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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v3 18/19] OvmfPkg/XenPvBlkDxe: Add BlockFront client.
This is the code that will do the actual communication between OVMF and
a PV block backend, where the block device lives. The protocol used is
describe in the blkif.h header.
This implementation originally comes from Mini-OS, a part of the Xen
Project.
License: This patch adds some files which are under the MIT license.
Signed-off-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxxx>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
---
Change in V3:
- Improve comment of XenBusReadUint64.
- Moving blkif.h to this patch
with the necessary #pragma pack(4) applied for Ia32.
- Add a note about the license in the commit message
- Add "The protocol used is describe in the blkif.h header." in the
commit message
- Have a mandatory sector-size multiple of 512 or fail to initialize.
- use Sector instead of Offset for IO request.
with Sector been 512-byte unit.
- print something if EventChannelNotify return an error.
Change in V2:
- trigger CoW is probably not needed on OVMF (as opposed to Mini-OS),
removed the test.
- comments
- renamed XenbusReadInteger to XenBusReadUint64
- remove callback from IoData, use simple status instead
- return a status from the synchronus io
- Close protocol if blockfront init fail.
- fix few debug print
- Rename XenbusIo to XenBusIo
- XenPvBlkWaitForBackendState will return an error if the new backend
states is not the expected state.
- Add the license
---
OvmfPkg/Include/IndustryStandard/Xen/io/blkif.h | 619 +++++++++++++++++++++++
OvmfPkg/XenPvBlkDxe/BlockFront.c | 647 ++++++++++++++++++++++++
OvmfPkg/XenPvBlkDxe/BlockFront.h | 87 ++++
OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.c | 13 +
OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf | 2 +
5 files changed, 1368 insertions(+)
create mode 100644 OvmfPkg/Include/IndustryStandard/Xen/io/blkif.h
create mode 100644 OvmfPkg/XenPvBlkDxe/BlockFront.c
create mode 100644 OvmfPkg/XenPvBlkDxe/BlockFront.h
diff --git a/OvmfPkg/Include/IndustryStandard/Xen/io/blkif.h
b/OvmfPkg/Include/IndustryStandard/Xen/io/blkif.h
new file mode 100644
index 0000000..2cfc1ab
--- /dev/null
+++ b/OvmfPkg/Include/IndustryStandard/Xen/io/blkif.h
@@ -0,0 +1,619 @@
+/******************************************************************************
+ * 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(__i386__)
+//
+// 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 __i386__
+ 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(__i386__)
+#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:
+ */
diff --git a/OvmfPkg/XenPvBlkDxe/BlockFront.c b/OvmfPkg/XenPvBlkDxe/BlockFront.c
new file mode 100644
index 0000000..a3e1555
--- /dev/null
+++ b/OvmfPkg/XenPvBlkDxe/BlockFront.c
@@ -0,0 +1,647 @@
+/** @file
+ Minimal block driver for Mini-OS.
+
+ Copyright (c) 2007-2008 Samuel Thibault.
+ Copyright (C) 2014, Citrix Ltd.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+ 1. Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ SUCH DAMAGE.
+**/
+
+#include <Library/PrintLib.h>
+#include <Library/DebugLib.h>
+
+#include "BlockFront.h"
+
+#include <IndustryStandard/Xen/io/protocols.h>
+#include <IndustryStandard/Xen/io/xenbus.h>
+
+//
+// Header used for UINT32_MAX and UINT16_MAX
+//
+#include "inttypes.h"
+
+/**
+ Helper to read an integer from XenStore.
+
+ If the number overflows according to the range defined by UINT64,
+ then ASSERT().
+
+ @param This A pointer to a XENBUS_PROTOCOL instance.
+ @param Node The XenStore node to read from.
+ @param FromBackend Read frontend or backend value.
+ @param ValuePtr Where to put the value.
+
+ @retval XENSTORE_STATUS_SUCCESS If succefull, will update ValuePtr.
+ @return Any other return value indicate the error,
+ ValuePtr is not updated in this case.
