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qemu-e2k/block/throttle-groups.c
Stefan Hajnoczi 341e0b5658 throttle-groups: forget timer and schedule next TGM on detach 
tg->any_timer_armed[] must be cleared when detaching pending timers from
the AioContext.  Failure to do so leads to hung I/O because it looks
like there are still timers pending when in fact they have been removed.

Other ThrottleGroupMembers might have requests pending too so it's
necessary to schedule the next TGM so it can set a timer.

This patch fixes hung I/O when QEMU is launched with drives that are in
the same throttling group:

  (guest)$ dd if=/dev/zero of=/dev/vdb oflag=direct bs=512 &
  (guest)$ dd if=/dev/zero of=/dev/vdc oflag=direct bs=512 &
  (qemu) stop
  (qemu) cont
  ...I/O is stuck...

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20171116112150.27607-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-11-16 14:12:57 +00:00

954 lines
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/*
* QEMU block throttling group infrastructure
*
* Copyright (C) Nodalink, EURL. 2014
* Copyright (C) Igalia, S.L. 2015
*
* Authors:
* Benoît Canet <benoit.canet@nodalink.com>
* Alberto Garcia <berto@igalia.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 or
* (at your option) version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "sysemu/block-backend.h"
#include "block/throttle-groups.h"
#include "qemu/throttle-options.h"
#include "qemu/queue.h"
#include "qemu/thread.h"
#include "sysemu/qtest.h"
#include "qapi/error.h"
#include "qapi-visit.h"
#include "qom/object.h"
#include "qom/object_interfaces.h"
static void throttle_group_obj_init(Object *obj);
static void throttle_group_obj_complete(UserCreatable *obj, Error **errp);
/* The ThrottleGroup structure (with its ThrottleState) is shared
* among different ThrottleGroupMembers and it's independent from
* AioContext, so in order to use it from different threads it needs
* its own locking.
*
* This locking is however handled internally in this file, so it's
* transparent to outside users.
*
* The whole ThrottleGroup structure is private and invisible to
* outside users, that only use it through its ThrottleState.
*
* In addition to the ThrottleGroup structure, ThrottleGroupMember has
* fields that need to be accessed by other members of the group and
* therefore also need to be protected by this lock. Once a
* ThrottleGroupMember is registered in a group those fields can be accessed
* by other threads any time.
*
* Again, all this is handled internally and is mostly transparent to
* the outside. The 'throttle_timers' field however has an additional
* constraint because it may be temporarily invalid (see for example
* blk_set_aio_context()). Therefore in this file a thread will
* access some other ThrottleGroupMember's timers only after verifying that
* that ThrottleGroupMember has throttled requests in the queue.
*/
typedef struct ThrottleGroup {
Object parent_obj;
/* refuse individual property change if initialization is complete */
bool is_initialized;
char *name; /* This is constant during the lifetime of the group */
QemuMutex lock; /* This lock protects the following four fields */
ThrottleState ts;
QLIST_HEAD(, ThrottleGroupMember) head;
ThrottleGroupMember *tokens[2];
bool any_timer_armed[2];
QEMUClockType clock_type;
/* This field is protected by the global QEMU mutex */
QTAILQ_ENTRY(ThrottleGroup) list;
} ThrottleGroup;
/* This is protected by the global QEMU mutex */
static QTAILQ_HEAD(, ThrottleGroup) throttle_groups =
QTAILQ_HEAD_INITIALIZER(throttle_groups);
/* This function reads throttle_groups and must be called under the global
* mutex.
*/
static ThrottleGroup *throttle_group_by_name(const char *name)
{
ThrottleGroup *iter;
/* Look for an existing group with that name */
QTAILQ_FOREACH(iter, &throttle_groups, list) {
if (!g_strcmp0(name, iter->name)) {
return iter;
}
}
return NULL;
}
/* This function reads throttle_groups and must be called under the global
* mutex.
*/
bool throttle_group_exists(const char *name)
{
return throttle_group_by_name(name) != NULL;
}
/* Increments the reference count of a ThrottleGroup given its name.
