drivers/net/xen-netback/common.h

   1 /*
   2  * This program is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU General Public License version 2
   4  * as published by the Free Software Foundation; or, when distributed
   5  * separately from the Linux kernel or incorporated into other
   6  * software packages, subject to the following license:
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this source file (the "Software"), to deal in the Software without
  10  * restriction, including without limitation the rights to use, copy, modify,
  11  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
  12  * and to permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  24  * IN THE SOFTWARE.
  25  */
  26
  27 #ifndef __XEN_NETBACK__COMMON_H__
  28 #define __XEN_NETBACK__COMMON_H__
  29
  30 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
  31
  32 #include <linux/module.h>
  33 #include <linux/interrupt.h>
  34 #include <linux/slab.h>
  35 #include <linux/ip.h>
  36 #include <linux/in.h>
  37 #include <linux/io.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/etherdevice.h>
  40 #include <linux/wait.h>
  41 #include <linux/sched.h>
  42
  43 #include <xen/interface/io/netif.h>
  44 #include <xen/interface/grant_table.h>
  45 #include <xen/grant_table.h>
  46 #include <xen/xenbus.h>
  47 #include <xen/page.h>
  48 #include <linux/debugfs.h>
  49
  50 typedef unsigned int pending_ring_idx_t;
  51
  52 struct pending_tx_info {
  53         struct xen_netif_tx_request req; /* tx request */
  54         unsigned int extra_count;
  55         /* Callback data for released SKBs. The callback is always
  56          * xenvif_zerocopy_callback, desc contains the pending_idx, which is
  57          * also an index in pending_tx_info array. It is initialized in
  58          * xenvif_alloc and it never changes.
  59          * skb_shinfo(skb)->destructor_arg points to the first mapped slot's
  60          * callback_struct in this array of struct pending_tx_info's, then ctx
  61          * to the next, or NULL if there is no more slot for this skb.
  62          * ubuf_to_vif is a helper which finds the struct xenvif from a pointer
  63          * to this field.
  64          */
  65         struct ubuf_info_msgzc callback_struct;
  66 };
  67
  68 #define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
  69 #define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
  70
  71 struct xenvif_rx_meta {
  72         int id;
  73         int size;
  74         int gso_type;
  75         int gso_size;
  76 };
  77
  78 #define GSO_BIT(type) \
  79         (1 << XEN_NETIF_GSO_TYPE_ ## type)
  80
  81 /* Discriminate from any valid pending_idx value. */
  82 #define INVALID_PENDING_IDX 0xFFFF
  83
  84 #define MAX_PENDING_REQS XEN_NETIF_TX_RING_SIZE
  85
  86 /* The maximum number of frags is derived from the size of a grant (same
  87  * as a Xen page size for now).
  88  */
  89 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
  90
  91 #define NETBACK_INVALID_HANDLE -1
  92
  93 /* To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating
  94  * the maximum slots a valid packet can use. Now this value is defined
  95  * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by
  96  * all backend.
  97  */
  98 #define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
  99
 100 /* Queue name is interface name with "-qNNN" appended */
 101 #define QUEUE_NAME_SIZE (IFNAMSIZ + 5)
 102
 103 /* IRQ name is queue name with "-tx" or "-rx" appended */
 104 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
 105
 106 struct xenvif;
 107
 108 struct xenvif_stats {
 109         /* Stats fields to be updated per-queue.
 110          * A subset of struct net_device_stats that contains only the
 111          * fields that are updated in netback.c for each queue.
