| 1 |
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| 2 | |
| 3 | * xen_netif.h
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| 4 | *
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| 5 | * Unified network-device I/O interface for Xen guest OSes.
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| 6 | *
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| 7 | * Copyright (c) 2003-2004, Keir Fraser
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| 8 |
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| 9 |
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| 10 | #ifndef __XEN_PUBLIC_IO_XEN_NETIF_H__
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| 11 | #define __XEN_PUBLIC_IO_XEN_NETIF_H__
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| 12 |
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| 13 | #include "ring.h"
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| 14 | #include "../grant_table.h"
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| 15 |
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| 16 | |
| 17 | * Older implementation of Xen network frontend / backend has an
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| 18 | * implicit dependency on the MAX_SKB_FRAGS as the maximum number of
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| 19 | * ring slots a skb can use. Netfront / netback may not work as
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| 20 | * expected when frontend and backend have different MAX_SKB_FRAGS.
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| 21 | *
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| 22 | * A better approach is to add mechanism for netfront / netback to
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| 23 | * negotiate this value. However we cannot fix all possible
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| 24 | * frontends, so we need to define a value which states the minimum
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| 25 | * slots backend must support.
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| 26 | *
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| 27 | * The minimum value derives from older Linux kernel's MAX_SKB_FRAGS
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| 28 | * (18), which is proved to work with most frontends. Any new backend
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| 29 | * which doesn't negotiate with frontend should expect frontend to
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| 30 | * send a valid packet using slots up to this value.
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| 31 |
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| 32 | #define XEN_NETIF_NR_SLOTS_MIN 18
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| 33 |
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| 34 | |
| 35 | * Notifications after enqueuing any type of message should be conditional on
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| 36 | * the appropriate req_event or rsp_event field in the shared ring.
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| 37 | * If the client sends notification for rx requests then it should specify
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| 38 | * feature 'feature-rx-notify' via xenbus. Otherwise the backend will assume
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| 39 | * that it cannot safely queue packets (as it may not be kicked to send them).
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| 40 |
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| 41 |
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| 42 | |
| 43 | * "feature-split-event-channels" is introduced to separate guest TX
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| 44 | * and RX notification. Backend either doesn't support this feature or
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| 45 | * advertises it via xenstore as 0 (disabled) or 1 (enabled).
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| 46 | *
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| 47 | * To make use of this feature, frontend should allocate two event
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| 48 | * channels for TX and RX, advertise them to backend as
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| 49 | * "event-channel-tx" and "event-channel-rx" respectively. If frontend
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| 50 | * doesn't want to use this feature, it just writes "event-channel"
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| 51 | * node as before.
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| 52 |
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| 53 |
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| 54 | |
| 55 | * Multiple transmit and receive queues:
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| 56 | * If supported, the backend will write the key "multi-queue-max-queues" to
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| 57 | * the directory for that vif, and set its value to the maximum supported
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| 58 | * number of queues.
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| 59 | * Frontends that are aware of this feature and wish to use it can write the
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| 60 | * key "multi-queue-num-queues", set to the number they wish to use, which
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| 61 | * must be greater than zero, and no more than the value reported by the backend
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| 62 | * in "multi-queue-max-queues".
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| 63 | *
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| 64 | * Queues replicate the shared rings and event channels.
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| 65 | * "feature-split-event-channels" may optionally be used when using
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| 66 | * multiple queues, but is not mandatory.
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| 67 | *
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| 68 | * Each queue consists of one shared ring pair, i.e. there must be the same
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| 69 | * number of tx and rx rings.
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| 70 | *
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| 71 | * For frontends requesting just one queue, the usual event-channel and
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| 72 | * ring-ref keys are written as before, simplifying the backend processing
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| 73 | * to avoid distinguishing between a frontend that doesn't understand the
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| 74 | * multi-queue feature, and one that does, but requested only one queue.
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| 75 | *
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| 76 | * Frontends requesting two or more queues must not write the toplevel
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| 77 | * event-channel (or event-channel-{tx,rx}) and {tx,rx}-ring-ref keys,
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| 78 | * instead writing those keys under sub-keys having the name "queue-N" where
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| 79 | * N is the integer ID of the queue for which those keys belong. Queues
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| 80 | * are indexed from zero. For example, a frontend with two queues and split
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| 81 | * event channels must write the following set of queue-related keys:
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| 82 | *
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| 83 | * /local/domain/1/device/vif/0/multi-queue-num-queues = "2"
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| 84 | * /local/domain/1/device/vif/0/queue-0 = ""
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| 85 | * /local/domain/1/device/vif/0/queue-0/tx-ring-ref = "<ring-ref-tx0>"
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| 86 | * /local/domain/1/device/vif/0/queue-0/rx-ring-ref = "<ring-ref-rx0>"
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| 87 | * /local/domain/1/device/vif/0/queue-0/event-channel-tx = "<evtchn-tx0>"
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| 88 | * /local/domain/1/device/vif/0/queue-0/event-channel-rx = "<evtchn-rx0>"
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| 89 | * /local/domain/1/device/vif/0/queue-1 = ""
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| 90 | * /local/domain/1/device/vif/0/queue-1/tx-ring-ref = "<ring-ref-tx1>"
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| 91 | * /local/domain/1/device/vif/0/queue-1/rx-ring-ref = "<ring-ref-rx1"
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| 92 | * /local/domain/1/device/vif/0/queue-1/event-channel-tx = "<evtchn-tx1>"
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| 93 | * /local/domain/1/device/vif/0/queue-1/event-channel-rx = "<evtchn-rx1>"
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| 94 | *
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| 95 | * If there is any inconsistency in the XenStore data, the backend may
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| 96 | * choose not to connect any queues, instead treating the request as an
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| 97 | * error. This includes scenarios where more (or fewer) queues were
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| 98 | * requested than the frontend provided details for.
