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- /*
- * 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 <xen/page.h>
- #include <asm/xen/hypercall.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 = true;
- 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);
- #define MAX_QUEUES_DEFAULT 8
- 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
- /* This is the maximum number of flows in the hash cache. */
- #define XENVIF_HASH_CACHE_SIZE_DEFAULT 64
- unsigned int xenvif_hash_cache_size = XENVIF_HASH_CACHE_SIZE_DEFAULT;
- module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
- MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
- /* The module parameter tells that we have to put data
- * for xen-netfront with the XDP_PACKET_HEADROOM offset
- * needed for XDP processing
- */
- bool provides_xdp_headroom = true;
- module_param(provides_xdp_headroom, bool, 0644);
- 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,
- unsigned int extra_count,
- s8 st);
- static void push_tx_responses(struct xenvif_queue *queue);
- static void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
- static inline int tx_work_todo(struct xenvif_queue *queue);
- 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_msgzc *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)skb_frag_off(frag);
- }
- static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
- {
- skb_frag_off_set(frag, pending_idx);
- }
- static inline pending_ring_idx_t pending_index(unsigned i)
- {
- return i & (MAX_PENDING_REQS-1);
- }
- void xenvif_kick_thread(struct xenvif_queue *queue)
- {
- wake_up(&queue->wq);
- }
- 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);
- else if (atomic_fetch_andnot(NETBK_TX_EOI | NETBK_COMMON_EOI,
- &queue->eoi_pending) &
- (NETBK_TX_EOI | NETBK_COMMON_EOI))
- xen_irq_lateeoi(queue->tx_irq, 0);
- }
- 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 = max(131072UL, 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);
- queue->rate_limited = false;
- }
- void xenvif_tx_credit_callback(struct timer_list *t)
- {
- struct xenvif_queue *queue = from_timer(queue, t, credit_timeout);
- 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,
- unsigned int extra_count, 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, extra_count, XEN_NETIF_RSP_ERROR);
- push_tx_responses(queue);
- spin_unlock_irqrestore(&queue->response_lock, flags);
- if (cons == end)
- break;
- RING_COPY_REQUEST(&queue->tx, cons++, txp);
- extra_count = 0; /* only the first frag can have extras */
- } 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->num_queues)
- xenvif_kick_thread(&vif->queues[0]);
- }
- static int xenvif_count_requests(struct xenvif_queue *queue,
- struct xen_netif_tx_request *first,
- unsigned int extra_count,
- 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;
- RING_COPY_REQUEST(&queue->tx, cons + slots, 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) > XEN_PAGE_SIZE)) {
- netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %u, 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, extra_count, cons + slots);
- return drop_err;
- }
- return slots;
- }
- struct xenvif_tx_cb {
- u16 copy_pending_idx[XEN_NETBK_LEGACY_SLOTS_MAX + 1];
- u8 copy_count;
- u32 split_mask;
- };
- #define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
- #define copy_pending_idx(skb, i) (XENVIF_TX_CB(skb)->copy_pending_idx[i])
- #define copy_count(skb) (XENVIF_TX_CB(skb)->copy_count)
- static inline void xenvif_tx_create_map_op(struct xenvif_queue *queue,
- u16 pending_idx,
