xref: /openbmc/qemu/migration/multifd-qpl.c (revision 95e82f9b)
1 /*
2  * Multifd qpl compression accelerator implementation
3  *
4  * Copyright (c) 2023 Intel Corporation
5  *
6  * Authors:
7  *  Yuan Liu<yuan1.liu@intel.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  */
12 
13 #include "qemu/osdep.h"
14 #include "qemu/module.h"
15 #include "qapi/error.h"
16 #include "qapi/qapi-types-migration.h"
17 #include "exec/ramblock.h"
18 #include "multifd.h"
19 #include "qpl/qpl.h"
20 
21 /* Maximum number of retries to resubmit a job if IAA work queues are full */
22 #define MAX_SUBMIT_RETRY_NUM (3)
23 
24 typedef struct {
25     /* the QPL hardware path job */
26     qpl_job *job;
27     /* indicates if fallback to software path is required */
28     bool fallback_sw_path;
29     /* output data from the software path */
30     uint8_t *sw_output;
31     /* output data length from the software path */
32     uint32_t sw_output_len;
33 } QplHwJob;
34 
35 typedef struct {
36     /* array of hardware jobs, the number of jobs equals the number pages */
37     QplHwJob *hw_jobs;
38     /* the QPL software job for the slow path and software fallback */
39     qpl_job *sw_job;
40     /* the number of pages that the QPL needs to process at one time */
41     uint32_t page_num;
42     /* array of compressed page buffers */
43     uint8_t *zbuf;
44     /* array of compressed page lengths */
45     uint32_t *zlen;
46     /* the status of the hardware device */
47     bool hw_avail;
48 } QplData;
49 
50 /**
51  * check_hw_avail: check if IAA hardware is available
52  *
53  * If the IAA hardware does not exist or is unavailable,
54  * the QPL hardware job initialization will fail.
55  *
56  * Returns true if IAA hardware is available, otherwise false.
57  *
58  * @job_size: indicates the hardware job size if hardware is available
59  */
60 static bool check_hw_avail(uint32_t *job_size)
61 {
62     qpl_path_t path = qpl_path_hardware;
63     uint32_t size = 0;
64     qpl_job *job;
65 
66     if (qpl_get_job_size(path, &size) != QPL_STS_OK) {
67         return false;
68     }
69     assert(size > 0);
70     job = g_malloc0(size);
71     if (qpl_init_job(path, job) != QPL_STS_OK) {
72         g_free(job);
73         return false;
74     }
75     g_free(job);
76     *job_size = size;
77     return true;
78 }
79 
80 /**
81  * multifd_qpl_free_sw_job: clean up software job
82  *
83  * Free the software job resources.
84  *
85  * @qpl: pointer to the QplData structure
86  */
87 static void multifd_qpl_free_sw_job(QplData *qpl)
88 {
89     assert(qpl);
90     if (qpl->sw_job) {
91         qpl_fini_job(qpl->sw_job);
92         g_free(qpl->sw_job);
93         qpl->sw_job = NULL;
94     }
95 }
96 
97 /**
98  * multifd_qpl_free_jobs: clean up hardware jobs
99  *
100  * Free all hardware job resources.
