/******************************************************************************
* displif.h
*
* Unified display 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) 2016-2017 EPAM Systems Inc.
*
* Authors: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
* Oleksandr Grytsov <oleksandr_grytsov@epam.com>
*/
#ifndef __XEN_PUBLIC_IO_DISPLIF_H__
#define __XEN_PUBLIC_IO_DISPLIF_H__
#include "ring.h"
#include "../grant_table.h"
/*
******************************************************************************
* Protocol version
******************************************************************************
*/
#define XENDISPL_PROTOCOL_VERSION "1"
/*
******************************************************************************
* Main features provided by the protocol
******************************************************************************
* This protocol aims to provide a unified protocol which fits more
* sophisticated use-cases than a framebuffer device can handle. At the
* moment basic functionality is supported with the intention to be extended:
* o multiple dynamically allocated/destroyed framebuffers
* o buffers of arbitrary sizes
* o buffer allocation at either back or front end
* o better configuration options including multiple display support
*
* Note: existing fbif can be used together with displif running at the
* same time, e.g. on Linux one provides framebuffer and another DRM/KMS
*
* Note: display resolution (XenStore's "resolution" property) defines
* visible area of the virtual display. At the same time resolution of
* the display and frame buffers may differ: buffers can be smaller, equal
* or bigger than the visible area. This is to enable use-cases, where backend
* may do some post-processing of the display and frame buffers supplied,
* e.g. those buffers can be just a part of the final composition.
*
******************************************************************************
* Direction of improvements
******************************************************************************
* Future extensions to the existing protocol may include:
* o display/connector cloning
* o allocation of objects other than display buffers
* o plane/overlay support
* o scaling support
* o rotation support
*
******************************************************************************
* Feature and Parameter Negotiation
******************************************************************************
*
* Front->back notifications: when enqueuing a new request, sending a
* notification can be made conditional on xendispl_req (i.e., the generic
* hold-off mechanism provided by the ring macros). Backends must set
* xendispl_req 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 xendispl_resp (i.e., the generic
* hold-off mechanism provided by the ring macros). Frontends must set
* xendispl_resp appropriately (e.g., using RING_FINAL_CHECK_FOR_RESPONSES()).
*
* The two halves of a para-virtual display driver utilize nodes within
* XenStore to communicate capabilities and to negotiate operating parameters.
* This section enumerates these nodes which reside in the respective front and
* backend portions of XenStore, following the XenBus convention.
*
* All data in 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.
*
******************************************************************************
* Example configuration
******************************************************************************
*
* Note: depending on the use-case backend can expose more display connectors
* than the underlying HW physically has by employing SW graphics compositors
*
* This is an example of backend and frontend configuration:
*
*--------------------------------- Backend -----------------------------------
*
* /local/domain/0/backend/vdispl/1/0/frontend-id = "1"
* /local/domain/0/backend/vdispl/1/0/frontend = "/local/domain/1/device/vdispl/0"
* /local/domain/0/backend/vdispl/1/0/state = "4"
* /local/domain/0/backend/vdispl/1/0/versions = "1,2"
*
*--------------------------------- Frontend ----------------------------------
*
* /local/domain/1/device/vdispl/0/backend-id = "0"
* /local/domain/1/device/vdispl/0/backend = "/local/domain/0/backend/vdispl/1/0"
* /local/domain/1/device/vdispl/0/state = "4"
* /local/domain/1/device/vdispl/0/version = "1"
* /local/domain/1/device/vdispl/0/be-alloc = "1"
*
*-------------------------- Connector 0 configuration ------------------------
*
* /local/domain/1/device/vdispl/0/0/resolution = "1920x1080"
* /local/domain/1/device/vdispl/0/0/req-ring-ref = "2832"
* /local/domain/1/device/vdispl/0/0/req-event-channel = "15"
* /local/domain/1/device/vdispl/0/0/evt-ring-ref = "387"
* /local/domain/1/device/vdispl/0/0/evt-event-channel = "16"
*
*-------------------------- Connector 1 configuration ------------------------
*
* /local/domain/1/device/vdispl/0/1/resolution = "800x600"
* /local/domain/1/device/vdispl/0/1/req-ring-ref = "2833"
* /local/domain/1/device/vdispl/0/1/req-event-channel = "17"
* /local/domain/1/device/vdispl/0/1/evt-ring-ref = "388"
* /local/domain/1/device/vdispl/0/1/evt-event-channel = "18"
*
******************************************************************************
* Backend XenBus Nodes
******************************************************************************
*
*----------------------------- Protocol version ------------------------------
*
* versions
* Values: <string>
*
* List of XENDISPL_LIST_SEPARATOR separated protocol versions supported
* by the backend. For example "1,2,3".
