| /* SPDX-License-Identifier: MIT */ |
| /****************************************************************************** |
| * xen_netif.h |
| * |
| * Unified network-device I/O interface for Xen guest OSes. |
| * |
| * Copyright (c) 2003-2004, Keir Fraser |
| */ |
| |
| #ifndef __XEN_PUBLIC_IO_XEN_NETIF_H__ |
| #define __XEN_PUBLIC_IO_XEN_NETIF_H__ |
| |
| #include "ring.h" |
| #include "../grant_table.h" |
| |
| /* |
| * Older implementation of Xen network frontend / backend has an |
| * implicit dependency on the MAX_SKB_FRAGS as the maximum number of |
| * ring slots a skb can use. Netfront / netback may not work as |
| * expected when frontend and backend have different MAX_SKB_FRAGS. |
| * |
| * A better approach is to add mechanism for netfront / netback to |
| * negotiate this value. However we cannot fix all possible |
| * frontends, so we need to define a value which states the minimum |
| * slots backend must support. |
| * |
| * The minimum value derives from older Linux kernel's MAX_SKB_FRAGS |
| * (18), which is proved to work with most frontends. Any new backend |
| * which doesn't negotiate with frontend should expect frontend to |
| * send a valid packet using slots up to this value. |
| */ |
| #define XEN_NETIF_NR_SLOTS_MIN 18 |
| |
| /* |
| * Notifications after enqueuing any type of message should be conditional on |
| * the appropriate req_event or rsp_event field in the shared ring. |
| * If the client sends notification for rx requests then it should specify |
| * feature 'feature-rx-notify' via xenbus. Otherwise the backend will assume |
| * that it cannot safely queue packets (as it may not be kicked to send them). |
| */ |
| |
| /* |
| * "feature-split-event-channels" is introduced to separate guest TX |
| * and RX notification. Backend either doesn't support this feature or |
| * advertises it via xenstore as 0 (disabled) or 1 (enabled). |
| * |
| * To make use of this feature, frontend should allocate two event |
| * channels for TX and RX, advertise them to backend as |
| * "event-channel-tx" and "event-channel-rx" respectively. If frontend |
| * doesn't want to use this feature, it just writes "event-channel" |
| * node as before. |
| */ |
| |
| /* |
| * Multiple transmit and receive queues: |
| * If supported, the backend will write the key "multi-queue-max-queues" to |
| * the directory for that vif, and set its value to the maximum supported |
| * number of queues. |
| * Frontends that are aware of this feature and wish to use it can write the |
| * key "multi-queue-num-queues", set to the number they wish to use, which |
| * must be greater than zero, and no more than the value reported by the backend |
| * in "multi-queue-max-queues". |
| * |
| * Queues replicate the shared rings and event channels. |
| * "feature-split-event-channels" may optionally be used when using |
| * multiple queues, but is not mandatory. |
| * |
| * Each queue consists of one shared ring pair, i.e. there must be the same |
| * number of tx and rx rings. |
| * |
| * For frontends requesting just one queue, the usual event-channel and |
| * ring-ref keys are written as before, simplifying the backend processing |
| * to avoid distinguishing between a frontend that doesn't understand the |
| * multi-queue feature, and one that does, but requested only one queue. |
| * |
| * Frontends requesting two or more queues must not write the toplevel |
| * event-channel (or event-channel-{tx,rx}) and {tx,rx}-ring-ref keys, |
| * instead writing those keys under sub-keys having the name "queue-N" where |
| * N is the integer ID of the queue for which those keys belong. Queues |
| * are indexed from zero. For example, a frontend with two queues and split |
| * event channels must write the following set of queue-related keys: |
| * |
| * /local/domain/1/device/vif/0/multi-queue-num-queues = "2" |
| * /local/domain/1/device/vif/0/queue-0 = "" |
| * /local/domain/1/device/vif/0/queue-0/tx-ring-ref = "<ring-ref-tx0>" |
| * /local/domain/1/device/vif/0/queue-0/rx-ring-ref = "<ring-ref-rx0>" |
| * /local/domain/1/device/vif/0/queue-0/event-channel-tx = "<evtchn-tx0>" |
| * /local/domain/1/device/vif/0/queue-0/event-channel-rx = "<evtchn-rx0>" |
| * /local/domain/1/device/vif/0/queue-1 = "" |
| * /local/domain/1/device/vif/0/queue-1/tx-ring-ref = "<ring-ref-tx1>" |
