viomb.c revision 1.6
1 /* $NetBSD: viomb.c,v 1.6 2016/07/07 06:55:41 msaitoh Exp $ */ 2 3 /* 4 * Copyright (c) 2010 Minoura Makoto. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: viomb.c,v 1.6 2016/07/07 06:55:41 msaitoh Exp $"); 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/kernel.h> 34 #include <sys/bus.h> 35 #include <sys/condvar.h> 36 #include <sys/device.h> 37 #include <sys/kthread.h> 38 #include <sys/mutex.h> 39 #include <sys/sysctl.h> 40 #include <uvm/uvm_page.h> 41 42 #include <dev/pci/pcidevs.h> 43 #include <dev/pci/pcireg.h> 44 #include <dev/pci/pcivar.h> 45 46 #include <dev/pci/virtioreg.h> 47 #include <dev/pci/virtiovar.h> 48 49 /* Configuration registers */ 50 #define VIRTIO_BALLOON_CONFIG_NUM_PAGES 0 /* 32bit */ 51 #define VIRTIO_BALLOON_CONFIG_ACTUAL 4 /* 32bit */ 52 53 /* Feature bits */ 54 #define VIRTIO_BALLOON_F_MUST_TELL_HOST (1<<0) 55 #define VIRTIO_BALLOON_F_STATS_VQ (1<<1) 56 57 #define VIRTIO_BALLOON_FLAG_BITS \ 58 VIRTIO_COMMON_FLAG_BITS \ 59 "\x02""STATS_VQ" \ 60 "\x01""MUST_TELL_HOST" 61 62 #define PGS_PER_REQ (256) /* 1MB, 4KB/page */ 63 64 CTASSERT((PAGE_SIZE) == (VIRTIO_PAGE_SIZE)); /* XXX */ 65 66 struct balloon_req { 67 bus_dmamap_t bl_dmamap; 68 struct pglist bl_pglist; 69 int bl_nentries; 70 uint32_t bl_pages[PGS_PER_REQ]; 71 }; 72 73 struct viomb_softc { 74 device_t sc_dev; 75 76 struct virtio_softc *sc_virtio; 77 struct virtqueue sc_vq[2]; 78 79 unsigned int sc_npages; 80 unsigned int sc_actual; 81 int sc_inflight; 82 struct balloon_req sc_req; 83 struct pglist sc_balloon_pages; 84 85 int sc_inflate_done; 86 int sc_deflate_done; 87 88 kcondvar_t sc_wait; 89 kmutex_t sc_waitlock; 90 }; 91 92 static int balloon_initialized = 0; /* multiple balloon is not allowed */ 93 94 static int viomb_match(device_t, cfdata_t, void *); 95 static void viomb_attach(device_t, device_t, void *); 96 static void viomb_read_config(struct viomb_softc *); 97 static int viomb_config_change(struct virtio_softc *); 98 static int inflate(struct viomb_softc *); 99 static int inflateq_done(struct virtqueue *); 100 static int inflate_done(struct viomb_softc *); 101 static int deflate(struct viomb_softc *); 102 static int deflateq_done(struct virtqueue *); 103 static int deflate_done(struct viomb_softc *); 104 static void viomb_thread(void *); 105 106 CFATTACH_DECL_NEW(viomb, sizeof(struct viomb_softc), 107 viomb_match, viomb_attach, NULL, NULL); 108 109 static int 110 viomb_match(device_t parent, cfdata_t match, void *aux) 111 { 112 struct virtio_softc *vsc = aux; 113 114 if (vsc->sc_childdevid == PCI_PRODUCT_VIRTIO_BALLOON) 115 return 1; 116 117 return 0; 118 } 119 120 static void 121 viomb_attach(device_t parent, device_t self, void *aux) 122 { 123 struct viomb_softc *sc = device_private(self); 124 struct virtio_softc *vsc = device_private(parent); 125 const struct sysctlnode *node; 126 uint32_t features; 127 char buf[256]; 128 129 if (vsc->sc_child != NULL) { 130 aprint_normal(": child already attached for %s; " 131 "something wrong...