xref: /openbsd/sys/dev/pv/viomb.c (revision 3bef86f7)
1 /* $OpenBSD: viomb.c,v 1.9 2023/05/29 08:13:35 sf Exp $	 */
2 /* $NetBSD: viomb.c,v 1.1 2011/10/30 12:12:21 hannken Exp $	 */
3 
4 /*
5  * Copyright (c) 2012 Talypov Dinar <dinar@i-nk.ru>
6  * Copyright (c) 2010 Minoura Makoto.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/malloc.h>
33 #include <sys/device.h>
34 #include <sys/task.h>
35 #include <sys/pool.h>
36 #include <sys/sensors.h>
37 
38 #include <uvm/uvm_extern.h>
39 
40 #include <dev/pv/virtioreg.h>
41 #include <dev/pv/virtiovar.h>
42 
43 #if VIRTIO_PAGE_SIZE!=PAGE_SIZE
44 #error non-4K page sizes are not supported yet
45 #endif
46 
47 #define	DEVNAME(sc)	sc->sc_dev.dv_xname
48 #if VIRTIO_DEBUG
49 #define VIOMBDEBUG(sc, format, args...)					  \
50 		do { printf("%s: " format, sc->sc_dev.dv_xname, ##args);} \
51 		while (0)
52 #else
53 #define VIOMBDEBUG(...)
54 #endif
55 
56 /* flags used to specify kind of operation,
57  * actually should be moved to virtiovar.h
58  */
59 #define VRING_READ		0
60 #define VRING_WRITE		1
61 
62 /* notify or don't notify */
63 #define VRING_NO_NOTIFY		0
64 #define VRING_NOTIFY		1
65 
66 /* Configuration registers */
67 #define VIRTIO_BALLOON_CONFIG_NUM_PAGES	0	/* 32bit */
68 #define VIRTIO_BALLOON_CONFIG_ACTUAL	4	/* 32bit */
69 
70 /* Feature bits */
71 #define VIRTIO_BALLOON_F_MUST_TELL_HOST (1ULL<<0)
72 #define VIRTIO_BALLOON_F_STATS_VQ	(1ULL<<1)
73 
74 static const struct virtio_feature_name viomb_feature_names[] = {
75 #if VIRTIO_DEBUG
76 	{VIRTIO_BALLOON_F_MUST_TELL_HOST, "TellHost"},
77 	{VIRTIO_BALLOON_F_STATS_VQ, "StatVQ"},
78 #endif
79 	{0, NULL}
80 };
81 #define PGS_PER_REQ		256	/* 1MB, 4KB/page */
82 #define VQ_INFLATE	0
83 #define VQ_DEFLATE	1
84 
85 struct balloon_req {
86 	bus_dmamap_t	 bl_dmamap;
87 	struct pglist	 bl_pglist;
88 	int		 bl_nentries;
89 	u_int32_t	*bl_pages;
90 };
91 
92 struct viomb_softc {
93 	struct device		sc_dev;
94 	struct virtio_softc	*sc_virtio;
95 	struct virtqueue	sc_vq[2];
96 	u_int32_t		sc_npages; /* desired pages */
97 	u_int32_t		sc_actual; /* current pages */
98 	struct balloon_req	sc_req;
99 	struct taskq		*sc_taskq;
100 	struct task		sc_task;
101 	struct pglist		sc_balloon_pages;
102 	struct ksensor		sc_sens[2];
103 	struct ksensordev	sc_sensdev;
104 };
105 
106 int	viomb_match(struct device *, void *, void *);
107 void	viomb_attach(struct device *, struct device *, void *);
108 void	viomb_worker(void *);
109 void	viomb_inflate(struct viomb_softc *);
110 void	viomb_deflate(struct viomb_softc *);
111 int	viomb_config_change(struct virtio_softc *);
112 void	viomb_read_config(struct viomb_softc *);
113 int	viomb_vq_dequeue(struct virtqueue *);
114 int	viomb_inflate_intr(struct virtqueue *);
115 int	viomb_deflate_intr(struct virtqueue *);