*
******************************************************************************
* Frontend XenBus Nodes
******************************************************************************
*
*-------------------------------- Addressing ---------------------------------
*
* dom-id
* Values: <uint16_t>
*
* Domain identifier.
*
* dev-id
* Values: <uint16_t>
*
* Device identifier.
*
* conn-idx
* Values: <uint8_t>
*
* Zero based contigous index of the connector.
* /local/domain/<dom-id>/device/vdispl/<dev-id>/<conn-idx>/...
*
*----------------------------- Protocol version ------------------------------
*
* version
* Values: <string>
*
* Protocol version, chosen among the ones supported by the backend.
*
*------------------------- Backend buffer allocation -------------------------
*
* be-alloc
* Values: "0", "1"
*
* If value is set to "1", then backend can be a buffer provider/allocator
* for this domain during XENDISPL_OP_DBUF_CREATE operation (see below
* for negotiation).
* If value is not "1" or omitted frontend must allocate buffers itself.
*
*----------------------------- Connector settings ----------------------------
*
* resolution
* Values: <width, uint32_t>x<height, uint32_t>
*
* Width and height of the connector in pixels separated by
* XENDISPL_RESOLUTION_SEPARATOR. This defines visible area of the
* display.
*
*------------------ Connector Request Transport Parameters -------------------
*
* This communication path is used to deliver requests from frontend to backend
* and get the corresponding responses from backend to frontend,
* set up per connector.
*
* req-event-channel
* Values: <uint32_t>
*
* The identifier of the Xen connector's control event channel
* used to signal activity in the ring buffer.
*
* req-ring-ref
* Values: <uint32_t>
*
* The Xen grant reference granting permission for the backend to map
* a sole page of connector's control ring buffer.
*
*------------------- Connector Event Transport Parameters --------------------
*
* This communication path is used to deliver asynchronous events from backend
* to frontend, set up per connector.
*
* evt-event-channel
* Values: <uint32_t>
*
* The identifier of the Xen connector's event channel
* used to signal activity in the ring buffer.
*
* evt-ring-ref
* Values: <uint32_t>
*
* The Xen grant reference granting permission for the backend to map
* a sole page of connector's event ring buffer.
*/
/*
******************************************************************************
* STATE DIAGRAMS
******************************************************************************
*
* Tool stack creates front and back state nodes with initial state
* XenbusStateInitialising.
* Tool stack creates and sets up frontend display configuration
* nodes per domain.
*
*-------------------------------- Normal flow --------------------------------
*
* Front Back
* ================================= =====================================
* XenbusStateInitialising XenbusStateInitialising
* o Query backend device identification
* data.
* o Open and validate backend device.
* |
* |
* V
* XenbusStateInitWait
*
* o Query frontend configuration
* o Allocate and initialize
* event channels per configured
* connector.
* o Publish transport parameters
* that will be in effect during
* this connection.
* |
* |
* V
* XenbusStateInitialised
*
* o Query frontend transport parameters.
* o Connect to the event channels.
* |
* |
* V
* XenbusStateConnected
*
* o Create and initialize OS
* virtual display connectors
* as per configuration.
* |
* |
* V
* XenbusStateConnected
*
* XenbusStateUnknown
* XenbusStateClosed
* XenbusStateClosing
* o Remove virtual display device
* o Remove event channels
* |
* |
* V
* XenbusStateClosed
*
*------------------------------- Recovery flow -------------------------------
*
* In case of frontend unrecoverable errors backend handles that as
* if frontend goes into the XenbusStateClosed state.
*
* In case of backend unrecoverable errors frontend tries removing
* the virtualized device. If this is possible at the moment of error,
* then frontend goes into the XenbusStateInitialising state and is ready for
* new connection with backend. If the virtualized device is still in use and
* cannot be removed, then frontend goes into the XenbusStateReconfiguring state
* until either the virtualized device is removed or backend initiates a new
* connection. On the virtualized device removal frontend goes into the
* XenbusStateInitialising state.
*
* Note on XenbusStateReconfiguring state of the frontend: if backend has
* unrecoverable errors then frontend cannot send requests to the backend
* and thus cannot provide functionality of the virtualized device anymore.