\n", device_xname(parent)); 132 return; 133 } 134 if (balloon_initialized++) { 135 aprint_normal(": balloon already exists; something wrong...\n"); 136 goto err_none; 137 } 138 139 sc->sc_dev = self; 140 sc->sc_virtio = vsc; 141 142 vsc->sc_child = self; 143 vsc->sc_ipl = IPL_VM; 144 vsc->sc_vqs = &sc->sc_vq[0]; 145 vsc->sc_nvqs = 2; 146 vsc->sc_config_change = viomb_config_change; 147 vsc->sc_intrhand = virtio_vq_intr; 148 vsc->sc_flags = 0; 149 150 features = virtio_negotiate_features(vsc, 151 VIRTIO_CONFIG_DEVICE_FEATURES); 152 153 snprintb(buf, sizeof(buf), VIRTIO_BALLOON_FLAG_BITS, features); 154 aprint_normal(": Features: %s\n", buf); 155 if ((virtio_alloc_vq(vsc, &sc->sc_vq[0], 0, 156 sizeof(uint32_t)*PGS_PER_REQ, 1, 157 "inflate") != 0) || 158 (virtio_alloc_vq(vsc, &sc->sc_vq[1], 1, 159 sizeof(uint32_t)*PGS_PER_REQ, 1, 160 "deflate") != 0)) { 161 goto err_none; 162 } 163 sc->sc_vq[0].vq_done = inflateq_done; 164 sc->sc_vq[1].vq_done = deflateq_done; 165 166 viomb_read_config(sc); 167 sc->sc_inflight = 0; 168 TAILQ_INIT(&sc->sc_balloon_pages); 169 170 if (bus_dmamap_create(vsc->sc_dmat, sizeof(uint32_t)*PGS_PER_REQ, 171 1, sizeof(uint32_t)*PGS_PER_REQ, 0, 172 BUS_DMA_NOWAIT, &sc->sc_req.bl_dmamap)) { 173 aprint_error_dev(sc->sc_dev, "dmamap creation failed.\n"); 174 goto err_vq; 175 } 176 if (bus_dmamap_load(vsc->sc_dmat, sc->sc_req.bl_dmamap, 177 &sc->sc_req.bl_pages[0], 178 sizeof(uint32_t) * PGS_PER_REQ, 179 NULL, BUS_DMA_NOWAIT)) { 180 aprint_error_dev(sc->sc_dev, "dmamap load failed.\n"); 181 goto err_dmamap; 182 } 183 184 sc->sc_inflate_done = sc->sc_deflate_done = 0; 185 mutex_init(&sc->sc_waitlock, MUTEX_DEFAULT, IPL_VM); /* spin */ 186 cv_init(&sc->sc_wait, "balloon"); 187 188 if (kthread_create(PRI_IDLE, KTHREAD_MPSAFE, NULL, 189 viomb_thread, sc, NULL, "viomb")) { 190 aprint_error_dev(sc->sc_dev, "cannot create kthread.\n"); 191 goto err_mutex; 192 } 193 194 sysctl_createv(NULL, 0, NULL, &node, 0, CTLTYPE_NODE, 195 "viomb", SYSCTL_DESCR("VirtIO Balloon status"), 196 NULL, 0, NULL, 0, 197 CTL_HW, CTL_CREATE, CTL_EOL); 198 sysctl_createv(NULL, 0, NULL, NULL, 0, CTLTYPE_INT, 199 "npages", SYSCTL_DESCR("VirtIO Balloon npages value"), 200 NULL, 0, &sc->sc_npages, 0, 201 CTL_HW, node->sysctl_num, CTL_CREATE, CTL_EOL); 202 sysctl_createv(NULL, 0, NULL, NULL, 0, CTLTYPE_INT, 203 "actual", SYSCTL_DESCR("VirtIO Balloon actual value"), 204 NULL, 0, &sc->sc_actual, 0, 205 CTL_HW, node->sysctl_num, CTL_CREATE, CTL_EOL); 206 return; 207 208 err_mutex: 209 cv_destroy(&sc->sc_wait); 210 mutex_destroy(&sc->sc_waitlock); 211 err_dmamap: 212 bus_dmamap_destroy(vsc->sc_dmat, sc->sc_req.bl_dmamap); 213 err_vq: 214 