1251767Sgibbs/****************************************************************************** 2251767Sgibbs * vscsiif.h 3288917Sroyger * 4251767Sgibbs * Based on the blkif.h code. 5288917Sroyger * 6251767Sgibbs * Permission is hereby granted, free of charge, to any person obtaining a copy 7251767Sgibbs * of this software and associated documentation files (the "Software"), to 8251767Sgibbs * deal in the Software without restriction, including without limitation the 9251767Sgibbs * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 10251767Sgibbs * sell copies of the Software, and to permit persons to whom the Software is 11251767Sgibbs * furnished to do so, subject to the following conditions: 12251767Sgibbs * 13251767Sgibbs * The above copyright notice and this permission notice shall be included in 14251767Sgibbs * all copies or substantial portions of the Software. 15251767Sgibbs * 16251767Sgibbs * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17251767Sgibbs * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18251767Sgibbs * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 19251767Sgibbs * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20251767Sgibbs * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 21251767Sgibbs * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 22251767Sgibbs * DEALINGS IN THE SOFTWARE. 23251767Sgibbs * 24251767Sgibbs * Copyright(c) FUJITSU Limited 2008. 25251767Sgibbs */ 26251767Sgibbs 27251767Sgibbs#ifndef __XEN__PUBLIC_IO_SCSI_H__ 28251767Sgibbs#define __XEN__PUBLIC_IO_SCSI_H__ 29251767Sgibbs 30251767Sgibbs#include "ring.h" 31251767Sgibbs#include "../grant_table.h" 32251767Sgibbs 33288917Sroyger/* 34288917Sroyger * Feature and Parameter Negotiation 35288917Sroyger * ================================= 36288917Sroyger * The two halves of a Xen pvSCSI driver utilize nodes within the XenStore to 37288917Sroyger * communicate capabilities and to negotiate operating parameters. This 38288917Sroyger * section enumerates these nodes which reside in the respective front and 39288917Sroyger * backend portions of the XenStore, following the XenBus convention. 40288917Sroyger * 41288917Sroyger * Any specified default value is in effect if the corresponding XenBus node 42288917Sroyger * is not present in the XenStore. 43288917Sroyger * 44288917Sroyger * XenStore nodes in sections marked "PRIVATE" are solely for use by the 45288917Sroyger * driver side whose XenBus tree contains them. 46288917Sroyger * 47288917Sroyger ***************************************************************************** 48288917Sroyger * Backend XenBus Nodes 49288917Sroyger ***************************************************************************** 50288917Sroyger * 51288917Sroyger *------------------ Backend Device Identification (PRIVATE) ------------------ 52288917Sroyger * 53288917Sroyger * p-devname 54288917Sroyger * Values: string 55288917Sroyger * 56288917Sroyger * A free string used to identify the physical device (e.g. a disk name). 57288917Sroyger * 58288917Sroyger * p-dev 59288917Sroyger * Values: string 60288917Sroyger * 61288917Sroyger * A string specifying the backend device: either a 4-tuple "h:c:t:l" 62288917Sroyger * (host, controller, target, lun, all integers), or a WWN (e.g. 63288917Sroyger * "naa.60014054ac780582"). 64288917Sroyger * 65288917Sroyger * v-dev 66288917Sroyger * Values: string 67288917Sroyger * 68288917Sroyger * A string specifying the frontend device in form of a 4-tuple "h:c:t:l" 69288917Sroyger * (host, controller, target, lun, all integers). 70288917Sroyger * 71288917Sroyger *--------------------------------- Features --------------------------------- 72288917Sroyger * 73288917Sroyger * feature-sg-grant 74288917Sroyger * Values: unsigned [VSCSIIF_SG_TABLESIZE...65535] 75288917Sroyger * Default Value: 0 76288917Sroyger * 77288917Sroyger * Specifies the maximum number of scatter/gather elements in grant pages 78288917Sroyger * supported. If not set, the backend supports up to VSCSIIF_SG_TABLESIZE 79288917Sroyger * SG elements specified directly in the request. 80288917Sroyger * 81288917Sroyger ***************************************************************************** 82288917Sroyger * Frontend XenBus Nodes 83288917Sroyger ***************************************************************************** 84288917Sroyger * 85288917Sroyger *----------------------- Request Transport Parameters ----------------------- 86288917Sroyger * 87288917Sroyger * event-channel 88288917Sroyger * Values: unsigned 89288917Sroyger * 90288917Sroyger * The identifier of the Xen event channel used to signal activity 91288917Sroyger * in the ring buffer. 