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| 99 | *
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| 100 | * Mapping of packets to queues is considered to be a function of the
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| 101 | * transmitting system (backend or frontend) and is not negotiated
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| 102 | * between the two. Guests are free to transmit packets on any queue
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| 103 | * they choose, provided it has been set up correctly. Guests must be
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| 104 | * prepared to receive packets on any queue they have requested be set up.
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| 105 |
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| 106 |
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| 107 | |
| 108 | * "feature-no-csum-offload" should be used to turn IPv4 TCP/UDP checksum
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| 109 | * offload off or on. If it is missing then the feature is assumed to be on.
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| 110 | * "feature-ipv6-csum-offload" should be used to turn IPv6 TCP/UDP checksum
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| 111 | * offload on or off. If it is missing then the feature is assumed to be off.
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| 112 |
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| 113 |
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| 114 | |
| 115 | * "feature-gso-tcpv4" and "feature-gso-tcpv6" advertise the capability to
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| 116 | * handle large TCP packets (in IPv4 or IPv6 form respectively). Neither
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| 117 | * frontends nor backends are assumed to be capable unless the flags are
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| 118 | * present.
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| 119 |
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| 120 |
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| 121 | |
| 122 | * "feature-multicast-control" and "feature-dynamic-multicast-control"
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| 123 | * advertise the capability to filter ethernet multicast packets in the
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| 124 | * backend. If the frontend wishes to take advantage of this feature then
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| 125 | * it may set "request-multicast-control". If the backend only advertises
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| 126 | * "feature-multicast-control" then "request-multicast-control" must be set
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| 127 | * before the frontend moves into the connected state. The backend will
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| 128 | * sample the value on this state transition and any subsequent change in
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| 129 | * value will have no effect. However, if the backend also advertises
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| 130 | * "feature-dynamic-multicast-control" then "request-multicast-control"
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| 131 | * may be set by the frontend at any time. In this case, the backend will
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| 132 | * watch the value and re-sample on watch events.
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| 133 | *
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| 134 | * If the sampled value of "request-multicast-control" is set then the
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| 135 | * backend transmit side should no longer flood multicast packets to the
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| 136 | * frontend, it should instead drop any multicast packet that does not
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| 137 | * match in a filter list.
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| 138 | * The list is amended by the frontend by sending dummy transmit requests
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| 139 | * containing XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL} extra-info fragments as
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| 140 | * specified below.
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| 141 | * Note that the filter list may be amended even if the sampled value of
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| 142 | * "request-multicast-control" is not set, however the filter should only
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| 143 | * be applied if it is set.
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| 144 |
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| 145 |
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| 146 | |
| 147 | * "xdp-headroom" is used to request that extra space is added
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| 148 | * for XDP processing. The value is measured in bytes and passed by
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| 149 | * the frontend to be consistent between both ends.
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| 150 | * If the value is greater than zero that means that
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| 151 | * an RX response is going to be passed to an XDP program for processing.
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| 152 | * XEN_NETIF_MAX_XDP_HEADROOM defines the maximum headroom offset in bytes
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| 153 | *
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| 154 | * "feature-xdp-headroom" is set to "1" by the netback side like other features
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| 155 | * so a guest can check if an XDP program can be processed.
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| 156 |
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| 157 | #define XEN_NETIF_MAX_XDP_HEADROOM 0x7FFF
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| 158 |
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| 159 | |
| 160 | * Control ring
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| 161 | * ============
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| 162 | *
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| 163 | * Some features, such as hashing (detailed below), require a
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| 164 | * significant amount of out-of-band data to be passed from frontend to
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| 165 | * backend. Use of xenstore is not suitable for large quantities of data
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| 166 | * because of quota limitations and so a dedicated 'control ring' is used.
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| 167 | * The ability of the backend to use a control ring is advertised by
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| 168 | * setting:
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| 169 | *
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| 170 | * /local/domain/X/backend/<domid>/<vif>/feature-ctrl-ring = "1"
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| 171 | *
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| 172 | * The frontend provides a control ring to the backend by setting:
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| 173 | *
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| 174 | * /local/domain/<domid>/device/vif/<vif>/ctrl-ring-ref = <gref>
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| 175 | * /local/domain/<domid>/device/vif/<vif>/event-channel-ctrl = <port>
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| 176 | *
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| 177 | * where <gref> is the grant reference of the shared page used to
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| 178 | * implement the control ring and <port> is an event channel to be used
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| 179 | * as a mailbox interrupt. These keys must be set before the frontend
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| 180 | * moves into the connected state.
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| 181 | *
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| 182 | * The control ring uses a fixed request/response message size and is
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| 183 | * balanced (i.e. one request to one response), so operationally it is much
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| 184 | * the same as a transmit or receive ring.
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| 185 | * Note that there is no requirement that responses are issued in the same
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| 186 | * order as requests.
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| 187 |
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| 188 |
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| 189 | |
| 190 | * Hash types
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| 191 | * ==========
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| 192 | *
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| 193 | * For the purposes of the definitions below, 'Packet[]' is an array of
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| 194 | * octets containing an IP packet without options, 'Array[X..Y]' means a
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| 195 | * sub-array of 'Array' containing bytes X thru Y inclusive, and '+' is
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| 196 | * used to indicate concatenation of arrays.