 112          */
 113         u64 rx_bytes;
 114         u64 rx_packets;
 115         u64 tx_bytes;
 116         u64 tx_packets;
 117
 118         /* Additional stats used by xenvif */
 119         unsigned long rx_gso_checksum_fixup;
 120         unsigned long tx_zerocopy_sent;
 121         unsigned long tx_zerocopy_success;
 122         unsigned long tx_zerocopy_fail;
 123         unsigned long tx_frag_overflow;
 124 };
 125
 126 #define COPY_BATCH_SIZE 64
 127
 128 struct xenvif_copy_state {
 129         struct gnttab_copy op[COPY_BATCH_SIZE];
 130         RING_IDX idx[COPY_BATCH_SIZE];
 131         unsigned int num;
 132         struct sk_buff_head *completed;
 133 };
 134
 135 struct xenvif_queue { /* Per-queue data for xenvif */
 136         unsigned int id; /* Queue ID, 0-based */
 137         char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
 138         struct xenvif *vif; /* Parent VIF */
 139
 140         /*
 141          * TX/RX common EOI handling.
 142          * When feature-split-event-channels = 0, interrupt handler sets
 143          * NETBK_COMMON_EOI, otherwise NETBK_RX_EOI and NETBK_TX_EOI are set
 144          * by the RX and TX interrupt handlers.
 145          * RX and TX handler threads will issue an EOI when either
 146          * NETBK_COMMON_EOI or their specific bits (NETBK_RX_EOI or
 147          * NETBK_TX_EOI) are set and they will reset those bits.
 148          */
 149         atomic_t eoi_pending;
 150 #define NETBK_RX_EOI            0x01
 151 #define NETBK_TX_EOI            0x02
 152 #define NETBK_COMMON_EOI        0x04
 153
 154         /* Use NAPI for guest TX */
 155         struct napi_struct napi;
 156         /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
 157         unsigned int tx_irq;
 158         /* Only used when feature-split-event-channels = 1 */
 159         char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
 160         struct xen_netif_tx_back_ring tx;
 161         struct sk_buff_head tx_queue;
 162         struct page *mmap_pages[MAX_PENDING_REQS];
 163         pending_ring_idx_t pending_prod;
 164         pending_ring_idx_t pending_cons;
 165         u16 pending_ring[MAX_PENDING_REQS];
 166         struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
 167         grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
 168
 169         struct gnttab_copy tx_copy_ops[2 * MAX_PENDING_REQS];
 170         struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS];
 171         struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS];
 172         /* passed to gnttab_[un]map_refs with pages under (un)mapping */
 173         struct page *pages_to_map[MAX_PENDING_REQS];
 174         struct page *pages_to_unmap[MAX_PENDING_REQS];
 175
 176         /* This prevents zerocopy callbacks  to race over dealloc_ring */
 177         spinlock_t callback_lock;
 178         /* This prevents dealloc thread and NAPI instance to race over response
 179          * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err
 180          * it only protect response creation
 181          */
 182         spinlock_t response_lock;
 183         pending_ring_idx_t dealloc_prod;
 184         pending_ring_idx_t dealloc_cons;
 185         u16 dealloc_ring[MAX_PENDING_REQS];
 186         struct task_struct *dealloc_task;
 187         wait_queue_head_t dealloc_wq;
 188         atomic_t inflight_packets;
 189
 190         /* Use kthread for guest RX */
 191         struct task_struct *task;
 192         wait_queue_head_t wq;
 193         /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
 194         unsigned int rx_irq;
 195         /* Only used when feature-split-event-channels = 1 */
 196         char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
 197         struct xen_netif_rx_back_ring rx;
 198         struct sk_buff_head rx_queue;
 199
 200         unsigned int rx_queue_max;
 201         unsigned int rx_queue_len;
 202         unsigned long last_rx_time;
