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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/net/xen-netback/netback.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/net/xen-netback/netback.c')
-rw-r--r--drivers/net/xen-netback/netback.c1797
1 files changed, 1797 insertions, 0 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
new file mode 100644
index 000000000..271604098
--- /dev/null
+++ b/drivers/net/xen-netback/netback.c
@@ -0,0 +1,1797 @@
+/*
+ * 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;
+ nr_slots--) {
+ if (unlikely(!txp->size)) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&queue->response_lock, flags);
+ make_tx_response(queue, txp, 0, XEN_NETIF_RSP_OKAY);
+ push_tx_responses(queue);
+ spin_unlock_irqrestore(&queue->response_lock, flags);
+ ++txp;
+ continue;
+ }
+
+ 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);
+ ++shinfo->nr_frags;
+ ++gop;
+
+ 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; ++txp) {
+ if (unlikely(!txp->size)) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&queue->response_lock, flags);
+ make_tx_response(queue, txp, 0,
+ XEN_NETIF_RSP_OKAY);
+ push_tx_responses(queue);
+ spin_unlock_irqrestore(&queue->response_lock,
+ flags);
+ continue;
+ }
+
+ 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);
+ ++shinfo->nr_frags;
+ ++gop;
+ }
+
+ if (shinfo->nr_frags) {
+ skb_shinfo(skb)->frag_list = nskb;
+ nskb = NULL;
+ }
+ }
+
+ if (nskb) {
+ /* A frag_list skb was allocated but it is no longer needed
+ * because enough slots were converted to copy ops above or some
+ * were empty.
+ */
+ 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");