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| 197 |
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| 198 |
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| 199 | |
| 200 | * A hash calculated over an IP version 4 header as follows:
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| 201 | *
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| 202 | * Buffer[0..8] = Packet[12..15] (source address) +
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| 203 | * Packet[16..19] (destination address)
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| 204 | *
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| 205 | * Result = Hash(Buffer, 8)
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| 206 |
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| 207 | #define _XEN_NETIF_CTRL_HASH_TYPE_IPV4 0
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| 208 | #define XEN_NETIF_CTRL_HASH_TYPE_IPV4 \
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| 209 | (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV4)
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| 210 |
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| 211 | |
| 212 | * A hash calculated over an IP version 4 header and TCP header as
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| 213 | * follows:
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| 214 | *
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| 215 | * Buffer[0..12] = Packet[12..15] (source address) +
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| 216 | * Packet[16..19] (destination address) +
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| 217 | * Packet[20..21] (source port) +
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| 218 | * Packet[22..23] (destination port)
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| 219 | *
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| 220 | * Result = Hash(Buffer, 12)
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| 221 |
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| 222 | #define _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP 1
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| 223 | #define XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP \
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| 224 | (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP)
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| 225 |
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| 226 | |
| 227 | * A hash calculated over an IP version 6 header as follows:
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| 228 | *
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| 229 | * Buffer[0..32] = Packet[8..23] (source address ) +
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| 230 | * Packet[24..39] (destination address)
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| 231 | *
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| 232 | * Result = Hash(Buffer, 32)
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| 233 |
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| 234 | #define _XEN_NETIF_CTRL_HASH_TYPE_IPV6 2
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| 235 | #define XEN_NETIF_CTRL_HASH_TYPE_IPV6 \
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| 236 | (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV6)
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| 237 |
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| 238 | |
| 239 | * A hash calculated over an IP version 6 header and TCP header as
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| 240 | * follows:
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| 241 | *
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| 242 | * Buffer[0..36] = Packet[8..23] (source address) +
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| 243 | * Packet[24..39] (destination address) +
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| 244 | * Packet[40..41] (source port) +
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| 245 | * Packet[42..43] (destination port)
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| 246 | *
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| 247 | * Result = Hash(Buffer, 36)
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| 248 |
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| 249 | #define _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP 3
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| 250 | #define XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP \
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| 251 | (1 << _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP)
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| 252 |
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| 253 | |
| 254 | * Hash algorithms
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| 255 | * ===============
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| 256 |
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| 257 |
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| 258 | #define XEN_NETIF_CTRL_HASH_ALGORITHM_NONE 0
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| 259 |
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| 260 | |
| 261 | * Toeplitz hash:
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| 262 |
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| 263 |
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| 264 | #define XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ 1
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| 265 |
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| 266 | |
| 267 | * This algorithm uses a 'key' as well as the data buffer itself.
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| 268 | * (Buffer[] and Key[] are treated as shift-registers where the MSB of
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| 269 | * Buffer/Key[0] is considered 'left-most' and the LSB of Buffer/Key[N-1]
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| 270 | * is the 'right-most').
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| 271 | *
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| 272 | * Value = 0
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| 273 | * For number of bits in Buffer[]
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| 274 | * If (left-most bit of Buffer[] is 1)
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| 275 | * Value ^= left-most 32 bits of Key[]
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| 276 | * Key[] << 1
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| 277 | * Buffer[] << 1
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| 278 | *
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| 279 | * The code below is provided for convenience where an operating system
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| 280 | * does not already provide an implementation.
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| 281 |
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| 282 | #ifdef XEN_NETIF_DEFINE_TOEPLITZ
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| 283 | static uint32_t xen_netif_toeplitz_hash(const uint8_t *key,
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| 284 | unsigned int keylen,
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| 285 | const uint8_t *buf, unsigned int buflen)
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| 286 | {
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| 287 | unsigned int keyi, bufi;
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| 288 | uint64_t prefix = 0;
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| 289 | uint64_t hash = 0;
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| 290 |
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| 291 |
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| 292 | for (keyi = 0; keyi < 8; keyi++) {
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| 293 | prefix <<= 8;
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| 294 | prefix |= (keyi < keylen) ? key[keyi] : 0;
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| 295 | }
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| 296 |
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| 297 | for (bufi = 0; bufi < buflen; bufi++) {
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| 298 | uint8_t byte = buf[bufi];
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| 299 | unsigned int bit;
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| 300 |
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| 301 | for (bit = 0; bit < 8; bit++) {
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| 302 | if (byte & 0x80)
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| 303 | hash ^= prefix;
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| 304 | prefix <<= 1;
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| 305 | byte <<= 1;
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| 306 | }
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| 307 |
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| 308 | |
| 309 | * 'prefix' has now been left-shifted by 8, so
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| 310 | * OR in the next byte.
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| 311 |
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| 312 | prefix |= (keyi < keylen) ? key[keyi] : 0;
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| 313 | keyi++;
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| 314 | }
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| 315 |
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| 316 |
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| 317 | return hash >> 32;
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| 318 | }
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| 319 | #endif
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| 320 |
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| 321 | |
| 322 | * Control requests (struct xen_netif_ctrl_request)
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| 323 | * ================================================
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| 324 | *
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| 325 | * All requests have the following format:
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| 326 | *
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| 327 | * 0 1 2 3 4 5 6 7 octet
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| 328 | * +-----+-----+-----+-----+-----+-----+-----+-----+
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| 329 | * | id | type | data[0] |
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| 330 | * +-----+-----+-----+-----+-----+-----+-----+-----+
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| 331 | * | data[1] | data[2] |
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| 332 | * +-----+-----+-----+-----+-----------------------+
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| 333 | *
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| 334 | * id: the request identifier, echoed in response.