101  *
102  * @qpl: pointer to the QplData structure
103  */
104 static void multifd_qpl_free_hw_job(QplData *qpl)
105 {
106     assert(qpl);
107     if (qpl->hw_jobs) {
108         for (int i = 0; i < qpl->page_num; i++) {
109             qpl_fini_job(qpl->hw_jobs[i].job);
110             g_free(qpl->hw_jobs[i].job);
111             qpl->hw_jobs[i].job = NULL;
112         }
113         g_free(qpl->hw_jobs);
114         qpl->hw_jobs = NULL;
115     }
116 }
117 
118 /**
119  * multifd_qpl_init_sw_job: initialize a software job
120  *
121  * Use the QPL software path to initialize a job
122  *
123  * @qpl: pointer to the QplData structure
124  * @errp: pointer to an error
125  */
126 static int multifd_qpl_init_sw_job(QplData *qpl, Error **errp)
127 {
128     qpl_path_t path = qpl_path_software;
129     uint32_t size = 0;
130     qpl_job *job = NULL;
131     qpl_status status;
132 
133     status = qpl_get_job_size(path, &size);
134     if (status != QPL_STS_OK) {
135         error_setg(errp, "qpl_get_job_size failed with error %d", status);
136         return -1;
137     }
138     job = g_malloc0(size);
139     status = qpl_init_job(path, job);
140     if (status != QPL_STS_OK) {
141         error_setg(errp, "qpl_init_job failed with error %d", status);
142         g_free(job);
143         return -1;
144     }
145     qpl->sw_job = job;
146     return 0;
147 }
148 
149 /**
150  * multifd_qpl_init_jobs: initialize hardware jobs
151  *
152  * Use the QPL hardware path to initialize jobs
153  *
154  * @qpl: pointer to the QplData structure
155  * @size: the size of QPL hardware path job
156  * @errp: pointer to an error
157  */
158 static void multifd_qpl_init_hw_job(QplData *qpl, uint32_t size, Error **errp)
159 {
160     qpl_path_t path = qpl_path_hardware;
161     qpl_job *job = NULL;
162     qpl_status status;
163 
164     qpl->hw_jobs = g_new0(QplHwJob, qpl->page_num);
165     for (int i = 0; i < qpl->page_num; i++) {
166         job = g_malloc0(size);
167         status = qpl_init_job(path, job);
168         /* the job initialization should succeed after check_hw_avail */
169         assert(status == QPL_STS_OK);
170         qpl->hw_jobs[i].job = job;
171     }
172 }
173 
174 /**
175  * multifd_qpl_init: initialize QplData structure
176  *
177  * Allocate and initialize a QplData structure
178  *
179  * Returns a QplData pointer on success or NULL on error
180  *
181  * @num: the number of pages
182  * @size: the page size
183  * @errp: pointer to an error
184  */
185 static QplData *multifd_qpl_init(uint32_t num, uint32_t size, Error **errp)
186 {
187     uint32_t job_size = 0;
188     QplData *qpl;
189 
190     qpl = g_new0(QplData, 1);
191     qpl->page_num = num;
192     if (multifd_qpl_init_sw_job(qpl, errp) != 0) {
193         g_free(qpl);
194         return NULL;
195     }
196     qpl->hw_avail = check_hw_avail(&job_size);
197     if (qpl->hw_avail) {
198         multifd_qpl_init_hw_job(qpl, job_size, errp);
199     }
200     qpl->zbuf = g_malloc0(size * num);
201     qpl->zlen = g_new0(uint32_t, num);
202     return qpl;
203 }
204 
205 /**
206  * multifd_qpl_deinit: clean up QplData structure
207  *
208  * Free jobs, buffers and the QplData structure
209  *
210  * @qpl: pointer to the QplData structure
211  */
212 static void multifd_qpl_deinit(QplData *qpl)
213 {
214     if (qpl) {
215         multifd_qpl_free_sw_job(qpl);
216         multifd_qpl_free_hw_job(qpl);
217         g_free(qpl->zbuf);
218         g_free(qpl->zlen);
219         g_free(qpl);
220     }
221 }
222 
223 static int multifd_qpl_send_setup(MultiFDSendParams *p, Error **errp)
224 {
225     QplData *qpl;
226     uint32_t page_size = multifd_ram_page_size();
227     uint32_t page_count = multifd_ram_page_count();
228 
229     qpl = multifd_qpl_init(page_count, page_size, errp);
230     if (!qpl) {
231         return -1;
232     }
233     p->compress_data = qpl;
234 
235     /*
236      * the page will be compressed independently and sent using an IOV. The
237      * additional two IOVs are used to store packet header and compressed data
238      * length
239      */
240     p->iov = g_new0(struct iovec, page_count + 2);
241     return 0;
242 }
243 
244 static void multifd_qpl_send_cleanup(MultiFDSendParams *p, Error **errp)
245 {
246     multifd_qpl_deinit(p->compress_data);
247     p->compress_data = NULL;
248     g_free(p->iov);
249     p->iov = NULL;
250 }
251 
252 /**
253  * multifd_qpl_prepare_job: prepare the job
254  *
255  * Set the QPL job parameters and properties.