116 
117 const struct cfattach viomb_ca = {
118 	sizeof(struct viomb_softc), viomb_match, viomb_attach
119 };
120 
121 struct cfdriver viomb_cd = {
122 	NULL, "viomb", DV_DULL
123 };
124 
125 int
126 viomb_match(struct device *parent, void *match, void *aux)
127 {
128 	struct virtio_softc *va = aux;
129 	if (va->sc_childdevid == PCI_PRODUCT_VIRTIO_BALLOON)
130 		return (1);
131 	return (0);
132 }
133 
134 void
135 viomb_attach(struct device *parent, struct device *self, void *aux)
136 {
137 	struct viomb_softc *sc = (struct viomb_softc *)self;
138 	struct virtio_softc *vsc = (struct virtio_softc *)parent;
139 	int i;
140 
141 	if (vsc->sc_child != NULL) {
142 		printf("child already attached for %s; something wrong...\n",
143 		    parent->dv_xname);
144 		return;
145 	}
146 
147 	/* fail on non-4K page size archs */
148 	if (VIRTIO_PAGE_SIZE != PAGE_SIZE){
149 		printf("non-4K page size arch found, needs %d, got %d\n",
150 		    VIRTIO_PAGE_SIZE, PAGE_SIZE);
151 		return;
152 	}
153 
154 	sc->sc_virtio = vsc;
155 	vsc->sc_vqs = &sc->sc_vq[VQ_INFLATE];
156 	vsc->sc_nvqs = 0;
157 	vsc->sc_child = self;
158 	vsc->sc_ipl = IPL_BIO;
159 	vsc->sc_config_change = viomb_config_change;
160 
161 	vsc->sc_driver_features = VIRTIO_BALLOON_F_MUST_TELL_HOST;
162 	if (virtio_negotiate_features(vsc, viomb_feature_names) != 0)
163 		goto err;
164 
165 	if ((virtio_alloc_vq(vsc, &sc->sc_vq[VQ_INFLATE], VQ_INFLATE,
166 	     sizeof(u_int32_t) * PGS_PER_REQ, 1, "inflate") != 0))
167 		goto err;
168 	vsc->sc_nvqs++;
169 	if ((virtio_alloc_vq(vsc, &sc->sc_vq[VQ_DEFLATE], VQ_DEFLATE,
170 	     sizeof(u_int32_t) * PGS_PER_REQ, 1, "deflate") != 0))
171 		goto err;
172 	vsc->sc_nvqs++;
173 
174 	sc->sc_vq[VQ_INFLATE].vq_done = viomb_inflate_intr;
175 	sc->sc_vq[VQ_DEFLATE].vq_done = viomb_deflate_intr;
176 	virtio_start_vq_intr(vsc, &sc->sc_vq[VQ_INFLATE]);
177 	virtio_start_vq_intr(vsc, &sc->sc_vq[VQ_DEFLATE]);
178 
179 	viomb_read_config(sc);
180 	TAILQ_INIT(&sc->sc_balloon_pages);
181 
182 	if ((sc->sc_req.bl_pages = dma_alloc(sizeof(u_int32_t) * PGS_PER_REQ,
183 	    PR_NOWAIT|PR_ZERO)) == NULL) {
184 		printf("%s: Can't alloc DMA memory.\n", DEVNAME(sc));
185 		goto err;
186 	}
187 	if (bus_dmamap_create(vsc->sc_dmat, sizeof(u_int32_t) * PGS_PER_REQ,
188 			      1, sizeof(u_int32_t) * PGS_PER_REQ, 0,
189 			      BUS_DMA_NOWAIT, &sc->sc_req.bl_dmamap)) {
190 		printf("%s: dmamap creation failed.\n", DEVNAME(sc));
191 		goto err;
192 	}
193 	if (bus_dmamap_load(vsc->sc_dmat, sc->sc_req.bl_dmamap,
194 			    &sc->sc_req.bl_pages[0],
195 			    sizeof(uint32_t) * PGS_PER_REQ,
196 			    NULL, BUS_DMA_NOWAIT)) {
197 		printf("%s: dmamap load failed.\n", DEVNAME(sc));
198 		goto err_dmamap;
199 	}
200 
201 	sc->sc_taskq = taskq_create("viomb", 1, IPL_BIO, 0);
