diff options
Diffstat (limited to 'include/xen/io')
| -rw-r--r-- | include/xen/io/blkif.h | 608 | ||||
| -rw-r--r-- | include/xen/io/console.h | 51 | ||||
| -rw-r--r-- | include/xen/io/protocols.h | 40 | ||||
| -rw-r--r-- | include/xen/io/ring.h | 312 | ||||
| -rw-r--r-- | include/xen/io/xenbus.h | 80 | ||||
| -rw-r--r-- | include/xen/io/xs_wire.h | 138 |
6 files changed, 1229 insertions, 0 deletions
diff --git a/include/xen/io/blkif.h b/include/xen/io/blkif.h new file mode 100644 index 0000000..c3e169c --- /dev/null +++ b/include/xen/io/blkif.h @@ -0,0 +1,608 @@ +/****************************************************************************** + * blkif.h + * + * Unified block-device I/O interface for Xen guest OSes. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + * Copyright (c) 2003-2004, Keir Fraser + * Copyright (c) 2012, Spectra Logic Corporation + */ + +#ifndef __XEN_PUBLIC_IO_BLKIF_H__ +#define __XEN_PUBLIC_IO_BLKIF_H__ + +#include "ring.h" +#include "../grant_table.h" + +/* + * Front->back notifications: When enqueuing a new request, sending a + * notification can be made conditional on req_event (i.e., the generic + * hold-off mechanism provided by the ring macros). Backends must set + * req_event appropriately (e.g., using RING_FINAL_CHECK_FOR_REQUESTS()). + * + * Back->front notifications: When enqueuing a new response, sending a + * notification can be made conditional on rsp_event (i.e., the generic + * hold-off mechanism provided by the ring macros). Frontends must set + * rsp_event appropriately (e.g., using RING_FINAL_CHECK_FOR_RESPONSES()). + */ + +#ifndef blkif_vdev_t +#define blkif_vdev_t uint16_t +#endif +#define blkif_sector_t uint64_t + +/* + * Feature and Parameter Negotiation + * ================================= + * The two halves of a Xen block driver utilize nodes within the XenStore to + * communicate capabilities and to negotiate operating parameters. This + * section enumerates these nodes which reside in the respective front and + * backend portions of the XenStore, following the XenBus convention. + * + * All data in the XenStore is stored as strings. Nodes specifying numeric + * values are encoded in decimal. Integer value ranges listed below are + * expressed as fixed sized integer types capable of storing the conversion + * of a properly formated node string, without loss of information. + * + * Any specified default value is in effect if the corresponding XenBus node + * is not present in the XenStore. + * + * XenStore nodes in sections marked "PRIVATE" are solely for use by the + * driver side whose XenBus tree contains them. + * + * XenStore nodes marked "DEPRECATED" in their notes section should only be + * used to provide interoperability with legacy implementations. + * + * See the XenBus state transition diagram below for details on when XenBus + * nodes must be published and when they can be queried. + * + ***************************************************************************** + * Backend XenBus Nodes + ***************************************************************************** + * + *------------------ Backend Device Identification (PRIVATE) ------------------ + * + * mode + * Values: "r" (read only), "w" (writable) + * + * The read or write access permissions to the backing store to be + * granted to the frontend. + * + * params + * Values: string + * + * A free formatted string providing sufficient information for the + * backend driver to open the backing device. (e.g. the path to the + * file or block device representing the backing store.) + * + * type + * Values: "file", "phy", "tap" + * + * The type of the backing device/object. + * + *--------------------------------- Features --------------------------------- + * + * feature-barrier + * Values: 0/1 (boolean) + * Default Value: 0 + * + * A value of "1" indicates that the backend can process requests + * containing the BLKIF_OP_WRITE_BARRIER request opcode. Requests + * of this type may still be returned at any time with the + * BLKIF_RSP_EOPNOTSUPP result code. + * + * feature-flush-cache + * Values: 0/1 (boolean) + * Default Value: 0 + * + * A value of "1" indicates that the backend can process requests + * containing the BLKIF_OP_FLUSH_DISKCACHE request opcode. Requests + * of this type may still be returned at any time with the + * BLKIF_RSP_EOPNOTSUPP result code. + * + * feature-discard + * Values: 0/1 (boolean) + * Default Value: 0 + * + * A value of "1" indicates that the backend can process requests + * containing the BLKIF_OP_DISCARD request opcode. Requests + * of this type may still be returned at any time with the + * BLKIF_RSP_EOPNOTSUPP result code. + * + * feature-persistent + * Values: 0/1 (boolean) + * Default Value: 0 + * Notes: 7 + * + * A value of "1" indicates that the backend can keep the grants used + * by the frontend driver mapped, so the same set of grants