- struct xen_netif_tx_request *txp,
- unsigned int extra_count,
- 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));
- queue->pending_tx_info[pending_idx].extra_count = extra_count;
- }
- 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);
- BUILD_BUG_ON(sizeof(*XENVIF_TX_CB(skb)) > sizeof(skb->cb));
- 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 void xenvif_get_requests(struct xenvif_queue *queue,
- struct sk_buff *skb,
- struct xen_netif_tx_request *first,
- struct xen_netif_tx_request *txfrags,
- unsigned *copy_ops,
- unsigned *map_ops,
- unsigned int frag_overflow,
- struct sk_buff *nskb,
- unsigned int extra_count,
- unsigned int data_len)
- {
- struct skb_shared_info *shinfo = skb_shinfo(skb);
- skb_frag_t *frags = shinfo->frags;
- u16 pending_idx;
- pending_ring_idx_t index;
- unsigned int nr_slots;
- struct gnttab_copy *cop = queue->tx_copy_ops + *copy_ops;
- struct gnttab_map_grant_ref *gop = queue->tx_map_ops + *map_ops;
- struct xen_netif_tx_request *txp = first;
- nr_slots = shinfo->nr_frags + frag_overflow + 1;
- copy_count(skb) = 0;
- XENVIF_TX_CB(skb)->split_mask = 0;
- /* Create copy ops for exactly data_len bytes into the skb head. */
- __skb_put(skb, data_len);
- while (data_len > 0) {
- int amount = data_len > txp->size ? txp->size : data_len;
- bool split = false;
- cop->source.u.ref = txp->gref;
- cop->source.domid = queue->vif->domid;
- cop->source.offset = txp->offset;
- cop->dest.domid = DOMID_SELF;
- cop->dest.offset = (offset_in_page(skb->data +
- skb_headlen(skb) -
- data_len)) & ~XEN_PAGE_MASK;
- cop->dest.u.gmfn = virt_to_gfn(skb->data + skb_headlen(skb)
- - data_len);
- /* Don't cross local page boundary! */
- if (cop->dest.offset + amount > XEN_PAGE_SIZE) {
- amount = XEN_PAGE_SIZE - cop->dest.offset;
- XENVIF_TX_CB(skb)->split_mask |= 1U << copy_count(skb);
- split = true;
- }
- cop->len = amount;
- cop->flags = GNTCOPY_source_gref;
- index = pending_index(queue->pending_cons);
- pending_idx = queue->pending_ring[index];
- callback_param(queue, pending_idx).ctx = NULL;
- copy_pending_idx(skb, copy_count(skb)) = pending_idx;
- if (!split)
- copy_count(skb)++;
- cop++;
- data_len -= amount;
- if (amount == txp->size) {
- /* The copy op covered the full tx_request */
- memcpy(&queue->pending_tx_info[pending_idx].req,
- txp, sizeof(*txp));
- queue->pending_tx_info[pending_idx].extra_count =
- (txp == first) ? extra_count : 0;
- if (txp == first)
- txp = txfrags;
- else
- txp++;
- queue->pending_cons++;
- nr_slots--;
- } else {
- /* The copy op partially covered the tx_request.
- * The remainder will be mapped or copied in the next
- * iteration.
- */
- txp->offset += amount;
- txp->size -= amount;
- }
- }
- for (shinfo->nr_frags = 0; nr_slots > 0 && shinfo->nr_frags < MAX_SKB_FRAGS;
- shinfo->nr_frags++, gop++, nr_slots--) {
- index = pending_index(queue->pending_cons++);
- pending_idx = queue->pending_ring[index];
- xenvif_tx_create_map_op(queue, pending_idx, txp,
- txp == first ? extra_count : 0, gop);
- frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
- if (txp == first)
- txp = txfrags;
- else
- txp++;
- }
- if (nr_slots > 0) {
- shinfo = skb_shinfo(nskb);
- frags = shinfo->frags;
- for (shinfo->nr_frags = 0; 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, 0,
- gop);
- frag_set_pending_idx(&frags[shinfo->nr_frags],
- pending_idx);
- }
- skb_shinfo(skb)->frag_list = nskb;
- } else if (nskb) {
- /* A frag_list skb was allocated but it is no longer needed
- * because enough slots were converted to copy ops above.