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| 335 | * type: the type of request (see below)
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| 336 | * data[]: any data associated with the request (determined by type)
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| 337 |
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| 338 |
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| 339 | struct xen_netif_ctrl_request {
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| 340 | uint16_t id;
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| 341 | uint16_t type;
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| 342 |
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| 343 | #define XEN_NETIF_CTRL_TYPE_INVALID 0
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| 344 | #define XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS 1
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| 345 | #define XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS 2
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| 346 | #define XEN_NETIF_CTRL_TYPE_SET_HASH_KEY 3
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| 347 | #define XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE 4
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| 348 | #define XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE 5
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| 349 | #define XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING 6
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| 350 | #define XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM 7
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| 351 |
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| 352 | uint32_t data[3];
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| 353 | };
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| 354 |
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| 355 | |
| 356 | * Control responses (struct xen_netif_ctrl_response)
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| 357 | * ==================================================
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| 358 | *
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| 359 | * All responses have the following format:
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| 360 | *
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| 361 | * 0 1 2 3 4 5 6 7 octet
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| 362 | * +-----+-----+-----+-----+-----+-----+-----+-----+
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| 363 | * | id | type | status |
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| 364 | * +-----+-----+-----+-----+-----+-----+-----+-----+
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| 365 | * | data |
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| 366 | * +-----+-----+-----+-----+
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| 367 | *
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| 368 | * id: the corresponding request identifier
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| 369 | * type: the type of the corresponding request
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| 370 | * status: the status of request processing
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| 371 | * data: any data associated with the response (determined by type and
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| 372 | * status)
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| 373 |
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| 374 |
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| 375 | struct xen_netif_ctrl_response {
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| 376 | uint16_t id;
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| 377 | uint16_t type;
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| 378 | uint32_t status;
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| 379 |
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| 380 | #define XEN_NETIF_CTRL_STATUS_SUCCESS 0
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| 381 | #define XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED 1
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| 382 | #define XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER 2
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| 383 | #define XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW 3
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| 384 |
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| 385 | uint32_t data;
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| 386 | };
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| 387 |
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| 388 | |
| 389 | * Control messages
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| 390 | * ================
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| 391 | *
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| 392 | * XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM
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| 393 | * --------------------------------------
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| 394 | *
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| 395 | * This is sent by the frontend to set the desired hash algorithm.
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| 396 | *
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| 397 | * Request:
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| 398 | *
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| 399 | * type = XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM
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| 400 | * data[0] = a XEN_NETIF_CTRL_HASH_ALGORITHM_* value
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| 401 | * data[1] = 0
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| 402 | * data[2] = 0
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| 403 | *
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| 404 | * Response:
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| 405 | *
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| 406 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
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| 407 | * supported
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| 408 | * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - The algorithm is not
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| 409 | * supported
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| 410 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
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| 411 | *
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| 412 | * NOTE: Setting data[0] to XEN_NETIF_CTRL_HASH_ALGORITHM_NONE disables
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| 413 | * hashing and the backend is free to choose how it steers packets
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| 414 | * to queues (which is the default behaviour).
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| 415 | *
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| 416 | * XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS
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| 417 | * ----------------------------------
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| 418 | *
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| 419 | * This is sent by the frontend to query the types of hash supported by
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| 420 | * the backend.
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| 421 | *
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| 422 | * Request:
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| 423 | *
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| 424 | * type = XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS
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| 425 | * data[0] = 0
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| 426 | * data[1] = 0
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| 427 | * data[2] = 0
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| 428 | *
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| 429 | * Response:
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| 430 | *
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| 431 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not supported
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| 432 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
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| 433 | * data = supported hash types (if operation was successful)
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| 434 | *
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| 435 | * NOTE: A valid hash algorithm must be selected before this operation can
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| 436 | * succeed.
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| 437 | *
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| 438 | * XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS
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| 439 | * ----------------------------------
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| 440 | *
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| 441 | * This is sent by the frontend to set the types of hash that the backend
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| 442 | * should calculate. (See above for hash type definitions).
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| 443 | * Note that the 'maximal' type of hash should always be chosen. For
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| 444 | * example, if the frontend sets both IPV4 and IPV4_TCP hash types then
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| 445 | * the latter hash type should be calculated for any TCP packet and the
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| 446 | * former only calculated for non-TCP packets.
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| 447 | *
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| 448 | * Request:
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| 449 | *
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| 450 | * type = XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS
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| 451 | * data[0] = bitwise OR of XEN_NETIF_CTRL_HASH_TYPE_* values
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| 452 | * data[1] = 0
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| 453 | * data[2] = 0
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| 454 | *
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| 455 | * Response:
|
| 456 | *
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| 457 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
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| 458 | * supported
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| 459 | * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - One or more flag
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| 460 | * value is invalid or
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| 461 | * unsupported
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| 462 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
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| 463 | * data = 0
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| 464 | *
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| 465 | * NOTE: A valid hash algorithm must be selected before this operation can
|
| 466 | * succeed.
|
| 467 | * Also, setting data[0] to zero disables hashing and the backend
|
| 468 | * is free to choose how it steers packets to queues.
|
| 469 | *
|
| 470 | * XEN_NETIF_CTRL_TYPE_SET_HASH_KEY
|
| 471 | * --------------------------------
|
| 472 | *
|
| 473 | * This is sent by the frontend to set the key of the hash if the algorithm
|
| 474 | * requires it. (See hash algorithms above).
