1227652Sgrehan/*- 2253132Sbryanv * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org> 3227652Sgrehan * All rights reserved. 4227652Sgrehan * 5227652Sgrehan * Redistribution and use in source and binary forms, with or without 6227652Sgrehan * modification, are permitted provided that the following conditions 7227652Sgrehan * are met: 8227652Sgrehan * 1. Redistributions of source code must retain the above copyright 9227652Sgrehan * notice unmodified, this list of conditions, and the following 10227652Sgrehan * disclaimer. 11227652Sgrehan * 2. Redistributions in binary form must reproduce the above copyright 12227652Sgrehan * notice, this list of conditions and the following disclaimer in the 13227652Sgrehan * documentation and/or other materials provided with the distribution. 14227652Sgrehan * 15227652Sgrehan * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16227652Sgrehan * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17227652Sgrehan * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18227652Sgrehan * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19227652Sgrehan * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20227652Sgrehan * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21227652Sgrehan * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22227652Sgrehan * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23227652Sgrehan * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24227652Sgrehan * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25227652Sgrehan */ 26227652Sgrehan 27227652Sgrehan/* Driver for VirtIO memory balloon devices. */ 28227652Sgrehan 29227652Sgrehan#include <sys/cdefs.h> 30227652Sgrehan__FBSDID("$FreeBSD$"); 31227652Sgrehan 32227652Sgrehan#include <sys/param.h> 33227652Sgrehan#include <sys/systm.h> 34227652Sgrehan#include <sys/kernel.h> 35227652Sgrehan#include <sys/endian.h> 36227652Sgrehan#include <sys/kthread.h> 37227652Sgrehan#include <sys/malloc.h> 38227652Sgrehan#include <sys/module.h> 39227652Sgrehan#include <sys/sglist.h> 40227652Sgrehan#include <sys/sysctl.h> 41227652Sgrehan#include <sys/lock.h> 42227652Sgrehan#include <sys/mutex.h> 43227652Sgrehan#include <sys/queue.h> 44227652Sgrehan 45227652Sgrehan#include <vm/vm.h> 46227652Sgrehan#include <vm/vm_page.h> 47227652Sgrehan 48227652Sgrehan#include <machine/bus.h> 49227652Sgrehan#include <machine/resource.h> 50227652Sgrehan#include <sys/bus.h> 51227652Sgrehan#include <sys/rman.h> 52227652Sgrehan 53227652Sgrehan#include <dev/virtio/virtio.h> 54227652Sgrehan#include <dev/virtio/virtqueue.h> 55227652Sgrehan#include <dev/virtio/balloon/virtio_balloon.h> 56227652Sgrehan 57227652Sgrehan#include "virtio_if.h" 58227652Sgrehan 59227652Sgrehanstruct vtballoon_softc { 60227652Sgrehan device_t vtballoon_dev; 61227652Sgrehan struct mtx vtballoon_mtx; 62227652Sgrehan uint64_t vtballoon_features; 63227652Sgrehan uint32_t vtballoon_flags; 64227652Sgrehan#define VTBALLOON_FLAG_DETACH 0x01 65227652Sgrehan 66227652Sgrehan struct virtqueue *vtballoon_inflate_vq; 67227652Sgrehan struct virtqueue *vtballoon_deflate_vq; 68227652Sgrehan 69227652Sgrehan uint32_t vtballoon_desired_npages; 70227652Sgrehan uint32_t vtballoon_current_npages; 71227652Sgrehan