- */
- kfree_skb(nskb);
- }
- (*copy_ops) = cop - queue->tx_copy_ops;
- (*map_ops) = gop - queue->tx_map_ops;
- }
- 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: 0x%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: 0x%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;
- /* 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]) ==
- copy_pending_idx(skb, copy_count(skb) - 1);
- int i, err = 0;
- for (i = 0; i < copy_count(skb); i++) {
- int newerr;
- /* Check status of header. */
- pending_idx = copy_pending_idx(skb, i);
- newerr = (*gopp_copy)->status;
- /* Split copies need to be handled together. */
- if (XENVIF_TX_CB(skb)->split_mask & (1U << i)) {
- (*gopp_copy)++;
- if (!newerr)
- newerr = (*gopp_copy)->status;
- }
- if (likely(!newerr)) {
- /* The first frag might still have this slot mapped */
- if (i < copy_count(skb) - 1 || !sharedslot)
- xenvif_idx_release(queue, pending_idx,
- XEN_NETIF_RSP_OKAY);
- } else {
- err = newerr;
- 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 (i < copy_count(skb) - 1 || !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 && !first_shinfo && 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;
- /* 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 = shinfo;
- shinfo = skb_shinfo(shinfo->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,
- unsigned int *extra_count,
- 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;
- }
- RING_COPY_REQUEST(&queue->tx, cons, &extra);
- queue->tx.req_cons = ++cons;
- (*extra_count)++;
- if (unlikely(!extra.type ||
- extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
- 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));
- } 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)) {
- queue->rate_limited = true;
- 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) {
- mod_timer(&queue->credit_timeout,
- next_credit);
- queue->credit_window_start = next_credit;
- queue->rate_limited = true;
- return true;
- }
- return false;
- }
- /* No locking is required in xenvif_mcast_add/del() as they are
- * only ever invoked from NAPI poll. An RCU list is used because
- * xenvif_mcast_match() is called asynchronously, during start_xmit.
- */
- static int xenvif_mcast_add(struct xenvif *vif, const u8 *addr)
- {
- struct xenvif_mcast_addr *mcast;
- if (vif->fe_mcast_count == XEN_NETBK_MCAST_MAX) {
- if (net_ratelimit())
- netdev_err(vif->dev,
- "Too many multicast addresses\n");
- return -ENOSPC;
- }
- mcast = kzalloc(sizeof(*mcast), GFP_ATOMIC);
- if (!mcast)
- return -ENOMEM;
- ether_addr_copy(mcast->addr, addr);
- list_add_tail_rcu(&mcast->entry, &vif->fe_mcast_addr);
- vif->fe_mcast_count++;
- return 0;
- }
- static void xenvif_mcast_del(struct xenvif *vif, const u8 *addr)
- {
- struct xenvif_mcast_addr *mcast;
- list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
- if (ether_addr_equal(addr, mcast->addr)) {
- --vif->fe_mcast_count;
- list_del_rcu(&mcast->entry);
- kfree_rcu(mcast, rcu);
- break;
- }
- }
- }
- bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr)
- {
- struct xenvif_mcast_addr *mcast;
- rcu_read_lock();
- list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
- if (ether_addr_equal(addr, mcast->addr)) {
- rcu_read_unlock();
- return true;
- }
- }
- rcu_read_unlock();
- return false;
- }
- void xenvif_mcast_addr_list_free(struct xenvif *vif)
- {
- /* No need for locking or RCU here. NAPI poll and TX queue
- * are stopped.
- */
- while (!list_empty(&vif->fe_mcast_addr)) {
- struct xenvif_mcast_addr *mcast;
- mcast = list_first_entry(&vif->fe_mcast_addr,
- struct xenvif_mcast_addr,
- entry);
- --vif->fe_mcast_count;
- list_del(&mcast->entry);
- kfree(mcast);
- }
- }
- static void xenvif_tx_build_gops(struct xenvif_queue *queue,
- int budget,
- unsigned *copy_ops,
- unsigned *map_ops)
- {
- struct sk_buff *skb, *nskb;
- int ret;
- unsigned int frag_overflow;
- 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];
- unsigned int extra_count;
- 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 = XEN_RING_NR_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. */
- RING_COPY_REQUEST(&queue->tx, idx, &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));
- extra_count = 0;
- if (txreq.flags & XEN_NETTXF_extra_info) {
- work_to_do = xenvif_get_extras(queue, extras,
- &extra_count,
- work_to_do);
- idx = queue->tx.req_cons;
- if (unlikely(work_to_do < 0))
- break;
- }
- if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1].type) {
- struct xen_netif_extra_info *extra;
- extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1];
- ret = xenvif_mcast_add(queue->vif, extra->u.mcast.addr);
- make_tx_response(queue, &txreq, extra_count,
- (ret == 0) ?
