| int hdrlen = skb_transport_header(skb) - |
| skb_mac_header(skb) + |
| tcp_hdrlen(skb); |
| |
| skb_shinfo(skb)->gso_segs = |
| DIV_ROUND_UP(skb->len - hdrlen, mss); |
| } |
| |
| 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) { |
| xenvif_skb_zerocopy_prepare(queue, skb); |
| queue->stats.tx_zerocopy_sent++; |
| } |
| |
| netif_receive_skb(skb); |
| } |
| |
| return work_done; |
| } |
| |
| void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success) |
| { |
| unsigned long flags; |
| pending_ring_idx_t index; |
| struct xenvif_queue *queue = ubuf_to_queue(ubuf); |
| |
| /* 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++; |
| xenvif_skb_zerocopy_complete(queue); |
| } |
| |
| static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue) |
| { |
| 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; |
| |
| dc = queue->dealloc_cons; |
| gop = queue->tx_unmap_ops; |
| |
| /* 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(); |
| } |
| } |
| |
| for (i = 0; i < gop - queue->tx_unmap_ops; ++i) |
| xenvif_idx_release(queue, pending_idx_release[i], |
| XEN_NETIF_RSP_OKAY); |
| } |
| |
| |
| /* 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; |
| |
| if (unlikely(!tx_work_todo(queue))) |
| return 0; |
| |
| xenvif_tx_build_gops(queue, budget, &nr_cops, &nr_mops); |
| |
| if (nr_cops == 0) |
| return 0; |
| |
| 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); |
| } |
| |
| work_done = xenvif_tx_submit(queue); |
| |
| return work_done; |
| } |
| |
| 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_queue *queue, |
| struct xen_netif_tx_request *txp, |
| s8 st) |
| { |
| RING_IDX i = queue->tx.rsp_prod_pvt; |
| struct xen_netif_tx_response *resp; |
| int notify; |
| |
| resp = RING_GET_RESPONSE(&queue->tx, i); |
| resp->id = txp->id; |
| resp->status = st; |
| |
| if (txp->flags & XEN_NETTXF_extra_info) |
| RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL; |
| |
| queue->tx.rsp_prod_pvt = ++i; |
| RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify); |
| if (notify) |
| 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; |
| 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_queue *queue) |
| { |
| if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))) |
| return 1; |
| |
| return 0; |
| } |
| |
| static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue) |
| { |
| return queue->dealloc_cons != queue->dealloc_prod; |
| } |
| |
| 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) |
| { |
| void *addr; |
| struct xen_netif_tx_sring *txs; |
| struct xen_netif_rx_sring *rxs; |
| |
| int err = -ENOMEM; |
| |
| 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(&queue->tx, txs, PAGE_SIZE); |
| |
| 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(&queue->rx, rxs, PAGE_SIZE); |
| |
| return 0; |
| |
| err: |
| xenvif_unmap_frontend_rings(queue); |
| 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 < XEN_NETBK_RX_SLOTS_MAX |
| && 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 >= XEN_NETBK_RX_SLOTS_MAX; |
| } |
| |
| static bool xenvif_have_rx_work(struct xenvif_queue *queue) |
| { |
| return (!skb_queue_empty(&queue->rx_queue) |
| && xenvif_rx_ring_slots_available(queue, XEN_NETBK_RX_SLOTS_MAX)) |
| || (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); |
| xenvif_rx_queue_purge(queue); |
| continue; |
| } |
| |
| 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 |
| * packets complete. |
| */ |
| return kthread_should_stop() && |
| !atomic_read(&queue->inflight_packets); |
| } |
| |
| int xenvif_dealloc_kthread(void *data) |
| { |
| struct xenvif_queue *queue = data; |
| |
| for (;;) { |
| wait_event_interruptible(queue->dealloc_wq, |
| tx_dealloc_work_todo(queue) || |
| xenvif_dealloc_kthread_should_stop(queue)); |
| if (xenvif_dealloc_kthread_should_stop(queue)) |
| 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; |
| |
| 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); |
| fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX; |
| } |
| |
| rc = xenvif_xenbus_init(); |
| if (rc) |
| goto failed_init; |
| |
| #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: |
| return rc; |
| } |
| |
| 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); |
| |
| MODULE_LICENSE("Dual BSD/GPL"); |
| MODULE_ALIAS("xen-backend:vif"); |