virtio_free_vq(vsc, &sc->sc_vq[1]); 215 virtio_free_vq(vsc, &sc->sc_vq[0]); 216 err_none: 217 vsc->sc_child = (void*)1; 218 return; 219 } 220 221 static void 222 viomb_read_config(struct viomb_softc *sc) 223 { 224 unsigned int reg; 225 226 /* these values are explicitly specified as little-endian */ 227 reg = virtio_read_device_config_4(sc->sc_virtio, 228 VIRTIO_BALLOON_CONFIG_NUM_PAGES); 229 sc->sc_npages = le32toh(reg); 230 231 reg = virtio_read_device_config_4(sc->sc_virtio, 232 VIRTIO_BALLOON_CONFIG_ACTUAL); 233 sc->sc_actual = le32toh(reg); 234 } 235 236 /* 237 * Config change callback: wakeup the kthread. 238 */ 239 static int 240 viomb_config_change(struct virtio_softc *vsc) 241 { 242 struct viomb_softc *sc = device_private(vsc->sc_child); 243 unsigned int old; 244 245 old = sc->sc_npages; 246 viomb_read_config(sc); 247 mutex_enter(&sc->sc_waitlock); 248 cv_signal(&sc->sc_wait); 249 mutex_exit(&sc->sc_waitlock); 250 if (sc->sc_npages > old) 251 printf("%s: inflating balloon from %u to %u.\n", 252 device_xname(sc->sc_dev), old, sc->sc_npages); 253 else if (sc->sc_npages < old) 254 printf("%s: deflating balloon from %u to %u.\n", 255 device_xname(sc->sc_dev), old, sc->sc_npages); 256 257 return 1; 258 } 259 260 /* 261 * Inflate: consume some amount of physical memory. 262 */ 263 static int 264 inflate(struct viomb_softc *sc) 265 { 266 struct virtio_softc *vsc = sc->sc_virtio; 267 int i, slot; 268 uint64_t nvpages, nhpages; 269 struct balloon_req *b; 270 struct vm_page *p; 271 struct virtqueue *vq = &sc->sc_vq[0]; 272 273 if (sc->sc_inflight) 274 return 0; 275 nvpages = sc->sc_npages - sc->sc_actual; 276 if (nvpages > PGS_PER_REQ) 277 nvpages = PGS_PER_REQ; 278 nhpages = nvpages * VIRTIO_PAGE_SIZE / PAGE_SIZE; 279 280 b = &sc->sc_req; 281 if (uvm_pglistalloc(nhpages*PAGE_SIZE, 0, UINT32_MAX*PAGE_SIZE, 282 0, 0, &b->bl_pglist, nhpages, 1)) { 283 printf("%s: %" PRIu64 " pages of physical memory " 284 "could not be allocated, retrying...\n", 285 device_xname(sc->sc_dev), nhpages); 286 return 1; /* sleep longer */ 287 } 288 289 b->bl_nentries = nvpages; 290 i = 0; 291 TAILQ_FOREACH(p, &b->bl_pglist, pageq.queue) { 292 b->bl_pages[i++] = p->phys_addr / VIRTIO_PAGE_SIZE; 293 } 294 KASSERT(i == nvpages); 295 296 if (virtio_enqueue_prep(vsc, vq, &slot) != 0) { 297 printf("%s: inflate enqueue failed.\n", 298 device_xname(sc->sc_dev)); 299 uvm_pglistfree(&b->bl_pglist); 300 return 0; 301 } 302 if (virtio_enqueue_reserve(vsc, vq, slot, 1)) { 303 printf("%s: inflate enqueue failed.