TAILQ_HEAD(,vm_page) vtballoon_pages; 72227652Sgrehan 73253132Sbryanv struct thread *vtballoon_td; 74227652Sgrehan uint32_t *vtballoon_page_frames; 75227652Sgrehan int vtballoon_timeout; 76227652Sgrehan}; 77227652Sgrehan 78227652Sgrehanstatic struct virtio_feature_desc vtballoon_feature_desc[] = { 79227652Sgrehan { VIRTIO_BALLOON_F_MUST_TELL_HOST, "MustTellHost" }, 80227652Sgrehan { VIRTIO_BALLOON_F_STATS_VQ, "StatsVq" }, 81227652Sgrehan 82227652Sgrehan { 0, NULL } 83227652Sgrehan}; 84227652Sgrehan 85227652Sgrehanstatic int vtballoon_probe(device_t); 86227652Sgrehanstatic int vtballoon_attach(device_t); 87227652Sgrehanstatic int vtballoon_detach(device_t); 88227652Sgrehanstatic int vtballoon_config_change(device_t); 89227652Sgrehan 90227652Sgrehanstatic void vtballoon_negotiate_features(struct vtballoon_softc *); 91227652Sgrehanstatic int vtballoon_alloc_virtqueues(struct vtballoon_softc *); 92227652Sgrehan 93253132Sbryanvstatic void vtballoon_vq_intr(void *); 94227652Sgrehan 95227652Sgrehanstatic void vtballoon_inflate(struct vtballoon_softc *, int); 96227652Sgrehanstatic void vtballoon_deflate(struct vtballoon_softc *, int); 97227652Sgrehan 98227652Sgrehanstatic void vtballoon_send_page_frames(struct vtballoon_softc *, 99227652Sgrehan struct virtqueue *, int); 100227652Sgrehan 101227652Sgrehanstatic void vtballoon_pop(struct vtballoon_softc *); 102227652Sgrehanstatic void vtballoon_stop(struct vtballoon_softc *); 103227652Sgrehan 104227652Sgrehanstatic vm_page_t 105227652Sgrehan vtballoon_alloc_page(struct vtballoon_softc *); 106227652Sgrehanstatic void vtballoon_free_page(struct vtballoon_softc *, vm_page_t); 107227652Sgrehan 108227652Sgrehanstatic int vtballoon_sleep(struct vtballoon_softc *); 109227652Sgrehanstatic void vtballoon_thread(void *); 110227652Sgrehanstatic void vtballoon_add_sysctl(struct vtballoon_softc *); 111227652Sgrehan 112227652Sgrehan/* Features desired/implemented by this driver. */ 113227652Sgrehan#define VTBALLOON_FEATURES 0 114227652Sgrehan 115227652Sgrehan/* Timeout between retries when the balloon needs inflating. */ 116227652Sgrehan#define VTBALLOON_LOWMEM_TIMEOUT hz 117227652Sgrehan 118227652Sgrehan/* 119227652Sgrehan * Maximum number of pages we'll request to inflate or deflate 120227652Sgrehan * the balloon in one virtqueue request. Both Linux and NetBSD 121227652Sgrehan * have settled on 256, doing up to 1MB at a time. 122227652Sgrehan */ 123227652Sgrehan#define VTBALLOON_PAGES_PER_REQUEST 256 124227652Sgrehan 125239472Semaste/* Must be able to fix all pages frames in one page (segment). */ 126239472SemasteCTASSERT(VTBALLOON_PAGES_PER_REQUEST * sizeof(uint32_t) <= PAGE_SIZE); 127239472Semaste 128227652Sgrehan#define VTBALLOON_MTX(_sc) &(_sc)->vtballoon_mtx 129227652Sgrehan#define VTBALLOON_LOCK_INIT(_sc, _name) mtx_init(VTBALLOON_MTX((_sc)), _name, \ 130253132Sbryanv "VirtIO Balloon Lock", MTX_DEF) 131253132Sbryanv#define VTBALLOON_LOCK(_sc) mtx_lock(VTBALLOON_MTX((_sc))) 132253132Sbryanv#define VTBALLOON_UNLOCK(_sc) mtx_unlock(VTBALLOON_MTX((_sc))) 133227652Sgrehan#define VTBALLOON_LOCK_DESTROY(_sc) mtx_destroy(VTBALLOON_MTX((_sc))) 134227652Sgrehan 135227652Sgrehanstatic device_method_t vtballoon_methods[] = { 136227652Sgrehan /* Device methods. */ 137227652Sgrehan DEVMETHOD(device_probe, vtballoon_probe), 138227652Sgrehan DEVMETHOD(device_attach, vtballoon_attach), 139227652Sgrehan DEVMETHOD(device_detach, vtballoon_detach), 140227652Sgrehan 141227652Sgrehan /* VirtIO methods. */ 142227652Sgrehan DEVMETHOD(virtio_config_change, vtballoon_config_change), 143227652Sgrehan 144239472Semaste DEVMETHOD_END 145227652Sgrehan}; 146227652Sgrehan 147227652Sgrehanstatic driver_t vtballoon_driver = { 148227652Sgrehan "vtballoon", 149227652Sgrehan vtballoon_methods, 150227652Sgrehan sizeof(struct vtballoon_softc) 151227652Sgrehan}; 152227652Sgrehanstatic devclass_t vtballoon_devclass; 153227652Sgrehan 154227652SgrehanDRIVER_MODULE(virtio_balloon, virtio_pci, vtballoon_driver, 155227652Sgrehan vtballoon_devclass, 0, 0); 156227652SgrehanMODULE_VERSION(virtio_balloon, 1); 157227652SgrehanMODULE_DEPEND(virtio_balloon, virtio, 1, 1, 1); 158227652Sgrehan 159227652Sgrehanstatic int 160227652Sgrehanvtballoon_probe(device_t dev) 161227652Sgrehan{ 162227652Sgrehan 163227652Sgrehan if (virtio_get_device_type(dev) != VIRTIO_ID_BALLOON) 164227652Sgrehan return (ENXIO); 165227652Sgrehan 166227652Sgrehan device_set_desc(dev, "VirtIO Balloon Adapter"); 167227652Sgrehan 168227652Sgrehan return (BUS_PROBE_DEFAULT); 169227652Sgrehan} 170227652Sgrehan 171227652Sgrehanstatic int 172227652Sgrehanvtballoon_attach(device_t dev) 173227652Sgrehan{ 174227652Sgrehan struct vtballoon_softc *sc; 175227652Sgrehan int error; 176227652Sgrehan 177227652Sgrehan sc = device_get_softc(dev); 178227652Sgrehan sc->vtballoon_dev = dev; 179227652Sgrehan 180227652Sgrehan VTBALLOON_LOCK_INIT(sc, device_get_nameunit(dev)); 181227652Sgrehan TAILQ_INIT(&sc->vtballoon_pages); 182227652Sgrehan 183227652Sgrehan vtballoon_add_sysctl(sc); 184227652Sgrehan 185227652Sgrehan virtio_set_feature_desc(dev, vtballoon_feature_desc); 186227652Sgrehan vtballoon_negotiate_features(sc); 187227652Sgrehan 188227652Sgrehan sc->vtballoon_page_frames = malloc(VTBALLOON_PAGES_PER_REQUEST * 189227652Sgrehan sizeof(uint32_t), M_DEVBUF, M_NOWAIT | M_ZERO); 190227652Sgrehan if (sc->vtballoon_page_frames == NULL) { 191227652Sgrehan error = ENOMEM; 192227652Sgrehan device_printf(dev, 193227652Sgrehan "cannot allocate page frame request array\n"); 194227652Sgrehan goto fail; 195227652Sgrehan } 196227652Sgrehan 197227652Sgrehan error = vtballoon_alloc_virtqueues(sc); 198227652Sgrehan if (error) { 199227652Sgrehan device_printf(dev, "cannot allocate virtqueues\n"); 200227652Sgrehan goto fail; 201227652Sgrehan } 202227652Sgrehan 203227652Sgrehan error = virtio_setup_intr(dev, INTR_TYPE_MISC); 204227652Sgrehan if (error) { 205227652Sgrehan device_printf(dev, "cannot setup virtqueue interrupts\n"); 206227652Sgrehan goto fail; 207227652Sgrehan } 208227652Sgrehan 209253132Sbryanv error = kthread_add(vtballoon_thread, sc, NULL, &sc->vtballoon_td, 210227652Sgrehan 0, 0, "virtio_balloon"); 211227652Sgrehan if (error) { 212253132Sbryanv device_printf(dev, "cannot create balloon kthread\n"); 213227652Sgrehan goto fail; 214227652Sgrehan } 215227652Sgrehan 216227652Sgrehan virtqueue_enable_intr(sc->vtballoon_inflate_vq); 217227652Sgrehan virtqueue_enable_intr(sc->vtballoon_deflate_vq); 