> 2023年7月25日 下午6:42,Li Feng <fen...@smartx.com> 写道:
>
> If the backend crashes and restarts, the device is broken.
> This patch adds reconnect for vhost-user-scsi.
>
> Tested with spdk backend.
>
> Signed-off-by: Li Feng <fen...@smartx.com>
> ---
> hw/scsi/vhost-scsi-common.c | 6 +
> hw/scsi/vhost-user-scsi.c | 220 +++++++++++++++++++++++---
> include/hw/virtio/vhost-scsi-common.h | 3 +
> include/hw/virtio/vhost-user-scsi.h | 3 +
> 4 files changed, 211 insertions(+), 21 deletions(-)
>
> diff --git a/hw/scsi/vhost-scsi-common.c b/hw/scsi/vhost-scsi-common.c
> index 664adb15b4..3fde477eee 100644
> --- a/hw/scsi/vhost-scsi-common.c
> +++ b/hw/scsi/vhost-scsi-common.c
> @@ -81,6 +81,7 @@ int vhost_scsi_common_start(VHostSCSICommon *vsc)
> error_report("Error start vhost dev");
> goto err_guest_notifiers;
> }
> + vsc->started_vu = true;
>
> /* guest_notifier_mask/pending not used yet, so just unmask
> * everything here. virtio-pci will do the right thing by
> @@ -106,6 +107,11 @@ void vhost_scsi_common_stop(VHostSCSICommon *vsc)
> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
> int ret = 0;
>
> + if (!vsc->started_vu) {
> + return;
> + }
> + vsc->started_vu = false;
> +
> vhost_dev_stop(&vsc->dev, vdev, true);
>
> if (k->set_guest_notifiers) {
> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
> index ee99b19e7a..bd32dcf999 100644
> --- a/hw/scsi/vhost-user-scsi.c
> +++ b/hw/scsi/vhost-user-scsi.c
> @@ -46,20 +46,25 @@ enum VhostUserProtocolFeature {
> static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
> {
> VHostUserSCSI *s = (VHostUserSCSI *)vdev;
> + DeviceState *dev = &s->parent_obj.parent_obj.parent_obj.parent_obj;
> VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
> - bool start = (status & VIRTIO_CONFIG_S_DRIVER_OK) && vdev->vm_running;
> + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
> + bool should_start = virtio_device_should_start(vdev, status);
> + int ret;
>
> - if (vhost_dev_is_started(&vsc->dev) == start) {
> + if (!s->connected) {
> return;
> }
>
> - if (start) {
> - int ret;
> + if (vhost_dev_is_started(&vsc->dev) == should_start) {
> + return;
> + }
>
> + if (should_start) {
> ret = vhost_scsi_common_start(vsc);
> if (ret < 0) {
> error_report("unable to start vhost-user-scsi: %s",
> strerror(-ret));
> - exit(1);
> + qemu_chr_fe_disconnect(&vs->conf.chardev);
> }
> } else {
> vhost_scsi_common_stop(vsc);
> @@ -85,8 +90,160 @@ static void vhost_user_scsi_reset(VirtIODevice *vdev)
> }
> }
>
> -static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
> +static void vhost_user_scsi_handle_output(VirtIODevice *vdev, VirtQueue *vq)
> {
> + VHostUserSCSI *s = (VHostUserSCSI *)vdev;
> + DeviceState *dev = &s->parent_obj.parent_obj.parent_obj.parent_obj;
> + VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
> + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
> +
> + Error *local_err = NULL;
> + int i, ret;
> +
> + if (!vdev->start_on_kick) {
> + return;
> + }
> +
> + if (!s->connected) {
> + return;
> + }
> +
> + if (vhost_dev_is_started(&vsc->dev)) {
> + return;
> + }
> +
> + /*
> + * Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
> + * vhost here instead of waiting for .set_status().
