From: Xie Yongji <xieyon...@baidu.com>
Since the new message VHOST_USER_SET_VRING_INFLIGHT,
the backend is able to restart safely. This patch
allow qemu to reconnect the backend after connection
closed.
Signed-off-by: Xie Yongji <xieyon...@baidu.com>
Signed-off-by: Ni Xun <ni...@baidu.com>
Signed-off-by: Zhang Yu <zhangy...@baidu.com>
---
hw/block/vhost-user-blk.c | 169 +++++++++++++++++++++++++++--
include/hw/virtio/vhost-user-blk.h | 4 +
2 files changed, 161 insertions(+), 12 deletions(-)
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 1451940845..663e91bcf6 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -101,7 +101,7 @@ const VhostDevConfigOps blk_ops = {
.vhost_dev_config_notifier = vhost_user_blk_handle_config_change,
};
-static void vhost_user_blk_start(VirtIODevice *vdev)
+static int vhost_user_blk_start(VirtIODevice *vdev)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
@@ -110,13 +110,13 @@ static void vhost_user_blk_start(VirtIODevice *vdev)
if (!k->set_guest_notifiers) {
error_report("binding does not support guest notifiers");
- return;
+ return -ENOSYS;
}
ret = vhost_dev_enable_notifiers(&s->dev, vdev);
if (ret < 0) {
error_report("Error enabling host notifiers: %d", -ret);
- return;
+ return ret;
}
ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
@@ -140,12 +140,13 @@ static void vhost_user_blk_start(VirtIODevice *vdev)
vhost_virtqueue_mask(&s->dev, vdev, i, false);
}
- return;
+ return ret;
err_guest_notifiers:
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)
@@ -164,7 +165,6 @@ static void vhost_user_blk_stop(VirtIODevice *vdev)
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);
@@ -174,21 +174,39 @@ static void vhost_user_blk_set_status(VirtIODevice *vdev,
uint8_t status)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
+ int ret;
if (!vdev->vm_running) {
should_start = false;
}
- if (s->dev.started == should_start) {
+ if (s->should_start == should_start) {
+ return;
+ }
+
+ if (!s->connected || s->dev.started == should_start) {
+ s->should_start = should_start;
return;
}
if (should_start) {
- vhost_user_blk_start(vdev);
+ s->should_start = true;
+ /* make sure we ignore fake guest kick by
+ * vhost_dev_enable_notifiers() */
+ barrier();
+ ret = vhost_user_blk_start(vdev);
+ if (ret < 0) {
+ error_report("vhost-user-blk: vhost start failed: %s",
+ strerror(-ret));
+ qemu_chr_fe_disconnect(&s->chardev);
+ }
} else {
vhost_user_blk_stop(vdev);
+ /* make sure we ignore fake guest kick by
+ * vhost_dev_disable_notifiers() */
+ barrier();
+ s->should_start = false;
}
-
}
static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
@@ -218,13 +236,22 @@ static uint64_t vhost_user_blk_get_features(VirtIODevice
*vdev,
static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VHostUserBlk *s = VHOST_USER_BLK(vdev);
- int i;
+ int i, ret;
if (!(virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) &&
!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1))) {
return;
}
+ if (s->should_start) {
+ return;
+ }
+ s->should_start = true;
+
+ if (!s->connected) {
+ return;
+ }
+
if (s->dev.started) {
return;
}
@@ -232,7 +259,13 @@ static void vhost_user_blk_handle_output(VirtIODevice
*vdev, VirtQueue *vq)
/* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
* vhost here instead of waiting for .set_status().