218227652Sgrehan 219227652Sgrehanfail: 220227652Sgrehan if (error) 221227652Sgrehan vtballoon_detach(dev); 222227652Sgrehan 223227652Sgrehan return (error); 224227652Sgrehan} 225227652Sgrehan 226227652Sgrehanstatic int 227227652Sgrehanvtballoon_detach(device_t dev) 228227652Sgrehan{ 229227652Sgrehan struct vtballoon_softc *sc; 230227652Sgrehan 231227652Sgrehan sc = device_get_softc(dev); 232227652Sgrehan 233253132Sbryanv if (sc->vtballoon_td != NULL) { 234227652Sgrehan VTBALLOON_LOCK(sc); 235227652Sgrehan sc->vtballoon_flags |= VTBALLOON_FLAG_DETACH; 236227652Sgrehan wakeup_one(sc); 237253132Sbryanv msleep(sc->vtballoon_td, VTBALLOON_MTX(sc), 0, "vtbdth", 0); 238227652Sgrehan VTBALLOON_UNLOCK(sc); 239227652Sgrehan 240253132Sbryanv sc->vtballoon_td = NULL; 241227652Sgrehan } 242227652Sgrehan 243227652Sgrehan if (device_is_attached(dev)) { 244227652Sgrehan vtballoon_pop(sc); 245227652Sgrehan vtballoon_stop(sc); 246227652Sgrehan } 247227652Sgrehan 248227652Sgrehan if (sc->vtballoon_page_frames != NULL) { 249227652Sgrehan free(sc->vtballoon_page_frames, M_DEVBUF); 250227652Sgrehan sc->vtballoon_page_frames = NULL; 251227652Sgrehan } 252227652Sgrehan 253227652Sgrehan VTBALLOON_LOCK_DESTROY(sc); 254227652Sgrehan 255227652Sgrehan return (0); 256227652Sgrehan} 257227652Sgrehan 258227652Sgrehanstatic int 259227652Sgrehanvtballoon_config_change(device_t dev) 260227652Sgrehan{ 261227652Sgrehan struct vtballoon_softc *sc; 262227652Sgrehan 263227652Sgrehan sc = device_get_softc(dev); 264227652Sgrehan 265227652Sgrehan VTBALLOON_LOCK(sc); 266227652Sgrehan wakeup_one(sc); 267227652Sgrehan VTBALLOON_UNLOCK(sc); 268227652Sgrehan 269227652Sgrehan return (1); 270227652Sgrehan} 271227652Sgrehan 272227652Sgrehanstatic void 273227652Sgrehanvtballoon_negotiate_features(struct vtballoon_softc *sc) 274227652Sgrehan{ 275227652Sgrehan device_t dev; 276227652Sgrehan uint64_t features; 277227652Sgrehan 278227652Sgrehan dev = sc->vtballoon_dev; 279227652Sgrehan features = virtio_negotiate_features(dev, VTBALLOON_FEATURES); 280227652Sgrehan sc->vtballoon_features = features; 281227652Sgrehan} 282227652Sgrehan 283227652Sgrehanstatic int 284227652Sgrehanvtballoon_alloc_virtqueues(struct vtballoon_softc *sc) 285227652Sgrehan{ 286227652Sgrehan device_t dev; 287227652Sgrehan struct vq_alloc_info vq_info[2]; 288227652Sgrehan int nvqs; 289227652Sgrehan 290227652Sgrehan dev = sc->vtballoon_dev; 291227652Sgrehan nvqs = 2; 292227652Sgrehan 293227652Sgrehan VQ_ALLOC_INFO_INIT(&vq_info[0], 0, vtballoon_vq_intr, sc, 294227652Sgrehan &sc->vtballoon_inflate_vq, "%s inflate", device_get_nameunit(dev)); 295227652Sgrehan 296227652Sgrehan VQ_ALLOC_INFO_INIT(&vq_info[1], 0, vtballoon_vq_intr, sc, 297227652Sgrehan &sc->vtballoon_deflate_vq, "%s deflate", device_get_nameunit(dev)); 298227652Sgrehan 299227652Sgrehan return (virtio_alloc_virtqueues(dev, 0, nvqs, vq_info)); 300227652Sgrehan} 301227652Sgrehan 302253132Sbryanvstatic void 303227652Sgrehanvtballoon_vq_intr(void *xsc) 304227652Sgrehan{ 305227652Sgrehan struct vtballoon_softc *sc; 306227652Sgrehan 307227652Sgrehan sc = xsc; 308227652Sgrehan 309227652Sgrehan VTBALLOON_LOCK(sc); 310227652Sgrehan wakeup_one(sc); 311227652Sgrehan VTBALLOON_UNLOCK(sc); 