* After backend is back to normal the virtualized device may still hold some
* state: configuration in use, allocated buffers, client application state etc.
* In most cases, this will require frontend to implement complex recovery
* reconnect logic. Instead, by going into XenbusStateReconfiguring state,
* frontend will make sure no new clients of the virtualized device are
* accepted, allow existing client(s) to exit gracefully by signaling error
* state etc.
* Once all the clients are gone frontend can reinitialize the virtualized
* device and get into XenbusStateInitialising state again signaling the
* backend that a new connection can be made.
*
* There are multiple conditions possible under which frontend will go from
* XenbusStateReconfiguring into XenbusStateInitialising, some of them are OS
* specific. For example:
* 1. The underlying OS framework may provide callbacks to signal that the last
* client of the virtualized device has gone and the device can be removed
* 2. Frontend can schedule a deferred work (timer/tasklet/workqueue)
* to periodically check if this is the right time to re-try removal of
* the virtualized device.
* 3. By any other means.
*
******************************************************************************
* REQUEST CODES
******************************************************************************
* Request codes [0; 15] are reserved and must not be used
*/
#define XENDISPL_OP_DBUF_CREATE 0x10
#define XENDISPL_OP_DBUF_DESTROY 0x11
#define XENDISPL_OP_FB_ATTACH 0x12
#define XENDISPL_OP_FB_DETACH 0x13
#define XENDISPL_OP_SET_CONFIG 0x14
#define XENDISPL_OP_PG_FLIP 0x15
/*
******************************************************************************
* EVENT CODES
******************************************************************************
*/
#define XENDISPL_EVT_PG_FLIP 0x00
/*
******************************************************************************
* XENSTORE FIELD AND PATH NAME STRINGS, HELPERS
******************************************************************************
*/
#define XENDISPL_DRIVER_NAME "vdispl"
#define XENDISPL_LIST_SEPARATOR ","
#define XENDISPL_RESOLUTION_SEPARATOR "x"
#define XENDISPL_FIELD_BE_VERSIONS "versions"
#define XENDISPL_FIELD_FE_VERSION "version"
#define XENDISPL_FIELD_REQ_RING_REF "req-ring-ref"
#define XENDISPL_FIELD_REQ_CHANNEL "req-event-channel"
#define XENDISPL_FIELD_EVT_RING_REF "evt-ring-ref"
#define XENDISPL_FIELD_EVT_CHANNEL "evt-event-channel"
#define XENDISPL_FIELD_RESOLUTION "resolution"
#define XENDISPL_FIELD_BE_ALLOC "be-alloc"
/*
******************************************************************************
* STATUS RETURN CODES
******************************************************************************
*
* Status return code is zero on success and -XEN_EXX on failure.
*
******************************************************************************
* Assumptions
******************************************************************************
* o usage of grant reference 0 as invalid grant reference:
* grant reference 0 is valid, but never exposed to a PV driver,
* because of the fact it is already in use/reserved by the PV console.
* o all references in this document to page sizes must be treated
* as pages of size XEN_PAGE_SIZE unless otherwise noted.
*
******************************************************************************
* Description of the protocol between frontend and backend driver
******************************************************************************
*
* The two halves of a Para-virtual display driver communicate with
* each other using shared pages and event channels.
* Shared page contains a ring with request/response packets.
*
* All reserved fields in the structures below must be 0.
* Display buffers's cookie of value 0 is treated as invalid.
* Framebuffer's cookie of value 0 is treated as invalid.
*
* For all request/response/event packets that use cookies:
* dbuf_cookie - uint64_t, unique to guest domain value used by the backend
* to map remote display buffer to its local one
* fb_cookie - uint64_t, unique to guest domain value used by the backend
* to map remote framebuffer to its local one
*
*---------------------------------- Requests ---------------------------------
*
* All requests/responses, which are not connector specific, must be sent over
* control ring of the connector which has the index value of 0:
* /local/domain/<dom-id>/device/vdispl/<dev-id>/0/req-ring-ref
*
* All request packets have the same length (64 octets)
* All request packets have common header:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | operation | reserved | 4
* +----------------+----------------+----------------+----------------+
* | reserved | 8
* +----------------+----------------+----------------+----------------+
* id - uint16_t, private guest value, echoed in response
* operation - uint8_t, operation code, XENDISPL_OP_???
*
* Request dbuf creation - request creation of a display buffer.