+**/
+STATIC
+XENSTORE_STATUS
+XenBusReadUint64 (
+ IN XENBUS_PROTOCOL *This,
+ IN CONST CHAR8 *Node,
+ IN BOOLEAN FromBackend,
+ OUT UINT64 *ValuePtr
+ )
+{
+ XENSTORE_STATUS Status;
+ CHAR8 *Ptr;
+
+ if (!FromBackend) {
+ Status = This->XsRead (This, XST_NIL, Node, (VOID**)&Ptr);
+ } else {
+ Status = This->XsBackendRead (This, XST_NIL, Node, (VOID**)&Ptr);
+ }
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ return Status;
+ }
+ // AsciiStrDecimalToUint64 will ASSERT if Ptr overflow UINT64.
+ *ValuePtr = AsciiStrDecimalToUint64 (Ptr);
+ FreePool (Ptr);
+ return Status;
+}
+
+/**
+ Free an instance of XEN_BLOCK_FRONT_DEVICE.
+
+ @param Dev The instance to free.
+**/
+STATIC
+VOID
+XenPvBlockFree (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ )
+{
+ XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
+
+ if (Dev->RingRef != 0) {
+ XenBusIo->GrantEndAccess (XenBusIo, Dev->RingRef);
+ }
+ if (Dev->Ring.sring != NULL) {
+ FreePages (Dev->Ring.sring, 1);
+ }
+ if (Dev->EventChannel != 0) {
+ XenBusIo->EventChannelClose (XenBusIo, Dev->EventChannel);
+ }
+ FreePool (Dev);
+}
+
+/**
+ Wait until until the backend has reached the ExpectedState.
+
+ @param Dev A XEN_BLOCK_FRONT_DEVICE instance.
+ @param ExpectedState The backend state expected.
+ @param LastStatePtr An optional pointer where to right the final state.
+
+ @return Return XENSTORE_STATUS_SUCCESS if the new backend state is
ExpectedState
+ or return an error otherwise.
+**/
+STATIC
+XENSTORE_STATUS
+XenPvBlkWaitForBackendState (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev,
+ IN XenbusState ExpectedState,
+ OUT XenbusState *LastStatePtr OPTIONAL
+ )
+{
+ XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
+ XenbusState State;
+ UINT64 Value;
+ XENSTORE_STATUS Status = XENSTORE_STATUS_SUCCESS;
+
+ while (TRUE) {
+ Status = XenBusReadUint64 (XenBusIo, "state", TRUE, &Value);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ return Status;
+ }
+ if (Value > XenbusStateReconfigured) {
+ //
+ // Value is not a State value.
+ //
+ return XENSTORE_STATUS_EIO;
+ }
+ State = Value;
+ if (State == ExpectedState) {
+ break;
+ } else if (State > ExpectedState) {
+ Status = XENSTORE_STATUS_FAIL;
+ break;
+ }
+ DEBUG ((EFI_D_INFO,
+ "XenPvBlk: waiting backend state %d, current: %d\n",
+ ExpectedState, State));
+ XenBusIo->WaitForWatch (XenBusIo, Dev->StateWatchToken);
+ }
+
+ if (LastStatePtr != NULL) {
+ *LastStatePtr = State;
+ }
+
+ return Status;
+}
+
+EFI_STATUS
+XenPvBlockFrontInitialization (
+ IN XENBUS_PROTOCOL *XenBusIo,
+ IN CONST CHAR8 *NodeName,
+ OUT XEN_BLOCK_FRONT_DEVICE **DevPtr
+ )
+{
+ XENSTORE_TRANSACTION xbt;
+ CHAR8 *DeviceType;
+ blkif_sring_t *SharedRing;
+ XENSTORE_STATUS Status;
+ XEN_BLOCK_FRONT_DEVICE *Dev;
+ XenbusState State;
+ UINT64 Value;
+
+ ASSERT (NodeName != NULL);
+
+ Dev = AllocateZeroPool (sizeof (XEN_BLOCK_FRONT_DEVICE));
+ Dev->Signature = XEN_BLOCK_FRONT_SIGNATURE;
+ Dev->NodeName = NodeName;
+ Dev->XenBusIo = XenBusIo;
+ Dev->DeviceId = XenBusIo->DeviceId;
+