- XEN_NETIF_RSP_OKAY :
- XEN_NETIF_RSP_ERROR);
- push_tx_responses(queue);
- continue;
- }
- if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1].type) {
- struct xen_netif_extra_info *extra;
- extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1];
- xenvif_mcast_del(queue->vif, extra->u.mcast.addr);
- make_tx_response(queue, &txreq, extra_count,
- XEN_NETIF_RSP_OKAY);
- push_tx_responses(queue);
- continue;
- }
- data_len = (txreq.size > XEN_NETBACK_TX_COPY_LEN) ?
- XEN_NETBACK_TX_COPY_LEN : txreq.size;
- ret = xenvif_count_requests(queue, &txreq, extra_count,
- 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, extra_count, idx);
- break;
- }
- /* No crossing a page as the payload mustn't fragment. */
- if (unlikely((txreq.offset + txreq.size) > XEN_PAGE_SIZE)) {
- netdev_err(queue->vif->dev, "Cross page boundary, txreq.offset: %u, size: %u\n",
- txreq.offset, txreq.size);
- xenvif_fatal_tx_err(queue->vif);
- break;
- }
- index = pending_index(queue->pending_cons);
- pending_idx = queue->pending_ring[index];
- if (ret >= XEN_NETBK_LEGACY_SLOTS_MAX - 1 && data_len < txreq.size)
- data_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, extra_count, idx);
- break;
- }
- skb_shinfo(skb)->nr_frags = ret;
- /* At this point shinfo->nr_frags is in fact the number of
- * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
- */
- frag_overflow = 0;
- nskb = NULL;
- if (skb_shinfo(skb)->nr_frags > MAX_SKB_FRAGS) {
- frag_overflow = skb_shinfo(skb)->nr_frags - MAX_SKB_FRAGS;
- BUG_ON(frag_overflow > MAX_SKB_FRAGS);
- skb_shinfo(skb)->nr_frags = MAX_SKB_FRAGS;
- nskb = xenvif_alloc_skb(0);
- if (unlikely(nskb == NULL)) {
- skb_shinfo(skb)->nr_frags = 0;
- kfree_skb(skb);
- xenvif_tx_err(queue, &txreq, extra_count, idx);
- if (net_ratelimit())
- netdev_err(queue->vif->dev,
- "Can't allocate the frag_list skb.\n");
- 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. */
- skb_shinfo(skb)->nr_frags = 0;
- kfree_skb(skb);
- kfree_skb(nskb);
- break;
- }
- }
- if (extras[XEN_NETIF_EXTRA_TYPE_HASH - 1].type) {
- struct xen_netif_extra_info *extra;
- enum pkt_hash_types type = PKT_HASH_TYPE_NONE;
- extra = &extras[XEN_NETIF_EXTRA_TYPE_HASH - 1];
- switch (extra->u.hash.type) {
- case _XEN_NETIF_CTRL_HASH_TYPE_IPV4:
- case _XEN_NETIF_CTRL_HASH_TYPE_IPV6:
- type = PKT_HASH_TYPE_L3;
- break;
- case _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP:
- case _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP:
- type = PKT_HASH_TYPE_L4;
- break;
- default:
- break;
- }
- if (type != PKT_HASH_TYPE_NONE)
- skb_set_hash(skb,
- *(u32 *)extra->u.hash.value,
- type);
- }
- xenvif_get_requests(queue, skb, &txreq, txfrags, copy_ops,
- map_ops, frag_overflow, nskb, extra_count,
- data_len);
- __skb_queue_tail(&queue->tx_queue, skb);
- queue->tx.req_cons = idx;
- if ((*map_ops >= ARRAY_SIZE(queue->tx_map_ops)) ||
- (*copy_ops >= ARRAY_SIZE(queue->tx_copy_ops)))
- break;
- }
- 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, f;
- 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(skb_frag_page(&frags[j]));
- 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;
- __skb_frag_set_page(&frags[i], page);
- skb_frag_off_set(&frags[i], 0);
- skb_frag_size_set(&frags[i], len);
- }
- /* Release all the original (foreign) frags. */
- for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
- skb_frag_unref(skb, f);
- uarg = skb_shinfo(skb)->destructor_arg;
- /* increase inflight counter to offset decrement in callback */
- atomic_inc(&queue->inflight_packets);
- uarg->callback(NULL, uarg, true);
- skb_shinfo(skb)->destructor_arg = NULL;
- /* Fill the skb with the new (local) frags. */
- memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t));