*
* If no ThrottleGroup is found with the given name a new one is
* created.
*
* This function edits throttle_groups and must be called under the global
* mutex.
*
* @name: the name of the ThrottleGroup
* @ret: the ThrottleState member of the ThrottleGroup
*/
ThrottleState *throttle_group_incref(const char *name)
{
ThrottleGroup *tg = NULL;
/* Look for an existing group with that name */
tg = throttle_group_by_name(name);
if (tg) {
object_ref(OBJECT(tg));
} else {
/* Create a new one if not found */
/* new ThrottleGroup obj will have a refcnt = 1 */
tg = THROTTLE_GROUP(object_new(TYPE_THROTTLE_GROUP));
tg->name = g_strdup(name);
throttle_group_obj_complete(USER_CREATABLE(tg), &error_abort);
}
return &tg->ts;
}
/* Decrease the reference count of a ThrottleGroup.
*
* When the reference count reaches zero the ThrottleGroup is
* destroyed.
*
* This function edits throttle_groups and must be called under the global
* mutex.
*
* @ts: The ThrottleGroup to unref, given by its ThrottleState member
*/
void throttle_group_unref(ThrottleState *ts)
{
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
object_unref(OBJECT(tg));
}
/* Get the name from a ThrottleGroupMember's group. The name (and the pointer)
* is guaranteed to remain constant during the lifetime of the group.
*
* @tgm: a ThrottleGroupMember
* @ret: the name of the group.
*/
const char *throttle_group_get_name(ThrottleGroupMember *tgm)
{
ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts);
return tg->name;
}
/* Return the next ThrottleGroupMember in the round-robin sequence, simulating
* a circular list.
*
* This assumes that tg->lock is held.
*
* @tgm: the current ThrottleGroupMember
* @ret: the next ThrottleGroupMember in the sequence
*/
static ThrottleGroupMember *throttle_group_next_tgm(ThrottleGroupMember *tgm)
{
ThrottleState *ts = tgm->throttle_state;
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
ThrottleGroupMember *next = QLIST_NEXT(tgm, round_robin);
if (!next) {
next = QLIST_FIRST(&tg->head);
}
return next;
}
/*
* Return whether a ThrottleGroupMember has pending requests.
*
* This assumes that tg->lock is held.
*
* @tgm: the ThrottleGroupMember
* @is_write: the type of operation (read/write)
* @ret: whether the ThrottleGroupMember has pending requests.
*/
static inline bool tgm_has_pending_reqs(ThrottleGroupMember *tgm,
bool is_write)
{
return tgm->pending_reqs[is_write];
}
/* Return the next ThrottleGroupMember in the round-robin sequence with pending
* I/O requests.
*
* This assumes that tg->lock is held.
*
* @tgm: the current ThrottleGroupMember
* @is_write: the type of operation (read/write)
* @ret: the next ThrottleGroupMember with pending requests, or tgm if
* there is none.
*/
static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm,
bool is_write)
{
ThrottleState *ts = tgm->throttle_state;
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
ThrottleGroupMember *token, *start;
start = token = tg->tokens[is_write];
/* get next bs round in round robin style */
token = throttle_group_next_tgm(token);
while (token != start && !tgm_has_pending_reqs(token, is_write)) {
token = throttle_group_next_tgm(token);
}
/* If no IO are queued for scheduling on the next round robin token
* then decide the token is the current tgm because chances are
* the current tgm got the current request queued.
*/
if (token == start && !tgm_has_pending_reqs(token, is_write)) {
token = tgm;
}
/* Either we return the original TGM, or one with pending requests */
assert(token == tgm || tgm_has_pending_reqs(token, is_write));
return token;
}
/* Check if the next I/O request for a ThrottleGroupMember needs to be
* throttled or not. If there's no timer set in this group, set one and update
* the token accordingly.
*
* This assumes that tg->lock is held.