256  *
257  * @job: pointer to the qpl_job structure
258  * @is_compression: indicates compression and decompression
259  * @input: pointer to the input data buffer
260  * @input_len: the length of the input data
261  * @output: pointer to the output data buffer
262  * @output_len: the length of the output data
263  */
264 static void multifd_qpl_prepare_job(qpl_job *job, bool is_compression,
265                                     uint8_t *input, uint32_t input_len,
266                                     uint8_t *output, uint32_t output_len)
267 {
268     job->op = is_compression ? qpl_op_compress : qpl_op_decompress;
269     job->next_in_ptr = input;
270     job->next_out_ptr = output;
271     job->available_in = input_len;
272     job->available_out = output_len;
273     job->flags = QPL_FLAG_FIRST | QPL_FLAG_LAST | QPL_FLAG_OMIT_VERIFY;
274     /* only supports compression level 1 */
275     job->level = 1;
276 }
277 
278 /**
279  * multifd_qpl_prepare_comp_job: prepare the compression job
280  *
281  * Set the compression job parameters and properties.
282  *
283  * @job: pointer to the qpl_job structure
284  * @input: pointer to the input data buffer
285  * @output: pointer to the output data buffer
286  * @size: the page size
287  */
288 static void multifd_qpl_prepare_comp_job(qpl_job *job, uint8_t *input,
289                                          uint8_t *output, uint32_t size)
290 {
291     /*
292      * Set output length to less than the page size to force the job to
293      * fail in case it compresses to a larger size. We'll send that page
294      * without compression and skip the decompression operation on the
295      * destination.
296      */
297     multifd_qpl_prepare_job(job, true, input, size, output, size - 1);
298 }
299 
300 /**
301  * multifd_qpl_prepare_decomp_job: prepare the decompression job
302  *
303  * Set the decompression job parameters and properties.
304  *
305  * @job: pointer to the qpl_job structure
306  * @input: pointer to the input data buffer
307  * @len: the length of the input data
308  * @output: pointer to the output data buffer
309  * @size: the page size
310  */
311 static void multifd_qpl_prepare_decomp_job(qpl_job *job, uint8_t *input,
312                                            uint32_t len, uint8_t *output,
313                                            uint32_t size)
314 {
315     multifd_qpl_prepare_job(job, false, input, len, output, size);
316 }
317 
318 /**
319  * multifd_qpl_fill_iov: fill in the IOV
320  *
321  * Fill in the QPL packet IOV
322  *
323  * @p: Params for the channel being used
324  * @data: pointer to the IOV data
325  * @len: The length of the IOV data
326  */
327 static void multifd_qpl_fill_iov(MultiFDSendParams *p, uint8_t *data,
328                                  uint32_t len)
329 {
330     p->iov[p->iovs_num].iov_base = data;
331     p->iov[p->iovs_num].iov_len = len;
332     p->iovs_num++;
333     p->next_packet_size += len;
334 }
335 
336 /**
337  * multifd_qpl_fill_packet: fill the compressed page into the QPL packet
338  *
339  * Fill the compressed page length and IOV into the QPL packet
340  *
341  * @idx: The index of the compressed length array
342  * @p: Params for the channel being used
343  * @data: pointer to the compressed page buffer
344  * @len: The length of the compressed page
345  */
346 static void multifd_qpl_fill_packet(uint32_t idx, MultiFDSendParams *p,
347                                     uint8_t *data, uint32_t len)
348 {
349     QplData *qpl = p->compress_data;
350 
351     qpl->zlen[idx] = cpu_to_be32(len);
352     multifd_qpl_fill_iov(p, data, len);
353 }
354 
355 /**
356  * multifd_qpl_submit_job: submit a job to the hardware
357  *
358  * Submit a QPL hardware job to the IAA device
359  *
360  * Returns true if the job is submitted successfully, otherwise false.
