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Diffstat (limited to 'OvmfPkg/Include/IndustryStandard/Xen/io/blkif.h')
| -rw-r--r-- | OvmfPkg/Include/IndustryStandard/Xen/io/blkif.h | 619 |
1 files changed, 0 insertions, 619 deletions
diff --git a/OvmfPkg/Include/IndustryStandard/Xen/io/blkif.h b/OvmfPkg/Include/IndustryStandard/Xen/io/blkif.h deleted file mode 100644 index ebed5799bc..0000000000 --- a/OvmfPkg/Include/IndustryStandard/Xen/io/blkif.h +++ /dev/null @@ -1,619 +0,0 @@ -/******************************************************************************
- * 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
-#endif
-#define blkif_sector_t UINT64
-
-/*
- * 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>
- * 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>
- * 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>
- * 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>
- * 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> (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>
- *
- * The logical sector size, in bytes, of the backend device.
- *
- * physical-sector-size
- * Values: <UINT32>
- *
- * The physical sector size, in bytes, of the backend device.
- *
- * sectors
- * Values: <UINT64>
- *
- * 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>
- *
- * The identifier of the Xen event channel used to signal activity
- * in the ring buffer.
- *
- * ring-ref
- * Values: <UINT32>
- * 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>
- * 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>
- * 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>
- * 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>
- *
- * 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 first_sect, last_sect;
-};
-
-/*
- * Starting ring element for any I/O request.
- */
-#if defined(MDE_CPU_IA32)
-//
-// pack(4) is necessary when these structs are compiled for Ia32.
-// Without it, the struct will have a different alignment than the one
-// a backend expect for a 32bit guest.
-//
-#pragma pack(4)
-#endif
-struct blkif_request {
- UINT8 operation; /* BLKIF_OP_??? */
- UINT8 nr_segments; /* number of segments */
- blkif_vdev_t handle; /* only for read/write requests */
- UINT64 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 operation; /* BLKIF_OP_DISCARD */
- UINT8 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 id; /* private guest value, echoed in resp */
- blkif_sector_t sector_number;/* start sector idx on disk */
- UINT64 nr_sectors; /* number of contiguous sectors to discard*/
-};
-typedef struct blkif_request_discard blkif_request_discard_t;
-
-struct blkif_request_indirect {
- UINT8 operation; /* BLKIF_OP_INDIRECT */
- UINT8 indirect_op; /* BLKIF_OP_{READ/WRITE} */
- UINT16 nr_segments; /* number of segments */
- UINT64 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 MDE_CPU_IA32
- UINT64 pad; /* Make it 64 byte aligned on i386 */
-#endif
-};
-typedef struct blkif_request_indirect blkif_request_indirect_t;
-
-struct blkif_response {
- UINT64 id; /* copied from request */
- UINT8 operation; /* copied from request */
- INT16 status; /* BLKIF_RSP_??? */
-};
-typedef struct blkif_response blkif_response_t;
-#if defined(MDE_CPU_IA32)
-#pragma pack()
-#endif
-
-/*
- * 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:
- */
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