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qemu/hw/block/vhost-user-blk.c

620 lines
17 KiB
C

/*
* vhost-user-blk host device
*
* Copyright(C) 2017 Intel Corporation.
*
* Authors:
* Changpeng Liu <changpeng.liu@intel.com>
*
* Largely based on the "vhost-user-scsi.c" and "vhost-scsi.c" implemented by:
* Felipe Franciosi <felipe@nutanix.com>
* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
* Nicholas Bellinger <nab@risingtidesystems.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qemu/cutils.h"
#include "hw/qdev-core.h"
#include "hw/qdev-properties.h"
#include "hw/qdev-properties-system.h"
#include "hw/virtio/virtio-blk-common.h"
#include "hw/virtio/vhost.h"
#include "hw/virtio/vhost-user-blk.h"
#include "hw/virtio/virtio.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio-access.h"
#include "sysemu/sysemu.h"
#include "sysemu/runstate.h"
static const int user_feature_bits[] = {
VIRTIO_BLK_F_SIZE_MAX,
VIRTIO_BLK_F_SEG_MAX,
VIRTIO_BLK_F_GEOMETRY,
VIRTIO_BLK_F_BLK_SIZE,
VIRTIO_BLK_F_TOPOLOGY,
VIRTIO_BLK_F_MQ,
VIRTIO_BLK_F_RO,
VIRTIO_BLK_F_FLUSH,
VIRTIO_BLK_F_CONFIG_WCE,
VIRTIO_BLK_F_DISCARD,
VIRTIO_BLK_F_WRITE_ZEROES,
VIRTIO_F_VERSION_1,
VIRTIO_RING_F_INDIRECT_DESC,
VIRTIO_RING_F_EVENT_IDX,
VIRTIO_F_NOTIFY_ON_EMPTY,
VIRTIO_F_RING_PACKED,
VIRTIO_F_IOMMU_PLATFORM,
VIRTIO_F_RING_RESET,
VIRTIO_F_IN_ORDER,
VIRTIO_F_NOTIFICATION_DATA,
VHOST_INVALID_FEATURE_BIT
};
static void vhost_user_blk_event(void *opaque, QEMUChrEvent event);
static void vhost_user_blk_update_config(VirtIODevice *vdev, uint8_t *config)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
/* Our num_queues overrides the device backend */
virtio_stw_p(vdev, &s->blkcfg.num_queues, s->num_queues);
memcpy(config, &s->blkcfg, vdev->config_len);
}
static void vhost_user_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
struct virtio_blk_config *blkcfg = (struct virtio_blk_config *)config;
int ret;
if (blkcfg->wce == s->blkcfg.wce) {
return;
}
ret = vhost_dev_set_config(&s->dev, &blkcfg->wce,
offsetof(struct virtio_blk_config, wce),
sizeof(blkcfg->wce),
VHOST_SET_CONFIG_TYPE_FRONTEND);
if (ret) {
error_report("set device config space failed");
return;
}
s->blkcfg.wce = blkcfg->wce;
}
static int vhost_user_blk_sync_config(DeviceState *dev, Error **errp)
{
int ret;
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserBlk *s = VHOST_USER_BLK(vdev);
ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg,
vdev->config_len, errp);
if (ret < 0) {
return ret;
}
memcpy(vdev->config, &s->blkcfg, vdev->config_len);
virtio_notify_config(vdev);
return 0;
}
static int vhost_user_blk_handle_config_change(struct vhost_dev *dev)
{
int ret;
Error *local_err = NULL;
if (!dev->started) {
return 0;
}
ret = vhost_user_blk_sync_config(DEVICE(dev->vdev), &local_err);
if (ret < 0) {
error_report_err(local_err);
return ret;
}
return 0;
}
const VhostDevConfigOps blk_ops = {
.vhost_dev_config_notifier = vhost_user_blk_handle_config_change,
};
static int vhost_user_blk_start(VirtIODevice *vdev, Error **errp)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int i, ret;
if (!k->set_guest_notifiers) {
error_setg(errp, "binding does not support guest notifiers");
return -ENOSYS;
}
ret = vhost_dev_enable_notifiers(&s->dev, vdev);
if (ret < 0) {
error_setg_errno(errp, -ret, "Error enabling host notifiers");
return ret;
}
ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
if (ret < 0) {
error_setg_errno(errp, -ret, "Error binding guest notifier");
goto err_host_notifiers;
}
s->dev.acked_features = vdev->guest_features;
ret = vhost_dev_prepare_inflight(&s->dev, vdev);
if (ret < 0) {
error_setg_errno(errp, -ret, "Error setting inflight format");
goto err_guest_notifiers;
}
if (!s->inflight->addr) {
ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight);
if (ret < 0) {
error_setg_errno(errp, -ret, "Error getting inflight");
goto err_guest_notifiers;
}
}
ret = vhost_dev_set_inflight(&s->dev, s->inflight);
if (ret < 0) {
error_setg_errno(errp, -ret, "Error setting inflight");
goto err_guest_notifiers;
}
/* guest_notifier_mask/pending not used yet, so just unmask
* everything here. virtio-pci will do the right thing by
* enabling/disabling irqfd.