*
* @tgm: the current ThrottleGroupMember
* @is_write: the type of operation (read/write)
* @ret: whether the I/O request needs to be throttled or not
*/
static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm,
bool is_write)
{
ThrottleState *ts = tgm->throttle_state;
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
ThrottleTimers *tt = &tgm->throttle_timers;
bool must_wait;
if (atomic_read(&tgm->io_limits_disabled)) {
return false;
}
/* Check if any of the timers in this group is already armed */
if (tg->any_timer_armed[is_write]) {
return true;
}
must_wait = throttle_schedule_timer(ts, tt, is_write);
/* If a timer just got armed, set tgm as the current token */
if (must_wait) {
tg->tokens[is_write] = tgm;
tg->any_timer_armed[is_write] = true;
}
return must_wait;
}
/* Start the next pending I/O request for a ThrottleGroupMember. Return whether
* any request was actually pending.
*
* @tgm: the current ThrottleGroupMember
* @is_write: the type of operation (read/write)
*/
static bool coroutine_fn throttle_group_co_restart_queue(ThrottleGroupMember *tgm,
bool is_write)
{
bool ret;
qemu_co_mutex_lock(&tgm->throttled_reqs_lock);
ret = qemu_co_queue_next(&tgm->throttled_reqs[is_write]);
qemu_co_mutex_unlock(&tgm->throttled_reqs_lock);
return ret;
}
/* Look for the next pending I/O request and schedule it.
*
* This assumes that tg->lock is held.
*
* @tgm: the current ThrottleGroupMember
* @is_write: the type of operation (read/write)
*/
static void schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
{
ThrottleState *ts = tgm->throttle_state;
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
bool must_wait;
ThrottleGroupMember *token;
/* Check if there's any pending request to schedule next */
token = next_throttle_token(tgm, is_write);
if (!tgm_has_pending_reqs(token, is_write)) {
return;
}
/* Set a timer for the request if it needs to be throttled */
must_wait = throttle_group_schedule_timer(token, is_write);
/* If it doesn't have to wait, queue it for immediate execution */
if (!must_wait) {
/* Give preference to requests from the current tgm */
if (qemu_in_coroutine() &&
throttle_group_co_restart_queue(tgm, is_write)) {
token = tgm;
} else {
ThrottleTimers *tt = &token->throttle_timers;
int64_t now = qemu_clock_get_ns(tg->clock_type);
timer_mod(tt->timers[is_write], now);
tg->any_timer_armed[is_write] = true;
}
tg->tokens[is_write] = token;
}
}
/* Check if an I/O request needs to be throttled, wait and set a timer
* if necessary, and schedule the next request using a round robin
* algorithm.
*
* @tgm: the current ThrottleGroupMember
* @bytes: the number of bytes for this I/O
* @is_write: the type of operation (read/write)
*/
void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm,
unsigned int bytes,
bool is_write)
{
bool must_wait;
ThrottleGroupMember *token;
ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts);
qemu_mutex_lock(&tg->lock);
/* First we check if this I/O has to be throttled. */
token = next_throttle_token(tgm, is_write);
must_wait = throttle_group_schedule_timer(token, is_write);
/* Wait if there's a timer set or queued requests of this type */
if (must_wait || tgm->pending_reqs[is_write]) {
tgm->pending_reqs[is_write]++;
qemu_mutex_unlock(&tg->lock);
qemu_co_mutex_lock(&tgm->throttled_reqs_lock);
qemu_co_queue_wait(&tgm->throttled_reqs[is_write],
&tgm->throttled_reqs_lock);
qemu_co_mutex_unlock(&tgm->throttled_reqs_lock);
qemu_mutex_lock(&tg->lock);
tgm->pending_reqs[is_write]--;
}