+ XenBusIo->XsRead (XenBusIo, XST_NIL, "device-type", (VOID**)&DeviceType);
+ if (AsciiStrCmp (DeviceType, "cdrom") == 0) {
+ Dev->MediaInfo.CdRom = TRUE;
+ } else {
+ Dev->MediaInfo.CdRom = FALSE;
+ }
+ FreePool (DeviceType);
+
+ Status = XenBusReadUint64 (XenBusIo, "backend-id", FALSE, &Value);
+ if (Status != XENSTORE_STATUS_SUCCESS || Value > UINT16_MAX) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to get backend-id (%d)\n",
+ Status));
+ goto Error;
+ }
+ Dev->DomainId = Value;
+ XenBusIo->EventChannelAllocate (XenBusIo, Dev->DomainId, &Dev->EventChannel);
+
+ SharedRing = (blkif_sring_t*) AllocatePages (1);
+ SHARED_RING_INIT (SharedRing);
+ FRONT_RING_INIT (&Dev->Ring, SharedRing, EFI_PAGE_SIZE);
+ XenBusIo->GrantAccess (XenBusIo,
+ Dev->DomainId,
+ (INTN) SharedRing >> EFI_PAGE_SHIFT,
+ FALSE,
+ &Dev->RingRef);
+
+Again:
+ Status = XenBusIo->XsTransactionStart (XenBusIo, &xbt);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_WARN, "XenPvBlk: Failed to start transaction, %d\n",
Status));
+ goto Error;
+ }
+
+ Status = XenBusIo->XsPrintf (XenBusIo, xbt, NodeName, "ring-ref", "%d",
+ Dev->RingRef);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to write ring-ref.\n"));
+ goto AbortTransaction;
+ }
+ Status = XenBusIo->XsPrintf (XenBusIo, xbt, NodeName,
+ "event-channel", "%d", Dev->EventChannel);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to write event-channel.\n"));
+ goto AbortTransaction;
+ }
+ Status = XenBusIo->XsPrintf (XenBusIo, xbt, NodeName,
+ "protocol", "%a", XEN_IO_PROTO_ABI_NATIVE);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to write protocol.\n"));
+ goto AbortTransaction;
+ }
+
+ Status = XenBusIo->SetState (XenBusIo, xbt, XenbusStateConnected);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Failed to switch state.\n"));
+ goto AbortTransaction;
+ }
+
+ Status = XenBusIo->XsTransactionEnd (XenBusIo, xbt, FALSE);
+ if (Status == XENSTORE_STATUS_EAGAIN) {
+ goto Again;
+ }
+
+ XenBusIo->RegisterWatchBackend (XenBusIo, "state", &Dev->StateWatchToken);
+
+ //
+ // Waiting for backend
+ //
+ Status = XenPvBlkWaitForBackendState (Dev, XenbusStateConnected, &State);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: backend for %a/%d not available, rc=%d state=%d\n",
+ XenBusIo->Type, XenBusIo->DeviceId, Status, State));
+ goto Error2;
+ }
+
+ Status = XenBusReadUint64 (XenBusIo, "info", TRUE, &Value);
+ if (Status != XENSTORE_STATUS_SUCCESS || Value > UINT32_MAX) {
+ goto Error2;
+ }
+ Dev->MediaInfo.VDiskInfo = Value;
+ if (Dev->MediaInfo.VDiskInfo & VDISK_READONLY) {
+ Dev->MediaInfo.ReadWrite = FALSE;
+ } else {
+ Dev->MediaInfo.ReadWrite = TRUE;
+ }
+
+ Status = XenBusReadUint64 (XenBusIo, "sectors", TRUE,
&Dev->MediaInfo.Sectors);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ goto Error2;
+ }
+
+ Status = XenBusReadUint64 (XenBusIo, "sector-size", TRUE, &Value);
+ if (Status != XENSTORE_STATUS_SUCCESS || Value > UINT32_MAX) {
+ goto Error2;
+ }
+ if (Value % 512 != 0) {
+ //
+ // This is not supported by the driver.