| * /local/domain/1/device/vif/0/queue-1/rx-ring-ref = "<ring-ref-rx1" |
| * /local/domain/1/device/vif/0/queue-1/event-channel-tx = "<evtchn-tx1>" |
| * /local/domain/1/device/vif/0/queue-1/event-channel-rx = "<evtchn-rx1>" |
| * |
| * If there is any inconsistency in the XenStore data, the backend may |
| * choose not to connect any queues, instead treating the request as an |
| * error. This includes scenarios where more (or fewer) queues were |
| * requested than the frontend provided details for. |
| * |
| * Mapping of packets to queues is considered to be a function of the |
| * transmitting system (backend or frontend) and is not negotiated |
| * between the two. Guests are free to transmit packets on any queue |
| * they choose, provided it has been set up correctly. Guests must be |
| * prepared to receive packets on any queue they have requested be set up. |
| */ |
| |
| /* |
| * "feature-no-csum-offload" should be used to turn IPv4 TCP/UDP checksum |
| * offload off or on. If it is missing then the feature is assumed to be on. |
| * "feature-ipv6-csum-offload" should be used to turn IPv6 TCP/UDP checksum |
| * offload on or off. If it is missing then the feature is assumed to be off. |
| */ |
| |
| /* |
| * "feature-gso-tcpv4" and "feature-gso-tcpv6" advertise the capability to |
| * handle large TCP packets (in IPv4 or IPv6 form respectively). Neither |
| * frontends nor backends are assumed to be capable unless the flags are |
| * present. |
| */ |
| |
| /* |
| * "feature-multicast-control" and "feature-dynamic-multicast-control" |
| * advertise the capability to filter ethernet multicast packets in the |
| * backend. If the frontend wishes to take advantage of this feature then |
| * it may set "request-multicast-control". If the backend only advertises |
| * "feature-multicast-control" then "request-multicast-control" must be set |
| * before the frontend moves into the connected state. The backend will |
| * sample the value on this state transition and any subsequent change in |
| * value will have no effect. However, if the backend also advertises |
| * "feature-dynamic-multicast-control" then "request-multicast-control" |
| * may be set by the frontend at any time. In this case, the backend will |
| * watch the value and re-sample on watch events. |
| * |
| * If the sampled value of "request-multicast-control" is set then the |
| * backend transmit side should no longer flood multicast packets to the |
| * frontend, it should instead drop any multicast packet that does not |
| * match in a filter list. |
| * The list is amended by the frontend by sending dummy transmit requests |
| * containing XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL} extra-info fragments as |
| * specified below. |
| * Note that the filter list may be amended even if the sampled value of |
| * "request-multicast-control" is not set, however the filter should only |
| * be applied if it is set. |
| */ |
| |
| /* |
| * "xdp-headroom" is used to request that extra space is added |
| * for XDP processing. The value is measured in bytes and passed by |
| * the frontend to be consistent between both ends. |
| * If the value is greater than zero that means that |
| * an RX response is going to be passed to an XDP program for processing. |
| * XEN_NETIF_MAX_XDP_HEADROOM defines the maximum headroom offset in bytes |
| * |
| * "feature-xdp-headroom" is set to "1" by the netback side like other features |
| * so a guest can check if an XDP program can be processed. |
| */ |
| #define XEN_NETIF_MAX_XDP_HEADROOM 0x7FFF |
| |
| /* |
| * Control ring |
| * ============ |
| * |
| * Some features, such as hashing (detailed below), require a |
| * significant amount of out-of-band data to be passed from frontend to |
| * backend. Use of xenstore is not suitable for large quantities of data |
| * because of quota limitations and so a dedicated 'control ring' is used. |
| * The ability of the backend to use a control ring is advertised by |
| * setting: |
| * |
| * /local/domain/X/backend/<domid>/<vif>/feature-ctrl-ring = "1" |
| * |
| * The frontend provides a control ring to the backend by setting: |
| * |
| * /local/domain/<domid>/device/vif/<vif>/ctrl-ring-ref = <gref> |
| * /local/domain/<domid>/device/vif/<vif>/event-channel-ctrl = <port> |