 203         unsigned int rx_slots_needed;
 204         bool stalled;
 205
 206         struct xenvif_copy_state rx_copy;
 207
 208         /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
 209         unsigned long   credit_bytes;
 210         unsigned long   credit_usec;
 211         unsigned long   remaining_credit;
 212         struct timer_list credit_timeout;
 213         u64 credit_window_start;
 214         bool rate_limited;
 215
 216         /* Statistics */
 217         struct xenvif_stats stats;
 218 };
 219
 220 enum state_bit_shift {
 221         /* This bit marks that the vif is connected */
 222         VIF_STATUS_CONNECTED,
 223 };
 224
 225 struct xenvif_mcast_addr {
 226         struct list_head entry;
 227         struct rcu_head rcu;
 228         u8 addr[6];
 229 };
 230
 231 #define XEN_NETBK_MCAST_MAX 64
 232
 233 #define XEN_NETBK_MAX_HASH_KEY_SIZE 40
 234 #define XEN_NETBK_MAX_HASH_MAPPING_SIZE 128
 235 #define XEN_NETBK_HASH_TAG_SIZE 40
 236
 237 struct xenvif_hash_cache_entry {
 238         struct list_head link;
 239         struct rcu_head rcu;
 240         u8 tag[XEN_NETBK_HASH_TAG_SIZE];
 241         unsigned int len;
 242         u32 val;
 243         int seq;
 244 };
 245
 246 struct xenvif_hash_cache {
 247         spinlock_t lock;
 248         struct list_head list;
 249         unsigned int count;
 250         atomic_t seq;
 251 };
 252
 253 struct xenvif_hash {
 254         unsigned int alg;
 255         u32 flags;
 256         bool mapping_sel;
 257         u8 key[XEN_NETBK_MAX_HASH_KEY_SIZE];
 258         u32 mapping[2][XEN_NETBK_MAX_HASH_MAPPING_SIZE];
 259         unsigned int size;
 260         struct xenvif_hash_cache cache;
 261 };
 262
 263 struct backend_info {
 264         struct xenbus_device *dev;
 265         struct xenvif *vif;
 266
 267         /* This is the state that will be reflected in xenstore when any
 268          * active hotplug script completes.
 269          */
 270         enum xenbus_state state;
 271
 272         enum xenbus_state frontend_state;
 273         struct xenbus_watch hotplug_status_watch;
 274         u8 have_hotplug_status_watch:1;
 275
 276         const char *hotplug_script;
 277 };
 278
 279 struct xenvif {
 280         /* Unique identifier for this interface. */
 281         domid_t          domid;
 282         unsigned int     handle;
 283
 284         u8               fe_dev_addr[6];
 285         struct list_head fe_mcast_addr;
 286         unsigned int     fe_mcast_count;
 287
 288         /* Frontend feature information. */
 289         int gso_mask;
 290
 291         u8 can_sg:1;
 292         u8 ip_csum:1;
 293         u8 ipv6_csum:1;
 294         u8 multicast_control:1;
 295
 296         /* headroom requested by xen-netfront */
 297         u16 xdp_headroom;
 298
 299         /* Is this interface disabled? True when backend discovers
 300          * frontend is rogue.
 301          */
 302         bool disabled;
 303         unsigned long status;
 304         unsigned long drain_timeout;
 305         unsigned long stall_timeout;
 306
 307         /* Queues */
 308         struct xenvif_queue *queues;
 309         unsigned int num_queues; /* active queues, resource allocated */
 310         unsigned int stalled_queues;
 311
 312         struct xenvif_hash hash;
 313
 314         struct xenbus_watch credit_watch;
 315         struct xenbus_watch mcast_ctrl_watch;
 316
 317         struct backend_info *be;
 318
 319         spinlock_t lock;
 320
 321 #ifdef CONFIG_DEBUG_FS
 322         struct dentry *xenvif_dbg_root;
 323 #endif
 324
 325         struct xen_netif_ctrl_back_ring ctrl;
 326         unsigned int ctrl_irq;
 327
 328         /* Miscellaneous private stuff. */
 329         struct net_device *dev;
 330 };
 331
 332 struct xenvif_rx_cb {
 333         unsigned long expires;
 334         int meta_slots_used;
 335 };
 336
 337 #define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb)
 338
 339 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
 340 {