312227652Sgrehan} 313227652Sgrehan 314227652Sgrehanstatic void 315227652Sgrehanvtballoon_inflate(struct vtballoon_softc *sc, int npages) 316227652Sgrehan{ 317227652Sgrehan struct virtqueue *vq; 318227652Sgrehan vm_page_t m; 319227652Sgrehan int i; 320227652Sgrehan 321227652Sgrehan vq = sc->vtballoon_inflate_vq; 322227652Sgrehan 323227652Sgrehan if (npages > VTBALLOON_PAGES_PER_REQUEST) 324227652Sgrehan npages = VTBALLOON_PAGES_PER_REQUEST; 325227652Sgrehan 326227652Sgrehan for (i = 0; i < npages; i++) { 327253132Sbryanv if ((m = vtballoon_alloc_page(sc)) == NULL) { 328253132Sbryanv sc->vtballoon_timeout = VTBALLOON_LOWMEM_TIMEOUT; 329227652Sgrehan break; 330253132Sbryanv } 331227652Sgrehan 332227652Sgrehan sc->vtballoon_page_frames[i] = 333227652Sgrehan VM_PAGE_TO_PHYS(m) >> VIRTIO_BALLOON_PFN_SHIFT; 334227652Sgrehan 335253132Sbryanv KASSERT(m->queue == PQ_NONE, 336253132Sbryanv ("%s: allocated page %p on queue", __func__, m)); 337227652Sgrehan TAILQ_INSERT_TAIL(&sc->vtballoon_pages, m, pageq); 338227652Sgrehan } 339227652Sgrehan 340227652Sgrehan if (i > 0) 341227652Sgrehan vtballoon_send_page_frames(sc, vq, i); 342227652Sgrehan} 343227652Sgrehan 344227652Sgrehanstatic void 345227652Sgrehanvtballoon_deflate(struct vtballoon_softc *sc, int npages) 346227652Sgrehan{ 347227652Sgrehan TAILQ_HEAD(, vm_page) free_pages; 348227652Sgrehan struct virtqueue *vq; 349227652Sgrehan vm_page_t m; 350227652Sgrehan int i; 351227652Sgrehan 352227652Sgrehan vq = sc->vtballoon_deflate_vq; 353227652Sgrehan TAILQ_INIT(&free_pages); 354227652Sgrehan 355227652Sgrehan if (npages > VTBALLOON_PAGES_PER_REQUEST) 356227652Sgrehan npages = VTBALLOON_PAGES_PER_REQUEST; 357227652Sgrehan 358227652Sgrehan for (i = 0; i < npages; i++) { 359227652Sgrehan m = TAILQ_FIRST(&sc->vtballoon_pages); 360253132Sbryanv KASSERT(m != NULL, ("%s: no more pages to deflate", __func__)); 361227652Sgrehan 362227652Sgrehan sc->vtballoon_page_frames[i] = 363227652Sgrehan VM_PAGE_TO_PHYS(m) >> VIRTIO_BALLOON_PFN_SHIFT; 364227652Sgrehan 365227652Sgrehan TAILQ_REMOVE(&sc->vtballoon_pages, m, pageq); 366227652Sgrehan TAILQ_INSERT_TAIL(&free_pages, m, pageq); 367227652Sgrehan } 368227652Sgrehan 369227652Sgrehan if (i > 0) { 370227652Sgrehan /* Always tell host first before freeing the pages. */ 371227652Sgrehan vtballoon_send_page_frames(sc, vq, i); 372227652Sgrehan 373227652Sgrehan while ((m = TAILQ_FIRST(&free_pages)) != NULL) { 374227652Sgrehan TAILQ_REMOVE(&free_pages, m, pageq); 375227652Sgrehan vtballoon_free_page(sc, m); 376227652Sgrehan } 377227652Sgrehan } 378227652Sgrehan 379227652Sgrehan KASSERT((TAILQ_EMPTY(&sc->vtballoon_pages) && 380227652Sgrehan sc->vtballoon_current_npages == 0) || 381227652Sgrehan (!TAILQ_EMPTY(&sc->vtballoon_pages) && 382253132Sbryanv sc->vtballoon_current_npages != 0), 383253132Sbryanv ("%s: bogus page count %d", __func__, 384253132Sbryanv sc->vtballoon_current_npages)); 385227652Sgrehan} 386227652Sgrehan 387227652Sgrehanstatic void 388227652Sgrehanvtballoon_send_page_frames(struct vtballoon_softc *sc, struct virtqueue *vq, 389227652Sgrehan int npages) 390227652Sgrehan{ 391227652Sgrehan struct sglist sg; 392227652Sgrehan struct sglist_seg segs[1]; 393227652Sgrehan void *c; 394227652Sgrehan