| * |
| * where <gref> is the grant reference of the shared page used to |
| * implement the control ring and <port> is an event channel to be used |
| * as a mailbox interrupt. These keys must be set before the frontend |
| * moves into the connected state. |
| * |
| * The control ring uses a fixed request/response message size and is |
| * balanced (i.e. one request to one response), so operationally it is much |
| * the same as a transmit or receive ring. |
| * Note that there is no requirement that responses are issued in the same |
| * order as requests. |
| */ |
| |
| /* |
| * Hash types |
| * ========== |
| * |
| * For the purposes of the definitions below, 'Packet[]' is an array of |
| * octets containing an IP packet without options, 'Array[X..Y]' means a |
| * sub-array of 'Array' containing bytes X thru Y inclusive, and '+' is |
| * used to indicate concatenation of arrays. |
| */ |
| |
| /* |
| * A hash calculated over an IP version 4 header as follows: |
| * |
| * Buffer[0..8] = Packet[12..15] (source address) + |
| * Packet[16..19] (destination address) |
| * |
| * Result = Hash(Buffer, 8) |
| */ |
| #define _XEN_NETIF_CTRL_HASH_TYPE_IPV4 0 |
| #define XEN_NETIF_CTRL_HASH_TYPE_IPV4 \ |
| (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV4) |
| |
| /* |
| * A hash calculated over an IP version 4 header and TCP header as |
| * follows: |
| * |
| * Buffer[0..12] = Packet[12..15] (source address) + |
| * Packet[16..19] (destination address) + |
| * Packet[20..21] (source port) + |
| * Packet[22..23] (destination port) |
| * |
| * Result = Hash(Buffer, 12) |
| */ |
| #define _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP 1 |
| #define XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP \ |
| (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP) |
| |
| /* |
| * A hash calculated over an IP version 6 header as follows: |
| * |
| * Buffer[0..32] = Packet[8..23] (source address ) + |
| * Packet[24..39] (destination address) |
| * |
| * Result = Hash(Buffer, 32) |
| */ |
| #define _XEN_NETIF_CTRL_HASH_TYPE_IPV6 2 |
| #define XEN_NETIF_CTRL_HASH_TYPE_IPV6 \ |
| (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV6) |
| |
| /* |
| * A hash calculated over an IP version 6 header and TCP header as |
| * follows: |
| * |
| * Buffer[0..36] = Packet[8..23] (source address) + |
| * Packet[24..39] (destination address) + |
| * Packet[40..41] (source port) + |
| * Packet[42..43] (destination port) |
| * |
| * Result = Hash(Buffer, 36) |
| */ |
| #define _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP 3 |
| #define XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP \ |
| (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP) |
| |
| /* |
| * Hash algorithms |
| * =============== |
| */ |
| |
| #define XEN_NETIF_CTRL_HASH_ALGORITHM_NONE 0 |
| |
| /* |
| * Toeplitz hash: |
| */ |
| |
| #define XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ 1 |
| |
| /* |
| * This algorithm uses a 'key' as well as the data buffer itself. |
| * (Buffer[] and Key[] are treated as shift-registers where the MSB of |
| * Buffer/Key[0] is considered 'left-most' and the LSB of Buffer/Key[N-1] |
| * is the 'right-most'). |
| * |
| * Value = 0 |
| * For number of bits in Buffer[] |
| * If (left-most bit of Buffer[] is 1) |
| * Value ^= left-most 32 bits of Key[] |
| * Key[] << 1 |
| * Buffer[] << 1 |
| * |
| * The code below is provided for convenience where an operating system |
| * does not already provide an implementation. |
| */ |
| #ifdef XEN_NETIF_DEFINE_TOEPLITZ |
| static uint32_t xen_netif_toeplitz_hash(const uint8_t *key, |
| unsigned int keylen, |
| const uint8_t *buf, unsigned int buflen) |
| { |
| unsigned int keyi, bufi; |
| uint64_t prefix = 0; |
| uint64_t hash = 0; |
| |
| /* Pre-load prefix with the first 8 bytes of the key */ |
| for (keyi = 0; keyi < 8; keyi++) { |
| prefix <<= 8; |
| prefix |= (keyi < keylen) ? key[keyi] : 0; |
| } |
| |
| for (bufi = 0; bufi < buflen; bufi++) { |
| uint8_t byte = buf[bufi]; |
| unsigned int bit; |
| |
| for (bit = 0; bit < 8; bit++) { |
| if (byte & 0x80) |
| hash ^= prefix; |
| prefix <<= 1; |
| byte <<= 1; |
| } |
| |
| /* |
| * 'prefix' has now been left-shifted by 8, so |
| * OR in the next byte. |
| */ |
| prefix |= (keyi < keylen) ? key[keyi] : 0; |