361  *
362  * @job: pointer to the qpl_job structure
363  */
364 static bool multifd_qpl_submit_job(qpl_job *job)
365 {
366     qpl_status status;
367     uint32_t num = 0;
368 
369 retry:
370     status = qpl_submit_job(job);
371     if (status == QPL_STS_QUEUES_ARE_BUSY_ERR) {
372         if (num < MAX_SUBMIT_RETRY_NUM) {
373             num++;
374             goto retry;
375         }
376     }
377     return (status == QPL_STS_OK);
378 }
379 
380 /**
381  * multifd_qpl_compress_pages_slow_path: compress pages using slow path
382  *
383  * Compress the pages using software. If compression fails, the uncompressed
384  * page will be sent.
385  *
386  * @p: Params for the channel being used
387  */
388 static void multifd_qpl_compress_pages_slow_path(MultiFDSendParams *p)
389 {
390     QplData *qpl = p->compress_data;
391     MultiFDPages_t *pages = &p->data->u.ram;
392     uint32_t size = multifd_ram_page_size();
393     qpl_job *job = qpl->sw_job;
394     uint8_t *zbuf = qpl->zbuf;
395     uint8_t *buf;
396 
397     for (int i = 0; i < pages->normal_num; i++) {
398         buf = pages->block->host + pages->offset[i];
399         multifd_qpl_prepare_comp_job(job, buf, zbuf, size);
400         if (qpl_execute_job(job) == QPL_STS_OK) {
401             multifd_qpl_fill_packet(i, p, zbuf, job->total_out);
402         } else {
403             /* send the uncompressed page */
404             multifd_qpl_fill_packet(i, p, buf, size);
405         }
406         zbuf += size;
407     }
408 }
409 
410 /**
411  * multifd_qpl_compress_pages: compress pages
412  *
413  * Submit the pages to the IAA hardware for compression. If hardware
414  * compression fails, it falls back to software compression. If software
415  * compression also fails, the uncompressed page is sent.
416  *
417  * @p: Params for the channel being used
418  */
419 static void multifd_qpl_compress_pages(MultiFDSendParams *p)
420 {
421     QplData *qpl = p->compress_data;
422     MultiFDPages_t *pages = &p->data->u.ram;
423     uint32_t size = multifd_ram_page_size();
424     QplHwJob *hw_job;
425     uint8_t *buf;
426     uint8_t *zbuf;
427 
428     for (int i = 0; i < pages->normal_num; i++) {
429         buf = pages->block->host + pages->offset[i];
430         zbuf = qpl->zbuf + (size * i);
431         hw_job = &qpl->hw_jobs[i];
432         multifd_qpl_prepare_comp_job(hw_job->job, buf, zbuf, size);
433         if (multifd_qpl_submit_job(hw_job->job)) {
434             hw_job->fallback_sw_path = false;
435         } else {
436             /*
437              * The IAA work queue is full, any immediate subsequent job
438              * submission is likely to fail, sending the page via the QPL
439              * software path at this point gives us a better chance of
440              * finding the queue open for the next pages.
441              */
442             hw_job->fallback_sw_path = true;
443             multifd_qpl_prepare_comp_job(qpl->sw_job, buf, zbuf, size);
444             if (qpl_execute_job(qpl->sw_job) == QPL_STS_OK) {
445                 hw_job->sw_output = zbuf;
446                 hw_job->sw_output_len = qpl->sw_job->total_out;
447             } else {
448                 hw_job->sw_output = buf;
449                 hw_job->sw_output_len = size;
450             }
451         }
452     }
453 
454     for (int i = 0; i < pages->normal_num; i++) {
455         buf = pages->block->host + pages->offset[i];
456         zbuf = qpl->zbuf + (size * i);
457         hw_job = &qpl->hw_jobs[i];
458         if (hw_job->fallback_sw_path) {
459             multifd_qpl_fill_packet(i, p, hw_job->sw_output,
460                                     hw_job->sw_output_len);
461             continue;
462         }
463         if (qpl_wait_job(hw_job->job) == QPL_STS_OK) {
464             multifd_qpl_fill_packet(i, p, zbuf, hw_job->job->total_out);
465         } else {
466             /* send the uncompressed page */