+ //
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: Unsupported sector-size value %d, "
+ "it must be a multiple of 512\n", Value));
+ goto Error2;
+ }
+ Dev->MediaInfo.SectorSize = Value;
+
+ // Default value
+ Value = 0;
+ XenBusReadUint64 (XenBusIo, "feature-barrier", TRUE, &Value);
+ if (Value == 1) {
+ Dev->MediaInfo.FeatureBarrier = TRUE;
+ } else {
+ Dev->MediaInfo.FeatureBarrier = FALSE;
+ }
+
+ // Default value
+ Value = 0;
+ XenBusReadUint64 (XenBusIo, "feature-flush-cache", TRUE, &Value);
+ if (Value == 1) {
+ Dev->MediaInfo.FeatureFlushCache = TRUE;
+ } else {
+ Dev->MediaInfo.FeatureFlushCache = FALSE;
+ }
+
+ DEBUG ((EFI_D_INFO, "XenPvBlk: New disk with %ld sectors of %d bytes\n",
+ Dev->MediaInfo.Sectors, Dev->MediaInfo.SectorSize));
+
+ *DevPtr = Dev;
+ return EFI_SUCCESS;
+
+Error2:
+ XenBusIo->UnregisterWatch (XenBusIo, Dev->StateWatchToken);
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "ring-ref");
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "event-channel");
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "protocol");
+ goto Error;
+AbortTransaction:
+ XenBusIo->XsTransactionEnd (XenBusIo, xbt, TRUE);
+Error:
+ XenPvBlockFree (Dev);
+ return EFI_DEVICE_ERROR;
+}
+
+VOID
+XenPvBlockFrontShutdown (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ )
+{
+ XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
+ XENSTORE_STATUS Status;
+ UINT64 Value;
+
+ XenPvBlockSync (Dev);
+
+ Status = XenBusIo->SetState (XenBusIo, XST_NIL, XenbusStateClosing);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while changing state to Closing: %d\n",
+ Status));
+ goto Close;
+ }
+
+ Status = XenPvBlkWaitForBackendState (Dev, XenbusStateClosing, NULL);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while waiting for closing backend state: %d\n",
+ Status));
+ goto Close;
+ }
+
+ Status = XenBusIo->SetState (XenBusIo, XST_NIL, XenbusStateClosed);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while changing state to Closed: %d\n",
+ Status));
+ goto Close;
+ }
+
+ Status = XenPvBlkWaitForBackendState (Dev, XenbusStateClosed, NULL);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while waiting for closed backend state: %d\n",
+ Status));
+ goto Close;
+ }
+
+ Status = XenBusIo->SetState (XenBusIo, XST_NIL, XenbusStateInitialising);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while changing state to initialising: %d\n",
+ Status));
+ goto Close;
+ }
+
+ while (TRUE) {
+ Status = XenBusReadUint64 (XenBusIo, "state", TRUE, &Value);
+ if (Status != XENSTORE_STATUS_SUCCESS) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: error while waiting for new backend state: %d\n",
+ Status));
+ goto Close;
+ }
+ if (Value <= XenbusStateInitWait || Value >= XenbusStateClosed) {
+ break;
+ }
+ DEBUG ((EFI_D_INFO,
+ "XenPvBlk: waiting backend state %d, current: %d\n",
+ XenbusStateInitWait, Value));
+ XenBusIo->WaitForWatch (XenBusIo, Dev->StateWatchToken);
+ }
+
+Close:
+ XenBusIo->UnregisterWatch (XenBusIo, Dev->StateWatchToken);
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "ring-ref");
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "event-channel");
+ XenBusIo->XsRemove (XenBusIo, XST_NIL, "protocol");
+
+ XenPvBlockFree (Dev);
+}
+
+STATIC
+VOID
+XenPvBlockWaitSlot (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ )
+{
+ /* Wait for a slot */
+ if (RING_FULL (&Dev->Ring)) {