int error; 395227652Sgrehan 396227652Sgrehan sglist_init(&sg, 1, segs); 397227652Sgrehan 398227652Sgrehan error = sglist_append(&sg, sc->vtballoon_page_frames, 399227652Sgrehan npages * sizeof(uint32_t)); 400227652Sgrehan KASSERT(error == 0, ("error adding page frames to sglist")); 401227652Sgrehan 402227652Sgrehan error = virtqueue_enqueue(vq, vq, &sg, 1, 0); 403227652Sgrehan KASSERT(error == 0, ("error enqueuing page frames to virtqueue")); 404239472Semaste virtqueue_notify(vq); 405227652Sgrehan 406227652Sgrehan /* 407227652Sgrehan * Inflate and deflate operations are done synchronously. The 408227652Sgrehan * interrupt handler will wake us up. 409227652Sgrehan */ 410227652Sgrehan VTBALLOON_LOCK(sc); 411227652Sgrehan while ((c = virtqueue_dequeue(vq, NULL)) == NULL) 412253132Sbryanv msleep(sc, VTBALLOON_MTX(sc), 0, "vtbspf", 0); 413227652Sgrehan VTBALLOON_UNLOCK(sc); 414227652Sgrehan 415227652Sgrehan KASSERT(c == vq, ("unexpected balloon operation response")); 416227652Sgrehan} 417227652Sgrehan 418227652Sgrehanstatic void 419227652Sgrehanvtballoon_pop(struct vtballoon_softc *sc) 420227652Sgrehan{ 421227652Sgrehan 422227652Sgrehan while (!TAILQ_EMPTY(&sc->vtballoon_pages)) 423227652Sgrehan vtballoon_deflate(sc, sc->vtballoon_current_npages); 424227652Sgrehan} 425227652Sgrehan 426227652Sgrehanstatic void 427227652Sgrehanvtballoon_stop(struct vtballoon_softc *sc) 428227652Sgrehan{ 429227652Sgrehan 430227652Sgrehan virtqueue_disable_intr(sc->vtballoon_inflate_vq); 431227652Sgrehan virtqueue_disable_intr(sc->vtballoon_deflate_vq); 432227652Sgrehan 433227652Sgrehan virtio_stop(sc->vtballoon_dev); 434227652Sgrehan} 435227652Sgrehan 436227652Sgrehanstatic vm_page_t 437227652Sgrehanvtballoon_alloc_page(struct vtballoon_softc *sc) 438227652Sgrehan{ 439227652Sgrehan vm_page_t m; 440227652Sgrehan 441227652Sgrehan m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | VM_ALLOC_WIRED | 442227652Sgrehan VM_ALLOC_NOOBJ); 443227652Sgrehan if (m != NULL) 444227652Sgrehan sc->vtballoon_current_npages++; 445227652Sgrehan 446227652Sgrehan return (m); 447227652Sgrehan} 448227652Sgrehan 449227652Sgrehanstatic void 450227652Sgrehanvtballoon_free_page(struct vtballoon_softc *sc, vm_page_t m) 451227652Sgrehan{ 452227652Sgrehan 453227652Sgrehan vm_page_unwire(m, 0); 454227652Sgrehan vm_page_free(m); 455227652Sgrehan sc->vtballoon_current_npages--; 456227652Sgrehan} 457227652Sgrehan 458227652Sgrehanstatic uint32_t 459227652Sgrehanvtballoon_desired_size(struct vtballoon_softc *sc) 460227652Sgrehan{ 461227652Sgrehan uint32_t desired; 462227652Sgrehan 463227652Sgrehan desired = virtio_read_dev_config_4(sc->vtballoon_dev, 464227652Sgrehan offsetof(struct virtio_balloon_config, num_pages)); 465227652Sgrehan 466227652Sgrehan return (le32toh(desired)); 467227652Sgrehan} 468227652Sgrehan 469227652Sgrehanstatic void 470227652Sgrehanvtballoon_update_size(struct vtballoon_softc *sc) 471227652Sgrehan{ 472227652Sgrehan 473227652Sgrehan virtio_write_dev_config_4(sc->vtballoon_dev, 474227652Sgrehan offsetof(struct virtio_balloon_config, actual), 475227652Sgrehan htole32(sc->vtballoon_current_npages)); 476227652Sgrehan} 477227652Sgrehan 478227652Sgrehanstatic int 479227652Sgrehanvtballoon_sleep(struct