/* The I/O will be executed, so do the accounting */
throttle_account(tgm->throttle_state, is_write, bytes);
/* Schedule the next request */
schedule_next_request(tgm, is_write);
qemu_mutex_unlock(&tg->lock);
}
typedef struct {
ThrottleGroupMember *tgm;
bool is_write;
} RestartData;
static void coroutine_fn throttle_group_restart_queue_entry(void *opaque)
{
RestartData *data = opaque;
ThrottleGroupMember *tgm = data->tgm;
ThrottleState *ts = tgm->throttle_state;
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
bool is_write = data->is_write;
bool empty_queue;
empty_queue = !throttle_group_co_restart_queue(tgm, is_write);
/* If the request queue was empty then we have to take care of
* scheduling the next one */
if (empty_queue) {
qemu_mutex_lock(&tg->lock);
schedule_next_request(tgm, is_write);
qemu_mutex_unlock(&tg->lock);
}
g_free(data);
}
static void throttle_group_restart_queue(ThrottleGroupMember *tgm, bool is_write)
{
Coroutine *co;
RestartData *rd = g_new0(RestartData, 1);
rd->tgm = tgm;
rd->is_write = is_write;
co = qemu_coroutine_create(throttle_group_restart_queue_entry, rd);
aio_co_enter(tgm->aio_context, co);
}
void throttle_group_restart_tgm(ThrottleGroupMember *tgm)
{
if (tgm->throttle_state) {
throttle_group_restart_queue(tgm, 0);
throttle_group_restart_queue(tgm, 1);
}
}
/* Update the throttle configuration for a particular group. Similar
* to throttle_config(), but guarantees atomicity within the
* throttling group.
*
* @tgm: a ThrottleGroupMember that is a member of the group
* @cfg: the configuration to set
*/
void throttle_group_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg)
{
ThrottleState *ts = tgm->throttle_state;
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
qemu_mutex_lock(&tg->lock);
throttle_config(ts, tg->clock_type, cfg);
qemu_mutex_unlock(&tg->lock);
throttle_group_restart_tgm(tgm);
}
/* Get the throttle configuration from a particular group. Similar to
* throttle_get_config(), but guarantees atomicity within the
* throttling group.
*
* @tgm: a ThrottleGroupMember that is a member of the group
* @cfg: the configuration will be written here
*/
void throttle_group_get_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg)
{
ThrottleState *ts = tgm->throttle_state;
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
qemu_mutex_lock(&tg->lock);
throttle_get_config(ts, cfg);
qemu_mutex_unlock(&tg->lock);
}
/* ThrottleTimers callback. This wakes up a request that was waiting
* because it had been throttled.
*
* @tgm: the ThrottleGroupMember whose request had been throttled
* @is_write: the type of operation (read/write)
*/
static void timer_cb(ThrottleGroupMember *tgm, bool is_write)
{
ThrottleState *ts = tgm->throttle_state;
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
/* The timer has just been fired, so we can update the flag */
qemu_mutex_lock(&tg->lock);
tg->any_timer_armed[is_write] = false;
qemu_mutex_unlock(&tg->lock);
/* Run the request that was waiting for this timer */
throttle_group_restart_queue(tgm, is_write);
}
static void read_timer_cb(void *opaque)
{
timer_cb(opaque, false);
}
static void write_timer_cb(void *opaque)
{
timer_cb(opaque, true);
}
/* Register a ThrottleGroupMember from the throttling group, also initializing
* its timers and updating its throttle_state pointer to point to it. If a
* throttling group with that name does not exist yet, it will be created.
*
* This function edits throttle_groups and must be called under the global
* mutex.