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id |_OP_DBUF_CREATE | reserved | 4
* +----------------+----------------+----------------+----------------+
* | reserved | 8
* +----------------+----------------+----------------+----------------+
* | dbuf_cookie low 32-bit | 12
* +----------------+----------------+----------------+----------------+
* | dbuf_cookie high 32-bit | 16
* +----------------+----------------+----------------+----------------+
* | width | 20
* +----------------+----------------+----------------+----------------+
* | height | 24
* +----------------+----------------+----------------+----------------+
* | bpp | 28
* +----------------+----------------+----------------+----------------+
* | buffer_sz | 32
* +----------------+----------------+----------------+----------------+
* | flags | 36
* +----------------+----------------+----------------+----------------+
* | gref_directory | 40
* +----------------+----------------+----------------+----------------+
* | reserved | 44
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 64
* +----------------+----------------+----------------+----------------+
*
* Must be sent over control ring of the connector which has the index
* value of 0:
* /local/domain/<dom-id>/device/vdispl/<dev-id>/0/req-ring-ref
* All unused bits in flags field must be set to 0.
*
* An attempt to create multiple display buffers with the same dbuf_cookie is
* an error. dbuf_cookie can be re-used after destroying the corresponding
* display buffer.
*
* Width and height of the display buffers can be smaller, equal or bigger
* than the connector's resolution. Depth/pixel format of the individual
* buffers can differ as well.
*
* width - uint32_t, width in pixels
* height - uint32_t, height in pixels
* bpp - uint32_t, bits per pixel
* buffer_sz - uint32_t, buffer size to be allocated, octets
* flags - uint32_t, flags of the operation
* o XENDISPL_DBUF_FLG_REQ_ALLOC - if set, then backend is requested
* to allocate the buffer with the parameters provided in this request.
* Page directory is handled as follows:
* Frontend on request:
* o allocates pages for the directory (gref_directory,
* gref_dir_next_page(s)
* o grants permissions for the pages of the directory to the backend
* o sets gref_dir_next_page fields
* Backend on response:
* o grants permissions for the pages of the buffer allocated to
* the frontend
* o fills in page directory with grant references
* (gref[] in struct xendispl_page_directory)
* gref_directory - grant_ref_t, a reference to the first shared page
* describing shared buffer references. At least one page exists. If shared
* buffer size (buffer_sz) exceeds what can be addressed by this single page,
* then reference to the next page must be supplied (see gref_dir_next_page
* below)
*/
#define XENDISPL_DBUF_FLG_REQ_ALLOC (1 << 0)
struct xendispl_dbuf_create_req {
uint64_t dbuf_cookie;
uint32_t width;
uint32_t height;
uint32_t bpp;
uint32_t buffer_sz;
uint32_t flags;
grant_ref_t gref_directory;
};
/*
* Shared page for XENDISPL_OP_DBUF_CREATE buffer descriptor (gref_directory in
* the request) employs a list of pages, describing all pages of the shared
* data buffer:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | gref_dir_next_page | 4
* +----------------+----------------+----------------+----------------+
* | gref[0] | 8
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | gref[i] | i*4+8
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | gref[N - 1] | N*4+8
* +----------------+----------------+----------------+----------------+
*
* gref_dir_next_page - grant_ref_t, reference to the next page describing
* page directory. Must be 0 if there are no more pages in the list.
* gref[i] - grant_ref_t, reference to a shared page of the buffer
* allocated at XENDISPL_OP_DBUF_CREATE
*
* Number of grant_ref_t entries in the whole page directory is not
* passed, but instead can be calculated as:
* num_grefs_total = (XENDISPL_OP_DBUF_CREATE.buffer_sz + XEN_PAGE_SIZE - 1) /
* XEN_PAGE_SIZE
*/
struct xendispl_page_directory {
grant_ref_t gref_dir_next_page;
grant_ref_t gref[1]; /* Variable length */
};
/*
* Request dbuf destruction - destroy a previously allocated display buffer:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id |_OP_DBUF_DESTROY| reserved | 4
* +----------------+----------------+----------------+----------------+
* | reserved | 8
* +----------------+----------------+----------------+----------------+
* | dbuf_cookie low 32-bit | 12
* +----------------+----------------+----------------+----------------+
* | dbuf_cookie high 32-bit | 16
* +----------------+----------------+----------------+----------------+
* | reserved | 20
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 64
* +----------------+----------------+----------------+----------------+
*
* Must be sent over control ring of the connector which has the index
* value of 0:
* /local/domain/<dom-id>/device/vdispl/<dev-id>/0/req-ring-ref
*/
struct xendispl_dbuf_destroy_req {
uint64_t dbuf_cookie;
};
/*
* Request framebuffer attachment - request attachment of a framebuffer to
* previously created display buffer.