|
| 475 | *
|
| 476 | * Request:
|
| 477 | *
|
| 478 | * type = XEN_NETIF_CTRL_TYPE_SET_HASH_KEY
|
| 479 | * data[0] = grant reference of page containing the key (assumed to
|
| 480 | * start at beginning of grant)
|
| 481 | * data[1] = size of key in octets
|
| 482 | * data[2] = 0
|
| 483 | *
|
| 484 | * Response:
|
| 485 | *
|
| 486 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
|
| 487 | * supported
|
| 488 | * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Key size is invalid
|
| 489 | * XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW - Key size is larger
|
| 490 | * than the backend
|
| 491 | * supports
|
| 492 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
|
| 493 | * data = 0
|
| 494 | *
|
| 495 | * NOTE: Any key octets not specified are assumed to be zero (the key
|
| 496 | * is assumed to be empty by default) and specifying a new key
|
| 497 | * invalidates any previous key, hence specifying a key size of
|
| 498 | * zero will clear the key (which ensures that the calculated hash
|
| 499 | * will always be zero).
|
| 500 | * The maximum size of key is algorithm and backend specific, but
|
| 501 | * is also limited by the single grant reference.
|
| 502 | * The grant reference may be read-only and must remain valid until
|
| 503 | * the response has been processed.
|
| 504 | *
|
| 505 | * XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE
|
| 506 | * -----------------------------------------
|
| 507 | *
|
| 508 | * This is sent by the frontend to query the maximum size of mapping
|
| 509 | * table supported by the backend. The size is specified in terms of
|
| 510 | * table entries.
|
| 511 | *
|
| 512 | * Request:
|
| 513 | *
|
| 514 | * type = XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE
|
| 515 | * data[0] = 0
|
| 516 | * data[1] = 0
|
| 517 | * data[2] = 0
|
| 518 | *
|
| 519 | * Response:
|
| 520 | *
|
| 521 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not supported
|
| 522 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
|
| 523 | * data = maximum number of entries allowed in the mapping table
|
| 524 | * (if operation was successful) or zero if a mapping table is
|
| 525 | * not supported (i.e. hash mapping is done only by modular
|
| 526 | * arithmetic).
|
| 527 | *
|
| 528 | * XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE
|
| 529 | * -------------------------------------
|
| 530 | *
|
| 531 | * This is sent by the frontend to set the actual size of the mapping
|
| 532 | * table to be used by the backend. The size is specified in terms of
|
| 533 | * table entries.
|
| 534 | * Any previous table is invalidated by this message and any new table
|
| 535 | * is assumed to be zero filled.
|
| 536 | *
|
| 537 | * Request:
|
| 538 | *
|
| 539 | * type = XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE
|
| 540 | * data[0] = number of entries in mapping table
|
| 541 | * data[1] = 0
|
| 542 | * data[2] = 0
|
| 543 | *
|
| 544 | * Response:
|
| 545 | *
|
| 546 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
|
| 547 | * supported
|
| 548 | * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Table size is invalid
|
| 549 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
|
| 550 | * data = 0
|
| 551 | *
|
| 552 | * NOTE: Setting data[0] to 0 means that hash mapping should be done
|
| 553 | * using modular arithmetic.
|
| 554 | *
|
| 555 | * XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING
|
| 556 | * ------------------------------------
|
| 557 | *
|
| 558 | * This is sent by the frontend to set the content of the table mapping
|
| 559 | * hash value to queue number. The backend should calculate the hash from
|
| 560 | * the packet header, use it as an index into the table (modulo the size
|
| 561 | * of the table) and then steer the packet to the queue number found at
|
| 562 | * that index.
|
| 563 | *
|
| 564 | * Request:
|
| 565 | *
|
| 566 | * type = XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING
|
| 567 | * data[0] = grant reference of page containing the mapping (sub-)table
|
| 568 | * (assumed to start at beginning of grant)
|
| 569 | * data[1] = size of (sub-)table in entries
|
| 570 | * data[2] = offset, in entries, of sub-table within overall table
|
| 571 | *
|
| 572 | * Response:
|
| 573 | *
|
| 574 | * status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED - Operation not
|
| 575 | * supported
|
| 576 | * XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER - Table size or content
|
| 577 | * is invalid
|
| 578 | * XEN_NETIF_CTRL_STATUS_BUFFER_OVERFLOW - Table size is larger
|
| 579 | * than the backend
|
| 580 | * supports
|
| 581 | * XEN_NETIF_CTRL_STATUS_SUCCESS - Operation successful
|
| 582 | * data = 0
|
| 583 | *
|
| 584 | * NOTE: The overall table has the following format:
|
| 585 | *
|
| 586 | * 0 1 2 3 4 5 6 7 octet
|
| 587 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 588 | * | mapping[0] | mapping[1] |
|
| 589 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 590 | * | . |
|
| 591 | * | . |
|
| 592 | * | . |
|
| 593 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 594 | * | mapping[N-2] | mapping[N-1] |
|
| 595 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 596 | *
|
| 597 | * where N is specified by a XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE
|
| 598 | * message and each mapping must specifies a queue between 0 and
|
| 599 | * "multi-queue-num-queues" (see above).
|
| 600 | * The backend may support a mapping table larger than can be
|
| 601 | * mapped by a single grant reference. Thus sub-tables within a
|
| 602 | * larger table can be individually set by sending multiple messages
|
| 603 | * with differing offset values. Specifying a new sub-table does not
|
| 604 | * invalidate any table data outside that range.