should be + * used in all transactions. The maximum number of grants the backend + * can map persistently depends on the implementation, but ideally it + * should be RING_SIZE * BLKIF_MAX_SEGMENTS_PER_REQUEST. Using this + * feature the backend doesn't need to unmap each grant, preventing + * costly TLB flushes. The backend driver should only map grants + * persistently if the frontend supports it. If a backend driver chooses + * to use the persistent protocol when the frontend doesn't support it, + * it will probably hit the maximum number of persistently mapped grants + * (due to the fact that the frontend won't be reusing the same grants), + * and fall back to non-persistent mode. Backend implementations may + * shrink or expand the number of persistently mapped grants without + * notifying the frontend depending on memory constraints (this might + * cause a performance degradation). + * + * If a backend driver wants to limit the maximum number of persistently + * mapped grants to a value less than RING_SIZE * + * BLKIF_MAX_SEGMENTS_PER_REQUEST a LRU strategy should be used to + * discard the grants that are less commonly used. Using a LRU in the + * backend driver paired with a LIFO queue in the frontend will + * allow us to have better performance in this scenario. + * + *----------------------- Request Transport Parameters ------------------------ + * + * max-ring-page-order + * Values: <uint32_t> + * Default Value: 0 + * Notes: 1, 3 + * + * The maximum supported size of the request ring buffer in units of + * lb(machine pages). (e.g. 0 == 1 page, 1 = 2 pages, 2 == 4 pages, + * etc.). + * + * max-ring-pages + * Values: <uint32_t> + * Default Value: 1 + * Notes: DEPRECATED, 2, 3 + * + * The maximum supported size of the request ring buffer in units of + * machine pages. The value must be a power of 2. + * + *------------------------- Backend Device Properties ------------------------- + * + * discard-alignment + * Values: <uint32_t> + * Default Value: 0 + * Notes: 4, 5 + * + * The offset, in bytes from the beginning of the virtual block device, + * to the first, addressable, discard extent on the underlying device. + * + * discard-granularity + * Values: <uint32_t> + * Default Value: <"sector-size"> + * Notes: 4 + * + * The size, in bytes, of the individually addressable discard extents + * of the underlying device. + * + * discard-secure + * Values: 0/1 (boolean) + * Default Value: 0 + * Notes: 10 + * + * A value of "1" indicates that the backend can process BLKIF_OP_DISCARD + * requests with the BLKIF_DISCARD_SECURE flag set. + * + * info + * Values: <uint32_t> (bitmap) + * + * A collection of bit flags describing attributes of the backing + * device. The VDISK_* macros define the meaning of each bit + * location. + * + * sector-size + * Values: <uint32_t> + * + * The logical sector size, in bytes, of the backend device. + * + * physical-sector-size + * Values: <uint32_t> + * + * The physical sector size, in bytes, of the backend device. + * + * sectors + * Values: <uint64_t> + * + * The size of the backend device, expressed in units of its logical + * sector size ("sector-size"). + * + ***************************************************************************** + * Frontend XenBus Nodes + ***************************************************************************** + * + *----------------------- Request Transport Parameters ----------------------- + * + * event-channel + * Values: <uint32_t> + * + * The identifier of the Xen event channel used to signal activity + * in the ring buffer. + * + * ring-ref + * Values: <uint32_t> + * Notes: 6 + * + * The Xen grant reference granting permission for the backend to map + * the sole page in a single page sized ring buffer. + * + * ring-ref%u + * Values: <uint32_t> + * Notes: 6 + * + * For a frontend providing a multi-page ring, a "number of ring pages" + * sized list of nodes, each containing a Xen grant reference granting + * permission for the backend to map the page of the ring located + * at page index "%u". Page indexes are zero based. + * + * protocol + * Values: string (XEN_IO_PROTO_ABI_*) + * Default Value: XEN_IO_PROTO_ABI_NATIVE + * + * The machine ABI rules governing the format of all ring request and + * response structures. + * + * ring-page-order + * Values: <uint32_t> + * Default Value: 0 + * Maximum Value: MAX(ffs(max-ring-pages) - 1, max-ring-page-order) + * Notes: 1, 3 + * + * The size of the frontend allocated request ring buffer in units + * of lb(machine pages). (e.g. 0 == 1 page, 1 = 2 pages, 2 == 4 pages, + * etc.). + * + * num-ring-pages + * Values: <uint32_t> + * Default Value: 1 + * Maximum Value: MAX(max-ring-pages,(0x1 << max-ring-page-order)) + * Notes: DEPRECATED, 2, 3 + * + * The size of the frontend allocated request ring buffer in units of + * machine pages. The value must be a power of 2. + * + * feature-persistent + * Values: 0/1 (boolean) + * Default Value: 0 + * Notes: 7, 8, 9 + * + * A value of "1" indicates that the frontend will reuse the same grants + * for all transactions, allowing the backend to map them with write + * access (even when it should be read-only). If the frontend hits the + * maximum number of allowed persistently mapped grants, it can fallback + * to non persistent mode. This will cause a performance degradation, + * since the the backend driver will still try to map those grants + * persistently. Since the persistent grants protocol is compatible with + * the previous protocol, a frontend driver can choose to work in + * persistent mode even when the backend doesn't support it. + * + * It is recommended that the frontend driver stores the persistently + * mapped grants in a LIFO queue, so a subset of all persistently mapped + * grants gets used commonly. This is done in case the backend driver + * decides to limit the maximum number of persistently mapped grants + * to a value less than RING_SIZE * BLKIF_MAX_SEGMENTS_PER_REQUEST. + * + *------------------------- Virtual Device Properties ------------------------- + * + * device-type + * Values: "disk", "cdrom", "floppy", etc. + * + * virtual-device + * Values: <uint32_t> + * + * A value indicating the physical device to virtualize within the + * frontend's domain. (e.g. "The first ATA disk", "The third SCSI + * disk", etc.) + * + * See docs/misc/vbd-interface.txt for details on the format of this + * value. + * + * Notes + * ----- + * (1) Multi-page ring buffer scheme first developed in the Citrix XenServer + * PV drivers. + * (2) Multi-page ring buffer scheme first used in some RedHat distributions + * including a distribution deployed on certain nodes of the Amazon + * EC2 cluster. + * (3) Support for multi-page ring buffers was implemented independently, + * in slightly different forms, by both Citrix and RedHat/Amazon. + * For full interoperability, block front and backends should publish + * identical ring parameters, adjusted for unit differences, to the + * XenStore nodes used in both schemes. + * (4) Devices that support discard functionality may internally allocate space + * (discardable extents) in units that are larger than the exported logical + * block size. If the backing device has such discardable extents the + * backend should provide both discard-granularity and discard-alignment. + * Providing just one of the two may be considered an error by the frontend. + * Backends supporting discard should include discard-granularity and + * discard-alignment even if it supports discarding individual sectors. + * Frontends should assume discard-alignment == 0 and discard-granularity + * == sector size if these keys are missing. + * (5) The discard-alignment parameter allows a physical device to be + * partitioned into virtual devices that do not necessarily begin or + * end on a discardable extent boundary. + * (6) When there is only a single page allocated to the request ring, + * 'ring-ref' is used to communicate the grant reference for this + * page to the backend. When using a multi-page ring, the 'ring-ref' + * node is not created. Instead 'ring-ref0' - 'ring-refN' are used. + * (7) When using persistent grants data has to be copied from/to the page + * where the grant is currently mapped. The overhead of doing this copy + * however doesn't suppress the speed improvement of not having to unmap + * the grants. + * (8) The frontend driver has to allow the backend driver to map all grants + * with write access, even when they should be mapped read-only, since + * further requests may reuse these grants and require write permissions. + * (9) Linux implementation doesn't have a limit on the maximum number of + * grants that can be persistently mapped in the frontend driver, but + * due to the frontent driver implementation it should never be bigger + * than RING_SIZE * BLKIF_MAX_SEGMENTS_PER_REQUEST. + *(10) The discard-secure property may be present and will be set to 1 if the + * backing device supports secure discard. + */ + +/* + * STATE DIAGRAMS + * + ***************************************************************************** + * Startup * + ***************************************************************************** + * + * Tool stack creates front and back nodes with state XenbusStateInitialising. + * + * Front Back + * ================================= ===================================== + * XenbusStateInitialising XenbusStateInitialising + * o Query virtual device o Query backend device identification + * properties. data. + * o Setup OS device instance. o Open and validate backend device. + * o Publish backend features and + * transport parameters. + * | + * | + * V + * XenbusStateInitWait + * + * o Query backend features and + * transport parameters. + * o Allocate and initialize the + * request ring. + * o