467             multifd_qpl_fill_packet(i, p, buf, size);
468         }
469     }
470 }
471 
472 static int multifd_qpl_send_prepare(MultiFDSendParams *p, Error **errp)
473 {
474     QplData *qpl = p->compress_data;
475     MultiFDPages_t *pages = &p->data->u.ram;
476     uint32_t len = 0;
477 
478     if (!multifd_send_prepare_common(p)) {
479         goto out;
480     }
481 
482     /* The first IOV is used to store the compressed page lengths */
483     len = pages->normal_num * sizeof(uint32_t);
484     multifd_qpl_fill_iov(p, (uint8_t *) qpl->zlen, len);
485     if (qpl->hw_avail) {
486         multifd_qpl_compress_pages(p);
487     } else {
488         multifd_qpl_compress_pages_slow_path(p);
489     }
490 
491 out:
492     p->flags |= MULTIFD_FLAG_QPL;
493     multifd_send_fill_packet(p);
494     return 0;
495 }
496 
497 static int multifd_qpl_recv_setup(MultiFDRecvParams *p, Error **errp)
498 {
499     QplData *qpl;
500     uint32_t page_size = multifd_ram_page_size();
501     uint32_t page_count = multifd_ram_page_count();
502 
503     qpl = multifd_qpl_init(page_count, page_size, errp);
504     if (!qpl) {
505         return -1;
506     }
507     p->compress_data = qpl;
508     return 0;
509 }
510 
511 static void multifd_qpl_recv_cleanup(MultiFDRecvParams *p)
512 {
513     multifd_qpl_deinit(p->compress_data);
514     p->compress_data = NULL;
515 }
516 
517 /**
518  * multifd_qpl_process_and_check_job: process and check a QPL job
519  *
520  * Process the job and check whether the job output length is the
521  * same as the specified length
522  *
523  * Returns true if the job execution succeeded and the output length
524  * is equal to the specified length, otherwise false.
525  *
526  * @job: pointer to the qpl_job structure
527  * @is_hardware: indicates whether the job is a hardware job
528  * @len: Specified output length
529  * @errp: pointer to an error
530  */
531 static bool multifd_qpl_process_and_check_job(qpl_job *job, bool is_hardware,
532                                               uint32_t len, Error **errp)
533 {
534     qpl_status status;
535 
536     status = (is_hardware ? qpl_wait_job(job) : qpl_execute_job(job));
537     if (status != QPL_STS_OK) {
538         error_setg(errp, "qpl job failed with error %d", status);
539         return false;
540     }
541     if (job->total_out != len) {
542         error_setg(errp, "qpl decompressed len %u, expected len %u",
543                    job->total_out, len);
544         return false;
545     }
546     return true;
547 }
548 
549 /**
550  * multifd_qpl_decompress_pages_slow_path: decompress pages using slow path
551  *
552  * Decompress the pages using software
553  *
554  * Returns 0 on success or -1 on error
555  *
556  * @p: Params for the channel being used
557  * @errp: pointer to an error
558  */
559 static int multifd_qpl_decompress_pages_slow_path(MultiFDRecvParams *p,
560                                                   Error **errp)
561 {
562     QplData *qpl = p->compress_data;
563     uint32_t size = multifd_ram_page_size();
564     qpl_job *job = qpl->sw_job;
565     uint8_t *zbuf = qpl->zbuf;
566     uint8_t *addr;
567     uint32_t len;
568 
569     for (int i = 0; i < p->normal_num; i++) {
570         len = qpl->zlen[i];
571         addr = p->host + p->normal[i];
572         /* the page is uncompressed, load it */
573         if (len == size) {
574             memcpy(addr, zbuf, size);
575             zbuf += size;
576             continue;
577         }
578         multifd_qpl_prepare_decomp_job(job, zbuf, len, addr, size);
579         if (!multifd_qpl_process_and_check_job(job, false, size, errp)) {
580             return -1;
581         }
582         zbuf += len;
583     }
584     return 0;
585 }
586 
587 /**
588  * multifd_qpl_decompress_pages: decompress pages
589  *
590  * Decompress the pages using the IAA hardware. If hardware
591  * decompression fails, it falls back to software decompression.