| keyi++; |
| } |
| |
| /* The valid part of the hash is in the upper 32 bits. */ |
| return hash >> 32; |
| } |
| #endif /* XEN_NETIF_DEFINE_TOEPLITZ */ |
| |
| /* |
| * Control requests (struct xen_netif_ctrl_request) |
| * ================================================ |
| * |
| * All requests have the following format: |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | id | type | data[0] | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | data[1] | data[2] | |
| * +-----+-----+-----+-----+-----------------------+ |
| * |
| * id: the request identifier, echoed in response. |
| * type: the type of request (see below) |
| * data[]: any data associated with the request (determined by type) |
| */ |
| |
| struct xen_netif_ctrl_request { |
| uint16_t id; |
| uint16_t type; |
| |
| #define XEN_NETIF_CTRL_TYPE_INVALID 0 |
| #define XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS 1 |
| #define XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS 2 |
| #define XEN_NETIF_CTRL_TYPE_SET_HASH_KEY 3 |
| #define XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE 4 |
| #define XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE 5 |
| #define XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING 6 |
| #define XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM 7 |
| |
| uint32_t data[3]; |
| }; |
| |
| /* |
| * Control responses (struct xen_netif_ctrl_response) |
| * ================================================== |
| * |
| * All responses have the following format: |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | id | type | status | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | data | |
| * +-----+-----+-----+-----+ |
| * |
| * id: the corresponding request identifier |
| * type: the type of the corresponding request |
| * status: the status of request processing |
| * data: any data associated with the response (determined by type and |
| * status) |
| */ |
| |
| struct xen_netif_ctrl_response { |
| uint16_t id; |
| uint16_t type; |
| uint32_t status; |
| |
| #define XEN_NETIF_CTRL_STATUS_SUCCESS 0 |
| #define XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED 1 |
| #define XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER 2 |
| #define XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW 3 |
| |
| uint32_t data; |
| }; |
| |
| /* |
| * Control messages |
| * ================ |
| * |
| * XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM |
| * -------------------------------------- |
| * |
| * This is sent by the frontend to set the desired hash algorithm. |
| * |
| * Request: |
| * |
| * type = XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM |
| * data[0] = a XEN_NETIF_CTRL_HASH_ALGORITHM_* value |
| * data[1] = 0 |
| * data[2] = 0 |
| * |
| * Response: |
| * |
| * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not |
| * supported |
| * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - The algorithm is not |
| * supported |
| * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
| * |
| * NOTE: Setting data[0] to XEN_NETIF_CTRL_HASH_ALGORITHM_NONE disables |
| * hashing and the backend is free to choose how it steers packets |
| * to queues (which is the default behaviour). |
| * |
| * XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS |
| * ---------------------------------- |
| * |
| * This is sent by the frontend to query the types of hash supported by |
| * the backend. |
| * |
| * Request: |
| * |
| * type = XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS |
| * data[0] = 0 |
| * data[1] = 0 |
| * data[2] = 0 |
| * |
| * Response: |
| * |
| * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not supported |
| * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
| * data = supported hash types (if operation was successful) |
| * |
| * NOTE: A valid hash algorithm must be selected before this operation can |
| * succeed. |
| * |
| * XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS |
| * ---------------------------------- |
| * |
| * This is sent by the frontend to set the types of hash that the backend |
| * should calculate. (See above for hash type definitions). |
| * Note that the 'maximal' type of hash should always be chosen. For |
| * example, if the frontend sets both IPV4 and IPV4_TCP hash types then |