> + */
> + ret = vhost_scsi_common_start(vsc);
> + if (ret < 0) {
> + error_reportf_err(local_err, "vhost-user-blk: vhost start failed: “);
Need fix typo in v3. s/vhost-user-blk/vhost-user-scsi/g
> + qemu_chr_fe_disconnect(&vs->conf.chardev);
> + return;
> + }
> +
> + /* Kick right away to begin processing requests already in vring */
> + for (i = 0; i < vsc->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 int vhost_user_scsi_connect(DeviceState *dev, Error **errp)
> +{
> + VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> + VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
> + VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
> + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
> + int ret = 0;
> +
> + if (s->connected) {
> + return 0;
> + }
> + s->connected = true;
> +
> + vsc->dev.num_queues = vs->conf.num_queues;
> + vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
> + vsc->dev.vqs = s->vhost_vqs;
> + vsc->dev.vq_index = 0;
> + vsc->dev.backend_features = 0;
> +
> + ret = vhost_dev_init(&vsc->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER,
> 0,
> + errp);
> + if (ret < 0) {
> + return ret;
> + }
> +
> + /* restore vhost state */
> + if (virtio_device_started(vdev, vdev->status)) {
> + ret = vhost_scsi_common_start(vsc);
> + if (ret < 0) {
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event);
> +
> +static void vhost_user_scsi_disconnect(DeviceState *dev)
> +{
> + VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> + VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
> + VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
> + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
> +
> + if (!s->connected) {
> + return;
> + }
> + s->connected = false;
> +
> + vhost_scsi_common_stop(vsc);
> +
> + vhost_dev_cleanup(&vsc->dev);
> +
> + /* Re-instate the event handler for new connections */
> + qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL,
> + vhost_user_scsi_event, NULL, dev, NULL, true);
> +}
> +
> +static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event)
> +{
> + DeviceState *dev = opaque;
> + VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> + VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
> + VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
> + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
> + Error *local_err = NULL;
> +
> + switch (event) {
> + case CHR_EVENT_OPENED:
> + if (vhost_user_scsi_connect(dev, &local_err) < 0) {
> + error_report_err(local_err);
> + qemu_chr_fe_disconnect(&vs->conf.chardev);
> + return;
> + }
> + break;
> + case CHR_EVENT_CLOSED:
> + /* defer close until later to avoid circular close */
> + vhost_user_async_close(dev, &vs->conf.chardev, &vsc->dev,
> + vhost_user_scsi_disconnect);
> + break;
> + case CHR_EVENT_BREAK:
> + case CHR_EVENT_MUX_IN:
> + case CHR_EVENT_MUX_OUT:
> + /* Ignore */
> + break;
> + }
> +}
> +
> +static int vhost_user_scsi_realize_connect(VHostUserSCSI *s, Error **errp)
> +{
> + DeviceState *dev = &s->parent_obj.parent_obj.parent_obj.parent_obj;
> + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
> + int ret;
> +
> + s->connected = false;
> +
> + ret = qemu_chr_fe_wait_connected(&vs->conf.chardev, errp);
> + if (ret < 0) {
> + return ret;
> + }
> +
> + ret = vhost_user_scsi_connect(dev, errp);
> + if (ret < 0) {
> + qemu_chr_fe_disconnect(&vs->conf.chardev);
> + return ret;
> + }
> + assert(s->connected);
> +
> + return 0;
> }
>
> static void vhost_user_scsi_realize(DeviceState *dev, Error **errp)
> @@ -94,18 +251,18 @@ static void vhost_user_scsi_realize(DeviceState *dev,
> Error **errp)
> VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
> VHostUserSCSI *s = VHOST_USER_SCSI(dev);
> VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
> - struct vhost_virtqueue *vqs = NULL;
> Error *err = NULL;
> int ret;