592  *
593  * Returns 0 on success or -1 on error
594  *
595  * @p: Params for the channel being used
596  * @errp: pointer to an error
597  */
598 static int multifd_qpl_decompress_pages(MultiFDRecvParams *p, Error **errp)
599 {
600     QplData *qpl = p->compress_data;
601     uint32_t size = multifd_ram_page_size();
602     uint8_t *zbuf = qpl->zbuf;
603     uint8_t *addr;
604     uint32_t len;
605     qpl_job *job;
606 
607     for (int i = 0; i < p->normal_num; i++) {
608         addr = p->host + p->normal[i];
609         len = qpl->zlen[i];
610         /* the page is uncompressed if received length equals the page size */
611         if (len == size) {
612             memcpy(addr, zbuf, size);
613             zbuf += size;
614             continue;
615         }
616 
617         job = qpl->hw_jobs[i].job;
618         multifd_qpl_prepare_decomp_job(job, zbuf, len, addr, size);
619         if (multifd_qpl_submit_job(job)) {
620             qpl->hw_jobs[i].fallback_sw_path = false;
621         } else {
622             /*
623              * The IAA work queue is full, any immediate subsequent job
624              * submission is likely to fail, sending the page via the QPL
625              * software path at this point gives us a better chance of
626              * finding the queue open for the next pages.
627              */
628             qpl->hw_jobs[i].fallback_sw_path = true;
629             job = qpl->sw_job;
630             multifd_qpl_prepare_decomp_job(job, zbuf, len, addr, size);
631             if (!multifd_qpl_process_and_check_job(job, false, size, errp)) {
632                 return -1;
633             }
634         }
635         zbuf += len;
636     }
637 
638     for (int i = 0; i < p->normal_num; i++) {
639         /* ignore pages that have already been processed */
640         if (qpl->zlen[i] == size || qpl->hw_jobs[i].fallback_sw_path) {
641             continue;
642         }
643 
644         job = qpl->hw_jobs[i].job;
645         if (!multifd_qpl_process_and_check_job(job, true, size, errp)) {
646             return -1;
647         }
648     }
649     return 0;
650 }
651 static int multifd_qpl_recv(MultiFDRecvParams *p, Error **errp)
652 {
653     QplData *qpl = p->compress_data;
654     uint32_t in_size = p->next_packet_size;
655     uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK;
656     uint32_t len = 0;
657     uint32_t zbuf_len = 0;
658     int ret;
659 
660     if (flags != MULTIFD_FLAG_QPL) {
661         error_setg(errp, "multifd %u: flags received %x flags expected %x",
662                    p->id, flags, MULTIFD_FLAG_QPL);
663         return -1;
664     }
665     multifd_recv_zero_page_process(p);
666     if (!p->normal_num) {
667         assert(in_size == 0);
668         return 0;
669     }
670 
671     /* read compressed page lengths */
672     len = p->normal_num * sizeof(uint32_t);
673     assert(len < in_size);
674     ret = qio_channel_read_all(p->c, (void *) qpl->zlen, len, errp);
675     if (ret != 0) {
676         return ret;
677     }
678     for (int i = 0; i < p->normal_num; i++) {
679         qpl->zlen[i] = be32_to_cpu(qpl->zlen[i]);
680         assert(qpl->zlen[i] <= multifd_ram_page_size());
681         zbuf_len += qpl->zlen[i];
682     }
683 
684     /* read compressed pages */
685     assert(in_size == len + zbuf_len);
686     ret = qio_channel_read_all(p->c, (void *) qpl->zbuf, zbuf_len, errp);
687     if (ret != 0) {
688         return ret;
689     }
690 
691     if (qpl->hw_avail) {
692         return multifd_qpl_decompress_pages(p, errp);
693     }
694     return multifd_qpl_decompress_pages_slow_path(p, errp);
695 }
696 
697 static const MultiFDMethods multifd_qpl_ops = {
698     .send_setup = multifd_qpl_send_setup,
699     .send_cleanup = multifd_qpl_send_cleanup,
700     .send_prepare = multifd_qpl_send_prepare,
701     .recv_setup = multifd_qpl_recv_setup,
702     .recv_cleanup = multifd_qpl_recv_cleanup,
703     .recv = multifd_qpl_recv,
704 };
705 
706 static void multifd_qpl_register(void)
707 {
708     multifd_register_ops(MULTIFD_COMPRESSION_QPL, &multifd_qpl_ops);
709 }
710 
711 migration_init(multifd_qpl_register);
712