| * the latter hash type should be calculated for any TCP packet and the |
| * former only calculated for non-TCP packets. |
| * |
| * Request: |
| * |
| * type = XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS |
| * data[0] = bitwise OR of XEN_NETIF_CTRL_HASH_TYPE_* values |
| * data[1] = 0 |
| * data[2] = 0 |
| * |
| * Response: |
| * |
| * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not |
| * supported |
| * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - One or more flag |
| * value is invalid or |
| * unsupported |
| * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
| * data = 0 |
| * |
| * NOTE: A valid hash algorithm must be selected before this operation can |
| * succeed. |
| * Also, setting data[0] to zero disables hashing and the backend |
| * is free to choose how it steers packets to queues. |
| * |
| * XEN_NETIF_CTRL_TYPE_SET_HASH_KEY |
| * -------------------------------- |
| * |
| * This is sent by the frontend to set the key of the hash if the algorithm |
| * requires it. (See hash algorithms above). |
| * |
| * Request: |
| * |
| * type = XEN_NETIF_CTRL_TYPE_SET_HASH_KEY |
| * data[0] = grant reference of page containing the key (assumed to |
| * start at beginning of grant) |
| * data[1] = size of key in octets |
| * data[2] = 0 |
| * |
| * Response: |
| * |
| * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not |
| * supported |
| * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Key size is invalid |
| * XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW - Key size is larger |
| * than the backend |
| * supports |
| * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
| * data = 0 |
| * |
| * NOTE: Any key octets not specified are assumed to be zero (the key |
| * is assumed to be empty by default) and specifying a new key |
| * invalidates any previous key, hence specifying a key size of |
| * zero will clear the key (which ensures that the calculated hash |
| * will always be zero). |
| * The maximum size of key is algorithm and backend specific, but |
| * is also limited by the single grant reference. |
| * The grant reference may be read-only and must remain valid until |
| * the response has been processed. |
| * |
| * XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE |
| * ----------------------------------------- |
| * |
| * This is sent by the frontend to query the maximum size of mapping |
| * table supported by the backend. The size is specified in terms of |
| * table entries. |
| * |
| * Request: |
| * |
| * type = XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE |
| * data[0] = 0 |
| * data[1] = 0 |
| * data[2] = 0 |
| * |
| * Response: |
| * |
| * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not supported |
| * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
| * data = maximum number of entries allowed in the mapping table |
| * (if operation was successful) or zero if a mapping table is |
| * not supported (i.e. hash mapping is done only by modular |
| * arithmetic). |
| * |
| * XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE |
| * ------------------------------------- |
| * |
| * This is sent by the frontend to set the actual size of the mapping |
| * table to be used by the backend. The size is specified in terms of |
| * table entries. |
| * Any previous table is invalidated by this message and any new table |
| * is assumed to be zero filled. |
| * |
| * Request: |
| * |
| * type = XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE |
| * data[0] = number of entries in mapping table |
| * data[1] = 0 |
| * data[2] = 0 |
| * |
| * Response: |
| * |
| * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not |
| * supported |
| * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Table size is invalid |
| * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
| * data = 0 |
| * |
| * NOTE: Setting data[0] to 0 means that hash mapping should be done |
| * using modular arithmetic. |
| * |
| * XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING |
| * ------------------------------------ |
| * |
| * This is sent by the frontend to set the content of the table mapping |
| * hash value to queue number. The backend should calculate the hash from |
| * the packet header, use it as an index into the table (modulo the size |
