NetBSD/sys/dev/pci/viomb.c

566 lines
15 KiB
C

/* $NetBSD: viomb.c,v 1.12 2021/01/20 19:46:48 reinoud Exp $ */
/*
* Copyright (c) 2010 Minoura Makoto.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: viomb.c,v 1.12 2021/01/20 19:46:48 reinoud Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/condvar.h>
#include <sys/device.h>
#include <sys/kthread.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <uvm/uvm_page.h>
#include <sys/module.h>
#include <dev/pci/virtioreg.h>
#include <dev/pci/virtiovar.h>
#include "ioconf.h"
/* Configuration registers */
#define VIRTIO_BALLOON_CONFIG_NUM_PAGES 0 /* 32bit */
#define VIRTIO_BALLOON_CONFIG_ACTUAL 4 /* 32bit */
/* Feature bits */
#define VIRTIO_BALLOON_F_MUST_TELL_HOST (1<<0)
#define VIRTIO_BALLOON_F_STATS_VQ (1<<1)
#define VIRTIO_BALLOON_FLAG_BITS \
VIRTIO_COMMON_FLAG_BITS \
"\x02""STATS_VQ" \
"\x01""MUST_TELL_HOST"
#define PGS_PER_REQ (256) /* 1MB, 4KB/page */
#define VQ_INFLATE 0
#define VQ_DEFLATE 1
CTASSERT((PAGE_SIZE) == (VIRTIO_PAGE_SIZE)); /* XXX */
struct balloon_req {
bus_dmamap_t bl_dmamap;
struct pglist bl_pglist;
int bl_nentries;
uint32_t bl_pages[PGS_PER_REQ];
};
struct viomb_softc {
device_t sc_dev;
struct virtio_softc *sc_virtio;
struct virtqueue sc_vq[2];
unsigned int sc_npages;
unsigned int sc_actual;
int sc_inflight;
struct balloon_req sc_req;
struct pglist sc_balloon_pages;
int sc_inflate_done;
int sc_deflate_done;
kcondvar_t sc_wait;
kmutex_t sc_waitlock;
};
static int balloon_initialized = 0; /* multiple balloon is not allowed */
static int viomb_match(device_t, cfdata_t, void *);
static void viomb_attach(device_t, device_t, void *);
static void viomb_read_config(struct viomb_softc *);
static int viomb_config_change(struct virtio_softc *);
static int inflate(struct viomb_softc *);
static int inflateq_done(struct virtqueue *);
static int inflate_done(struct viomb_softc *);
static int deflate(struct viomb_softc *);
static int deflateq_done(struct virtqueue *);
static int deflate_done(struct viomb_softc *);
static void viomb_thread(void *);
CFATTACH_DECL_NEW(viomb, sizeof(struct viomb_softc),
viomb_match, viomb_attach, NULL, NULL);
static int
viomb_match(device_t parent, cfdata_t match, void *aux)
{
struct virtio_attach_args *va = aux;
if (va->sc_childdevid == VIRTIO_DEVICE_ID_BALLOON)
return 1;
return 0;
}
static void
viomb_attach(device_t parent, device_t self, void *aux)
{
struct viomb_softc *sc = device_private(self);
struct virtio_softc *vsc = device_private(parent);
const struct sysctlnode *node;
uint64_t features;
if (virtio_child(vsc) != NULL) {
aprint_normal(": child already attached for %s; "
"something wrong...\n", device_xname(parent));
return;
}
if (balloon_initialized++) {
aprint_normal(": balloon already exists; something wrong...\n");
return;
}
/* fail on non-4K page size archs */
if (VIRTIO_PAGE_SIZE != PAGE_SIZE){
aprint_normal("non-4K page size arch found, needs %d, got %d\n",
VIRTIO_PAGE_SIZE, PAGE_SIZE);
return;
}
sc->sc_dev = self;
sc->sc_virtio = vsc;
virtio_child_attach_start(vsc, self, IPL_VM, sc->sc_vq,
viomb_config_change, virtio_vq_intr, 0,