> + int retries = VU_REALIZE_CONN_RETRIES;
>
> if (!vs->conf.chardev.chr) {
> error_setg(errp, "vhost-user-scsi: missing chardev");
> return;
> }
>
> - virtio_scsi_common_realize(dev, vhost_dummy_handle_output,
> - vhost_dummy_handle_output,
> - vhost_dummy_handle_output, &err);
> + virtio_scsi_common_realize(dev, vhost_user_scsi_handle_output,
> + vhost_user_scsi_handle_output,
> + vhost_user_scsi_handle_output, &err);
> if (err != NULL) {
> error_propagate(errp, err);
> return;
> @@ -115,18 +272,28 @@ static void vhost_user_scsi_realize(DeviceState *dev,
> Error **errp)
> goto free_virtio;
> }
>
> - vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
> - vsc->dev.vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
> - vsc->dev.vq_index = 0;
> - vsc->dev.backend_features = 0;
> - vqs = vsc->dev.vqs;
> + vsc->inflight = g_new0(struct vhost_inflight, 1);
> + s->vhost_vqs = g_new0(struct vhost_virtqueue,
> + VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues);
> +
> + assert(!*errp);
> + do {
> + if (*errp) {
> + error_prepend(errp, "Reconnecting after error: ");
> + error_report_err(*errp);
> + *errp = NULL;
> + }
> + ret = vhost_user_scsi_realize_connect(s, errp);
> + } while (ret < 0 && retries--);
>
> - ret = vhost_dev_init(&vsc->dev, &s->vhost_user,
> - VHOST_BACKEND_TYPE_USER, 0, errp);
> if (ret < 0) {
> goto free_vhost;
> }
>
> + /* we're fully initialized, now we can operate, so add the handler */
> + qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL,
> + vhost_user_scsi_event, NULL, (void *)dev,
> + NULL, true);
> /* Channel and lun both are 0 for bootable vhost-user-scsi disk */
> vsc->channel = 0;
> vsc->lun = 0;
> @@ -135,8 +302,12 @@ static void vhost_user_scsi_realize(DeviceState *dev,
> Error **errp)
> return;
>
> free_vhost:
> + g_free(s->vhost_vqs);
> + s->vhost_vqs = NULL;
> + g_free(vsc->inflight);
> + vsc->inflight = NULL;
> vhost_user_cleanup(&s->vhost_user);
> - g_free(vqs);
> +
> free_virtio:
> virtio_scsi_common_unrealize(dev);
> }
> @@ -146,16 +317,23 @@ static void vhost_user_scsi_unrealize(DeviceState *dev)
> VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> VHostUserSCSI *s = VHOST_USER_SCSI(dev);
> VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
> - struct vhost_virtqueue *vqs = vsc->dev.vqs;
> + VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
>
> /* This will stop the vhost backend. */
> vhost_user_scsi_set_status(vdev, 0);
> + qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL, NULL, NULL, NULL,
> + NULL, false);
>
> vhost_dev_cleanup(&vsc->dev);
> - g_free(vqs);
> + g_free(s->vhost_vqs);
> + s->vhost_vqs = NULL;
> +
> + vhost_dev_free_inflight(vsc->inflight);
> + g_free(vsc->inflight);
> + vsc->inflight = NULL;
>
> - virtio_scsi_common_unrealize(dev);
> vhost_user_cleanup(&s->vhost_user);
> + virtio_scsi_common_unrealize(dev);
> }
>
> static Property vhost_user_scsi_properties[] = {
> diff --git a/include/hw/virtio/vhost-scsi-common.h
> b/include/hw/virtio/vhost-scsi-common.h
> index 18f115527c..daa183018c 100644
> --- a/include/hw/virtio/vhost-scsi-common.h
> +++ b/include/hw/virtio/vhost-scsi-common.h
> @@ -37,6 +37,9 @@ struct VHostSCSICommon {
> bool migratable;
>
> struct vhost_inflight *inflight;
> +
> + /* vhost_scsi_common_start/vhost_scsi_common_stop */
> + bool started_vu;
> };
>
> int vhost_scsi_common_start(VHostSCSICommon *vsc);
> diff --git a/include/hw/virtio/vhost-user-scsi.h
> b/include/hw/virtio/vhost-user-scsi.h
> index 521b08e559..c66acc68b7 100644
> --- a/include/hw/virtio/vhost-user-scsi.h
> +++ b/include/hw/virtio/vhost-user-scsi.h
> @@ -29,6 +29,9 @@ OBJECT_DECLARE_SIMPLE_TYPE(VHostUserSCSI, VHOST_USER_SCSI)
> struct VHostUserSCSI {
> VHostSCSICommon parent_obj;
> VhostUserState vhost_user;
> + bool connected;
> +
> + struct vhost_virtqueue *vhost_vqs;
> };
>
> #endif /* VHOST_USER_SCSI_H */
> --
> 2.41.0
>