| * of the table) and then steer the packet to the queue number found at |
| * that index. |
| * |
| * Request: |
| * |
| * type = XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING |
| * data[0] = grant reference of page containing the mapping (sub-)table |
| * (assumed to start at beginning of grant) |
| * data[1] = size of (sub-)table in entries |
| * data[2] = offset, in entries, of sub-table within overall table |
| * |
| * Response: |
| * |
| * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not |
| * supported |
| * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Table size or content |
| * is invalid |
| * XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW - Table size is larger |
| * than the backend |
| * supports |
| * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful |
| * data = 0 |
| * |
| * NOTE: The overall table has the following format: |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | mapping[0] | mapping[1] | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | . | |
| * | . | |
| * | . | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | mapping[N-2] | mapping[N-1] | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * |
| * where N is specified by a XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE |
| * message and each mapping must specifies a queue between 0 and |
| * "multi-queue-num-queues" (see above). |
| * The backend may support a mapping table larger than can be |
| * mapped by a single grant reference. Thus sub-tables within a |
| * larger table can be individually set by sending multiple messages |
| * with differing offset values. Specifying a new sub-table does not |
| * invalidate any table data outside that range. |
| * The grant reference may be read-only and must remain valid until |
| * the response has been processed. |
| */ |
| |
| DEFINE_RING_TYPES(xen_netif_ctrl, |
| struct xen_netif_ctrl_request, |
| struct xen_netif_ctrl_response); |
| |
| /* |
| * Guest transmit |
| * ============== |
| * |
| * This is the 'wire' format for transmit (frontend -> backend) packets: |
| * |
| * Fragment 1: xen_netif_tx_request_t - flags = XEN_NETTXF_* |
| * size = total packet size |
| * [Extra 1: xen_netif_extra_info_t] - (only if fragment 1 flags include |
| * XEN_NETTXF_extra_info) |
| * ... |
| * [Extra N: xen_netif_extra_info_t] - (only if extra N-1 flags include |
| * XEN_NETIF_EXTRA_MORE) |
| * ... |
| * Fragment N: xen_netif_tx_request_t - (only if fragment N-1 flags include |
| * XEN_NETTXF_more_data - flags on preceding |
| * extras are not relevant here) |
| * flags = 0 |
| * size = fragment size |
| * |
| * NOTE: |
| * |
| * This format slightly is different from that used for receive |
| * (backend -> frontend) packets. Specifically, in a multi-fragment |
| * packet the actual size of fragment 1 can only be determined by |
| * subtracting the sizes of fragments 2..N from the total packet size. |
| * |
| * Ring slot size is 12 octets, however not all request/response |
| * structs use the full size. |
| * |
| * tx request data (xen_netif_tx_request_t) |
| * ------------------------------------ |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | grant ref | offset | flags | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | id | size | |
| * +-----+-----+-----+-----+ |
| * |
| * grant ref: Reference to buffer page. |
| * offset: Offset within buffer page. |
| * flags: XEN_NETTXF_*. |
| * id: request identifier, echoed in response. |
| * size: packet size in bytes. |
| * |
| * tx response (xen_netif_tx_response_t) |
| * --------------------------------- |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | id | status | unused | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | unused | |
| * +-----+-----+-----+-----+ |
| * |
| * id: reflects id in transmit request |
| * status: XEN_NETIF_RSP_* |
| * |
| * Guest receive |
| * ============= |
| * |
| * This is the 'wire' format for receive (backend -> frontend) packets: |
| * |
| * Fragment 1: xen_netif_rx_request_t - flags = XEN_NETRXF_* |
| * size = fragment size |
| * [Extra 1: xen_netif_extra_info_t] - (only if fragment 1 flags include |
| * XEN_NETRXF_extra_info) |
| * ... |
| * [Extra N: xen_netif_extra_info_t] - (only if extra N-1 flags include |
| * XEN_NETIF_EXTRA_MORE) |