|
| 605 | * The grant reference may be read-only and must remain valid until
|
| 606 | * the response has been processed.
|
| 607 |
|
| 608 |
|
| 609 | DEFINE_RING_TYPES(xen_netif_ctrl,
|
| 610 | struct xen_netif_ctrl_request,
|
| 611 | struct xen_netif_ctrl_response);
|
| 612 |
|
| 613 | |
| 614 | * Guest transmit
|
| 615 | * ==============
|
| 616 | *
|
| 617 | * This is the 'wire' format for transmit (frontend -> backend) packets:
|
| 618 | *
|
| 619 | * Fragment 1: xen_netif_tx_request_t - flags = XEN_NETTXF_*
|
| 620 | * size = total packet size
|
| 621 | * [Extra 1: xen_netif_extra_info_t] - (only if fragment 1 flags include
|
| 622 | * XEN_NETTXF_extra_info)
|
| 623 | * ...
|
| 624 | * [Extra N: xen_netif_extra_info_t] - (only if extra N-1 flags include
|
| 625 | * XEN_NETIF_EXTRA_MORE)
|
| 626 | * ...
|
| 627 | * Fragment N: xen_netif_tx_request_t - (only if fragment N-1 flags include
|
| 628 | * XEN_NETTXF_more_data - flags on preceding
|
| 629 | * extras are not relevant here)
|
| 630 | * flags = 0
|
| 631 | * size = fragment size
|
| 632 | *
|
| 633 | * NOTE:
|
| 634 | *
|
| 635 | * This format slightly is different from that used for receive
|
| 636 | * (backend -> frontend) packets. Specifically, in a multi-fragment
|
| 637 | * packet the actual size of fragment 1 can only be determined by
|
| 638 | * subtracting the sizes of fragments 2..N from the total packet size.
|
| 639 | *
|
| 640 | * Ring slot size is 12 octets, however not all request/response
|
| 641 | * structs use the full size.
|
| 642 | *
|
| 643 | * tx request data (xen_netif_tx_request_t)
|
| 644 | * ------------------------------------
|
| 645 | *
|
| 646 | * 0 1 2 3 4 5 6 7 octet
|
| 647 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 648 | * | grant ref | offset | flags |
|
| 649 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 650 | * | id | size |
|
| 651 | * +-----+-----+-----+-----+
|
| 652 | *
|
| 653 | * grant ref: Reference to buffer page.
|
| 654 | * offset: Offset within buffer page.
|
| 655 | * flags: XEN_NETTXF_*.
|
| 656 | * id: request identifier, echoed in response.
|
| 657 | * size: packet size in bytes.
|
| 658 | *
|
| 659 | * tx response (xen_netif_tx_response_t)
|
| 660 | * ---------------------------------
|
| 661 | *
|
| 662 | * 0 1 2 3 4 5 6 7 octet
|
| 663 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 664 | * | id | status | unused |
|
| 665 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 666 | * | unused |
|
| 667 | * +-----+-----+-----+-----+
|
| 668 | *
|
| 669 | * id: reflects id in transmit request
|
| 670 | * status: XEN_NETIF_RSP_*
|
| 671 | *
|
| 672 | * Guest receive
|
| 673 | * =============
|
| 674 | *
|
| 675 | * This is the 'wire' format for receive (backend -> frontend) packets:
|
| 676 | *
|
| 677 | * Fragment 1: xen_netif_rx_request_t - flags = XEN_NETRXF_*
|
| 678 | * size = fragment size
|
| 679 | * [Extra 1: xen_netif_extra_info_t] - (only if fragment 1 flags include
|
| 680 | * XEN_NETRXF_extra_info)
|
| 681 | * ...
|
| 682 | * [Extra N: xen_netif_extra_info_t] - (only if extra N-1 flags include
|
| 683 | * XEN_NETIF_EXTRA_MORE)
|
| 684 | * ...
|
| 685 | * Fragment N: xen_netif_rx_request_t - (only if fragment N-1 flags include
|
| 686 | * XEN_NETRXF_more_data - flags on preceding
|
| 687 | * extras are not relevant here)
|
| 688 | * flags = 0
|
| 689 | * size = fragment size
|
| 690 | *
|
| 691 | * NOTE:
|
| 692 | *
|
| 693 | * This format slightly is different from that used for transmit
|
| 694 | * (frontend -> backend) packets. Specifically, in a multi-fragment
|
| 695 | * packet the size of the packet can only be determined by summing the
|
| 696 | * sizes of fragments 1..N.
|
| 697 | *
|
| 698 | * Ring slot size is 8 octets.
|
| 699 | *
|
| 700 | * rx request (xen_netif_rx_request_t)
|
| 701 | * -------------------------------
|
| 702 | *
|
| 703 | * 0 1 2 3 4 5 6 7 octet
|
| 704 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 705 | * | id | pad | gref |
|
| 706 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 707 | *
|
| 708 | * id: request identifier, echoed in response.
|
| 709 | * gref: reference to incoming granted frame.
|
| 710 | *
|
| 711 | * rx response (xen_netif_rx_response_t)
|
| 712 | * ---------------------------------
|
| 713 | *
|
| 714 | * 0 1 2 3 4 5 6 7 octet
|
| 715 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 716 | * | id | offset | flags | status |
|
| 717 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 718 | *
|
| 719 | * id: reflects id in receive request
|
| 720 | * offset: offset in page of start of received packet
|
| 721 | * flags: XEN_NETRXF_*
|
| 722 | * status: -ve: XEN_NETIF_RSP_*; +ve: Rx'ed pkt size.