+ while (TRUE) {
+ XenPvBlockAsyncIoPoll (Dev);
+ if (!RING_FULL (&Dev->Ring)) {
+ break;
+ }
+ /* Really no slot, could wait for an event on Dev->EventChannel. */
+ }
+ }
+}
+
+VOID
+XenPvBlockAsyncIo (
+ IN OUT XEN_BLOCK_FRONT_IO *IoData,
+ IN BOOLEAN IsWrite
+ )
+{
+ XEN_BLOCK_FRONT_DEVICE *Dev = IoData->Dev;
+ XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
+ blkif_request_t *Request;
+ RING_IDX RingIndex;
+ BOOLEAN Notify;
+ INT32 NumSegments, Index;
+ UINTN Start, End;
+
+ // Can't io at non-sector-aligned location
+ ASSERT(!(IoData->Sector & ((Dev->MediaInfo.SectorSize / 512) - 1)));
+ // Can't io non-sector-sized amounts
+ ASSERT(!(IoData->Size & (Dev->MediaInfo.SectorSize - 1)));
+ // Can't io non-sector-aligned buffer
+ ASSERT(!((UINTN) IoData->Buffer & (Dev->MediaInfo.SectorSize - 1)));
+
+ Start = (UINTN) IoData->Buffer & ~EFI_PAGE_MASK;
+ End = ((UINTN) IoData->Buffer + IoData->Size + EFI_PAGE_SIZE - 1) &
~EFI_PAGE_MASK;
+ IoData->NumRef = NumSegments = (End - Start) / EFI_PAGE_SIZE;
+
+ ASSERT (NumSegments <= BLKIF_MAX_SEGMENTS_PER_REQUEST);
+
+ XenPvBlockWaitSlot (Dev);
+ RingIndex = Dev->Ring.req_prod_pvt;
+ Request = RING_GET_REQUEST (&Dev->Ring, RingIndex);
+
+ Request->operation = IsWrite ? BLKIF_OP_WRITE : BLKIF_OP_READ;
+ Request->nr_segments = NumSegments;
+ Request->handle = Dev->DeviceId;
+ Request->id = (UINTN) IoData;
+ Request->sector_number = IoData->Sector;
+
+ for (Index = 0; Index < NumSegments; Index++) {
+ Request->seg[Index].first_sect = 0;
+ Request->seg[Index].last_sect = EFI_PAGE_SIZE / 512 - 1;
+ }
+ Request->seg[0].first_sect = ((UINTN) IoData->Buffer & EFI_PAGE_MASK) / 512;
+ Request->seg[NumSegments - 1].last_sect =
+ (((UINTN) IoData->Buffer + IoData->Size - 1) & EFI_PAGE_MASK) / 512;
+ for (Index = 0; Index < NumSegments; Index++) {
+ UINTN Data = Start + Index * EFI_PAGE_SIZE;
+ XenBusIo->GrantAccess (XenBusIo, Dev->DomainId,
+ Data >> EFI_PAGE_SHIFT, IsWrite,
+ &Request->seg[Index].gref);
+ IoData->GrantRef[Index] = Request->seg[Index].gref;
+ }
+
+ Dev->Ring.req_prod_pvt = RingIndex + 1;
+
+ MemoryFence ();
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY (&Dev->Ring, Notify);
+
+ if (Notify) {
+ UINT32 ReturnCode;
+ ReturnCode = XenBusIo->EventChannelNotify (XenBusIo, Dev->EventChannel);
+ if (ReturnCode != 0) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: Unexpected return value from EventChannelNotify:
%d\n",
+ ReturnCode));
+ }
+ }
+}
+
+EFI_STATUS
+XenPvBlockIo (
+ IN OUT XEN_BLOCK_FRONT_IO *IoData,
+ IN BOOLEAN IsWrite
+ )
+{
+ //
+ // Status value that correspond to an IO in progress.
+ //
+ IoData->Status = EFI_ALREADY_STARTED;
+ XenPvBlockAsyncIo (IoData, IsWrite);
+
+ while (IoData->Status == EFI_ALREADY_STARTED) {
+ XenPvBlockAsyncIoPoll (IoData->Dev);
+ }
+
+ return IoData->Status;
+}
+
+STATIC
+VOID
+XenPvBlockPushOperation (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev,
+ IN UINT8 Operation,
+ IN UINT64 Id
+ )
+{
+ INT32 Index;
+ blkif_request_t *Request;
+ BOOLEAN Notify;
+
+ XenPvBlockWaitSlot (Dev);
+ Index = Dev->Ring.req_prod_pvt;
+ Request = RING_GET_REQUEST(&Dev->Ring, Index);
+ Request->operation = Operation;
+ Request->nr_segments = 0;
+ Request->handle = Dev->DeviceId;
+ Request->id = Id;
+ /* Not needed anyway, but the backend will check it */
+ Request->sector_number = 0;
+ Dev->Ring.req_prod_pvt = Index + 1;
+ MemoryFence ();