| * ... |
| * Fragment N: xen_netif_rx_request_t - (only if fragment N-1 flags include |
| * XEN_NETRXF_more_data - flags on preceding |
| * extras are not relevant here) |
| * flags = 0 |
| * size = fragment size |
| * |
| * NOTE: |
| * |
| * This format slightly is different from that used for transmit |
| * (frontend -> backend) packets. Specifically, in a multi-fragment |
| * packet the size of the packet can only be determined by summing the |
| * sizes of fragments 1..N. |
| * |
| * Ring slot size is 8 octets. |
| * |
| * rx request (xen_netif_rx_request_t) |
| * ------------------------------- |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | id | pad | gref | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * |
| * id: request identifier, echoed in response. |
| * gref: reference to incoming granted frame. |
| * |
| * rx response (xen_netif_rx_response_t) |
| * --------------------------------- |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | id | offset | flags | status | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * |
| * id: reflects id in receive request |
| * offset: offset in page of start of received packet |
| * flags: XEN_NETRXF_* |
| * status: -ve: XEN_NETIF_RSP_*; +ve: Rx'ed pkt size. |
| * |
| * NOTE: Historically, to support GSO on the frontend receive side, Linux |
| * netfront does not make use of the rx response id (because, as |
| * described below, extra info structures overlay the id field). |
| * Instead it assumes that responses always appear in the same ring |
| * slot as their corresponding request. Thus, to maintain |
| * compatibility, backends must make sure this is the case. |
| * |
| * Extra Info |
| * ========== |
| * |
| * Can be present if initial request or response has NET{T,R}XF_extra_info, |
| * or previous extra request has XEN_NETIF_EXTRA_MORE. |
| * |
| * The struct therefore needs to fit into either a tx or rx slot and |
| * is therefore limited to 8 octets. |
| * |
| * NOTE: Because extra info data overlays the usual request/response |
| * structures, there is no id information in the opposite direction. |
| * So, if an extra info overlays an rx response the frontend can |
| * assume that it is in the same ring slot as the request that was |
| * consumed to make the slot available, and the backend must ensure |
| * this assumption is true. |
| * |
| * extra info (xen_netif_extra_info_t) |
| * ------------------------------- |
| * |
| * General format: |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * |type |flags| type specific data | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * | padding for tx | |
| * +-----+-----+-----+-----+ |
| * |
| * type: XEN_NETIF_EXTRA_TYPE_* |
| * flags: XEN_NETIF_EXTRA_FLAG_* |
| * padding for tx: present only in the tx case due to 8 octet limit |
| * from rx case. Not shown in type specific entries |
| * below. |
| * |
| * XEN_NETIF_EXTRA_TYPE_GSO: |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * |type |flags| size |type | pad | features | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * |
| * type: Must be XEN_NETIF_EXTRA_TYPE_GSO |
| * flags: XEN_NETIF_EXTRA_FLAG_* |
| * size: Maximum payload size of each segment. For example, |
| * for TCP this is just the path MSS. |
| * type: XEN_NETIF_GSO_TYPE_*: This determines the protocol of |
| * the packet and any extra features required to segment the |
| * packet properly. |
| * features: EN_XEN_NETIF_GSO_FEAT_*: This specifies any extra GSO |
| * features required to process this packet, such as ECN |
| * support for TCPv4. |
| * |
| * XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}: |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * |type |flags| addr | |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * |
| * type: Must be XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL} |
| * flags: XEN_NETIF_EXTRA_FLAG_* |
| * addr: address to add/remove |
| * |
| * XEN_NETIF_EXTRA_TYPE_HASH: |
| * |
| * A backend that supports teoplitz hashing is assumed to accept |
| * this type of extra info in transmit packets. |
| * A frontend that enables hashing is assumed to accept |
| * this type of extra info in receive packets. |
| * |
| * 0 1 2 3 4 5 6 7 octet |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * |type |flags|htype| alg |LSB ---- value ---- MSB| |