202 	if (sc->sc_taskq == NULL)
203 		goto err_dmamap;
204 	task_set(&sc->sc_task, viomb_worker, sc);
205 
206 	strlcpy(sc->sc_sensdev.xname, DEVNAME(sc),
207 	    sizeof(sc->sc_sensdev.xname));
208 	strlcpy(sc->sc_sens[0].desc, "desired",
209 	    sizeof(sc->sc_sens[0].desc));
210 	sc->sc_sens[0].type = SENSOR_INTEGER;
211 	sensor_attach(&sc->sc_sensdev, &sc->sc_sens[0]);
212 	sc->sc_sens[0].value = sc->sc_npages << PAGE_SHIFT;
213 
214 	strlcpy(sc->sc_sens[1].desc, "current",
215 	    sizeof(sc->sc_sens[1].desc));
216 	sc->sc_sens[1].type = SENSOR_INTEGER;
217 	sensor_attach(&sc->sc_sensdev, &sc->sc_sens[1]);
218 	sc->sc_sens[1].value = sc->sc_actual << PAGE_SHIFT;
219 
220 	sensordev_install(&sc->sc_sensdev);
221 
222 	printf("\n");
223 	virtio_set_status(vsc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER_OK);
224 	return;
225 err_dmamap:
226 	bus_dmamap_destroy(vsc->sc_dmat, sc->sc_req.bl_dmamap);
227 err:
228 	if (sc->sc_req.bl_pages)
229 		dma_free(sc->sc_req.bl_pages, sizeof(u_int32_t) * PGS_PER_REQ);
230 	for (i = 0; i < vsc->sc_nvqs; i++)
231 		virtio_free_vq(vsc, &sc->sc_vq[i]);
232 	vsc->sc_nvqs = 0;
233 	vsc->sc_child = VIRTIO_CHILD_ERROR;
234 	return;
235 }
236 
237 /*
238  * Config change
239  */
240 int
241 viomb_config_change(struct virtio_softc *vsc)
242 {
243 	struct viomb_softc *sc = (struct viomb_softc *)vsc->sc_child;
244 
245 	task_add(sc->sc_taskq, &sc->sc_task);
246 
247 	return (1);
248 }
249 
250 void
251 viomb_worker(void *arg1)
252 {
253 	struct viomb_softc *sc = (struct viomb_softc *)arg1;
254 	int s;
255 
256 	s = splbio();
257 	viomb_read_config(sc);
258 	if (sc->sc_npages > sc->sc_actual){
259 		VIOMBDEBUG(sc, "inflating balloon from %u to %u.\n",
260 			   sc->sc_actual, sc->sc_npages);
261 		viomb_inflate(sc);
262 		}
263 	else if (sc->sc_npages < sc->sc_actual){
264 		VIOMBDEBUG(sc, "deflating balloon from %u to %u.\n",
265 			   sc->sc_actual, sc->sc_npages);
266 		viomb_deflate(sc);
267 	}
268 
269 	sc->sc_sens[0].value = sc->sc_npages << PAGE_SHIFT;
270 	sc->sc_sens[1].value = sc->sc_actual << PAGE_SHIFT;
271 
272 	splx(s);
273 }
274 
275 void
276 viomb_inflate(struct viomb_softc *sc)
277 {
278 	struct virtio_softc *vsc = (struct virtio_softc *)sc->sc_virtio;
279 	struct balloon_req *b;
280 	struct vm_page *p;
281 	struct virtqueue *vq = &sc->sc_vq[VQ_INFLATE];
282 	u_int32_t nvpages;
283 	int slot, error, i = 0;
284 
285 	nvpages = sc->sc_npages - sc->sc_actual;
286 	if (nvpages > PGS_PER_REQ)
287 		nvpages = PGS_PER_REQ;
288 	b = &sc->sc_req;
289 
290 	if ((error = uvm_pglistalloc(nvpages * PAGE_SIZE, 0,
291 				     dma_constraint.ucr_high,
292 				     0, 0, &b->bl_pglist, nvpages,
293 				     UVM_PLA_NOWAIT))) {
294 		printf("%s unable to allocate %u physmem pages,"