*/
for (i = 0; i < s->dev.nvqs; i++) {
vhost_virtqueue_mask(&s->dev, vdev, i, false);
}
s->dev.vq_index_end = s->dev.nvqs;
ret = vhost_dev_start(&s->dev, vdev, true);
if (ret < 0) {
error_setg_errno(errp, -ret, "Error starting vhost");
goto err_guest_notifiers;
}
s->started_vu = true;
return ret;
err_guest_notifiers:
for (i = 0; i < s->dev.nvqs; i++) {
vhost_virtqueue_mask(&s->dev, vdev, i, true);
}
k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
err_host_notifiers:
vhost_dev_disable_notifiers(&s->dev, vdev);
return ret;
}
static void vhost_user_blk_stop(VirtIODevice *vdev)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int ret;
if (!s->started_vu) {
return;
}
s->started_vu = false;
if (!k->set_guest_notifiers) {
return;
}
vhost_dev_stop(&s->dev, vdev, true);
ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
if (ret < 0) {
error_report("vhost guest notifier cleanup failed: %d", ret);
return;
}
vhost_dev_disable_notifiers(&s->dev, vdev);
}
static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
bool should_start = virtio_device_should_start(vdev, status);
Error *local_err = NULL;
int ret;
if (!s->connected) {
return;
}
if (vhost_dev_is_started(&s->dev) == should_start) {
return;
}
if (should_start) {
ret = vhost_user_blk_start(vdev, &local_err);
if (ret < 0) {
error_reportf_err(local_err, "vhost-user-blk: vhost start failed: ");
qemu_chr_fe_disconnect(&s->chardev);
}
} else {
vhost_user_blk_stop(vdev);
}
}
static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
uint64_t features,
Error **errp)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
/* Turn on pre-defined features */
virtio_add_feature(&features, VIRTIO_BLK_F_SIZE_MAX);
virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH);
virtio_add_feature(&features, VIRTIO_BLK_F_RO);
if (s->num_queues > 1) {
virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
}
return vhost_get_features(&s->dev, user_feature_bits, features);
}
static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
Error *local_err = NULL;
int i, ret;
if (!vdev->start_on_kick) {
return;
}
if (!s->connected) {
return;
}
if (vhost_dev_is_started(&s->dev)) {
return;
}
/* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
* vhost here instead of waiting for .set_status().