*/
- vhost_user_blk_start(vdev);
+ ret = vhost_user_blk_start(vdev);
+ if (ret < 0) {
+ error_report("vhost-user-blk: vhost start failed: %s",
+ strerror(-ret));
+ 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++) {
@@ -245,6 +278,106 @@ static void vhost_user_blk_handle_output(VirtIODevice
*vdev, VirtQueue *vq)
}
}
+static void vhost_user_blk_reset(VirtIODevice *vdev)
+{
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+ if (s->vhost_user) {
+ vhost_user_inflight_reset(s->vhost_user);
+ }
+}
+
+static int vhost_user_blk_connect(DeviceState *dev)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+ int ret = 0;
+
+ if (s->connected) {
+ return 0;
+ }
+ s->connected = true;
+
+ s->dev.nvqs = s->num_queues;
+ s->dev.vqs = s->vqs;
+ s->dev.vq_index = 0;
+ s->dev.backend_features = 0;
+
+ vhost_dev_set_config_notifier(&s->dev, &blk_ops);
+
+ ret = vhost_dev_init(&s->dev, s->vhost_user, VHOST_BACKEND_TYPE_USER, 0);
+ if (ret < 0) {
+ error_report("vhost-user-blk: vhost initialization failed: %s",
+ strerror(-ret));
+ return ret;
+ }
+
+ if (s->should_start && !s->dev.started) {
+ ret = vhost_user_blk_start(vdev);
+ if (ret < 0) {
+ error_report("vhost-user-blk: vhost start failed: %s",
+ strerror(-ret));
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static void vhost_user_blk_disconnect(DeviceState *dev)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+ if (!s->connected) {
+ return;
+ }
+ s->connected = false;
+
+ if (s->dev.started) {
+ vhost_user_blk_stop(vdev);
+ }
+
+ vhost_dev_cleanup(&s->dev);
+}
+
+static gboolean vhost_user_blk_watch(GIOChannel *chan, GIOCondition cond,
+ void *opaque)
+{
+ DeviceState *dev = opaque;
+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+ qemu_chr_fe_disconnect(&s->chardev);
+
+ return true;
+}
+
+static void vhost_user_blk_event(void *opaque, int event)
+{
+ DeviceState *dev = opaque;
+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+ switch (event) {
+ case CHR_EVENT_OPENED:
+ if (vhost_user_blk_connect(dev) < 0) {
+ qemu_chr_fe_disconnect(&s->chardev);
+ return;
+ }
+ s->watch = qemu_chr_fe_add_watch(&s->chardev, G_IO_HUP,
+ vhost_user_blk_watch, dev);
+ break;
+ case CHR_EVENT_CLOSED:
+ vhost_user_blk_disconnect(dev);
+ if (s->watch) {
+ g_source_remove(s->watch);
+ s->watch = 0;
+ }
+ break;
+ }
+}
+
static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
@@ -284,8 +417,13 @@ static void vhost_user_blk_device_realize(DeviceState
*dev, Error **errp)
vhost_user_blk_handle_output);
}
+ s->vqs = g_new(struct vhost_virtqueue, s->num_queues);
+ s->watch = 0;
+ s->should_start = false;
+ s->connected = true;
+
s->dev.nvqs = s->num_queues;
- s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
+ s->dev.vqs = s->vqs;
s->dev.vq_index = 0;
s->dev.backend_features = 0;
@@ -309,6 +447,9 @@ static void vhost_user_blk_device_realize(DeviceState *dev,
Error **errp)
s->blkcfg.num_queues = s->num_queues;
}
+ qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event,
+ NULL, (void *)dev, NULL, true);
+
return;
vhost_err:
@@ -328,8 +469,11 @@ static void vhost_user_blk_device_unrealize(DeviceState
*dev, Error **errp)
VHostUserBlk *s = VHOST_USER_BLK(dev);
vhost_user_blk_set_status(vdev, 0);
+ qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL,
+ NULL, NULL, NULL, false);
vhost_dev_cleanup(&s->dev);
- g_free(s->dev.vqs);
+
+ g_free(s->vqs);
virtio_cleanup(vdev);
if (s->vhost_user) {
@@ -379,6 +523,7 @@ static void vhost_user_blk_class_init(ObjectClass *klass,
void *data)
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;
}
static const TypeInfo vhost_user_blk_info = {
diff --git a/include/hw/virtio/vhost-user-blk.h
b/include/hw/virtio/vhost-user-blk.h
index d52944aeeb..560bb21459 100644
--- a/include/hw/virtio/vhost-user-blk.h
+++ b/include/hw/virtio/vhost-user-blk.h
@@ -37,6 +37,10 @@ typedef struct VHostUserBlk {
uint32_t config_wce;
struct vhost_dev dev;
VhostUserState *vhost_user;
+ struct vhost_virtqueue *vqs;
+ guint watch;
+ bool should_start;
+ bool connected;
} VHostUserBlk;
#endif
--
2.17.1