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY (&Dev->Ring, Notify);
+ if (Notify) {
+ XENBUS_PROTOCOL *XenBusIo = Dev->XenBusIo;
+ UINT32 ReturnCode;
+ ReturnCode = XenBusIo->EventChannelNotify (XenBusIo, Dev->EventChannel);
+ if (ReturnCode != 0) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: Unexpected return value from EventChannelNotify:
%d\n",
+ ReturnCode));
+ }
+ }
+}
+
+VOID
+XenPvBlockSync (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ )
+{
+ if (Dev->MediaInfo.ReadWrite) {
+ if (Dev->MediaInfo.FeatureBarrier) {
+ XenPvBlockPushOperation (Dev, BLKIF_OP_WRITE_BARRIER, 0);
+ }
+
+ if (Dev->MediaInfo.FeatureFlushCache) {
+ XenPvBlockPushOperation (Dev, BLKIF_OP_FLUSH_DISKCACHE, 0);
+ }
+ }
+
+ /* Note: This won't finish if another thread enqueues requests. */
+ while (TRUE) {
+ XenPvBlockAsyncIoPoll (Dev);
+ if (RING_FREE_REQUESTS (&Dev->Ring) == RING_SIZE (&Dev->Ring)) {
+ break;
+ }
+ }
+}
+
+VOID
+XenPvBlockAsyncIoPoll (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ )
+{
+ RING_IDX ProducerIndex, ConsumerIndex;
+ blkif_response_t *Response;
+ INT32 More;
+
+ do {
+ ProducerIndex = Dev->Ring.sring->rsp_prod;
+ /* Ensure we see queued responses up to 'ProducerIndex'. */
+ MemoryFence ();
+ ConsumerIndex = Dev->Ring.rsp_cons;
+
+ while (ConsumerIndex != ProducerIndex) {
+ XEN_BLOCK_FRONT_IO *IoData = NULL;
+ INT16 Status;
+
+ Response = RING_GET_RESPONSE (&Dev->Ring, ConsumerIndex);
+
+ IoData = (VOID *) (UINTN) Response->id;
+ Status = Response->status;
+
+ switch (Response->operation) {
+ case BLKIF_OP_READ:
+ case BLKIF_OP_WRITE:
+ {
+ INT32 Index;
+
+ if (Status != BLKIF_RSP_OKAY) {
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: "
+ "%a error %d on %a at sector %p, num bytes %p\n",
+ Response->operation == BLKIF_OP_READ ? "read" : "write",
+ Status, IoData->Dev->NodeName,
+ IoData->Sector,
+ IoData->Size));
+ }
+
+ for (Index = 0; Index < IoData->NumRef; Index++) {
+ Dev->XenBusIo->GrantEndAccess (Dev->XenBusIo,
IoData->GrantRef[Index]);
+ }
+
+ break;
+ }
+
+ case BLKIF_OP_WRITE_BARRIER:
+ if (Status != BLKIF_RSP_OKAY) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: write barrier error %d\n", Status));
+ }
+ break;
+ case BLKIF_OP_FLUSH_DISKCACHE:
+ if (Status != BLKIF_RSP_OKAY) {
+ DEBUG ((EFI_D_ERROR, "XenPvBlk: flush error %d\n", Status));
+ }
+ break;
+
+ default:
+ DEBUG ((EFI_D_ERROR,
+ "XenPvBlk: unrecognized block operation %d response (status
%d)\n",
+ Response->operation, Status));
+ break;
+ }
+
+ Dev->Ring.rsp_cons = ++ConsumerIndex;
+ if (IoData != NULL) {
+ IoData->Status = Status ? EFI_DEVICE_ERROR : EFI_SUCCESS;
+ }
+ if (Dev->Ring.rsp_cons != ConsumerIndex) {
+ /* We reentered, we must not continue here */
+ break;
+ }
+ }
+
+ RING_FINAL_CHECK_FOR_RESPONSES (&Dev->Ring, More);
+ } while (More != 0);
+}
diff --git a/OvmfPkg/XenPvBlkDxe/BlockFront.h b/OvmfPkg/XenPvBlkDxe/BlockFront.h
new file mode 100644
index 0000000..761f09b
--- /dev/null
+++ b/OvmfPkg/XenPvBlkDxe/BlockFront.h
@@ -0,0 +1,87 @@
+#include "XenPvBlkDxe.h"
+
+#include <IndustryStandard/Xen/event_channel.h>
+#include <IndustryStandard/Xen/io/blkif.h>
+
+typedef struct _XEN_BLOCK_FRONT_DEVICE XEN_BLOCK_FRONT_DEVICE;
+typedef struct _XEN_BLOCK_FRONT_IO XEN_BLOCK_FRONT_IO;
+
+struct _XEN_BLOCK_FRONT_IO
+{
+ XEN_BLOCK_FRONT_DEVICE *Dev;
+ UINT8 *Buffer;
+ UINTN Size;
+ UINTN Sector; ///< 512 bytes sector.