*
* @tgm: the ThrottleGroupMember to insert
* @groupname: the name of the group
* @ctx: the AioContext to use
*/
void throttle_group_register_tgm(ThrottleGroupMember *tgm,
const char *groupname,
AioContext *ctx)
{
int i;
ThrottleState *ts = throttle_group_incref(groupname);
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
tgm->throttle_state = ts;
tgm->aio_context = ctx;
qemu_mutex_lock(&tg->lock);
/* If the ThrottleGroup is new set this ThrottleGroupMember as the token */
for (i = 0; i < 2; i++) {
if (!tg->tokens[i]) {
tg->tokens[i] = tgm;
}
}
QLIST_INSERT_HEAD(&tg->head, tgm, round_robin);
throttle_timers_init(&tgm->throttle_timers,
tgm->aio_context,
tg->clock_type,
read_timer_cb,
write_timer_cb,
tgm);
qemu_co_mutex_init(&tgm->throttled_reqs_lock);
qemu_co_queue_init(&tgm->throttled_reqs[0]);
qemu_co_queue_init(&tgm->throttled_reqs[1]);
qemu_mutex_unlock(&tg->lock);
}
/* Unregister a ThrottleGroupMember from its group, removing it from the list,
* destroying the timers and setting the throttle_state pointer to NULL.
*
* The ThrottleGroupMember must not have pending throttled requests, so the
* caller has to drain them first.
*
* The group will be destroyed if it's empty after this operation.
*
* @tgm the ThrottleGroupMember to remove
*/
void throttle_group_unregister_tgm(ThrottleGroupMember *tgm)
{
ThrottleState *ts = tgm->throttle_state;
ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
ThrottleGroupMember *token;
int i;
if (!ts) {
/* Discard already unregistered tgm */
return;
}
assert(tgm->pending_reqs[0] == 0 && tgm->pending_reqs[1] == 0);
assert(qemu_co_queue_empty(&tgm->throttled_reqs[0]));
assert(qemu_co_queue_empty(&tgm->throttled_reqs[1]));
qemu_mutex_lock(&tg->lock);
for (i = 0; i < 2; i++) {
if (tg->tokens[i] == tgm) {
token = throttle_group_next_tgm(tgm);
/* Take care of the case where this is the last tgm in the group */
if (token == tgm) {
token = NULL;
}
tg->tokens[i] = token;
}
}
/* remove the current tgm from the list */
QLIST_REMOVE(tgm, round_robin);
throttle_timers_destroy(&tgm->throttle_timers);
qemu_mutex_unlock(&tg->lock);
throttle_group_unref(&tg->ts);
tgm->throttle_state = NULL;
}
void throttle_group_attach_aio_context(ThrottleGroupMember *tgm,
AioContext *new_context)
{
ThrottleTimers *tt = &tgm->throttle_timers;
throttle_timers_attach_aio_context(tt, new_context);
tgm->aio_context = new_context;
}
void throttle_group_detach_aio_context(ThrottleGroupMember *tgm)
{
ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts);
ThrottleTimers *tt = &tgm->throttle_timers;
int i;
/* Requests must have been drained */
assert(tgm->pending_reqs[0] == 0 && tgm->pending_reqs[1] == 0);
assert(qemu_co_queue_empty(&tgm->throttled_reqs[0]));
assert(qemu_co_queue_empty(&tgm->throttled_reqs[1]));
/* Kick off next ThrottleGroupMember, if necessary */
qemu_mutex_lock(&tg->lock);
for (i = 0; i < 2; i++) {
if (timer_pending(tt->timers[i])) {
tg->any_timer_armed[i] = false;
schedule_next_request(tgm, i);
}
}
qemu_mutex_unlock(&tg->lock);
throttle_timers_detach_aio_context(tt);
tgm->aio_context = NULL;
}
#undef THROTTLE_OPT_PREFIX
#define THROTTLE_OPT_PREFIX "x-"
/* Helper struct and array for QOM property setter/getter */
typedef struct {
const char *name;
BucketType type;
enum {
AVG,
MAX,
BURST_LENGTH,
IOPS_SIZE,
} category;
} ThrottleParamInfo;
static ThrottleParamInfo properties[] = {
{
THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_TOTAL,
THROTTLE_OPS_TOTAL, AVG,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_TOTAL_MAX,
THROTTLE_OPS_TOTAL, MAX,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_TOTAL_MAX_LENGTH,