VIRTIO_BALLOON_F_MUST_TELL_HOST, VIRTIO_BALLOON_FLAG_BITS);
features = virtio_features(vsc);
if (features == 0)
goto err_none;
viomb_read_config(sc);
sc->sc_inflight = 0;
TAILQ_INIT(&sc->sc_balloon_pages);
sc->sc_inflate_done = sc->sc_deflate_done = 0;
mutex_init(&sc->sc_waitlock, MUTEX_DEFAULT, IPL_VM); /* spin */
cv_init(&sc->sc_wait, "balloon");
if (virtio_alloc_vq(vsc, &sc->sc_vq[VQ_INFLATE], 0,
sizeof(uint32_t)*PGS_PER_REQ, 1,
"inflate") != 0)
goto err_mutex;
if (virtio_alloc_vq(vsc, &sc->sc_vq[VQ_DEFLATE], 1,
sizeof(uint32_t)*PGS_PER_REQ, 1,
"deflate") != 0)
goto err_vq0;
sc->sc_vq[VQ_INFLATE].vq_done = inflateq_done;
sc->sc_vq[VQ_DEFLATE].vq_done = deflateq_done;
if (bus_dmamap_create(virtio_dmat(vsc), sizeof(uint32_t)*PGS_PER_REQ,
1, sizeof(uint32_t)*PGS_PER_REQ, 0,
BUS_DMA_NOWAIT, &sc->sc_req.bl_dmamap)) {
aprint_error_dev(sc->sc_dev, "dmamap creation failed.\n");
goto err_vq;
}
if (bus_dmamap_load(virtio_dmat(vsc), sc->sc_req.bl_dmamap,
&sc->sc_req.bl_pages[0],
sizeof(uint32_t) * PGS_PER_REQ,
NULL, BUS_DMA_NOWAIT)) {
aprint_error_dev(sc->sc_dev, "dmamap load failed.\n");
goto err_dmamap;
}
if (virtio_child_attach_finish(vsc) != 0)
goto err_out;
if (kthread_create(PRI_IDLE, KTHREAD_MPSAFE, NULL,
viomb_thread, sc, NULL, "viomb")) {
aprint_error_dev(sc->sc_dev, "cannot create kthread.\n");
goto err_out;
}
sysctl_createv(NULL, 0, NULL, &node, 0, CTLTYPE_NODE,
"viomb", SYSCTL_DESCR("VirtIO Balloon status"),
NULL, 0, NULL, 0,
CTL_HW, CTL_CREATE, CTL_EOL);
sysctl_createv(NULL, 0, NULL, NULL, 0, CTLTYPE_INT,
"npages", SYSCTL_DESCR("VirtIO Balloon npages value"),
NULL, 0, &sc->sc_npages, 0,
CTL_HW, node->sysctl_num, CTL_CREATE, CTL_EOL);
sysctl_createv(NULL, 0, NULL, NULL, 0, CTLTYPE_INT,
"actual", SYSCTL_DESCR("VirtIO Balloon actual value"),
NULL, 0, &sc->sc_actual, 0,
CTL_HW, node->sysctl_num, CTL_CREATE, CTL_EOL);
return;
err_out:
err_dmamap:
bus_dmamap_destroy(virtio_dmat(vsc), sc->sc_req.bl_dmamap);
err_vq:
virtio_free_vq(vsc, &sc->sc_vq[VQ_DEFLATE]);
err_vq0:
virtio_free_vq(vsc, &sc->sc_vq[VQ_INFLATE]);
err_mutex:
cv_destroy(&sc->sc_wait);
mutex_destroy(&sc->sc_waitlock);
err_none:
virtio_child_attach_failed(vsc);
return;
}
static void
viomb_read_config(struct viomb_softc *sc)
{
/* these values are explicitly specified as little-endian */
sc->sc_npages = virtio_read_device_config_le_4(sc->sc_virtio,
VIRTIO_BALLOON_CONFIG_NUM_PAGES);
sc->sc_actual = virtio_read_device_config_le_4(sc->sc_virtio,
VIRTIO_BALLOON_CONFIG_ACTUAL);
}
/*
* Config change callback: wakeup the kthread.
*/
static int
viomb_config_change(struct virtio_softc *vsc)
{
struct viomb_softc *sc = device_private(virtio_child(vsc));
unsigned int old;
old = sc->sc_npages;
viomb_read_config(sc);
mutex_enter(&sc->sc_waitlock);
cv_signal(&sc->sc_wait);
mutex_exit(&sc->sc_waitlock);
if (sc->sc_npages > old)
printf("%s: inflating balloon from %u to %u.\n",
device_xname(sc->sc_dev), old, sc->sc_npages);
else if (sc->sc_npages < old)
printf("%s: deflating balloon from %u to %u.\n",
device_xname(sc->sc_dev), old, sc->sc_npages);
return 1;
}
/*
* Inflate: consume some amount of physical memory.