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | _OP_FB_ATTACH | reserved | 4
* +----------------+----------------+----------------+----------------+
* | reserved | 8
* +----------------+----------------+----------------+----------------+
* | dbuf_cookie low 32-bit | 12
* +----------------+----------------+----------------+----------------+
* | dbuf_cookie high 32-bit | 16
* +----------------+----------------+----------------+----------------+
* | fb_cookie low 32-bit | 20
* +----------------+----------------+----------------+----------------+
* | fb_cookie high 32-bit | 24
* +----------------+----------------+----------------+----------------+
* | width | 28
* +----------------+----------------+----------------+----------------+
* | height | 32
* +----------------+----------------+----------------+----------------+
* | pixel_format | 36
* +----------------+----------------+----------------+----------------+
* | reserved | 40
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 64
* +----------------+----------------+----------------+----------------+
*
* Must be sent over control ring of the connector which has the index
* value of 0:
* /local/domain/<dom-id>/device/vdispl/<dev-id>/0/req-ring-ref
* Width and height can be smaller, equal or bigger than the connector's
* resolution.
*
* An attempt to create multiple frame buffers with the same fb_cookie is
* an error. fb_cookie can be re-used after destroying the corresponding
* frame buffer.
*
* width - uint32_t, width in pixels
* height - uint32_t, height in pixels
* pixel_format - uint32_t, pixel format of the framebuffer, FOURCC code
*/
struct xendispl_fb_attach_req {
uint64_t dbuf_cookie;
uint64_t fb_cookie;
uint32_t width;
uint32_t height;
uint32_t pixel_format;
};
/*
* Request framebuffer detach - detach a previously
* attached framebuffer from the display buffer in request:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | _OP_FB_DETACH | reserved | 4
* +----------------+----------------+----------------+----------------+
* | reserved | 8
* +----------------+----------------+----------------+----------------+
* | fb_cookie low 32-bit | 12
* +----------------+----------------+----------------+----------------+
* | fb_cookie high 32-bit | 16
* +----------------+----------------+----------------+----------------+
* | reserved | 20
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 64
* +----------------+----------------+----------------+----------------+
*
* Must be sent over control ring of the connector which has the index
* value of 0:
* /local/domain/<dom-id>/device/vdispl/<dev-id>/0/req-ring-ref
*/
struct xendispl_fb_detach_req {
uint64_t fb_cookie;
};
/*
* Request configuration set/reset - request to set or reset
* the configuration/mode of the display:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | _OP_SET_CONFIG | reserved | 4
* +----------------+----------------+----------------+----------------+
* | reserved | 8
* +----------------+----------------+----------------+----------------+
* | fb_cookie low 32-bit | 12
* +----------------+----------------+----------------+----------------+
* | fb_cookie high 32-bit | 16
* +----------------+----------------+----------------+----------------+
* | x | 20
* +----------------+----------------+----------------+----------------+
* | y | 24
* +----------------+----------------+----------------+----------------+
* | width | 28
* +----------------+----------------+----------------+----------------+
* | height | 32
* +----------------+----------------+----------------+----------------+
* | bpp | 40
* +----------------+----------------+----------------+----------------+
* | reserved | 44
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 64
* +----------------+----------------+----------------+----------------+
*
* Pass all zeros to reset, otherwise command is treated as
* configuration set.
* Framebuffer's cookie defines which framebuffer/dbuf must be
* displayed while enabling display (applying configuration).
* x, y, width and height are bound by the connector's resolution and must not
* exceed it.
*
* x - uint32_t, starting position in pixels by X axis
* y - uint32_t, starting position in pixels by Y axis
* width - uint32_t, width in pixels
* height - uint32_t, height in pixels
* bpp - uint32_t, bits per pixel
*/
struct xendispl_set_config_req {
uint64_t fb_cookie;
uint32_t x;
uint32_t y;
uint32_t width;
uint32_t height;
uint32_t bpp;
};
/*
* Request page flip - request to flip a page identified by the framebuffer
* cookie:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | _OP_PG_FLIP | reserved | 4
* +----------------+----------------+----------------+----------------+
* | reserved | 8
* +----------------+----------------+----------------+----------------+
* | fb_cookie low 32-bit | 12
* +----------------+----------------+----------------+----------------+
* | fb_cookie high 32-bit | 16
* +----------------+----------------+----------------+----------------+
* | reserved | 20
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 64
* +----------------+----------------+----------------+----------------+
*/
struct xendispl_page_flip_req {
uint64_t fb_cookie;
};
/*
*---------------------------------- Responses --------------------------------
*
* All response packets have the same length (64 octets)
*
* All response packets have common header:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | reserved | 4
* +----------------+----------------+----------------+----------------+
* | status | 8
* +----------------+----------------+----------------+----------------+
* | reserved | 12
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 64
* +----------------+----------------+----------------+----------------+
*
* id - uint16_t, private guest value, echoed from request
* status - int32_t, response status, zero on success and -XEN_EXX on failure
*
*----------------------------------- Events ----------------------------------
*
* Events are sent via a shared page allocated by the front and propagated by
* evt-event-channel/evt-ring-ref XenStore entries
* All event packets have the same length (64 octets)
* All event packets have common header:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | type | reserved | 4
* +----------------+----------------+----------------+----------------+
* | reserved | 8
* +----------------+----------------+----------------+----------------+
*
* id - uint16_t, event id, may be used by front
* type - uint8_t, type of the event
*
*
* Page flip complete event - event from back to front on page flip completed:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | _EVT_PG_FLIP | reserved | 4
* +----------------+----------------+----------------+----------------+
* | reserved | 8
* +----------------+----------------+----------------+----------------+
* | fb_cookie low 32-bit | 12
* +----------------+----------------+----------------+----------------+
* | fb_cookie high 32-bit | 16
* +----------------+----------------+----------------+----------------+
* | reserved | 20
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 64
* +----------------+----------------+----------------+----------------+
*/
struct xendispl_pg_flip_evt {
uint64_t fb_cookie;
};
struct xendispl_req {
uint16_t id;
uint8_t operation;
uint8_t reserved[5];
union {
struct xendispl_dbuf_create_req dbuf_create;
struct xendispl_dbuf_destroy_req dbuf_destroy;
struct xendispl_fb_attach_req fb_attach;
struct xendispl_fb_detach_req fb_detach;
struct xendispl_set_config_req set_config;
struct xendispl_page_flip_req pg_flip;
uint8_t reserved[56];
} op;
};
struct xendispl_resp {
uint16_t id;
uint8_t operation;
uint8_t reserved;
int32_t status;
uint8_t reserved1[56];
};
struct xendispl_evt {
uint16_t id;
uint8_t type;
uint8_t reserved[5];
union {
struct xendispl_pg_flip_evt pg_flip;
uint8_t reserved[56];
} op;
};
DEFINE_RING_TYPES(xen_displif, struct xendispl_req, struct xendispl_resp);
/*
******************************************************************************
* Back to front events delivery
******************************************************************************
* In order to deliver asynchronous events from back to front a shared page is
* allocated by front and its granted reference propagated to back via
* XenStore entries (evt-ring-ref/evt-event-channel).
* This page has a common header used by both front and back to synchronize
* access and control event's ring buffer, while back being a producer of the
* events and front being a consumer. The rest of the page after the header
* is used for event packets.
*
* Upon reception of an event(s) front may confirm its reception
* for either each event, group of events or none.
*/
struct xendispl_event_page {
uint32_t in_cons;
uint32_t in_prod;
uint8_t reserved[56];
};
#define XENDISPL_EVENT_PAGE_SIZE 4096
#define XENDISPL_IN_RING_OFFS (sizeof(struct xendispl_event_page))
#define XENDISPL_IN_RING_SIZE (XENDISPL_EVENT_PAGE_SIZE - XENDISPL_IN_RING_OFFS)
#define XENDISPL_IN_RING_LEN (XENDISPL_IN_RING_SIZE / sizeof(struct xendispl_evt))
#define XENDISPL_IN_RING(page) \
((struct xendispl_evt *)((char *)(page) + XENDISPL_IN_RING_OFFS))
#define XENDISPL_IN_RING_REF(page, idx) \
(XENDISPL_IN_RING((page))[(idx) % XENDISPL_IN_RING_LEN])
#endif /* __XEN_PUBLIC_IO_DISPLIF_H__ */
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/