THROTTLE_OPS_TOTAL, BURST_LENGTH,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_READ,
THROTTLE_OPS_READ, AVG,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_READ_MAX,
THROTTLE_OPS_READ, MAX,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_READ_MAX_LENGTH,
THROTTLE_OPS_READ, BURST_LENGTH,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_WRITE,
THROTTLE_OPS_WRITE, AVG,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_WRITE_MAX,
THROTTLE_OPS_WRITE, MAX,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_WRITE_MAX_LENGTH,
THROTTLE_OPS_WRITE, BURST_LENGTH,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_BPS_TOTAL,
THROTTLE_BPS_TOTAL, AVG,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_BPS_TOTAL_MAX,
THROTTLE_BPS_TOTAL, MAX,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_BPS_TOTAL_MAX_LENGTH,
THROTTLE_BPS_TOTAL, BURST_LENGTH,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_BPS_READ,
THROTTLE_BPS_READ, AVG,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_BPS_READ_MAX,
THROTTLE_BPS_READ, MAX,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_BPS_READ_MAX_LENGTH,
THROTTLE_BPS_READ, BURST_LENGTH,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_BPS_WRITE,
THROTTLE_BPS_WRITE, AVG,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_BPS_WRITE_MAX,
THROTTLE_BPS_WRITE, MAX,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_BPS_WRITE_MAX_LENGTH,
THROTTLE_BPS_WRITE, BURST_LENGTH,
},
{
THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_SIZE,
0, IOPS_SIZE,
}
};
/* This function edits throttle_groups and must be called under the global
* mutex */
static void throttle_group_obj_init(Object *obj)
{
ThrottleGroup *tg = THROTTLE_GROUP(obj);
tg->clock_type = QEMU_CLOCK_REALTIME;
if (qtest_enabled()) {
/* For testing block IO throttling only */
tg->clock_type = QEMU_CLOCK_VIRTUAL;
}
tg->is_initialized = false;
qemu_mutex_init(&tg->lock);
throttle_init(&tg->ts);
QLIST_INIT(&tg->head);
}
/* This function edits throttle_groups and must be called under the global
* mutex */
static void throttle_group_obj_complete(UserCreatable *obj, Error **errp)
{
ThrottleGroup *tg = THROTTLE_GROUP(obj);
ThrottleConfig cfg;
/* set group name to object id if it exists */
if (!tg->name && tg->parent_obj.parent) {
tg->name = object_get_canonical_path_component(OBJECT(obj));
}
/* We must have a group name at this point */
assert(tg->name);
/* error if name is duplicate */
if (throttle_group_exists(tg->name)) {
error_setg(errp, "A group with this name already exists");
return;
}
/* check validity */
throttle_get_config(&tg->ts, &cfg);
if (!throttle_is_valid(&cfg, errp)) {
return;
}
throttle_config(&tg->ts, tg->clock_type, &cfg);
QTAILQ_INSERT_TAIL(&throttle_groups, tg, list);
tg->is_initialized = true;
}
/* This function edits throttle_groups and must be called under the global
* mutex */
static void throttle_group_obj_finalize(Object *obj)
{
ThrottleGroup *tg = THROTTLE_GROUP(obj);
if (tg->is_initialized) {
QTAILQ_REMOVE(&throttle_groups, tg, list);
}
qemu_mutex_destroy(&tg->lock);
g_free(tg->name);
}
static void throttle_group_set(Object *obj, Visitor *v, const char * name,
void *opaque, Error **errp)
{
ThrottleGroup *tg = THROTTLE_GROUP(obj);
ThrottleConfig *cfg;
ThrottleParamInfo *info = opaque;
Error *local_err = NULL;
int64_t value;
/* If we have finished initialization, don't accept individual property
* changes through QOM. Throttle configuration limits must be set in one
* transaction, as certain combinations are invalid.
