1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
/* SPDX-License-Identifier: GPL-2.0 OR MIT */
/*
* Xen para-virtual DRM device
*
* Copyright (C) 2016-2018 EPAM Systems Inc.
*
* Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
*/
#ifndef __XEN_DRM_FRONT_H_
#define __XEN_DRM_FRONT_H_
#include <drm/drmP.h>
#include <drm/drm_simple_kms_helper.h>
#include <linux/scatterlist.h>
#include "xen_drm_front_cfg.h"
/**
* DOC: Driver modes of operation in terms of display buffers used
*
* Depending on the requirements for the para-virtualized environment, namely
* requirements dictated by the accompanying DRM/(v)GPU drivers running in both
* host and guest environments, display buffers can be allocated by either
* frontend driver or backend.
*/
/**
* DOC: Buffers allocated by the frontend driver
*
* In this mode of operation driver allocates buffers from system memory.
*
* Note! If used with accompanying DRM/(v)GPU drivers this mode of operation
* may require IOMMU support on the platform, so accompanying DRM/vGPU
* hardware can still reach display buffer memory while importing PRIME
* buffers from the frontend driver.
*/
/**
* DOC: Buffers allocated by the backend
*
* This mode of operation is run-time configured via guest domain configuration
* through XenStore entries.
*
* For systems which do not provide IOMMU support, but having specific
* requirements for display buffers it is possible to allocate such buffers
* at backend side and share those with the frontend.
* For example, if host domain is 1:1 mapped and has DRM/GPU hardware expecting
* physically contiguous memory, this allows implementing zero-copying
* use-cases.
*
* Note, while using this scenario the following should be considered:
*
* #. If guest domain dies then pages/grants received from the backend
* cannot be claimed back
*
* #. Misbehaving guest may send too many requests to the
* backend exhausting its grant references and memory
* (consider this from security POV)
*/
/**
* DOC: Driver limitations
*
* #. Only primary plane without additional properties is supported.
*
* #. Only one video mode per connector supported which is configured
* via XenStore.
*
* #. All CRTCs operate at fixed frequency of 60Hz.
*/
/* timeout in ms to wait for backend to respond */
#define XEN_DRM_FRONT_WAIT_BACK_MS 3000
#ifndef GRANT_INVALID_REF
/*
* Note on 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.
*/
#define GRANT_INVALID_REF 0
#endif
struct xen_drm_front_info {
struct xenbus_device *xb_dev;
struct xen_drm_front_drm_info *drm_info;
/* to protect data between backend IO code and interrupt handler */
spinlock_t io_lock;
int num_evt_pairs;
struct xen_drm_front_evtchnl_pair *evt_pairs;
struct xen_drm_front_cfg cfg;
/* display buffers */
struct list_head dbuf_list;
};
struct xen_drm_front_drm_pipeline {
struct xen_drm_front_drm_info *drm_info;
int index;
struct drm_simple_display_pipe pipe;
struct drm_connector conn;
/* These are only for connector mode checking */
int width, height;
struct drm_pending_vblank_event *pending_event;
struct delayed_work pflip_to_worker;
bool conn_connected;
};
struct xen_drm_front_drm_info {
struct xen_drm_front_info *front_info;
struct drm_device *drm_dev;
struct xen_drm_front_drm_pipeline pipeline[XEN_DRM_FRONT_MAX_CRTCS];
};
static inline u64 xen_drm_front_fb_to_cookie(struct drm_framebuffer *fb)
{
return (u64)fb;
}
static inline u64 xen_drm_front_dbuf_to_cookie(struct drm_gem_object *gem_obj)
{
return (u64)gem_obj;
}
int xen_drm_front_mode_set(struct xen_drm_front_drm_pipeline *pipeline,
u32 x, u32 y, u32 width, u32 height,
u32 bpp, u64 fb_cookie);
int xen_drm_front_dbuf_create(struct xen_drm_front_info *front_info,
u64 dbuf_cookie, u32 width, u32 height,
u32 bpp, u64 size, struct page **pages);
int xen_drm_front_fb_attach(struct xen_drm_front_info *front_info,
u64 dbuf_cookie, u64 fb_cookie, u32 width,
u32 height, u32 pixel_format);
int xen_drm_front_fb_detach(struct xen_drm_front_info *front_info,
u64 fb_cookie);
int xen_drm_front_page_flip(struct xen_drm_front_info *front_info,
int conn_idx, u64 fb_cookie);
void xen_drm_front_on_frame_done(struct xen_drm_front_info *front_info,
int conn_idx, u64 fb_cookie);
#endif /* __XEN_DRM_FRONT_H_ */
|