vtballoon_softc *sc) 480227652Sgrehan{ 481227652Sgrehan int rc, timeout; 482227652Sgrehan uint32_t current, desired; 483227652Sgrehan 484227652Sgrehan rc = 0; 485227652Sgrehan current = sc->vtballoon_current_npages; 486227652Sgrehan 487227652Sgrehan VTBALLOON_LOCK(sc); 488227652Sgrehan for (;;) { 489227652Sgrehan if (sc->vtballoon_flags & VTBALLOON_FLAG_DETACH) { 490227652Sgrehan rc = 1; 491227652Sgrehan break; 492227652Sgrehan } 493227652Sgrehan 494227652Sgrehan desired = vtballoon_desired_size(sc); 495227652Sgrehan sc->vtballoon_desired_npages = desired; 496227652Sgrehan 497227652Sgrehan /* 498227652Sgrehan * If given, use non-zero timeout on the first time through 499227652Sgrehan * the loop. On subsequent times, timeout will be zero so 500227652Sgrehan * we will reevaluate the desired size of the balloon and 501227652Sgrehan * break out to retry if needed. 502227652Sgrehan */ 503227652Sgrehan timeout = sc->vtballoon_timeout; 504227652Sgrehan sc->vtballoon_timeout = 0; 505227652Sgrehan 506227652Sgrehan if (current > desired) 507227652Sgrehan break; 508227652Sgrehan if (current < desired && timeout == 0) 509227652Sgrehan break; 510227652Sgrehan 511253132Sbryanv msleep(sc, VTBALLOON_MTX(sc), 0, "vtbslp", timeout); 512227652Sgrehan } 513227652Sgrehan VTBALLOON_UNLOCK(sc); 514227652Sgrehan 515227652Sgrehan return (rc); 516227652Sgrehan} 517227652Sgrehan 518227652Sgrehanstatic void 519227652Sgrehanvtballoon_thread(void *xsc) 520227652Sgrehan{ 521227652Sgrehan struct vtballoon_softc *sc; 522227652Sgrehan uint32_t current, desired; 523227652Sgrehan 524227652Sgrehan sc = xsc; 525227652Sgrehan 526227652Sgrehan for (;;) { 527227652Sgrehan if (vtballoon_sleep(sc) != 0) 528227652Sgrehan break; 529227652Sgrehan 530227652Sgrehan current = sc->vtballoon_current_npages; 531227652Sgrehan desired = sc->vtballoon_desired_npages; 532227652Sgrehan 533227652Sgrehan if (desired != current) { 534227652Sgrehan if (desired > current) 535227652Sgrehan vtballoon_inflate(sc, desired - current); 536227652Sgrehan else 537227652Sgrehan vtballoon_deflate(sc, current - desired); 538227652Sgrehan 539227652Sgrehan vtballoon_update_size(sc); 540227652Sgrehan } 541227652Sgrehan } 542227652Sgrehan 543253132Sbryanv kthread_exit(); 544227652Sgrehan} 545227652Sgrehan 546227652Sgrehanstatic void 547227652Sgrehanvtballoon_add_sysctl(struct vtballoon_softc *sc) 548227652Sgrehan{ 549227652Sgrehan device_t dev; 550227652Sgrehan struct sysctl_ctx_list *ctx; 551227652Sgrehan struct sysctl_oid *tree; 552227652Sgrehan struct sysctl_oid_list *child; 553227652Sgrehan 554227652Sgrehan dev = sc->vtballoon_dev; 555227652Sgrehan ctx = device_get_sysctl_ctx(dev); 556227652Sgrehan tree = device_get_sysctl_tree(dev); 557227652Sgrehan child = SYSCTL_CHILDREN(tree); 558227652Sgrehan 559227652Sgrehan SYSCTL_ADD_UINT(ctx, child, OID_AUTO, "desired", 560227652Sgrehan CTLFLAG_RD, &sc->vtballoon_desired_npages, sizeof(uint32_t), 561227652Sgrehan "Desired balloon size in pages"); 562227652Sgrehan 563227652Sgrehan SYSCTL_ADD_UINT(ctx, child, OID_AUTO, "current", 564227652Sgrehan CTLFLAG_RD, &sc->vtballoon_current_npages, sizeof(uint32_t), 565227652Sgrehan "Current balloon size in pages"); 566227652Sgrehan} 567