295 		    "error %d\n", DEVNAME(sc), nvpages, error);
296 		return;
297 	}
298 
299 	b->bl_nentries = nvpages;
300 	TAILQ_FOREACH(p, &b->bl_pglist, pageq)
301 		b->bl_pages[i++] = p->phys_addr / VIRTIO_PAGE_SIZE;
302 
303 	KASSERT(i == nvpages);
304 
305 	if ((virtio_enqueue_prep(vq, &slot)) > 0) {
306 		printf("%s:virtio_enqueue_prep() vq_num %d\n",
307 		       DEVNAME(sc), vq->vq_num);
308 		goto err;
309 	}
310 	if (virtio_enqueue_reserve(vq, slot, 1)) {
311 		printf("%s:virtio_enqueue_reserve vq_num %d\n",
312 		       DEVNAME(sc), vq->vq_num);
313 		goto err;
314 	}
315 	bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap, 0,
316 			sizeof(u_int32_t) * nvpages, BUS_DMASYNC_PREWRITE);
317 	virtio_enqueue_p(vq, slot, b->bl_dmamap, 0,
318 			 sizeof(u_int32_t) * nvpages, VRING_READ);
319 	virtio_enqueue_commit(vsc, vq, slot, VRING_NOTIFY);
320 	return;
321 err:
322 	uvm_pglistfree(&b->bl_pglist);
323 	return;
324 }
325 
326 void
327 viomb_deflate(struct viomb_softc *sc)
328 {
329 	struct virtio_softc *vsc = (struct virtio_softc *)sc->sc_virtio;
330 	struct balloon_req *b;
331 	struct vm_page *p;
332 	struct virtqueue *vq = &sc->sc_vq[VQ_DEFLATE];
333 	u_int64_t nvpages;
334 	int i, slot;
335 
336 	nvpages = sc->sc_actual - sc->sc_npages;
337 	if (nvpages > PGS_PER_REQ)
338 		nvpages = PGS_PER_REQ;
339 	b = &sc->sc_req;
340 	b->bl_nentries = nvpages;
341 
342 	TAILQ_INIT(&b->bl_pglist);
343 	for (i = 0; i < nvpages; i++) {
344 		p = TAILQ_FIRST(&sc->sc_balloon_pages);
345 		if (p == NULL){
346 		    b->bl_nentries = i - 1;
347 		    break;
348 		}
349 		TAILQ_REMOVE(&sc->sc_balloon_pages, p, pageq);
350 		TAILQ_INSERT_TAIL(&b->bl_pglist, p, pageq);
351 		b->bl_pages[i] = p->phys_addr / VIRTIO_PAGE_SIZE;
352 	}
353 
354 	if (virtio_enqueue_prep(vq, &slot)) {
355 		printf("%s:virtio_get_slot(def) vq_num %d\n",
356 		       DEVNAME(sc), vq->vq_num);
357 		goto err;
358 	}
359 	if (virtio_enqueue_reserve(vq, slot, 1)) {
360 		printf("%s:virtio_enqueue_reserve() vq_num %d\n",
361 		       DEVNAME(sc), vq->vq_num);
362 		goto err;
363 	}
364 	bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap, 0,
365 		    sizeof(u_int32_t) * nvpages,
366 		    BUS_DMASYNC_PREWRITE);
367 	virtio_enqueue_p(vq, slot, b->bl_dmamap, 0,
368 			 sizeof(u_int32_t) * nvpages, VRING_READ);
369 
370 	if (!virtio_has_feature(vsc, VIRTIO_BALLOON_F_MUST_TELL_HOST))
371 		uvm_pglistfree(&b->bl_pglist);
372 	virtio_enqueue_commit(vsc, vq, slot, VRING_NOTIFY);
373 	return;
374 err:
375 	TAILQ_CONCAT(&sc->sc_balloon_pages, &b->bl_pglist, pageq);
376 	return;
377 }
378 
379 void
380 viomb_read_config(struct viomb_softc *sc)
381 {
382 	struct virtio_softc *vsc = (struct virtio_softc *)sc->sc_virtio;
383 	u_int32_t reg;
384 
385 	/* these values are explicitly specified as little-endian */