|
| 723 | *
|
| 724 | * NOTE: Historically, to support GSO on the frontend receive side, Linux
|
| 725 | * netfront does not make use of the rx response id (because, as
|
| 726 | * described below, extra info structures overlay the id field).
|
| 727 | * Instead it assumes that responses always appear in the same ring
|
| 728 | * slot as their corresponding request. Thus, to maintain
|
| 729 | * compatibility, backends must make sure this is the case.
|
| 730 | *
|
| 731 | * Extra Info
|
| 732 | * ==========
|
| 733 | *
|
| 734 | * Can be present if initial request or response has NET{T,R}XF_extra_info,
|
| 735 | * or previous extra request has XEN_NETIF_EXTRA_MORE.
|
| 736 | *
|
| 737 | * The struct therefore needs to fit into either a tx or rx slot and
|
| 738 | * is therefore limited to 8 octets.
|
| 739 | *
|
| 740 | * NOTE: Because extra info data overlays the usual request/response
|
| 741 | * structures, there is no id information in the opposite direction.
|
| 742 | * So, if an extra info overlays an rx response the frontend can
|
| 743 | * assume that it is in the same ring slot as the request that was
|
| 744 | * consumed to make the slot available, and the backend must ensure
|
| 745 | * this assumption is true.
|
| 746 | *
|
| 747 | * extra info (xen_netif_extra_info_t)
|
| 748 | * -------------------------------
|
| 749 | *
|
| 750 | * General format:
|
| 751 | *
|
| 752 | * 0 1 2 3 4 5 6 7 octet
|
| 753 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 754 | * |type |flags| type specific data |
|
| 755 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 756 | * | padding for tx |
|
| 757 | * +-----+-----+-----+-----+
|
| 758 | *
|
| 759 | * type: XEN_NETIF_EXTRA_TYPE_*
|
| 760 | * flags: XEN_NETIF_EXTRA_FLAG_*
|
| 761 | * padding for tx: present only in the tx case due to 8 octet limit
|
| 762 | * from rx case. Not shown in type specific entries
|
| 763 | * below.
|
| 764 | *
|
| 765 | * XEN_NETIF_EXTRA_TYPE_GSO:
|
| 766 | *
|
| 767 | * 0 1 2 3 4 5 6 7 octet
|
| 768 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 769 | * |type |flags| size |type | pad | features |
|
| 770 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 771 | *
|
| 772 | * type: Must be XEN_NETIF_EXTRA_TYPE_GSO
|
| 773 | * flags: XEN_NETIF_EXTRA_FLAG_*
|
| 774 | * size: Maximum payload size of each segment. For example,
|
| 775 | * for TCP this is just the path MSS.
|
| 776 | * type: XEN_NETIF_GSO_TYPE_*: This determines the protocol of
|
| 777 | * the packet and any extra features required to segment the
|
| 778 | * packet properly.
|
| 779 | * features: EN_XEN_NETIF_GSO_FEAT_*: This specifies any extra GSO
|
| 780 | * features required to process this packet, such as ECN
|
| 781 | * support for TCPv4.
|
| 782 | *
|
| 783 | * XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}:
|
| 784 | *
|
| 785 | * 0 1 2 3 4 5 6 7 octet
|
| 786 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 787 | * |type |flags| addr |
|
| 788 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 789 | *
|
| 790 | * type: Must be XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}
|
| 791 | * flags: XEN_NETIF_EXTRA_FLAG_*
|
| 792 | * addr: address to add/remove
|
| 793 | *
|
| 794 | * XEN_NETIF_EXTRA_TYPE_HASH:
|
| 795 | *
|
| 796 | * A backend that supports teoplitz hashing is assumed to accept
|
| 797 | * this type of extra info in transmit packets.
|
| 798 | * A frontend that enables hashing is assumed to accept
|
| 799 | * this type of extra info in receive packets.