92288917Sroyger * 93288917Sroyger * ring-ref 94288917Sroyger * Values: unsigned 95288917Sroyger * 96288917Sroyger * The Xen grant reference granting permission for the backend to map 97288917Sroyger * the sole page in a single page sized ring buffer. 98288917Sroyger * 99288917Sroyger * protocol 100288917Sroyger * Values: string (XEN_IO_PROTO_ABI_*) 101288917Sroyger * Default Value: XEN_IO_PROTO_ABI_NATIVE 102288917Sroyger * 103288917Sroyger * The machine ABI rules governing the format of all ring request and 104288917Sroyger * response structures. 105288917Sroyger */ 106251767Sgibbs 107288917Sroyger/* Requests from the frontend to the backend */ 108251767Sgibbs 109288917Sroyger/* 110288917Sroyger * Request a SCSI operation specified via a CDB in vscsiif_request.cmnd. 111288917Sroyger * The target is specified via channel, id and lun. 112288917Sroyger * 113288917Sroyger * The operation to be performed is specified via a CDB in cmnd[], the length 114288917Sroyger * of the CDB is in cmd_len. sc_data_direction specifies the direction of data 115288917Sroyger * (to the device, from the device, or none at all). 116288917Sroyger * 117288917Sroyger * If data is to be transferred to or from the device the buffer(s) in the 118288917Sroyger * guest memory is/are specified via one or multiple scsiif_request_segment 119288917Sroyger * descriptors each specifying a memory page via a grant_ref_t, a offset into 120288917Sroyger * the page and the length of the area in that page. All scsiif_request_segment 121288917Sroyger * areas concatenated form the resulting data buffer used by the operation. 122288917Sroyger * If the number of scsiif_request_segment areas is not too large (less than 123288917Sroyger * or equal VSCSIIF_SG_TABLESIZE) the areas can be specified directly in the 124288917Sroyger * seg[] array and the number of valid scsiif_request_segment elements is to be 125288917Sroyger * set in nr_segments. 126288917Sroyger * 127288917Sroyger * If "feature-sg-grant" in the Xenstore is set it is possible to specify more 128288917Sroyger * than VSCSIIF_SG_TABLESIZE scsiif_request_segment elements via indirection. 129288917Sroyger * The maximum number of allowed scsiif_request_segment elements is the value 130288917Sroyger * of the "feature-sg-grant" entry from Xenstore. When using indirection the 131288917Sroyger * seg[] array doesn't contain specifications of the data buffers, but 132288917Sroyger * references to scsiif_request_segment arrays, which in turn reference the 133288917Sroyger * data buffers. While nr_segments holds the number of populated seg[] entries 134288917Sroyger * (plus the set VSCSIIF_SG_GRANT bit), the number of scsiif_request_segment 135288917Sroyger * elements referencing the target data buffers is calculated from the lengths 136288917Sroyger * of the seg[] elements (the sum of all valid seg[].length divided by the 137288917Sroyger * size of one scsiif_request_segment structure). The frontend may use a mix of 138288917Sroyger * direct and indirect requests. 139288917Sroyger */ 140288917Sroyger#define VSCSIIF_ACT_SCSI_CDB 1 141251767Sgibbs 142251767Sgibbs/* 143288917Sroyger * Request abort of a running operation for the specified target given by 144288917Sroyger * channel, id, lun and the operation's rqid in ref_rqid. 145288917Sroyger */ 146288917Sroyger#define VSCSIIF_ACT_SCSI_ABORT 2 147288917Sroyger 148288917Sroyger/* 149288917Sroyger * Request a device reset of the specified target (channel and id). 150288917Sroyger */ 151288917Sroyger#define VSCSIIF_ACT_SCSI_RESET 3 152288917Sroyger 153288917Sroyger/* 154288917Sroyger * Preset scatter/gather elements for a following request. Deprecated. 155288917Sroyger * Keeping the define only to avoid usage of the value "4" for other actions. 156288917Sroyger */ 157288917Sroyger#define VSCSIIF_ACT_SCSI_SG_PRESET 4 158288917Sroyger 159288917Sroyger/* 160251767Sgibbs * Maximum scatter/gather segments per request. 161251767Sgibbs * 162288917Sroyger * Considering balance between allocating at least 16 "vscsiif_request" 163288917Sroyger * structures on one page (4096 bytes) and the number of scatter/gather 164288917Sroyger * elements needed, we decided to use 26 as a magic number. 165288917Sroyger * 166288917Sroyger * If "feature-sg-grant" is set, more scatter/gather elements can be specified 167288917Sroyger * by placing them in one or more (up to VSCSIIF_SG_TABLESIZE) granted pages. 