*/
static int
inflate(struct viomb_softc *sc)
{
struct virtio_softc *vsc = sc->sc_virtio;
int i, slot;
uint64_t nvpages, nhpages;
struct balloon_req *b;
struct vm_page *p;
struct virtqueue *vq = &sc->sc_vq[VQ_INFLATE];
if (sc->sc_inflight)
return 0;
nvpages = sc->sc_npages - sc->sc_actual;
if (nvpages > PGS_PER_REQ)
nvpages = PGS_PER_REQ;
nhpages = nvpages * VIRTIO_PAGE_SIZE / PAGE_SIZE;
b = &sc->sc_req;
if (uvm_pglistalloc(nhpages*PAGE_SIZE, 0, UINT32_MAX*PAGE_SIZE,
0, 0, &b->bl_pglist, nhpages, 1)) {
printf("%s: %" PRIu64 " pages of physical memory "
"could not be allocated, retrying...\n",
device_xname(sc->sc_dev), nhpages);
return 1; /* sleep longer */
}
b->bl_nentries = nvpages;
i = 0;
TAILQ_FOREACH(p, &b->bl_pglist, pageq.queue) {
b->bl_pages[i++] =
htole32(VM_PAGE_TO_PHYS(p) / VIRTIO_PAGE_SIZE);
}
KASSERT(i == nvpages);
if (virtio_enqueue_prep(vsc, vq, &slot) != 0) {
printf("%s: inflate enqueue failed.\n",
device_xname(sc->sc_dev));
uvm_pglistfree(&b->bl_pglist);
return 0;
}
if (virtio_enqueue_reserve(vsc, vq, slot, 1)) {
printf("%s: inflate enqueue failed.\n",
device_xname(sc->sc_dev));
uvm_pglistfree(&b->bl_pglist);
return 0;
}
bus_dmamap_sync(virtio_dmat(vsc), b->bl_dmamap, 0,
sizeof(uint32_t)*nvpages, BUS_DMASYNC_PREWRITE);
virtio_enqueue(vsc, vq, slot, b->bl_dmamap, true);
virtio_enqueue_commit(vsc, vq, slot, true);
sc->sc_inflight += nvpages;
return 0;
}
static int
inflateq_done(struct virtqueue *vq)
{
struct virtio_softc *vsc = vq->vq_owner;
struct viomb_softc *sc = device_private(virtio_child(vsc));
mutex_enter(&sc->sc_waitlock);
sc->sc_inflate_done = 1;
cv_signal(&sc->sc_wait);
mutex_exit(&sc->sc_waitlock);
return 1;
}
static int
inflate_done(struct viomb_softc *sc)
{
struct virtio_softc *vsc = sc->sc_virtio;
struct virtqueue *vq = &sc->sc_vq[VQ_INFLATE];
struct balloon_req *b;
int r, slot;
uint64_t nvpages;
struct vm_page *p;
r = virtio_dequeue(vsc, vq, &slot, NULL);
if (r != 0) {
printf("%s: inflate dequeue failed, errno %d.\n",
device_xname(sc->sc_dev), r);
return 1;
}
virtio_dequeue_commit(vsc, vq, slot);
b = &sc->sc_req;
nvpages = b->bl_nentries;
bus_dmamap_sync(virtio_dmat(vsc), b->bl_dmamap,
0,
sizeof(uint32_t)*nvpages,
BUS_DMASYNC_POSTWRITE);
while (!TAILQ_EMPTY(&b->bl_pglist)) {
p = TAILQ_FIRST(&b->bl_pglist);
TAILQ_REMOVE(&b->bl_pglist, p, pageq.queue);
TAILQ_INSERT_TAIL(&sc->sc_balloon_pages, p, pageq.queue);
}
sc->sc_inflight -= nvpages;
virtio_write_device_config_le_4(vsc,
VIRTIO_BALLOON_CONFIG_ACTUAL,
sc->sc_actual + nvpages);
viomb_read_config(sc);
return 1;
}
/*
* Deflate: free previously allocated memory.
*/
static int
deflate(struct viomb_softc *sc)
{
struct virtio_softc *vsc = sc->sc_virtio;
int i, slot;
uint64_t nvpages, nhpages;
struct balloon_req *b;
struct vm_page *p;
struct virtqueue *vq = &sc->sc_vq[VQ_DEFLATE];
nvpages = (sc->sc_actual + sc->sc_inflight) - sc->sc_npages;
if (nvpages > PGS_PER_REQ)
nvpages = PGS_PER_REQ;
nhpages = nvpages * VIRTIO_PAGE_SIZE / PAGE_SIZE;
b = &sc->sc_req;
b->bl_nentries = nvpages;
TAILQ_INIT(&b->bl_pglist);
for (i = 0; i < nhpages; i++) {
p = TAILQ_FIRST(&sc->sc_balloon_pages);
if (p == NULL)
break;
TAILQ_REMOVE(&sc->sc_balloon_pages, p, pageq.queue);
TAILQ_INSERT_TAIL(&b->bl_pglist, p, pageq.queue);
b->bl_pages[i] =
htole32(VM_PAGE_TO_PHYS(p) / VIRTIO_PAGE_SIZE);
}