| * +-----+-----+-----+-----+-----+-----+-----+-----+ |
| * |
| * type: Must be XEN_NETIF_EXTRA_TYPE_HASH |
| * flags: XEN_NETIF_EXTRA_FLAG_* |
| * htype: Hash type (one of _XEN_NETIF_CTRL_HASH_TYPE_* - see above) |
| * alg: The algorithm used to calculate the hash (one of |
| * XEN_NETIF_CTRL_HASH_TYPE_ALGORITHM_* - see above) |
| * value: Hash value |
| */ |
| |
| /* Protocol checksum field is blank in the packet (hardware offload)? */ |
| #define _XEN_NETTXF_csum_blank (0) |
| #define XEN_NETTXF_csum_blank (1U<<_XEN_NETTXF_csum_blank) |
| |
| /* Packet data has been validated against protocol checksum. */ |
| #define _XEN_NETTXF_data_validated (1) |
| #define XEN_NETTXF_data_validated (1U<<_XEN_NETTXF_data_validated) |
| |
| /* Packet continues in the next request descriptor. */ |
| #define _XEN_NETTXF_more_data (2) |
| #define XEN_NETTXF_more_data (1U<<_XEN_NETTXF_more_data) |
| |
| /* Packet to be followed by extra descriptor(s). */ |
| #define _XEN_NETTXF_extra_info (3) |
| #define XEN_NETTXF_extra_info (1U<<_XEN_NETTXF_extra_info) |
| |
| #define XEN_NETIF_MAX_TX_SIZE 0xFFFF |
| struct xen_netif_tx_request { |
| grant_ref_t gref; |
| uint16_t offset; |
| uint16_t flags; |
| uint16_t id; |
| uint16_t size; |
| }; |
| |
| /* Types of xen_netif_extra_info descriptors. */ |
| #define XEN_NETIF_EXTRA_TYPE_NONE (0) /* Never used - invalid */ |
| #define XEN_NETIF_EXTRA_TYPE_GSO (1) /* u.gso */ |
| #define XEN_NETIF_EXTRA_TYPE_MCAST_ADD (2) /* u.mcast */ |
| #define XEN_NETIF_EXTRA_TYPE_MCAST_DEL (3) /* u.mcast */ |
| #define XEN_NETIF_EXTRA_TYPE_HASH (4) /* u.hash */ |
| #define XEN_NETIF_EXTRA_TYPE_XDP (5) /* u.xdp */ |
| #define XEN_NETIF_EXTRA_TYPE_MAX (6) |
| |
| /* xen_netif_extra_info_t flags. */ |
| #define _XEN_NETIF_EXTRA_FLAG_MORE (0) |
| #define XEN_NETIF_EXTRA_FLAG_MORE (1U<<_XEN_NETIF_EXTRA_FLAG_MORE) |
| |
| /* GSO types */ |
| #define XEN_NETIF_GSO_TYPE_NONE (0) |
| #define XEN_NETIF_GSO_TYPE_TCPV4 (1) |
| #define XEN_NETIF_GSO_TYPE_TCPV6 (2) |
| |
| /* |
| * This structure needs to fit within both xen_netif_tx_request_t and |
| * xen_netif_rx_response_t for compatibility. |
| */ |
| struct xen_netif_extra_info { |
| uint8_t type; |
| uint8_t flags; |
| union { |
| struct { |
| uint16_t size; |
| uint8_t type; |
| uint8_t pad; |
| uint16_t features; |
| } gso; |
| struct { |
| uint8_t addr[6]; |
| } mcast; |
| struct { |
| uint8_t type; |
| uint8_t algorithm; |
| uint8_t value[4]; |
| } hash; |
| struct { |
| uint16_t headroom; |
| uint16_t pad[2]; |
| } xdp; |
| uint16_t pad[3]; |
| } u; |
| }; |
| |
| struct xen_netif_tx_response { |
| uint16_t id; |
| int16_t status; |
| }; |
| |
| struct xen_netif_rx_request { |
| uint16_t id; /* Echoed in response message. */ |
| uint16_t pad; |
| grant_ref_t gref; |
| }; |
| |
| /* Packet data has been validated against protocol checksum. */ |
| #define _XEN_NETRXF_data_validated (0) |
| #define XEN_NETRXF_data_validated (1U<<_XEN_NETRXF_data_validated) |
| |
| /* Protocol checksum field is blank in the packet (hardware offload)? */ |
| #define _XEN_NETRXF_csum_blank (1) |
| #define XEN_NETRXF_csum_blank (1U<<_XEN_NETRXF_csum_blank) |
| |
| /* Packet continues in the next request descriptor. */ |
| #define _XEN_NETRXF_more_data (2) |
| #define XEN_NETRXF_more_data (1U<<_XEN_NETRXF_more_data) |
| |
| /* Packet to be followed by extra descriptor(s). */ |
| #define _XEN_NETRXF_extra_info (3) |
| #define XEN_NETRXF_extra_info (1U<<_XEN_NETRXF_extra_info) |
| |
| /* Packet has GSO prefix. Deprecated but included for compatibility */ |
| #define _XEN_NETRXF_gso_prefix (4) |
| #define XEN_NETRXF_gso_prefix (1U<<_XEN_NETRXF_gso_prefix) |
| |
| struct xen_netif_rx_response { |
| uint16_t id; |
| uint16_t offset; |
| uint16_t flags; |
| int16_t status; |
| }; |
| |
| /* |
| * Generate xen_netif ring structures and types. |
| */ |
| |
| DEFINE_RING_TYPES(xen_netif_tx, struct xen_netif_tx_request, |
| struct xen_netif_tx_response); |
| DEFINE_RING_TYPES(xen_netif_rx, struct xen_netif_rx_request, |
| struct xen_netif_rx_response); |
| |
| #define XEN_NETIF_RSP_DROPPED -2 |
| #define XEN_NETIF_RSP_ERROR -1 |
| #define XEN_NETIF_RSP_OKAY 0 |
| /* No response: used for auxiliary requests (e.g., xen_netif_extra_info_t). */ |
| #define XEN_NETIF_RSP_NULL 1 |
| |
| #endif |