\n", 304 device_xname(sc->sc_dev)); 305 uvm_pglistfree(&b->bl_pglist); 306 return 0; 307 } 308 bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap, 0, 309 sizeof(uint32_t)*nvpages, BUS_DMASYNC_PREWRITE); 310 virtio_enqueue(vsc, vq, slot, b->bl_dmamap, true); 311 virtio_enqueue_commit(vsc, vq, slot, true); 312 sc->sc_inflight += nvpages; 313 314 return 0; 315 } 316 317 static int 318 inflateq_done(struct virtqueue *vq) 319 { 320 struct virtio_softc *vsc = vq->vq_owner; 321 struct viomb_softc *sc = device_private(vsc->sc_child); 322 323 mutex_enter(&sc->sc_waitlock); 324 sc->sc_inflate_done = 1; 325 cv_signal(&sc->sc_wait); 326 mutex_exit(&sc->sc_waitlock); 327 328 return 1; 329 } 330 331 static int 332 inflate_done(struct viomb_softc *sc) 333 { 334 struct virtio_softc *vsc = sc->sc_virtio; 335 struct virtqueue *vq = &sc->sc_vq[0]; 336 struct balloon_req *b; 337 int r, slot; 338 uint64_t nvpages; 339 struct vm_page *p; 340 341 r = virtio_dequeue(vsc, vq, &slot, NULL); 342 if (r != 0) { 343 printf("%s: inflate dequeue failed, errno %d.\n", 344 device_xname(sc->sc_dev), r); 345 return 1; 346 } 347 virtio_dequeue_commit(vsc, vq, slot); 348 349 b = &sc->sc_req; 350 nvpages = b->bl_nentries; 351 bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap, 352 offsetof(struct balloon_req, bl_pages), 353 sizeof(uint32_t)*nvpages, 354 BUS_DMASYNC_POSTWRITE); 355 while (!TAILQ_EMPTY(&b->bl_pglist)) { 356 p = TAILQ_FIRST(&b->bl_pglist); 357 TAILQ_REMOVE(&b->bl_pglist, p, pageq.queue); 358 TAILQ_INSERT_TAIL(&sc->sc_balloon_pages, p, pageq.queue); 359 } 360 361 sc->sc_inflight -= nvpages; 362 virtio_write_device_config_4(vsc, 363 VIRTIO_BALLOON_CONFIG_ACTUAL, 364 sc->sc_actual + nvpages); 365 viomb_read_config(sc); 366 367 return 1; 368 } 369 370 /* 371 * Deflate: free previously allocated memory. 372 */ 373 static int 374 deflate(struct viomb_softc *sc) 375 { 376 struct virtio_softc *vsc = sc->sc_virtio; 377 int i, slot; 378 uint64_t nvpages, nhpages; 379 struct balloon_req *b; 380 struct vm_page *p; 381 struct virtqueue *vq = &sc->sc_vq[1]; 382 383 nvpages = (sc->sc_actual + sc->sc_inflight) - sc->sc_npages; 384 if (nvpages > PGS_PER_REQ) 385 nvpages = PGS_PER_REQ; 386 nhpages = nvpages * VIRTIO_PAGE_SIZE / PAGE_SIZE; 387 388 b = &sc->sc_req; 389 390 b->bl_nentries = nvpages; 391 TAILQ_INIT(&b->bl_pglist); 392 for (i = 0; i < nhpages; i++) { 393 p = TAILQ_FIRST(&sc->sc_balloon_pages); 394 if (p == NULL) 395 break; 396 TAILQ_REMOVE(&sc->sc_balloon_pages, p, pageq.queue); 397 TAILQ_INSERT_TAIL(&b->bl_pglist, p, pageq.queue); 398 b->bl_pages[i] = p->phys_addr / VIRTIO_PAGE_SIZE; 399 } 400 401 if (virtio_enqueue_prep(vsc, vq, &slot) != 0) { 402 printf("%s: deflate enqueue failed.\n", 403 device_xname(sc->sc_dev)); 404 TAILQ_FOREACH_REVERSE(p, &b->bl_pglist, pglist, pageq.queue) { 405 TAILQ_REMOVE(&b->bl_pglist, p, pageq.queue); 406 TAILQ_INSERT_HEAD(&sc->sc_balloon_pages, p, 407 pageq.queue); 408 } 409 return 0; 410 } 411 if (virtio_enqueue_reserve(vsc, vq, slot, 1) != 0) { 412 printf("%s: deflate enqueue failed.