if (virtio_enqueue_prep(vsc, vq, &slot) != 0) {
printf("%s: deflate enqueue failed.\n",
device_xname(sc->sc_dev));
TAILQ_FOREACH_REVERSE(p, &b->bl_pglist, pglist, pageq.queue) {
TAILQ_REMOVE(&b->bl_pglist, p, pageq.queue);
TAILQ_INSERT_HEAD(&sc->sc_balloon_pages, p,
pageq.queue);
}
return 0;
}
if (virtio_enqueue_reserve(vsc, vq, slot, 1) != 0) {
printf("%s: deflate enqueue failed.\n",
device_xname(sc->sc_dev));
TAILQ_FOREACH_REVERSE(p, &b->bl_pglist, pglist, pageq.queue) {
TAILQ_REMOVE(&b->bl_pglist, p, pageq.queue);
TAILQ_INSERT_HEAD(&sc->sc_balloon_pages, p,
pageq.queue);
}
return 0;
}
bus_dmamap_sync(virtio_dmat(vsc), b->bl_dmamap, 0,
sizeof(uint32_t)*nvpages, BUS_DMASYNC_PREWRITE);
virtio_enqueue(vsc, vq, slot, b->bl_dmamap, true);
virtio_enqueue_commit(vsc, vq, slot, true);
sc->sc_inflight -= nvpages;
if (!(virtio_features(vsc) & VIRTIO_BALLOON_F_MUST_TELL_HOST))
uvm_pglistfree(&b->bl_pglist);
return 0;
}
static int
deflateq_done(struct virtqueue *vq)
{
struct virtio_softc *vsc = vq->vq_owner;
struct viomb_softc *sc = device_private(virtio_child(vsc));
mutex_enter(&sc->sc_waitlock);
sc->sc_deflate_done = 1;
cv_signal(&sc->sc_wait);
mutex_exit(&sc->sc_waitlock);
return 1;
}
static int
deflate_done(struct viomb_softc *sc)
{
struct virtio_softc *vsc = sc->sc_virtio;
struct virtqueue *vq = &sc->sc_vq[VQ_DEFLATE];
struct balloon_req *b;
int r, slot;
uint64_t nvpages;
r = virtio_dequeue(vsc, vq, &slot, NULL);
if (r != 0) {
printf("%s: deflate dequeue failed, errno %d\n",
device_xname(sc->sc_dev), r);
return 1;
}
virtio_dequeue_commit(vsc, vq, slot);
b = &sc->sc_req;
nvpages = b->bl_nentries;
bus_dmamap_sync(virtio_dmat(vsc), b->bl_dmamap,
0,
sizeof(uint32_t)*nvpages,
BUS_DMASYNC_POSTWRITE);
if (virtio_features(vsc) & VIRTIO_BALLOON_F_MUST_TELL_HOST)
uvm_pglistfree(&b->bl_pglist);
sc->sc_inflight += nvpages;
virtio_write_device_config_le_4(vsc,
VIRTIO_BALLOON_CONFIG_ACTUAL,
sc->sc_actual - nvpages);
viomb_read_config(sc);
return 1;
}
/*
* Kthread: sleeps, eventually inflate and deflate.
*/
static void
viomb_thread(void *arg)
{
struct viomb_softc *sc = arg;
int sleeptime, r;
for ( ; ; ) {
sleeptime = 30000;
if (sc->sc_npages > sc->sc_actual + sc->sc_inflight) {
if (sc->sc_inflight == 0) {
r = inflate(sc);
if (r != 0)
sleeptime = 10000;
else
sleeptime = 1000;
} else
sleeptime = 100;
} else if (sc->sc_npages < sc->sc_actual + sc->sc_inflight) {
if (sc->sc_inflight == 0)
r = deflate(sc);
sleeptime = 100;
}
again:
mutex_enter(&sc->sc_waitlock);
if (sc->sc_inflate_done) {
sc->sc_inflate_done = 0;
mutex_exit(&sc->sc_waitlock);
inflate_done(sc);
goto again;
}
if (sc->sc_deflate_done) {
sc->sc_deflate_done = 0;
mutex_exit(&sc->sc_waitlock);
deflate_done(sc);
goto again;
}
cv_timedwait(&sc->sc_wait, &sc->sc_waitlock,
mstohz(sleeptime));
mutex_exit(&sc->sc_waitlock);
}
}
MODULE(MODULE_CLASS_DRIVER, viomb, "virtio");
#ifdef _MODULE
#include "ioconf.c"
#endif
static int
viomb_modcmd(modcmd_t cmd, void *opaque)
{
int error = 0;
#ifdef _MODULE
switch (cmd) {
case MODULE_CMD_INIT:
error = config_init_component(cfdriver_ioconf_viomb,
cfattach_ioconf_viomb, cfdata_ioconf_viomb);
break;
case MODULE_CMD_FINI:
error = config_fini_component(cfdriver_ioconf_viomb,
cfattach_ioconf_viomb, cfdata_ioconf_viomb);
break;
default:
error = ENOTTY;
break;
}
#endif
return error;
}