- skb_shinfo(skb)->nr_frags = i;
- skb->truesize += i * PAGE_SIZE;
- 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;
- pending_idx = copy_pending_idx(skb, 0);
- 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;
- }
- 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))) {
- struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
- xenvif_skb_zerocopy_prepare(queue, nskb);
- 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;
- }
- /* Copied all the bits from the frag list -- free it. */
- skb_frag_list_init(skb);
- kfree_skb(nskb);
- }
- 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);
- /* 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, hdrlen;
- /* GSO implies having the L4 header. */
- WARN_ON_ONCE(!skb_transport_header_was_set(skb));
- if (unlikely(!skb_transport_header_was_set(skb))) {
- kfree_skb(skb);
- continue;
- }
- mss = skb_shinfo(skb)->gso_size;
- hdrlen = skb_tcp_all_headers(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 sk_buff *skb, struct ubuf_info *ubuf_base,
- bool zerocopy_success)
- {
- unsigned long flags;
- pending_ring_idx_t index;
- struct ubuf_info_msgzc *ubuf = uarg_to_msgzc(ubuf_base);
- 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_msgzc *) 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);
- 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 %tu 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: 0x%llx handle: 0x%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 = 0, 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);
- if (ret) {
- unsigned int i;
- netdev_err(queue->vif->dev, "Map fail: nr %u ret %d\n",
- nr_mops, ret);
- for (i = 0; i < nr_mops; ++i)
- WARN_ON_ONCE(queue->tx_map_ops[i].status ==
- GNTST_okay);
- }
- }
- 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,
- pending_tx_info->extra_count, status);
- /* Release the pending index before pusing the Tx response so
- * its available before a new Tx request is pushed by the
- * frontend.
- */
- index = pending_index(queue->pending_prod++);
- queue->pending_ring[index] = pending_idx;
- push_tx_responses(queue);
- spin_unlock_irqrestore(&queue->response_lock, flags);
- }
- static void make_tx_response(struct xenvif_queue *queue,
- struct xen_netif_tx_request *txp,
- unsigned int extra_count,
- s8 st)
- {
- RING_IDX i = queue->tx.rsp_prod_pvt;
- struct xen_netif_tx_response *resp;
- resp = RING_GET_RESPONSE(&queue->tx, i);
- resp->id = txp->id;
- resp->status = st;
- while (extra_count-- != 0)
- RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL;
- queue->tx.rsp_prod_pvt = ++i;
- }
- static void push_tx_responses(struct xenvif_queue *queue)
- {
- int notify;
- RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify);
- if (notify)
- notify_remote_via_irq(queue->tx_irq);
- }
- static 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: 0x%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_data_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_data_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;
- RING_IDX rsp_prod, req_prod;
- int err;
- err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
- &tx_ring_ref, 1, &addr);
- if (err)
- goto err;
- txs = (struct xen_netif_tx_sring *)addr;
- rsp_prod = READ_ONCE(txs->rsp_prod);
- req_prod = READ_ONCE(txs->req_prod);
- BACK_RING_ATTACH(&queue->tx, txs, rsp_prod, XEN_PAGE_SIZE);
- err = -EIO;
- if (req_prod - rsp_prod > RING_SIZE(&queue->tx))
- goto err;
- err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
- &rx_ring_ref, 1, &addr);
- if (err)
- goto err;
- rxs = (struct xen_netif_rx_sring *)addr;
- rsp_prod = READ_ONCE(rxs->rsp_prod);
- req_prod = READ_ONCE(rxs->req_prod);