 341         return to_xenbus_device(vif->dev->dev.parent);
 342 }
 343
 344 void xenvif_tx_credit_callback(struct timer_list *t);
 345
 346 struct xenvif *xenvif_alloc(struct device *parent,
 347                             domid_t domid,
 348                             unsigned int handle);
 349
 350 int xenvif_init_queue(struct xenvif_queue *queue);
 351 void xenvif_deinit_queue(struct xenvif_queue *queue);
 352
 353 int xenvif_connect_data(struct xenvif_queue *queue,
 354                         unsigned long tx_ring_ref,
 355                         unsigned long rx_ring_ref,
 356                         unsigned int tx_evtchn,
 357                         unsigned int rx_evtchn);
 358 void xenvif_disconnect_data(struct xenvif *vif);
 359 int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
 360                         unsigned int evtchn);
 361 void xenvif_disconnect_ctrl(struct xenvif *vif);
 362 void xenvif_free(struct xenvif *vif);
 363
 364 int xenvif_xenbus_init(void);
 365 void xenvif_xenbus_fini(void);
 366
 367 /* (Un)Map communication rings. */
 368 void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue);
 369 int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
 370                                    grant_ref_t tx_ring_ref,
 371                                    grant_ref_t rx_ring_ref);
 372
 373 /* Check for SKBs from frontend and schedule backend processing */
 374 void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
 375
 376 /* Prevent the device from generating any further traffic. */
 377 void xenvif_carrier_off(struct xenvif *vif);
 378
 379 int xenvif_tx_action(struct xenvif_queue *queue, int budget);
 380
 381 int xenvif_kthread_guest_rx(void *data);
 382 void xenvif_kick_thread(struct xenvif_queue *queue);
 383
 384 int xenvif_dealloc_kthread(void *data);
 385
 386 irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data);
 387
 388 bool xenvif_have_rx_work(struct xenvif_queue *queue, bool test_kthread);
 389 bool xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
 390
 391 void xenvif_carrier_on(struct xenvif *vif);
 392
 393 /* Callbacks from stack when TX packet can be released */
 394 extern const struct ubuf_info_ops xenvif_ubuf_ops;
 395
 396 static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
 397 {
 398         return MAX_PENDING_REQS -
 399                 queue->pending_prod + queue->pending_cons;
 400 }
 401
 402 irqreturn_t xenvif_interrupt(int irq, void *dev_id);
 403
 404 extern bool separate_tx_rx_irq;
 405 extern bool provides_xdp_headroom;
 406
 407 extern unsigned int rx_drain_timeout_msecs;
 408 extern unsigned int rx_stall_timeout_msecs;
 409 extern unsigned int xenvif_max_queues;
 410 extern unsigned int xenvif_hash_cache_size;
 411
 412 #ifdef CONFIG_DEBUG_FS
 413 extern struct dentry *xen_netback_dbg_root;
 414 #endif
 415
 416 void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
 417                                  struct sk_buff *skb);
 418 void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue);
 419
 420 /* Multicast control */
 421 bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr);
 422 void xenvif_mcast_addr_list_free(struct xenvif *vif);
 423
 424 /* Hash */
 425 void xenvif_init_hash(struct xenvif *vif);
 426 void xenvif_deinit_hash(struct xenvif *vif);
 427
 428 u32 xenvif_set_hash_alg(struct xenvif *vif, u32 alg);
 429 u32 xenvif_get_hash_flags(struct xenvif *vif, u32 *flags);
 430 u32 xenvif_set_hash_flags(struct xenvif *vif, u32 flags);
 431 u32 xenvif_set_hash_key(struct xenvif *vif, u32 gref, u32 len);
 432 u32 xenvif_set_hash_mapping_size(struct xenvif *vif, u32 size);
 433 u32 xenvif_set_hash_mapping(struct xenvif *vif, u32 gref, u32 len,
 434                             u32 off);
 435
 436 void xenvif_set_skb_hash(struct xenvif *vif, struct sk_buff *skb);
 437
 438 #ifdef CONFIG_DEBUG_FS
 439 void xenvif_dump_hash_info(struct xenvif *vif, struct seq_file *m);
 440 #endif
 441
 442 #endif /* __XEN_NETBACK__COMMON_H__ */