From 7962e432b4e40e4395a93aa121045c58f34195fb Mon Sep 17 00:00:00 2001 From: Li Feng Date: Mon, 9 Oct 2023 12:46:59 +0800 Subject: [PATCH] vhost-user-scsi: support reconnect to backend If the backend crashes and restarts, the device is broken. This patch adds reconnect for vhost-user-scsi. This patch also improves the error messages, and reports some silent errors. Tested with spdk backend. Signed-off-by: Li Feng Message-Id: <20231009044735.941655-4-fengli@smartx.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Manos Pitsidianakis --- hw/scsi/vhost-scsi-common.c | 16 +- hw/scsi/vhost-scsi.c | 6 +- hw/scsi/vhost-user-scsi.c | 201 +++++++++++++++++++++++--- include/hw/virtio/vhost-scsi-common.h | 2 +- include/hw/virtio/vhost-user-scsi.h | 6 + 5 files changed, 201 insertions(+), 30 deletions(-) diff --git a/hw/scsi/vhost-scsi-common.c b/hw/scsi/vhost-scsi-common.c index a61cd0e907..4c8637045d 100644 --- a/hw/scsi/vhost-scsi-common.c +++ b/hw/scsi/vhost-scsi-common.c @@ -16,6 +16,7 @@ */ #include "qemu/osdep.h" +#include "qapi/error.h" #include "qemu/error-report.h" #include "qemu/module.h" #include "hw/virtio/vhost.h" @@ -25,7 +26,7 @@ #include "hw/virtio/virtio-access.h" #include "hw/fw-path-provider.h" -int vhost_scsi_common_start(VHostSCSICommon *vsc) +int vhost_scsi_common_start(VHostSCSICommon *vsc, Error **errp) { int ret, i; VirtIODevice *vdev = VIRTIO_DEVICE(vsc); @@ -35,18 +36,19 @@ int vhost_scsi_common_start(VHostSCSICommon *vsc) VirtIOSCSICommon *vs = (VirtIOSCSICommon *)vsc; if (!k->set_guest_notifiers) { - error_report("binding does not support guest notifiers"); + error_setg(errp, "binding does not support guest notifiers"); return -ENOSYS; } ret = vhost_dev_enable_notifiers(&vsc->dev, vdev); if (ret < 0) { + error_setg_errno(errp, -ret, "Error enabling host notifiers"); return ret; } ret = k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, true); if (ret < 0) { - error_report("Error binding guest notifier"); + error_setg_errno(errp, -ret, "Error binding guest notifier"); goto err_host_notifiers; } @@ -54,7 +56,7 @@ int vhost_scsi_common_start(VHostSCSICommon *vsc) ret = vhost_dev_prepare_inflight(&vsc->dev, vdev); if (ret < 0) { - error_report("Error setting inflight format: %d", -ret); + error_setg_errno(errp, -ret, "Error setting inflight format"); goto err_guest_notifiers; } @@ -64,21 +66,21 @@ int vhost_scsi_common_start(VHostSCSICommon *vsc) vs->conf.virtqueue_size, vsc->inflight); if (ret < 0) { - error_report("Error getting inflight: %d", -ret); + error_setg_errno(errp, -ret, "Error getting inflight"); goto err_guest_notifiers; } } ret = vhost_dev_set_inflight(&vsc->dev, vsc->inflight); if (ret < 0) { - error_report("Error setting inflight: %d", -ret); + error_setg_errno(errp, -ret, "Error setting inflight"); goto err_guest_notifiers; } } ret = vhost_dev_start(&vsc->dev, vdev, true); if (ret < 0) { - error_report("Error start vhost dev"); + error_setg_errno(errp, -ret, "Error starting vhost dev"); goto err_guest_notifiers; } diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c index 443f67daa4..95cadb93e7 100644 --- a/hw/scsi/vhost-scsi.c +++ b/hw/scsi/vhost-scsi.c @@ -75,6 +75,7 @@ static int vhost_scsi_start(VHostSCSI *s) int ret, abi_version; VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s); const VhostOps *vhost_ops = vsc->dev.vhost_ops; + Error *local_err = NULL; ret = vhost_ops->vhost_scsi_get_abi_version(&vsc->dev, &abi_version); if (ret < 0) { @@ -88,14 +89,15 @@ static int vhost_scsi_start(VHostSCSI *s) return -ENOSYS; } - ret = vhost_scsi_common_start(vsc); + ret = vhost_scsi_common_start(vsc, &local_err); if (ret < 0) { + error_reportf_err(local_err, "Error starting vhost-scsi"); return ret; } ret = vhost_scsi_set_endpoint(s); if (ret < 0) { - error_report("Error setting vhost-scsi endpoint"); + error_reportf_err(local_err, "Error setting vhost-scsi endpoint"); vhost_scsi_common_stop(vsc); } diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c index b7c6100f3e..24c250d3f8 100644 --- a/hw/scsi/vhost-user-scsi.c +++ b/hw/scsi/vhost-user-scsi.c @@ -39,26 +39,56 @@ static const int user_feature_bits[] = { VHOST_INVALID_FEATURE_BIT }; +static int vhost_user_scsi_start(VHostUserSCSI *s, Error **errp) +{ + VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s); + int ret; + + ret = vhost_scsi_common_start(vsc, errp); + s->started_vu = !(ret < 0); + + return ret; +} + +static void vhost_user_scsi_stop(VHostUserSCSI *s) +{ + VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s); + + if (!s->started_vu) { + return; + } + s->started_vu = false; + + vhost_scsi_common_stop(vsc); +} + static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status) { VHostUserSCSI *s = (VHostUserSCSI *)vdev; + DeviceState *dev = DEVICE(vdev); 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); + Error *local_err = NULL; + 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; + } - ret = vhost_scsi_common_start(vsc); + if (should_start) { + ret = vhost_user_scsi_start(s, &local_err); if (ret < 0) { - error_report("unable to start vhost-user-scsi: %s", strerror(-ret)); - exit(1); + error_reportf_err(local_err, "unable to start vhost-user-scsi: %s", + strerror(-ret)); + qemu_chr_fe_disconnect(&vs->conf.chardev); } } else { - vhost_scsi_common_stop(vsc); + vhost_user_scsi_stop(s); } } @@ -66,14 +96,124 @@ static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *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_user_scsi_start(s, errp); + } + + return ret; +} + +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_user_scsi_stop(s); + + 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 = DEVICE(s); + 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) { + ERRP_GUARD(); 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"); @@ -92,18 +232,28 @@ 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; @@ -112,8 +262,12 @@ 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); } @@ -123,16 +277,23 @@ 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..c5d2c09455 100644 --- a/include/hw/virtio/vhost-scsi-common.h +++ b/include/hw/virtio/vhost-scsi-common.h @@ -39,7 +39,7 @@ struct VHostSCSICommon { struct vhost_inflight *inflight; }; -int vhost_scsi_common_start(VHostSCSICommon *vsc); +int vhost_scsi_common_start(VHostSCSICommon *vsc, Error **errp); void vhost_scsi_common_stop(VHostSCSICommon *vsc); char *vhost_scsi_common_get_fw_dev_path(FWPathProvider *p, BusState *bus, DeviceState *dev); diff --git a/include/hw/virtio/vhost-user-scsi.h b/include/hw/virtio/vhost-user-scsi.h index 521b08e559..78fe616ccb 100644 --- a/include/hw/virtio/vhost-user-scsi.h +++ b/include/hw/virtio/vhost-user-scsi.h @@ -28,7 +28,13 @@ OBJECT_DECLARE_SIMPLE_TYPE(VHostUserSCSI, VHOST_USER_SCSI) struct VHostUserSCSI { VHostSCSICommon parent_obj; + + /* Properties */ + bool connected; + bool started_vu; + VhostUserState vhost_user; + struct vhost_virtqueue *vhost_vqs; }; #endif /* VHOST_USER_SCSI_H */