|
| 800 | *
|
| 801 | * 0 1 2 3 4 5 6 7 octet
|
| 802 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 803 | * |type |flags|htype| alg |LSB ---- value ---- MSB|
|
| 804 | * +-----+-----+-----+-----+-----+-----+-----+-----+
|
| 805 | *
|
| 806 | * type: Must be XEN_NETIF_EXTRA_TYPE_HASH
|
| 807 | * flags: XEN_NETIF_EXTRA_FLAG_*
|
| 808 | * htype: Hash type (one of _XEN_NETIF_CTRL_HASH_TYPE_* - see above)
|
| 809 | * alg: The algorithm used to calculate the hash (one of
|
| 810 | * XEN_NETIF_CTRL_HASH_TYPE_ALGORITHM_* - see above)
|
| 811 | * value: Hash value
|
| 812 |
|
| 813 |
|
| 814 |
|
| 815 | #define _XEN_NETTXF_csum_blank (0)
|
| 816 | #define XEN_NETTXF_csum_blank (1U<<_XEN_NETTXF_csum_blank)
|
| 817 |
|
| 818 |
|
| 819 | #define _XEN_NETTXF_data_validated (1)
|
| 820 | #define XEN_NETTXF_data_validated (1U<<_XEN_NETTXF_data_validated)
|
| 821 |
|
| 822 |
|
| 823 | #define _XEN_NETTXF_more_data (2)
|
| 824 | #define XEN_NETTXF_more_data (1U<<_XEN_NETTXF_more_data)
|
| 825 |
|
| 826 |
|
| 827 | #define _XEN_NETTXF_extra_info (3)
|
| 828 | #define XEN_NETTXF_extra_info (1U<<_XEN_NETTXF_extra_info)
|
| 829 |
|
| 830 | #define XEN_NETIF_MAX_TX_SIZE 0xFFFF
|
| 831 | struct xen_netif_tx_request {
|
| 832 | grant_ref_t gref;
|
| 833 | uint16_t offset;
|
| 834 | uint16_t flags;
|
| 835 | uint16_t id;
|
| 836 | uint16_t size;
|
| 837 | };
|
| 838 |
|
| 839 |
|
| 840 | #define XEN_NETIF_EXTRA_TYPE_NONE (0)
|
| 841 | #define XEN_NETIF_EXTRA_TYPE_GSO (1)
|
| 842 | #define XEN_NETIF_EXTRA_TYPE_MCAST_ADD (2)
|
| 843 | #define XEN_NETIF_EXTRA_TYPE_MCAST_DEL (3)
|
| 844 | #define XEN_NETIF_EXTRA_TYPE_HASH (4)
|
| 845 | #define XEN_NETIF_EXTRA_TYPE_XDP (5)
|
| 846 | #define XEN_NETIF_EXTRA_TYPE_MAX (6)
|
| 847 |
|
| 848 |
|
| 849 | #define _XEN_NETIF_EXTRA_FLAG_MORE (0)
|
| 850 | #define XEN_NETIF_EXTRA_FLAG_MORE (1U<<_XEN_NETIF_EXTRA_FLAG_MORE)
|
| 851 |
|
| 852 |
|
| 853 | #define XEN_NETIF_GSO_TYPE_NONE (0)
|
| 854 | #define XEN_NETIF_GSO_TYPE_TCPV4 (1)
|
| 855 | #define XEN_NETIF_GSO_TYPE_TCPV6 (2)
|
| 856 |
|
| 857 | |
| 858 | * This structure needs to fit within both xen_netif_tx_request_t and
|
| 859 | * xen_netif_rx_response_t for compatibility.
|
| 860 |
|
| 861 | struct xen_netif_extra_info {
|
| 862 | uint8_t type;
|
| 863 | uint8_t flags;
|
| 864 | union {
|
| 865 | struct {
|
| 866 | uint16_t size;
|
| 867 | uint8_t type;
|
| 868 | uint8_t pad;
|
| 869 | uint16_t features;
|
| 870 | } gso;
|
| 871 | struct {
|
| 872 | uint8_t addr[6];
|
| 873 | } mcast;
|
| 874 | struct {
|
| 875 | uint8_t type;
|
| 876 | uint8_t algorithm;
|
| 877 | uint8_t value[4];
|
| 878 | } hash;
|
| 879 | struct {
|
| 880 | uint16_t headroom;
|
| 881 | uint16_t pad[2];
|
| 882 | } xdp;
|
| 883 | uint16_t pad[3];
|
| 884 | } u;
|
| 885 | };
|
| 886 |
|
| 887 | struct xen_netif_tx_response {
|
| 888 | uint16_t id;
|
| 889 | int16_t status;
|
| 890 | };
|
| 891 |
|
| 892 | struct xen_netif_rx_request {
|
| 893 | uint16_t id;
|
| 894 | uint16_t pad;
|
| 895 | grant_ref_t gref;
|
| 896 | };
|
| 897 |
|
| 898 |
|
| 899 | #define _XEN_NETRXF_data_validated (0)
|
| 900 | #define XEN_NETRXF_data_validated (1U<<_XEN_NETRXF_data_validated)
|
| 901 |
|
| 902 |
|
| 903 | #define _XEN_NETRXF_csum_blank (1)
|
| 904 | #define XEN_NETRXF_csum_blank (1U<<_XEN_NETRXF_csum_blank)
|
| 905 |
|
| 906 |
|
| 907 | #define _XEN_NETRXF_more_data (2)
|
| 908 | #define XEN_NETRXF_more_data (1U<<_XEN_NETRXF_more_data)
|
| 909 |
|
| 910 |
|
| 911 | #define _XEN_NETRXF_extra_info (3)
|
| 912 | #define XEN_NETRXF_extra_info (1U<<_XEN_NETRXF_extra_info)
|
| 913 |
|
| 914 |
|
| 915 | #define _XEN_NETRXF_gso_prefix (4)
|
| 916 | #define XEN_NETRXF_gso_prefix (1U<<_XEN_NETRXF_gso_prefix)
|
| 917 |
|
| 918 | struct xen_netif_rx_response {
|
| 919 | uint16_t id;
|
| 920 | uint16_t offset;
|
| 921 | uint16_t flags;
|
| 922 | int16_t status;
|
| 923 | };
|
| 924 |
|
| 925 | |
| 926 | * Generate xen_netif ring structures and types.
|
| 927 |
|
| 928 |
|
| 929 | DEFINE_RING_TYPES(xen_netif_tx, struct xen_netif_tx_request,
|
| 930 | struct xen_netif_tx_response);
|
| 931 | DEFINE_RING_TYPES(xen_netif_rx, struct xen_netif_rx_request,
|
| 932 | struct xen_netif_rx_response);
|
| 933 |
|
| 934 | #define XEN_NETIF_RSP_DROPPED -2
|
| 935 | #define XEN_NETIF_RSP_ERROR -1
|
| 936 | #define XEN_NETIF_RSP_OKAY 0
|
| 937 |
|
| 938 | #define XEN_NETIF_RSP_NULL 1
|
| 939 |
|
| 940 | #endif
|