386 	reg = virtio_read_device_config_4(vsc, VIRTIO_BALLOON_CONFIG_NUM_PAGES);
387 	sc->sc_npages = letoh32(reg);
388 	reg = virtio_read_device_config_4(vsc, VIRTIO_BALLOON_CONFIG_ACTUAL);
389 	sc->sc_actual = letoh32(reg);
390 	VIOMBDEBUG(sc, "sc->sc_npages %u, sc->sc_actual %u\n",
391 		   sc->sc_npages, sc->sc_actual);
392 }
393 
394 int
395 viomb_vq_dequeue(struct virtqueue *vq)
396 {
397 	struct virtio_softc *vsc = vq->vq_owner;
398 	struct viomb_softc *sc = (struct viomb_softc *)vsc->sc_child;
399 	int r, slot;
400 
401 	r = virtio_dequeue(vsc, vq, &slot, NULL);
402 	if (r != 0) {
403 		printf("%s: dequeue failed, errno %d\n", DEVNAME(sc), r);
404 		return(r);
405 	}
406 	virtio_dequeue_commit(vq, slot);
407 	return(0);
408 }
409 
410 /*
411  * interrupt handling for vq's
412  */
413 int
414 viomb_inflate_intr(struct virtqueue *vq)
415 {
416 	struct virtio_softc *vsc = vq->vq_owner;
417 	struct viomb_softc *sc = (struct viomb_softc *)vsc->sc_child;
418 	struct balloon_req *b;
419 	u_int64_t nvpages;
420 
421 	if (viomb_vq_dequeue(vq))
422 		return(1);
423 
424 	b = &sc->sc_req;
425 	nvpages = b->bl_nentries;
426 	bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap, 0,
427 			sizeof(u_int32_t) * nvpages,
428 			BUS_DMASYNC_POSTWRITE);
429 	TAILQ_CONCAT(&sc->sc_balloon_pages, &b->bl_pglist, pageq);
430 	VIOMBDEBUG(sc, "updating sc->sc_actual from %u to %llu\n",
431 		   sc->sc_actual, sc->sc_actual + nvpages);
432 	virtio_write_device_config_4(vsc, VIRTIO_BALLOON_CONFIG_ACTUAL,
433 				     sc->sc_actual + nvpages);
434 	viomb_read_config(sc);
435 
436 	/* if we have more work to do, add it to the task list */
437 	if (sc->sc_npages > sc->sc_actual)
438 		task_add(sc->sc_taskq, &sc->sc_task);
439 
440 	return (1);
441 }
442 
443 int
444 viomb_deflate_intr(struct virtqueue *vq)
445 {
446 	struct virtio_softc *vsc = vq->vq_owner;
447 	struct viomb_softc *sc = (struct viomb_softc *)vsc->sc_child;
448 	struct balloon_req *b;
449 	u_int64_t nvpages;
450 
451 	if (viomb_vq_dequeue(vq))
452 		return(1);
453 
454 	b = &sc->sc_req;
455 	nvpages = b->bl_nentries;
456 	bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap, 0,
457 			sizeof(u_int32_t) * nvpages,
458 			BUS_DMASYNC_POSTWRITE);
459 
460 	if (virtio_has_feature(vsc, VIRTIO_BALLOON_F_MUST_TELL_HOST))
461 		uvm_pglistfree(&b->bl_pglist);
462 
463 	VIOMBDEBUG(sc, "updating sc->sc_actual from %u to %llu\n",
464 		sc->sc_actual, sc->sc_actual - nvpages);
465 	virtio_write_device_config_4(vsc, VIRTIO_BALLOON_CONFIG_ACTUAL,
466 				     sc->sc_actual - nvpages);
467 	viomb_read_config(sc);
468 
469 	/* if we have more work to do, add it to tasks list */
470 	if (sc->sc_npages < sc->sc_actual)
471 		task_add(sc->sc_taskq, &sc->sc_task);
472 
473 	return(1);
474 }
475