Publish transport parameters + * that will be in effect during + * this connection. + * | + * | + * V + * XenbusStateInitialised + * + * o Query frontend transport parameters. + * o Connect to the request ring and + * event channel. + * o Publish backend device properties. + * | + * | + * V + * XenbusStateConnected + * + * o Query backend device properties. + * o Finalize OS virtual device + * instance. + * | + * | + * V + * XenbusStateConnected + * + * Note: Drivers that do not support any optional features, or the negotiation + * of transport parameters, can skip certain states in the state machine: + * + * o A frontend may transition to XenbusStateInitialised without + * waiting for the backend to enter XenbusStateInitWait. In this + * case, default transport parameters are in effect and any + * transport parameters published by the frontend must contain + * their default values. + * + * o A backend may transition to XenbusStateInitialised, bypassing + * XenbusStateInitWait, without waiting for the frontend to first + * enter the XenbusStateInitialised state. In this case, default + * transport parameters are in effect and any transport parameters + * published by the backend must contain their default values. + * + * Drivers that support optional features and/or transport parameter + * negotiation must tolerate these additional state transition paths. + * In general this means performing the work of any skipped state + * transition, if it has not already been performed, in addition to the + * work associated with entry into the current state. + */ + +/* + * REQUEST CODES. + */ +#define BLKIF_OP_READ 0 +#define BLKIF_OP_WRITE 1 +/* + * All writes issued prior to a request with the BLKIF_OP_WRITE_BARRIER + * operation code ("barrier request") must be completed prior to the + * execution of the barrier request. All writes issued after the barrier + * request must not execute until after the completion of the barrier request. + * + * Optional. See "feature-barrier" XenBus node documentation above. + */ +#define BLKIF_OP_WRITE_BARRIER 2 +/* + * Commit any uncommitted contents of the backing device's volatile cache + * to stable storage. + * + * Optional. See "feature-flush-cache" XenBus node documentation above. + */ +#define BLKIF_OP_FLUSH_DISKCACHE 3 +/* + * Used in SLES sources for device specific command packet + * contained within the request. Reserved for that purpose. + */ +#define BLKIF_OP_RESERVED_1 4 +/* + * Indicate to the backend device that a region of storage is no longer in + * use, and may be discarded at any time without impact to the client. If + * the BLKIF_DISCARD_SECURE flag is set on the request, all copies of the + * discarded region on the device must be rendered unrecoverable before the + * command returns. + * + * This operation is analogous to performing a trim (ATA) or unamp (SCSI), + * command on a native device. + * + * More information about trim/unmap operations can be found at: + * http://t13.org/Documents/UploadedDocuments/docs2008/ + * e07154r6-Data_Set_Management_Proposal_for_ATA-ACS2.doc + * http://www.seagate.com/staticfiles/support/disc/manuals/ + * Interface%20manuals/100293068c.pdf + * + * Optional. See "feature-discard", "discard-alignment", + * "discard-granularity", and "discard-secure" in the XenBus node + * documentation above. + */ +#define BLKIF_OP_DISCARD 5 + +/* + * Recognized if "feature-max-indirect-segments" in present in the backend + * xenbus info. The "feature-max-indirect-segments" node contains the maximum + * number of segments allowed by the backend per request. If the node is + * present, the frontend might use blkif_request_indirect structs in order to + * issue requests with more than BLKIF_MAX_SEGMENTS_PER_REQUEST (11). The + * maximum number of indirect segments is fixed by the backend, but the + * frontend can issue requests with any number of indirect segments as long as + * it's less than the number provided by the backend. The indirect_grefs field + * in blkif_request_indirect should be filled by the frontend with the + * grant references of the pages that are holding the indirect segments. + * These pages are filled with an array of blkif_request_segment that hold the + * information about the segments. The number of indirect pages to use is + * determined by the number of segments an indirect request contains. Every + * indirect page can contain a maximum of + * (PAGE_SIZE / sizeof(struct blkif_request_segment)) segments, so to + * calculate the number of indirect pages to use we have to do + * ceil(indirect_segments / (PAGE_SIZE / sizeof(struct blkif_request_segment))). + * + * If a backend does not recognize BLKIF_OP_INDIRECT, it should *not* + * create the "feature-max-indirect-segments" node! + */ +#define BLKIF_OP_INDIRECT 6 + +/* + * Maximum scatter/gather segments per request. + * This is carefully chosen so that