*/
ret = vhost_user_blk_start(vdev, &local_err);
if (ret < 0) {
error_reportf_err(local_err, "vhost-user-blk: vhost start failed: ");
qemu_chr_fe_disconnect(&s->chardev);
return;
}
/* Kick right away to begin processing requests already in vring */
for (i = 0; i < s->dev.nvqs; i++) {
VirtQueue *kick_vq = virtio_get_queue(vdev, i);
if (!virtio_queue_get_desc_addr(vdev, i)) {
continue;
}
event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
}
}
static void vhost_user_blk_reset(VirtIODevice *vdev)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
vhost_dev_free_inflight(s->inflight);
}
static int vhost_user_blk_connect(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserBlk *s = VHOST_USER_BLK(vdev);
int ret = 0;
if (s->connected) {
return 0;
}
s->dev.num_queues = s->num_queues;
s->dev.nvqs = s->num_queues;
s->dev.vqs = s->vhost_vqs;
s->dev.vq_index = 0;
s->dev.backend_features = 0;
vhost_dev_set_config_notifier(&s->dev, &blk_ops);
s->vhost_user.supports_config = true;
ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0,
errp);
if (ret < 0) {
return ret;
}
s->connected = true;
/* restore vhost state */
if (virtio_device_started(vdev, vdev->status)) {
ret = vhost_user_blk_start(vdev, errp);
}
return ret;
}
static void vhost_user_blk_disconnect(DeviceState *dev)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserBlk *s = VHOST_USER_BLK(vdev);
if (!s->connected) {
goto done;
}
s->connected = false;
vhost_user_blk_stop(vdev);
vhost_dev_cleanup(&s->dev);
done:
/* Re-instate the event handler for new connections */
qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event,
NULL, dev, NULL, true);
}
static void vhost_user_blk_event(void *opaque, QEMUChrEvent event)
{
DeviceState *dev = opaque;
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserBlk *s = VHOST_USER_BLK(vdev);
Error *local_err = NULL;
switch (event) {
case CHR_EVENT_OPENED:
if (vhost_user_blk_connect(dev, &local_err) < 0) {
error_report_err(local_err);
qemu_chr_fe_disconnect(&s->chardev);
return;
}
break;
case CHR_EVENT_CLOSED:
/* defer close until later to avoid circular close */
vhost_user_async_close(dev, &s->chardev, &s->dev,
vhost_user_blk_disconnect);
break;
case CHR_EVENT_BREAK:
case CHR_EVENT_MUX_IN:
case CHR_EVENT_MUX_OUT:
/* Ignore */
break;
}
}
static int vhost_user_blk_realize_connect(VHostUserBlk *s, Error **errp)
{
DeviceState *dev = DEVICE(s);
int ret;
s->connected = false;
ret = qemu_chr_fe_wait_connected(&s->chardev, errp);
if (ret < 0) {
return ret;
}
ret = vhost_user_blk_connect(dev, errp);
if (ret < 0) {
qemu_chr_fe_disconnect(&s->chardev);
return ret;
}
assert(s->connected);
ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg,
VIRTIO_DEVICE(s)->config_len, errp);
if (ret < 0) {
qemu_chr_fe_disconnect(&s->chardev);
vhost_dev_cleanup(&s->dev);
return ret;
}
return 0;
}
static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
{
ERRP_GUARD();
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserBlk *s = VHOST_USER_BLK(vdev);
size_t config_size;
int retries;
int i, ret;
if (!s->chardev.chr) {
error_setg(errp, "chardev is mandatory");
return;
}
if (s->num_queues == VHOST_USER_BLK_AUTO_NUM_QUEUES) {
s->num_queues = 1;
}
if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) {
error_setg(errp, "invalid number of IO queues");
return;
}
if (!s->queue_size) {
error_setg(errp, "queue size must be non-zero");
return;
}
if (s->queue_size > VIRTQUEUE_MAX_SIZE) {
error_setg(errp, "queue size must not exceed %d",
VIRTQUEUE_MAX_SIZE);
return;
}
if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) {
return;
}
config_size = virtio_get_config_size(&virtio_blk_cfg_size_params,
vdev->host_features);
virtio_init(vdev, VIRTIO_ID_BLOCK, config_size);