168288917Sroyger * In this case the vscsiif_request seg elements don't contain references to 169288917Sroyger * the user data, but to the SG elements referencing the user data. 170251767Sgibbs */ 171251767Sgibbs#define VSCSIIF_SG_TABLESIZE 26 172251767Sgibbs 173251767Sgibbs/* 174288917Sroyger * based on Linux kernel 2.6.18, still valid 175288917Sroyger * 176288917Sroyger * Changing these values requires support of multiple protocols via the rings 177288917Sroyger * as "old clients" will blindly use these values and the resulting structure 178288917Sroyger * sizes. 179251767Sgibbs */ 180251767Sgibbs#define VSCSIIF_MAX_COMMAND_SIZE 16 181251767Sgibbs#define VSCSIIF_SENSE_BUFFERSIZE 96 182251767Sgibbs 183288917Sroygerstruct scsiif_request_segment { 184288917Sroyger grant_ref_t gref; 185288917Sroyger uint16_t offset; 186288917Sroyger uint16_t length; 187288917Sroyger}; 188288917Sroygertypedef struct scsiif_request_segment vscsiif_segment_t; 189251767Sgibbs 190288917Sroyger#define VSCSIIF_SG_PER_PAGE (PAGE_SIZE / sizeof(struct scsiif_request_segment)) 191288917Sroyger 192288917Sroyger/* Size of one request is 252 bytes */ 193251767Sgibbsstruct vscsiif_request { 194251767Sgibbs uint16_t rqid; /* private guest value, echoed in resp */ 195251767Sgibbs uint8_t act; /* command between backend and frontend */ 196288917Sroyger uint8_t cmd_len; /* valid CDB bytes */ 197251767Sgibbs 198288917Sroyger uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE]; /* the CDB */ 199288917Sroyger uint16_t timeout_per_command; /* deprecated: timeout in secs, 0=default */ 200288917Sroyger uint16_t channel, id, lun; /* (virtual) device specification */ 201288917Sroyger uint16_t ref_rqid; /* command abort reference */ 202288917Sroyger uint8_t sc_data_direction; /* for DMA_TO_DEVICE(1) 203288917Sroyger DMA_FROM_DEVICE(2) 204288917Sroyger DMA_NONE(3) requests */ 205288917Sroyger uint8_t nr_segments; /* Number of pieces of scatter-gather */ 206288917Sroyger/* 207288917Sroyger * flag in nr_segments: SG elements via grant page 208288917Sroyger * 209288917Sroyger * If VSCSIIF_SG_GRANT is set, the low 7 bits of nr_segments specify the number 210288917Sroyger * of grant pages containing SG elements. Usable if "feature-sg-grant" set. 211288917Sroyger */ 212288917Sroyger#define VSCSIIF_SG_GRANT 0x80 213251767Sgibbs 214288917Sroyger vscsiif_segment_t seg[VSCSIIF_SG_TABLESIZE]; 215251767Sgibbs uint32_t reserved[3]; 216251767Sgibbs}; 217251767Sgibbstypedef struct vscsiif_request vscsiif_request_t; 218251767Sgibbs 219288917Sroyger/* 220288917Sroyger * The following interface is deprecated! 221288917Sroyger */ 222288917Sroyger#define VSCSIIF_SG_LIST_SIZE ((sizeof(vscsiif_request_t) - 4) \ 223288917Sroyger / sizeof(vscsiif_segment_t)) 224288917Sroyger 225288917Sroygerstruct vscsiif_sg_list { 226288917Sroyger /* First two fields must match struct vscsiif_request! */ 227288917Sroyger uint16_t rqid; /* private guest value, must match main req */ 228288917Sroyger uint8_t act; /* VSCSIIF_ACT_SCSI_SG_PRESET */ 229288917Sroyger uint8_t nr_segments; /* Number of pieces of scatter-gather */ 230288917Sroyger vscsiif_segment_t seg[VSCSIIF_SG_LIST_SIZE]; 231288917Sroyger}; 232288917Sroygertypedef struct vscsiif_sg_list vscsiif_sg_list_t; 233288917Sroyger/* End of deprecated interface */ 234288917Sroyger 235288917Sroyger/* Size of one response is 252 bytes */ 236251767Sgibbsstruct vscsiif_response { 237288917Sroyger uint16_t rqid; /* identifies request */ 238288917Sroyger uint8_t act; /* deprecated: valid only if SG_PRESET supported */ 239251767Sgibbs uint8_t sense_len; 240251767Sgibbs uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE]; 241251767Sgibbs int32_t rslt; 242251767Sgibbs uint32_t residual_len; /* request bufflen - 243251767Sgibbs return the value from physical device */ 244251767Sgibbs uint32_t reserved[36]; 245251767Sgibbs}; 246251767Sgibbstypedef struct vscsiif_response vscsiif_response_t; 247251767Sgibbs 248251767SgibbsDEFINE_RING_TYPES(vscsiif, struct vscsiif_request, struct vscsiif_response); 249251767Sgibbs 250251767Sgibbs 251251767Sgibbs#endif /*__XEN__PUBLIC_IO_SCSI_H__*/ 252251767Sgibbs/* 253251767Sgibbs * Local variables: 254251767Sgibbs * mode: C 255288917Sroyger * c-file-style: "BSD" 256251767Sgibbs * c-basic-offset: 4 257251767Sgibbs * tab-width: 4 258251767Sgibbs * indent-tabs-mode: nil 259251767Sgibbs * End: 260251767Sgibbs */ 261