\n", 413 device_xname(sc->sc_dev)); 414 TAILQ_FOREACH_REVERSE(p, &b->bl_pglist, pglist, pageq.queue) { 415 TAILQ_REMOVE(&b->bl_pglist, p, pageq.queue); 416 TAILQ_INSERT_HEAD(&sc->sc_balloon_pages, p, 417 pageq.queue); 418 } 419 return 0; 420 } 421 bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap, 0, 422 sizeof(uint32_t)*nvpages, BUS_DMASYNC_PREWRITE); 423 virtio_enqueue(vsc, vq, slot, b->bl_dmamap, true); 424 virtio_enqueue_commit(vsc, vq, slot, true); 425 sc->sc_inflight -= nvpages; 426 427 if (!(vsc->sc_features & VIRTIO_BALLOON_F_MUST_TELL_HOST)) 428 uvm_pglistfree(&b->bl_pglist); 429 430 return 0; 431 } 432 433 static int 434 deflateq_done(struct virtqueue *vq) 435 { 436 struct virtio_softc *vsc = vq->vq_owner; 437 struct viomb_softc *sc = device_private(vsc->sc_child); 438 439 mutex_enter(&sc->sc_waitlock); 440 sc->sc_deflate_done = 1; 441 cv_signal(&sc->sc_wait); 442 mutex_exit(&sc->sc_waitlock); 443 444 return 1; 445 } 446 447 static int 448 deflate_done(struct viomb_softc *sc) 449 { 450 struct virtio_softc *vsc = sc->sc_virtio; 451 struct virtqueue *vq = &sc->sc_vq[1]; 452 struct balloon_req *b; 453 int r, slot; 454 uint64_t nvpages; 455 456 r = virtio_dequeue(vsc, vq, &slot, NULL); 457 if (r != 0) { 458 printf("%s: deflate dequeue failed, errno %d\n", 459 device_xname(sc->sc_dev), r); 460 return 1; 461 } 462 virtio_dequeue_commit(vsc, vq, slot); 463 464 b = &sc->sc_req; 465 nvpages = b->bl_nentries; 466 bus_dmamap_sync(vsc->sc_dmat, b->bl_dmamap, 467 offsetof(struct balloon_req, bl_pages), 468 sizeof(uint32_t)*nvpages, 469 BUS_DMASYNC_POSTWRITE); 470 471 if (vsc->sc_features & VIRTIO_BALLOON_F_MUST_TELL_HOST) 472 uvm_pglistfree(&b->bl_pglist); 473 474 sc->sc_inflight += nvpages; 475 virtio_write_device_config_4(vsc, 476 VIRTIO_BALLOON_CONFIG_ACTUAL, 477 sc->sc_actual - nvpages); 478 viomb_read_config(sc); 479 480 return 1; 481 } 482 483 /* 484 * Kthread: sleeps, eventually inflate and deflate. 485 */ 486 static void 487 viomb_thread(void *arg) 488 { 489 struct viomb_softc *sc = arg; 490 int sleeptime, r; 491 492 for ( ; ; ) { 493 sleeptime = 30000; 494 if (sc->sc_npages > sc->sc_actual + sc->sc_inflight) { 495 if (sc->sc_inflight == 0) { 496 r = inflate(sc); 497 if (r != 0) 498 sleeptime = 10000; 499 else 500 sleeptime = 1000; 501 } else 502 sleeptime = 100; 503 } else if (sc->sc_npages < sc->sc_actual + sc->sc_inflight) { 504 if (sc->sc_inflight == 0) 505 r = deflate(sc); 506 sleeptime = 100; 507 } 508 509 again: 510 mutex_enter(&sc->sc_waitlock); 511 if (sc->sc_inflate_done) { 512 sc->sc_inflate_done = 0; 513 mutex_exit(&sc->sc_waitlock); 514 inflate_done(sc); 515 goto again; 516 } 517 if (sc->sc_deflate_done) { 518 sc->sc_deflate_done = 0; 519 mutex_exit(&sc->sc_waitlock); 520 deflate_done(sc); 521 goto again; 522 } 523 cv_timedwait(&sc->sc_wait, &sc->sc_waitlock, 524 mstohz(sleeptime)); 525 mutex_exit(&sc->sc_waitlock); 526 } 527 } 528
Indexes created Sat Sep 27 22:09:54 GMT 2025