s->virtqs = g_new(VirtQueue *, s->num_queues);
for (i = 0; i < s->num_queues; i++) {
s->virtqs[i] = virtio_add_queue(vdev, s->queue_size,
vhost_user_blk_handle_output);
}
s->inflight = g_new0(struct vhost_inflight, 1);
s->vhost_vqs = g_new0(struct vhost_virtqueue, s->num_queues);
retries = VU_REALIZE_CONN_RETRIES;
assert(!*errp);
do {
if (*errp) {
error_prepend(errp, "Reconnecting after error: ");
error_report_err(*errp);
*errp = NULL;
}
ret = vhost_user_blk_realize_connect(s, errp);
} while (ret < 0 && retries--);
if (ret < 0) {
goto virtio_err;
}
/* we're fully initialized, now we can operate, so add the handler */
qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL,
vhost_user_blk_event, NULL, (void *)dev,
NULL, true);
return;
virtio_err:
g_free(s->vhost_vqs);
s->vhost_vqs = NULL;
g_free(s->inflight);
s->inflight = NULL;
for (i = 0; i < s->num_queues; i++) {
virtio_delete_queue(s->virtqs[i]);
}
g_free(s->virtqs);
virtio_cleanup(vdev);
vhost_user_cleanup(&s->vhost_user);
}
static void vhost_user_blk_device_unrealize(DeviceState *dev)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserBlk *s = VHOST_USER_BLK(dev);
int i;
virtio_set_status(vdev, 0);
qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL,
NULL, NULL, NULL, false);
vhost_dev_cleanup(&s->dev);
vhost_dev_free_inflight(s->inflight);
g_free(s->vhost_vqs);
s->vhost_vqs = NULL;
g_free(s->inflight);
s->inflight = NULL;
for (i = 0; i < s->num_queues; i++) {
virtio_delete_queue(s->virtqs[i]);
}
g_free(s->virtqs);
virtio_cleanup(vdev);
vhost_user_cleanup(&s->vhost_user);
}
static void vhost_user_blk_instance_init(Object *obj)
{
VHostUserBlk *s = VHOST_USER_BLK(obj);
device_add_bootindex_property(obj, &s->bootindex, "bootindex",
"/disk@0,0", DEVICE(obj));
}
static struct vhost_dev *vhost_user_blk_get_vhost(VirtIODevice *vdev)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
return &s->dev;
}
static const VMStateDescription vmstate_vhost_user_blk = {
.name = "vhost-user-blk",
.minimum_version_id = 1,
.version_id = 1,
.fields = (const VMStateField[]) {
VMSTATE_VIRTIO_DEVICE,
VMSTATE_END_OF_LIST()
},
};
static Property vhost_user_blk_properties[] = {
DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev),
DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues,
VHOST_USER_BLK_AUTO_NUM_QUEUES),
DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128),
DEFINE_PROP_BIT64("config-wce", VHostUserBlk, parent_obj.host_features,
VIRTIO_BLK_F_CONFIG_WCE, true),
DEFINE_PROP_BIT64("discard", VHostUserBlk, parent_obj.host_features,
VIRTIO_BLK_F_DISCARD, true),
DEFINE_PROP_BIT64("write-zeroes", VHostUserBlk, parent_obj.host_features,
VIRTIO_BLK_F_WRITE_ZEROES, true),
DEFINE_PROP_END_OF_LIST(),
};
static void vhost_user_blk_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
device_class_set_props(dc, vhost_user_blk_properties);
dc->vmsd = &vmstate_vhost_user_blk;
dc->sync_config = vhost_user_blk_sync_config;
set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
vdc->realize = vhost_user_blk_device_realize;
vdc->unrealize = vhost_user_blk_device_unrealize;
vdc->get_config = vhost_user_blk_update_config;
vdc->set_config = vhost_user_blk_set_config;
vdc->get_features = vhost_user_blk_get_features;
vdc->set_status = vhost_user_blk_set_status;
vdc->reset = vhost_user_blk_reset;
vdc->get_vhost = vhost_user_blk_get_vhost;
}
static const TypeInfo vhost_user_blk_info = {
.name = TYPE_VHOST_USER_BLK,
.parent = TYPE_VIRTIO_DEVICE,
.instance_size = sizeof(VHostUserBlk),
.instance_init = vhost_user_blk_instance_init,
.class_init = vhost_user_blk_class_init,
};
static void virtio_register_types(void)
{
type_register_static(&vhost_user_blk_info);
}
type_init(virtio_register_types)