*/
if (tg->is_initialized) {
error_setg(&local_err, "Property cannot be set after initialization");
goto ret;
}
visit_type_int64(v, name, &value, &local_err);
if (local_err) {
goto ret;
}
if (value < 0) {
error_setg(&local_err, "Property values cannot be negative");
goto ret;
}
cfg = &tg->ts.cfg;
switch (info->category) {
case AVG:
cfg->buckets[info->type].avg = value;
break;
case MAX:
cfg->buckets[info->type].max = value;
break;
case BURST_LENGTH:
if (value > UINT_MAX) {
error_setg(&local_err, "%s value must be in the"
"range [0, %u]", info->name, UINT_MAX);
goto ret;
}
cfg->buckets[info->type].burst_length = value;
break;
case IOPS_SIZE:
cfg->op_size = value;
break;
}
ret:
error_propagate(errp, local_err);
return;
}
static void throttle_group_get(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
ThrottleGroup *tg = THROTTLE_GROUP(obj);
ThrottleConfig cfg;
ThrottleParamInfo *info = opaque;
int64_t value;
throttle_get_config(&tg->ts, &cfg);
switch (info->category) {
case AVG:
value = cfg.buckets[info->type].avg;
break;
case MAX:
value = cfg.buckets[info->type].max;
break;
case BURST_LENGTH:
value = cfg.buckets[info->type].burst_length;
break;
case IOPS_SIZE:
value = cfg.op_size;
break;
}
visit_type_int64(v, name, &value, errp);
}
static void throttle_group_set_limits(Object *obj, Visitor *v,
const char *name, void *opaque,
Error **errp)
{
ThrottleGroup *tg = THROTTLE_GROUP(obj);
ThrottleConfig cfg;
ThrottleLimits arg = { 0 };
ThrottleLimits *argp = &arg;
Error *local_err = NULL;
visit_type_ThrottleLimits(v, name, &argp, &local_err);
if (local_err) {
goto ret;
}
qemu_mutex_lock(&tg->lock);
throttle_get_config(&tg->ts, &cfg);
throttle_limits_to_config(argp, &cfg, &local_err);
if (local_err) {
goto unlock;
}
throttle_config(&tg->ts, tg->clock_type, &cfg);
unlock:
qemu_mutex_unlock(&tg->lock);
ret:
error_propagate(errp, local_err);
return;
}
static void throttle_group_get_limits(Object *obj, Visitor *v,
const char *name, void *opaque,
Error **errp)
{
ThrottleGroup *tg = THROTTLE_GROUP(obj);
ThrottleConfig cfg;
ThrottleLimits arg = { 0 };
ThrottleLimits *argp = &arg;
qemu_mutex_lock(&tg->lock);
throttle_get_config(&tg->ts, &cfg);
qemu_mutex_unlock(&tg->lock);
throttle_config_to_limits(&cfg, argp);
visit_type_ThrottleLimits(v, name, &argp, errp);
}
static bool throttle_group_can_be_deleted(UserCreatable *uc)
{
return OBJECT(uc)->ref == 1;
}
static void throttle_group_obj_class_init(ObjectClass *klass, void *class_data)
{
size_t i = 0;
UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
ucc->complete = throttle_group_obj_complete;
ucc->can_be_deleted = throttle_group_can_be_deleted;
/* individual properties */
for (i = 0; i < sizeof(properties) / sizeof(ThrottleParamInfo); i++) {
object_class_property_add(klass,
properties[i].name,
"int",
throttle_group_get,
throttle_group_set,
NULL, &properties[i],
&error_abort);
}
/* ThrottleLimits */
object_class_property_add(klass,
"limits", "ThrottleLimits",
throttle_group_get_limits,
throttle_group_set_limits,
NULL, NULL,
&error_abort);
}
static const TypeInfo throttle_group_info = {
.name = TYPE_THROTTLE_GROUP,
.parent = TYPE_OBJECT,
.class_init = throttle_group_obj_class_init,
.instance_size = sizeof(ThrottleGroup),
.instance_init = throttle_group_obj_init,
.instance_finalize = throttle_group_obj_finalize,
.interfaces = (InterfaceInfo[]) {
{ TYPE_USER_CREATABLE },
{ }
},
};
static void throttle_groups_init(void)
{
type_register_static(&throttle_group_info);
}
type_init(throttle_groups_init);
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