- BACK_RING_ATTACH(&queue->rx, rxs, rsp_prod, XEN_PAGE_SIZE);
- err = -EIO;
- if (req_prod - rsp_prod > RING_SIZE(&queue->rx))
- goto err;
- return 0;
- err:
- xenvif_unmap_frontend_data_rings(queue);
- return err;
- }
- 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 void make_ctrl_response(struct xenvif *vif,
- const struct xen_netif_ctrl_request *req,
- u32 status, u32 data)
- {
- RING_IDX idx = vif->ctrl.rsp_prod_pvt;
- struct xen_netif_ctrl_response rsp = {
- .id = req->id,
- .type = req->type,
- .status = status,
- .data = data,
- };
- *RING_GET_RESPONSE(&vif->ctrl, idx) = rsp;
- vif->ctrl.rsp_prod_pvt = ++idx;
- }
- static void push_ctrl_response(struct xenvif *vif)
- {
- int notify;
- RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->ctrl, notify);
- if (notify)
- notify_remote_via_irq(vif->ctrl_irq);
- }
- static void process_ctrl_request(struct xenvif *vif,
- const struct xen_netif_ctrl_request *req)
- {
- u32 status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED;
- u32 data = 0;
- switch (req->type) {
- case XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM:
- status = xenvif_set_hash_alg(vif, req->data[0]);
- break;
- case XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS:
- status = xenvif_get_hash_flags(vif, &data);
- break;
- case XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS:
- status = xenvif_set_hash_flags(vif, req->data[0]);
- break;
- case XEN_NETIF_CTRL_TYPE_SET_HASH_KEY:
- status = xenvif_set_hash_key(vif, req->data[0],
- req->data[1]);
- break;
- case XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE:
- status = XEN_NETIF_CTRL_STATUS_SUCCESS;
- data = XEN_NETBK_MAX_HASH_MAPPING_SIZE;
- break;
- case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE:
- status = xenvif_set_hash_mapping_size(vif,
- req->data[0]);
- break;
- case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING:
- status = xenvif_set_hash_mapping(vif, req->data[0],
- req->data[1],
- req->data[2]);
- break;
- default:
- break;
- }
- make_ctrl_response(vif, req, status, data);
- push_ctrl_response(vif);
- }
- static void xenvif_ctrl_action(struct xenvif *vif)
- {
- for (;;) {
- RING_IDX req_prod, req_cons;
- req_prod = vif->ctrl.sring->req_prod;
- req_cons = vif->ctrl.req_cons;
- /* Make sure we can see requests before we process them. */
- rmb();
- if (req_cons == req_prod)
- break;
- while (req_cons != req_prod) {
- struct xen_netif_ctrl_request req;
- RING_COPY_REQUEST(&vif->ctrl, req_cons, &req);
- req_cons++;
- process_ctrl_request(vif, &req);
- }
- vif->ctrl.req_cons = req_cons;
- vif->ctrl.sring->req_event = req_cons + 1;
- }
- }
- static bool xenvif_ctrl_work_todo(struct xenvif *vif)
- {
- if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->ctrl)))
- return true;
- return false;
- }
- irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data)
- {
- struct xenvif *vif = data;
- unsigned int eoi_flag = XEN_EOI_FLAG_SPURIOUS;
- while (xenvif_ctrl_work_todo(vif)) {
- xenvif_ctrl_action(vif);
- eoi_flag = 0;
- }
- xen_irq_lateeoi(irq, eoi_flag);
- return IRQ_HANDLED;
- }
- static int __init netback_init(void)
- {
- int rc = 0;
- if (!xen_domain())
- return -ENODEV;
- /* Allow as many queues as there are CPUs but max. 8 if user has not
- * specified a value.
- */
- if (xenvif_max_queues == 0)
- xenvif_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
- 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);
- #endif /* CONFIG_DEBUG_FS */
- return 0;
- failed_init:
- return rc;
- }
- module_init(netback_init);
- static void __exit netback_fini(void)
- {
- #ifdef CONFIG_DEBUG_FS
- 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");
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