+
+ grant_ref_t GrantRef[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+ INT32 NumRef;
+
+ EFI_STATUS Status;
+};
+
+typedef struct
+{
+ UINT64 Sectors;
+ UINT32 SectorSize;
+ UINT32 VDiskInfo;
+ BOOLEAN ReadWrite;
+ BOOLEAN CdRom;
+ BOOLEAN FeatureBarrier;
+ BOOLEAN FeatureFlushCache;
+} XEN_BLOCK_FRONT_MEDIA_INFO;
+
+#define XEN_BLOCK_FRONT_SIGNATURE SIGNATURE_32 ('X', 'p', 'v', 'B')
+struct _XEN_BLOCK_FRONT_DEVICE {
+ UINT32 Signature;
+ EFI_BLOCK_IO_PROTOCOL BlockIo;
+ domid_t DomainId;
+
+ blkif_front_ring_t Ring;
+ grant_ref_t RingRef;
+ evtchn_port_t EventChannel;
+ blkif_vdev_t DeviceId;
+
+ CONST CHAR8 *NodeName;
+ XEN_BLOCK_FRONT_MEDIA_INFO MediaInfo;
+
+ VOID *StateWatchToken;
+
+ XENBUS_PROTOCOL *XenBusIo;
+};
+
+#define XEN_BLOCK_FRONT_FROM_BLOCK_IO(b) \
+ CR (b, XEN_BLOCK_FRONT_DEVICE, BlockIo, XEN_BLOCK_FRONT_SIGNATURE)
+
+EFI_STATUS
+XenPvBlockFrontInitialization (
+ IN XENBUS_PROTOCOL *XenBusIo,
+ IN CONST CHAR8 *NodeName,
+ OUT XEN_BLOCK_FRONT_DEVICE **DevPtr
+ );
+
+VOID
+XenPvBlockFrontShutdown (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ );
+
+VOID
+XenPvBlockAsyncIo (
+ IN OUT XEN_BLOCK_FRONT_IO *IoData,
+ IN BOOLEAN IsWrite
+ );
+
+EFI_STATUS
+XenPvBlockIo (
+ IN OUT XEN_BLOCK_FRONT_IO *IoData,
+ IN BOOLEAN IsWrite
+ );
+
+VOID
+XenPvBlockAsyncIoPoll (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ );
+
+VOID
+XenPvBlockSync (
+ IN XEN_BLOCK_FRONT_DEVICE *Dev
+ );
diff --git a/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.c
b/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.c
index ad45e69..a732a04 100644
--- a/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.c
+++ b/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.c
@@ -36,6 +36,8 @@
#include "XenPvBlkDxe.h"
+#include "BlockFront.h"
+
///
/// Driver Binding Protocol instance
@@ -274,6 +276,7 @@ XenPvBlkDxeDriverBindingStart (
{
EFI_STATUS Status;
XENBUS_PROTOCOL *XenBusIo;
+ XEN_BLOCK_FRONT_DEVICE *Dev;
Status = gBS->OpenProtocol (
ControllerHandle,
@@ -287,7 +290,17 @@ XenPvBlkDxeDriverBindingStart (
return Status;
}
+ Status = XenPvBlockFrontInitialization (XenBusIo, XenBusIo->Node, &Dev);
+ if (EFI_ERROR (Status)) {
+ goto CloseProtocol;
+ }
+
return EFI_SUCCESS;
+
+CloseProtocol:
+ gBS->CloseProtocol (ControllerHandle, &gXenBusProtocolGuid,
+ This->DriverBindingHandle, ControllerHandle);
+ return Status;
}
/**
diff --git a/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
b/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
index 4103996..9a6e17b 100644
--- a/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
+++ b/OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
@@ -50,6 +50,8 @@
XenPvBlkDxe.c
ComponentName.c
ComponentName.h
+ BlockFront.c
+ BlockFront.h
[LibraryClasses]
--
Anthony PERARD
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