sizeof(blkif_ring_t) <= PAGE_SIZE. + * NB. This could be 12 if the ring indexes weren't stored in the same page. + */ +#define BLKIF_MAX_SEGMENTS_PER_REQUEST 11 + +/* + * Maximum number of indirect pages to use per request. + */ +#define BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST 8 + +/* + * NB. first_sect and last_sect in blkif_request_segment, as well as + * sector_number in blkif_request, are always expressed in 512-byte units. + * However they must be properly aligned to the real sector size of the + * physical disk, which is reported in the "physical-sector-size" node in + * the backend xenbus info. Also the xenbus "sectors" node is expressed in + * 512-byte units. + */ +struct blkif_request_segment { + grant_ref_t gref; /* reference to I/O buffer frame */ + /* @first_sect: first sector in frame to transfer (inclusive). */ + /* @last_sect: last sector in frame to transfer (inclusive). */ + uint8_t first_sect, last_sect; +}; + +/* + * Starting ring element for any I/O request. + */ +struct blkif_request { + uint8_t operation; /* BLKIF_OP_??? */ + uint8_t nr_segments; /* number of segments */ + blkif_vdev_t handle; /* only for read/write requests */ + uint64_t id; /* private guest value, echoed in resp */ + blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ + struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; +}; +typedef struct blkif_request blkif_request_t; + +/* + * Cast to this structure when blkif_request.operation == BLKIF_OP_DISCARD + * sizeof(struct blkif_request_discard) <= sizeof(struct blkif_request) + */ +struct blkif_request_discard { + uint8_t operation; /* BLKIF_OP_DISCARD */ + uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */ +#define BLKIF_DISCARD_SECURE (1<<0) /* ignored if discard-secure=0 */ + blkif_vdev_t handle; /* same as for read/write requests */ + uint64_t id; /* private guest value, echoed in resp */ + blkif_sector_t sector_number;/* start sector idx on disk */ + uint64_t nr_sectors; /* number of contiguous sectors to discard*/ +}; +typedef struct blkif_request_discard blkif_request_discard_t; + +struct blkif_request_indirect { + uint8_t operation; /* BLKIF_OP_INDIRECT */ + uint8_t indirect_op; /* BLKIF_OP_{READ/WRITE} */ + uint16_t nr_segments; /* number of segments */ + uint64_t id; /* private guest value, echoed in resp */ + blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ + blkif_vdev_t handle; /* same as for read/write requests */ + grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST]; +#ifdef __i386__ + uint64_t pad; /* Make it 64 byte aligned on i386 */ +#endif +}; +typedef struct blkif_request_indirect blkif_request_indirect_t; + +struct blkif_response { + uint64_t id; /* copied from request */ + uint8_t operation; /* copied from request */ + int16_t status; /* BLKIF_RSP_??? */ +}; +typedef struct blkif_response blkif_response_t; + +/* + * STATUS RETURN CODES. + */ + /* Operation not supported (only happens on barrier writes). */ +#define BLKIF_RSP_EOPNOTSUPP -2 + /* Operation failed for some unspecified reason (-EIO). */ +#define BLKIF_RSP_ERROR -1 + /* Operation completed successfully. */ +#define BLKIF_RSP_OKAY 0 + +/* + * Generate blkif ring structures and types. + */ +DEFINE_RING_TYPES(blkif, struct blkif_request, struct blkif_response); + +#define VDISK_CDROM 0x1 +#define VDISK_REMOVABLE 0x2 +#define VDISK_READONLY 0x4 + +#endif /* __XEN_PUBLIC_IO_BLKIF_H__ */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/include/xen/io/console.h b/include/xen/io/console.h new file mode 100644 index 0000000..e2cd97f --- /dev/null +++ b/include/xen/io/console.h @@ -0,0 +1,51 @@ +/****************************************************************************** + * console.h + * + * Console I/O interface for Xen guest OSes. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + * Copyright (c) 2005, Keir Fraser + */ + +#ifndef __XEN_PUBLIC_IO_CONSOLE_H__ +#define __XEN_PUBLIC_IO_CONSOLE_H__ + +typedef uint32_t XENCONS_RING_IDX; + +#define MASK_XENCONS_IDX(idx, ring) ((idx) & (sizeof(ring)-1)) + +struct xencons_interface { + char in[1024]; + char out[2048]; + XENCONS_RING_IDX in_cons, in_prod; + XENCONS_RING_IDX out_cons, out_prod; +}; + +#endif /* __XEN_PUBLIC_IO_CONSOLE_H__ */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/include/xen/io/protocols.h b/include/xen/io/protocols.h new file mode 100644 index 0000000..80b196b --- /dev/null +++ b/include/xen/io/protocols.h @@ -0,0 +1,40 @@ +/****************************************************************************** + * protocols.h + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +#ifndef __XEN_PROTOCOLS_H__ +#define __XEN_PROTOCOLS_H__ + +#define XEN_IO_PROTO_ABI_X86_32 "x86_32-abi" +#define XEN_IO_PROTO_ABI_X86_64 "x86_64-abi" +#define XEN_IO_PROTO_ABI_ARM "arm-abi" + +#if defined(__i386__) +# define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_X86_32 +#elif defined(__x86_64__) +# define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_X86_64 +#elif defined(__arm__) || defined(__aarch64__) +# define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_ARM +#else +# error arch fixup needed here +#endif + +#endif diff --git a/include/xen/io/ring.h b/include/xen/io/ring.h new file mode 100644 index 0000000..73e13d7 --- /dev/null +++ b/include/xen/io/ring.h @@ -0,0 +1,312 @@ +/****************************************************************************** + * ring.h + * + * Shared producer-consumer ring macros. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + * Tim Deegan and Andrew Warfield November 2004. + */ + +#ifndef __XEN_PUBLIC_IO_RING_H__ +#define __XEN_PUBLIC_IO_RING_H__ + +#include "../xen-compat.h" + +#if __XEN_INTERFACE_VERSION__ < 0x00030208 +#define xen_mb() mb() +#define xen_rmb() rmb() +#define xen_wmb() wmb() +#endif + +typedef unsigned int RING_IDX; + +/* Round a 32-bit unsigned constant down to the nearest power of two. */ +#define __RD2(_x) (((_x) & 0x00000002) ? 0x2 : ((_x) & 0x1)) +#define __RD4(_x) (((_x) & 0x0000000c) ? __RD2((_x)>>2)<<2 : __RD2(_x)) +#define __RD8(_x) (((_x) & 0x000000f0) ? __RD4((_x)>>4)<<4 : __RD4(_x)) +#define __RD16(_x) (((_x) & 0x0000ff00) ? __RD8((_x)>>8)<<8 : __RD8(_x)) +#define __RD32(_x) (((_x) & 0xffff0000) ? __RD16((_x)>>16)<<16 : __RD16(_x)) + +/* + * Calculate size of a shared ring, given the total available space for the + * ring and indexes (_sz), and the name tag of the request/response structure. + * A ring contains as many entries as will fit, rounded down to the nearest + * power of two (so we can mask with (size-1) to loop around). + */ +#define __CONST_RING_SIZE(_s, _sz) \ + (__RD32(((_sz) - offsetof(struct _s##_sring, ring)) / \ + sizeof(((struct _s##_sring *)0)->ring[0]))) +/* + * The same for passing in an actual pointer instead of a name tag. + */ +#define __RING_SIZE(_s, _sz) \ + (__RD32(((_sz) - (long)(_s)->ring + (long)(_s)) / sizeof((_s)->ring[0]))) + +/* + * Macros to make the correct C datatypes for a new kind of ring. + * + * To make a new ring datatype, you need to have two message structures, + * let's say request_t, and response_t already defined. + * + * In a header where you want the ring datatype declared, you then do: + * + * DEFINE_RING_TYPES(mytag, request_t, response_t); + * + * These expand out to give you a set of types, as you can see below. + * The most important of these are: + * + * mytag_sring_t - The shared ring. + * mytag_front_ring_t - The 'front' half of the ring. + * mytag_back_ring_t - The 'back' half of the ring. + * + * To initialize a ring in your code you need to know the location and size + * of the shared memory area (PAGE_SIZE, for instance). To initialise + * the front half: + * + * mytag_front_ring_t front_ring; + * SHARED_RING_INIT((mytag_sring_t *)shared_page); + * FRONT_RING_INIT(&front_ring, (mytag_sring_t *)shared_page, PAGE_SIZE); + * + * Initializing the back follows similarly (note that only the front + * initializes the shared ring): + * + * mytag_back_ring_t back_ring; + * BACK_RING_INIT(&back_ring, (mytag_sring_t *)shared_page, PAGE_SIZE); + */ + +#define DEFINE_RING_TYPES(__name, __req_t, __rsp_t) \ + \ +/* Shared ring entry */ \ +union __name##_sring_entry { \ + __req_t req; \ + __rsp_t rsp; \ +}; \ + \ +/* Shared ring page */ \ +struct __name##_sring { \ + RING_IDX req_prod, req_event; \ + RING_IDX rsp_prod, rsp_event; \ + union { \ + struct { \ + uint8_t smartpoll_active; \ + } netif; \ + struct { \ + uint8_t msg; \ + } tapif_user; \ + uint8_t pvt_pad[4]; \ + } private; \ + uint8_t __pad[44]; \ + union __name##_sring_entry ring[1]; /* variable-length */ \ +}; \ + \ +/* "Front" end's private variables */ \ +struct __name##_front_ring { \ + RING_IDX req_prod_pvt; \ + RING_IDX rsp_cons; \ + unsigned int nr_ents; \ + struct __name##_sring *sring; \ +}; \ + \ +/* "Back" end's private variables */ \ +struct __name##_back_ring { \ + RING_IDX rsp_prod_pvt; \ + RING_IDX req_cons; \ + unsigned int nr_ents; \ + struct __name##_sring *sring; \ +}; \ + \ +/* Syntactic sugar */ \ +typedef struct __name##_sring __name##_sring_t; \ +typedef struct __name##_front_ring __name##_front_ring_t; \ +typedef struct __name##_back_ring __name##_back_ring_t + +/* + * Macros for manipulating rings. + * + * FRONT_RING_whatever works on the "front end" of a ring: here + * requests are pushed on to the ring and responses taken off it. + * + * BACK_RING_whatever works on the "back end" of a ring: here + * requests are taken off the ring and responses put on. + * + * N.B. these macros do NO INTERLOCKS OR FLOW CONTROL. + * This is OK in 1-for-1 request-response situations where the + * requestor (front end) never has more than RING_SIZE()-1 + * outstanding requests. + */ + +/* Initialising empty rings */ +#define SHARED_RING_INIT(_s) do { \ + (_s)->req_prod = (_s)->rsp_prod = 0; \ + (_s)->req_event = (_s)->rsp_event = 1; \ + (void)memset((_s)->private.pvt_pad, 0, sizeof((_s)->private.pvt_pad)); \ + (void)memset((_s)->__pad, 0, sizeof((_s)->__pad)); \ +} while(0) + +#define FRONT_RING_INIT(_r, _s, __size) do { \ + (_r)->req_prod_pvt = 0; \ + (_r)->rsp_cons = 0; \ + (_r)->nr_ents = __RING_SIZE(_s, __size); \ + (_r)->sring = (_s); \ +} while (0) + +#define BACK_RING_INIT(_r, _s, __size) do { \ + (_r)->rsp_prod_pvt = 0; \ + (_r)->req_cons = 0; \ + (_r)->nr_ents = __RING_SIZE(_s, __size); \ + (_r)->sring = (_s); \ +} while (0) + +/* How big is this ring? */ +#define RING_SIZE(_r) \ + ((_r)->nr_ents) + +/* Number of free requests (for use on front side only). */ +#define RING_FREE_REQUESTS(_r) \ + (RING_SIZE(_r) - ((_r)->req_prod_pvt - (_r)->rsp_cons)) + +/* Test if there is an empty slot available on the front ring. + * (This is only meaningful from the front. ) + */ +#define RING_FULL(_r) \ + (RING_FREE_REQUESTS(_r) == 0) + +/* Test if there are outstanding messages to be processed on a ring. */ +#define RING_HAS_UNCONSUMED_RESPONSES(_r) \ + ((_r)->sring->rsp_prod - (_r)->rsp_cons) + +#ifdef __GNUC__ +#define RING_HAS_UNCONSUMED_REQUESTS(_r) ({ \ + unsigned int req = (_r)->sring->req_prod - (_r)->req_cons; \ + unsigned int rsp = RING_SIZE(_r) - \ + ((_r)->req_cons - (_r)->rsp_prod_pvt); \ + req < rsp ? req : rsp; \ +}) +#else +/* Same as above, but without the nice GCC ({ ... }) syntax. */ +#define RING_HAS_UNCONSUMED_REQUESTS(_r) \ + ((((_r)->sring->req_prod - (_r)->req_cons) < \ + (RING_SIZE(_r) - ((_r)->req_cons - (_r)->rsp_prod_pvt))) ? \ + ((_r)->sring->req_prod - (_r)->req_cons) : \ + (RING_SIZE(_r) - ((_r)->req_cons - (_r)->rsp_prod_pvt))) +#endif + +/* Direct access to individual ring elements, by index. */ +#define RING_GET_REQUEST(_r, _idx) \ + (&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].req)) + +#define RING_GET_RESPONSE(_r, _idx) \ + (&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].rsp)) + +/* Loop termination condition: Would the specified index overflow the ring? */ +#define RING_REQUEST_CONS_OVERFLOW(_r, _cons) \ + (((_cons) - (_r)->rsp_prod_pvt) >= RING_SIZE(_r)) + +/* Ill-behaved frontend determination: Can there be this many requests? */ +#define RING_REQUEST_PROD_OVERFLOW(_r, _prod) \ + (((_prod) - (_r)->rsp_prod_pvt) > RING_SIZE(_r)) + +#define RING_PUSH_REQUESTS(_r) do { \ + xen_wmb(); /* back sees requests /before/ updated producer index */ \ + (_r)->sring->req_prod = (_r)->req_prod_pvt; \ +} while (0) + +#define RING_PUSH_RESPONSES(_r) do { \ + xen_wmb(); /* front sees resps /before/ updated producer index */ \ + (_r)->sring->rsp_prod = (_r)->rsp_prod_pvt; \ +} while (0) + +/* + * Notification hold-off (req_event and rsp_event): + * + * When queueing requests or responses on a shared ring, it may not always be + * necessary to notify the remote end. For example, if requests are in flight + * in a backend, the front may be able to queue further requests without + * notifying the back (if the back checks for new requests when it queues + * responses). + * + * When enqueuing requests or responses: + * + * Use RING_PUSH_{REQUESTS,RESPONSES}_AND_CHECK_NOTIFY(). The second argument + * is a boolean return value. True indicates that the receiver requires an + * asynchronous notification. + * + * After dequeuing requests or responses (before sleeping the connection): + * + * Use RING_FINAL_CHECK_FOR_REQUESTS() or RING_FINAL_CHECK_FOR_RESPONSES(). + * The second argument is a boolean return value. True indicates that there + * are pending messages on the ring (i.e., the connection should not be put + * to sleep). + * + * These macros will set the req_event/rsp_event field to trigger a + * notification on the very next message that is enqueued. If you want to + * create batches of work (i.e., only receive a notification after several + * messages have been enqueued) then you will need to create a customised + * version of the FINAL_CHECK macro in your own code, which sets the event + * field appropriately. + */ + +#define RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(_r, _notify) do { \ + RING_IDX __old = (_r)->sring->req_prod; \ + RING_IDX __new = (_r)->req_prod_pvt; \ + xen_wmb(); /* back sees requests /before/ updated producer index */ \ + (_r)->sring->req_prod = __new; \ + xen_mb(); /* back sees new requests /before/ we check req_event */ \ + (_notify) = ((RING_IDX)(__new - (_r)->sring->req_event) < \ + (RING_IDX)(__new - __old)); \ +} while (0) + +#define RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(_r, _notify) do { \ + RING_IDX __old = (_r)->sring->rsp_prod; \ + RING_IDX __new = (_r)->rsp_prod_pvt; \ + xen_wmb(); /* front sees resps /before/ updated producer index */ \ + (_r)->sring->rsp_prod = __new; \ + xen_mb(); /* front sees new resps /before/ we check rsp_event */ \ + (_notify) = ((RING_IDX)(__new - (_r)->sring->rsp_event) < \ + (RING_IDX)(__new - __old)); \ +} while (0) + +#define RING_FINAL_CHECK_FOR_REQUESTS(_r, _work_to_do) do { \ + (_work_to_do) = RING_HAS_UNCONSUMED_REQUESTS(_r); \ + if (_work_to_do) break; \ + (_r)->sring->req_event = (_r)->req_cons + 1; \ + xen_mb(); \ + (_work_to_do) = RING_HAS_UNCONSUMED_REQUESTS(_r); \ +} while (0) + +#define RING_FINAL_CHECK_FOR_RESPONSES(_r, _work_to_do) do { \ + (_work_to_do) = RING_HAS_UNCONSUMED_RESPONSES(_r); \ + if (_work_to_do) break; \ + (_r)->sring->rsp_event = (_r)->rsp_cons + 1; \ + xen_mb(); \ + (_work_to_do) = RING_HAS_UNCONSUMED_RESPONSES(_r); \ +} while (0) + +#endif /* __XEN_PUBLIC_IO_RING_H__ */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/include/xen/io/xenbus.h b/include/xen/io/xenbus.h new file mode 100644 index 0000000..927f9db --- /dev/null +++ b/include/xen/io/xenbus.h @@ -0,0 +1,80 @@ +/***************************************************************************** + * xenbus.h + * + * Xenbus protocol details. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + * Copyright (C) 2005 XenSource Ltd. + */ + +#ifndef _XEN_PUBLIC_IO_XENBUS_H +#define _XEN_PUBLIC_IO_XENBUS_H + +/* + * The state of either end of the Xenbus, i.e. the current communication + * status of initialisation across the bus. States here imply nothing about + * the state of the connection between the driver and the kernel's device + * layers. + */ +enum xenbus_state { + XenbusStateUnknown = 0, + + XenbusStateInitialising = 1, + + /* + * InitWait: Finished early initialisation but waiting for information + * from the peer or hotplug scripts. + */ + XenbusStateInitWait = 2, + + /* + * Initialised: Waiting for a connection from the peer. + */ + XenbusStateInitialised = 3, + + XenbusStateConnected = 4, + + /* + * Closing: The device is being closed due to an error or an unplug event. + */ + XenbusStateClosing = 5, + + XenbusStateClosed = 6, + + /* + * Reconfiguring: The device is being reconfigured. + */ + XenbusStateReconfiguring = 7, + + XenbusStateReconfigured = 8 +}; +typedef enum xenbus_state XenbusState; + +#endif /* _XEN_PUBLIC_IO_XENBUS_H */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/include/xen/io/xs_wire.h b/include/xen/io/xs_wire.h new file mode 100644 index 0000000..585f0c8 --- /dev/null +++ b/include/xen/io/xs_wire.h @@ -0,0 +1,138 @@ +/* + * Details of the "wire" protocol between Xen Store Daemon and client + * library or guest kernel. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + * Copyright (C) 2005 Rusty Russell IBM Corporation + */ + +#ifndef _XS_WIRE_H +#define _XS_WIRE_H + +enum xsd_sockmsg_type +{ + XS_DEBUG, + XS_DIRECTORY, + XS_READ, + XS_GET_PERMS, + XS_WATCH, + XS_UNWATCH, + XS_TRANSACTION_START, + XS_TRANSACTION_END, + XS_INTRODUCE, + XS_RELEASE, + XS_GET_DOMAIN_PATH, + XS_WRITE, + XS_MKDIR, + XS_RM, + XS_SET_PERMS, + XS_WATCH_EVENT, + XS_ERROR, + XS_IS_DOMAIN_INTRODUCED, + XS_RESUME, + XS_SET_TARGET, + XS_RESTRICT, + XS_RESET_WATCHES +}; + +#define XS_WRITE_NONE "NONE" +#define XS_WRITE_CREATE "CREATE" +#define XS_WRITE_CREATE_EXCL "CREATE|EXCL" + +/* We hand errors as strings, for portability. */ +struct xsd_errors +{ + int errnum; + const char *errstring; +}; +#ifdef EINVAL +#define XSD_ERROR(x) { x, #x } +/* LINTED: static unused */ +static struct xsd_errors xsd_errors[] +#if defined(__GNUC__) +__attribute__((unused)) +#endif + = { + XSD_ERROR(EINVAL), + XSD_ERROR(EACCES), + XSD_ERROR(EEXIST), + XSD_ERROR(EISDIR), + XSD_ERROR(ENOENT), + XSD_ERROR(ENOMEM), + XSD_ERROR(ENOSPC), + XSD_ERROR(EIO), + XSD_ERROR(ENOTEMPTY), + XSD_ERROR(ENOSYS), + XSD_ERROR(EROFS), + XSD_ERROR(EBUSY), + XSD_ERROR(EAGAIN), + XSD_ERROR(EISCONN), + XSD_ERROR(E2BIG) +}; +#endif + +struct xsd_sockmsg +{ + uint32_t type; /* XS_??? */ + uint32_t req_id;/* Request identifier, echoed in daemon's response. */ + uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */ + uint32_t len; /* Length of data following this. */ + + /* Generally followed by nul-terminated string(s). */ +}; + +enum xs_watch_type +{ + XS_WATCH_PATH = 0, + XS_WATCH_TOKEN +}; + +/* + * `incontents 150 xenstore_struct XenStore wire protocol. + * + * Inter-domain shared memory communications. */ +#define XENSTORE_RING_SIZE 1024 +typedef uint32_t XENSTORE_RING_IDX; +#define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1)) +struct xenstore_domain_interface { + char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */ + char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */ + XENSTORE_RING_IDX req_cons, req_prod; + XENSTORE_RING_IDX rsp_cons, rsp_prod; +}; + +/* Violating this is very bad. See docs/misc/xenstore.txt. */ +#define XENSTORE_PAYLOAD_MAX 4096 + +/* Violating these just gets you an error back */ +#define XENSTORE_ABS_PATH_MAX 3072 +#define XENSTORE_REL_PATH_MAX 2048 + +#endif /* _XS_WIRE_H */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ |