aboutsummaryrefslogtreecommitdiff
path: root/lib/muser.h
blob: f0756a7b380df9e3f4c4bf9e835b2a09ca5b2cc5 (plain)
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
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
/*
 * Copyright (c) 2019 Nutanix Inc. All rights reserved.
 *
 * Authors: Thanos Makatos <thanos@nutanix.com>
 *          Swapnil Ingle <swapnil.ingle@nutanix.com>
 *          Felipe Franciosi <felipe@nutanix.com>
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *      * Redistributions of source code must retain the above copyright
 *        notice, this list of conditions and the following disclaimer.
 *      * 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.
 *      * Neither the name of Nutanix nor the names of its contributors may be
 *        used to endorse or promote products derived from this software without
 *        specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 <COPYRIGHT HOLDER> 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.
 *
 */

#ifndef LIB_MUSER_H
#define LIB_MUSER_H

#include <stdint.h>
#include <sys/uio.h>
#include <unistd.h>

#include "pci.h"

/*
 * Influential enviroment variables:
 *
 * LM_TERSE_LOGGING: define to make libmuser log only erroneous PCI accesses.
 *                   (this should really be done with a more fine grained debug
 *                    level)
 */
#ifndef LM_TERSE_LOGGING
#define LM_TERSE_LOGGING 0
#endif

typedef uint64_t dma_addr_t;

typedef struct {
    int region;
    int length;
    uint64_t offset;
} dma_sg_t;

typedef struct lm_ctx lm_ctx_t;

// Region flags.
#define LM_REG_FLAG_READ    (1 << 0)
#define LM_REG_FLAG_WRITE   (1 << 1)
#define LM_REG_FLAG_MMAP    (1 << 2)    // TODO: how this relates to IO bar?
#define LM_REG_FLAG_RW      (LM_REG_FLAG_READ | LM_REG_FLAG_WRITE)
#define LM_REG_FLAG_MEM     (1 << 3)    // if unset, bar is IO

struct lm_mmap_area {
    uint64_t start;
    uint64_t size;
};

struct lm_sparse_mmap_areas {
    int nr_mmap_areas;
    struct lm_mmap_area areas[];
};

/**
 * Prototype for region access callback. When a region is accessed, libmuser
 * calls the previously registered callback with the following arguments:
 *
 * @pvt: private data originally set in dev_info
 * @buf: buffer containing the data to be written or data to be read into
 * @count: number of bytes being read or written
 * @offset: byte offset within the region
 * @is_write: whether or not this is a write
 *
 * @returns the number of bytes read or written, or a negative integer on error
 */
typedef ssize_t (lm_region_access_t) (void *pvt, char * const buf, size_t count,
                                      loff_t offset, const bool is_write);

/**
 * Prototype for memory access callback. The program MUST first map device
 * memory in its own virtual address space using lm_mmap, do any additional
 * work required, and finally return that memory. When a region is memory
 * mapped, libmuser calls previously register callback with the following
 * arguments:
 *
 * @pvt: private data originally set in dev_info
 * @off: offset of memory area being memory mapped
 * @len: length of memory area being memory mapped
 *
 * @returns the memory address returned by lm_mmap, or MAP_FAILED on failure
 */
typedef unsigned long (lm_map_region_t) (void *pvt, unsigned long off,
                                         unsigned long len);

/**
 * Creates a mapping of a device region into the caller's virtual memory. It
 * must be called by lm_map_region_t.
 *
 * @lm_ctx: the libmuser context to create mapping from
 * @offset: offset of the region being mapped
 * @length: size of the region being mapped
 *
 * @returns a pointer to the requested memory or MAP_FAILED on error. Sets errno.
 */
void *lm_mmap(lm_ctx_t * lm_ctx, off_t offset, size_t length);

typedef struct  {

    /*
     * Region flags, see LM_REG_FLAG_XXX above.
     */
    uint32_t            flags;

    /*
     * Size of the region.
     */
    uint32_t            size;

    /*
     * Callback function that is called when the region is read or written.
     */
    lm_region_access_t  *fn;

    /*
     * Callback function that is called when the region is memory mapped.
     * Required if LM_REG_FLAG_MEM is set, otherwise ignored.
     */
    lm_map_region_t     *map;
    struct lm_sparse_mmap_areas *mmap_areas; /* sparse mmap areas */
} lm_reg_info_t;

enum {
    LM_DEV_INTX_IRQ_IDX,
    LM_DEV_MSI_IRQ_IDX,
    LM_DEV_MSIX_IRQ_IDX,
    LM_DEV_ERR_IRQ_IDX,
    LM_DEV_REQ_IRQ_IDX,
    LM_DEV_NUM_IRQS = 5
};

enum {
    LM_DEV_BAR0_REG_IDX,
    LM_DEV_BAR1_REG_IDX,
    LM_DEV_BAR2_REG_IDX,
    LM_DEV_BAR3_REG_IDX,
    LM_DEV_BAR4_REG_IDX,
    LM_DEV_BAR5_REG_IDX,
    LM_DEV_ROM_REG_IDX,
    LM_DEV_CFG_REG_IDX,
    LM_DEV_VGA_REG_IDX,
    LM_DEV_NUM_REGS = 9
};

typedef struct {
    uint32_t            irq_count[LM_DEV_NUM_IRQS];

    /*
     * Per-region information. Only supported regions need to be defined,
     * unsupported regions should be left to 0.
     */
    lm_reg_info_t       reg_info[LM_DEV_NUM_REGS];

    /*
     * Device and vendor ID.
     */
    lm_pci_hdr_id_t     id;

    /*
     * Subsystem vendor and device ID.
     */
    lm_pci_hdr_ss_t     ss;

    /*
     * Class code.
     */
    lm_pci_hdr_cc_t     cc;
} lm_pci_info_t;

/*
 * Returns a pointer to the non-standard part of the PCI configuration space.
 */
lm_pci_config_space_t *lm_get_pci_config_space(lm_ctx_t * const lm_ctx);

#define LM_DMA_REGIONS  0x10

typedef enum {
    LM_ERR,
    LM_INF,
    LM_DBG
} lm_log_lvl_t;

/**
 * Callback function signature for log function
 *
 * @lm_log_fn_t: typedef for log function.
 */
typedef void (lm_log_fn_t) (void *pvt, const char *const msg);

/**
 * Callback function that gets called when a capability is accessed. The
 * callback is not called when the ID and next fields are accessed, these are
 * hanlded by the library.
 *
 * @pvt: private pointer
 * @id: capability ID being accessed
 * @buf: pointer to data being read or written
 * @count: number of bytes being read or written
 * @offset: offset within the capability
 * @is_write: whether the capability is read or written
 *
 * @returns the number of bytes read or written
 */
typedef ssize_t (lm_cap_access_t) (void *pvt, const uint8_t id,
                                   char * const buf, size_t count,
                                   loff_t offset, const bool is_write);

typedef struct {

    /*
     * Capability ID, as defined by the PCI specification. Also defined as
     * PCI_CAP_ID_XXX in <linux/pci_regs.h>.
     */
    uint8_t id;

    /*
     * Size of the capability.
     */
    size_t size;

    /*
     * Function to call back when the capability gets read or written.
     */
    lm_cap_access_t *fn;
} lm_cap_t;

#define LM_MAX_CAPS (PCI_CFG_SPACE_SIZE - PCI_STD_HEADER_SIZEOF) / PCI_CAP_SIZEOF

/**
 * Device information structure, used to create the lm_ctx.
 * To be filled and passed to lm_ctx_create()
 */
typedef struct {
    char            *uuid;

    /*
     * Private data passed to various lm_XXX functions.
     */
    void            *pvt;

    /*
     * Whether an extended PCI configuration space should be created.
     */
    bool            extended;

    /*
     * Function to call for logging. Optional.
     */
    lm_log_fn_t     *log;

    /*
     * Log level. Messages above this level are not logged. Optional
     */
    lm_log_lvl_t    log_lvl;

    /*
     * PCI configuration.
     */
    lm_pci_info_t   pci_info;

    /*
     * Function that is called when the guest resets the device. Optional.
     */
    int (*reset)    (void *pvt);

    /*
     * PCI capabilities. The user needs to only define the ID and size of each
     * capability. The actual capability is not maintained by libmuser. When a
     * capability is accessed the appropriate callback function is called.
     */
    lm_cap_t        caps[LM_MAX_CAPS];

    /*
     * Number of capabilities in above array.
     */
    int             nr_caps;
} lm_dev_info_t;

/**
 * Creates libmuser context.
 *
 * @dev_info: device information used to create the context.
 *
 * @returns the lm_ctx to be used or NULL on error. Sets errno.
 */
lm_ctx_t *lm_ctx_create(lm_dev_info_t * dev_info);

/**
 * Destroys libmuser context.
 *
 * @lm_ctx: the libmuser context to destroy
 */
void lm_ctx_destroy(lm_ctx_t * lm_ctx);

/**
 * Once the lm_ctx is configured lm_ctx_drive() drives it. This function waits
 * for commands coming from muser.ko and then processes it.
 *
 * @lm_ctx: the libmuser context to drive
 *
 * @returns 0 on success, -errno on failure.
 */
int lm_ctx_drive(lm_ctx_t * lm_ctx);

/**
 * Creates and runs an lm_ctx.
 *
 * @dev_info: device information used to create the context
 *
 * @returns 0 on success, -1 on failure. Sets errno.
 */
int lm_ctx_run(lm_dev_info_t *dev_info);

/**
 * Triggers an interrupt.
 *
 * libmuser takes care of using the IRQ type (INTx, MSI/X), the caller needs
 * only specify to the sub-index.
 *
 * @lm_ctx: the libmuser context to trigger interrupt
 * @subindex: vector subindex to trigger interrupt on
 *
 * @returns 0 on success, or -1 on failure. Sets errno.
 */
int lm_irq_trigger(lm_ctx_t * lm_ctx, uint32_t subindex);

/* Helper functions */

/**
 * Converts a guest physical address to a dma_sg_t element which can
 * be later passed on to lm_map_sg to memory map the GPA. It is the caller's
 * responsibility to unmap it by calling lm_unmap_sg.
 *
 */

/**
 * Takes a guest physical address and returns a list of scatter/gather entries
 * than can be individually mapped in the program's virtual memory.  A single
 * linear guest physical address span may need to be split into multiple
 * scatter/gather regions due to limitations of how memory can be mapped.
 *
 * @lm_ctx: the libmuser context
 * @dma_addr: the guest physical address
 * @len: size of memory to be mapped
 * @sg: array that receives the scatter/gather entries to be mapped
 * @max_sg: maximum number of elements in above array
 *
 * @returns the number of scatter/gather entries created on success, and on
 * failure:
 *  -1:         if the GPA address span is invalid, or
 *  (-x - 1):   if @max_sg is too small, where x is the number of scatter/gather
 *              entries necessary to complete this request.
 */
int lm_addr_to_sg(lm_ctx_t * const lm_ctx, dma_addr_t dma_addr, uint32_t len,
                  dma_sg_t *sg, int max_sg);

/**
 * Maps a list scatter/gather entries from the guest's physical address space
 * to the program's virtual memory. It is the caller's responsibility to remove
 * the mappings by calling lm_unmap_sg.
 *
 * @lm_ctx: the libmuser context
 * @prot: protection flags, defined as PROT_XXX in <sys/mman.h>
 * @sg: array of scatter/gather entries returned by lm_addr_to_sg
 * @iov: array of iovec structures (defined in <sys/uio.h>) to receive each
 *       mapping
 * @cnt: number of scatter/gather entries to map
 *
 * @returns 0 on success, -1 on failure
 */
int
lm_map_sg(lm_ctx_t * const lm_ctx, int prot, const dma_sg_t * sg,
          struct iovec *iov, int cnt);

/**
 * Unmaps a list scatter/gather entries (previously mapped by lm_map_sg) from
 * the program's virtual memory.
 *
 * @lm_ctx: the libmuser context
 * @sg: array of scatter/gather entries to unmap
 * @iov: array of iovec structures for each scatter/gather entry
 * @cnt: number of scatter/gather entries to unmap
 */
void
lm_unmap_sg(lm_ctx_t * const lm_ctx, const dma_sg_t * sg,
            struct iovec *iov, int cnt);

/**
 * Returns the PCI region given the position and size of an address span in the
 * PCI configuration space.
 *
 * @pos: offset of the address span
 * @count: size of the address span
 * @off: output parameter that receives the relative offset within the region.
 *
 * Returns the PCI region (LM_DEV_XXX_REG_IDX), or -errno on error.
 */
int
lm_get_region(const loff_t pos, const size_t count, loff_t * const off);

/*
 * Advanced stuff.
 */

/**
 * Returns the non-standard part of the PCI configuragion space.
 */
uint8_t *lm_get_pci_non_std_config_space(lm_ctx_t * const lm_ctx);

#ifdef DEBUG
void
dump_buffer(lm_ctx_t const *const lm_ctx, char const *const prefix,
            unsigned char const *const buf, const uint32_t count);
#endif

#endif                          /* LIB_MUSER_H */

/* ex: set tabstop=4 shiftwidth=4 softtabstop=4 expandtab: */