> 2025年4月4日 05:15，Michael S. Tsirkin <m...@redhat.com> 写道：
>
> On Tue, Apr 01, 2025 at 11:18:17AM -0400, Haoqian He wrote:
>> Live migration should be terminated if the vhost-user backend crashes
>> before the migration completes.
>>
>> Specifically, since the vhost device will be stopped when VM is stopped
>> before the end of the live migration, in current implementation if the
>> backend crashes, vhost-user device set_status() won't return failure,
>> live migration won't perceive the disconnection between QEMU and the
>> backend.
>>
>> When the VM is migrated to the destination, the inflight IO will be
>> resubmitted, and if the IO was completed out of order before, it will
>> cause IO error.
>>
>> To fix this issue:
>> 1. Add the return value to set_status() for VirtioDeviceClass.
>> a. For the vhost-user device, return failure when the backend crashes.
>> b. For other virtio devices, always return 0.
>> 2. Return failure if vhost_dev_stop() failed for vhost-user device.
>>
>> If QEMU loses connection with the vhost-user backend, virtio set_status()
>> can return failure to the upper layer, migration_completion() can handle
>> the error, terminate the live migration, and restore the VM, so that
>> inflight IO can be completed normally.
>>
>> Signed-off-by: Haoqian He <haoqian...@smartx.com>
>> ---
>> backends/vhost-user.c | 20 +++++++++----------
>> hw/block/vhost-user-blk.c | 27 ++++++++++++++------------
>> hw/block/virtio-blk.c | 5 +++--
>> hw/char/virtio-serial-bus.c | 3 ++-
>> hw/display/vhost-user-gpu.c | 12 +++++++++---
>> hw/input/virtio-input.c | 3 ++-
>> hw/net/virtio-net.c | 3 ++-
>> hw/scsi/vhost-scsi-common.c | 13 +++++++------
>> hw/scsi/vhost-scsi.c | 5 +++--
>> hw/scsi/vhost-user-scsi.c | 18 ++++++++++-------
>> hw/virtio/vdpa-dev.c | 5 +++--
>> hw/virtio/vhost-user-base.c | 23 +++++++++++++---------
>> hw/virtio/vhost-user-fs.c | 23 +++++++++++++---------
>> hw/virtio/vhost-user-scmi.c | 27 +++++++++++++++-----------
>> hw/virtio/vhost-user-vsock.c | 15 +++++++++-----
>> hw/virtio/vhost-vsock-common.c | 12 ++++++------
>> hw/virtio/vhost-vsock.c | 11 ++++++-----
>> hw/virtio/virtio-balloon.c | 3 ++-
>> hw/virtio/virtio-crypto.c | 3 ++-
>> hw/virtio/virtio-iommu.c | 3 ++-
>> hw/virtio/virtio-rng.c | 5 +++--
>> hw/virtio/virtio.c | 23 +++++++++++++++-------
>> include/hw/virtio/vhost-scsi-common.h | 2 +-
>> include/hw/virtio/vhost-vsock-common.h | 2 +-
>> include/hw/virtio/virtio.h | 2 +-
>> include/system/vhost-user-backend.h | 2 +-
>> 26 files changed, 161 insertions(+), 109 deletions(-)
>>
>> diff --git a/backends/vhost-user.c b/backends/vhost-user.c
>> index d0e4d71a63..5409e9d4eb 100644
>> --- a/backends/vhost-user.c
>> +++ b/backends/vhost-user.c
>> @@ -97,30 +97,28 @@ err_host_notifiers:
>> vhost_dev_disable_notifiers(&b->dev, b->vdev);
>> }
>>
>> -void
>> +int
>> vhost_user_backend_stop(VhostUserBackend *b)
>> {
>> BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev)));
>> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
>> - int ret = 0;
>> + int ret;
>>
>> if (!b->started) {
>> - return;
>> + return 0;
>> }
>>
>> - vhost_dev_stop(&b->dev, b->vdev, true);
>> + ret = vhost_dev_stop(&b->dev, b->vdev, true);
>>
>> - if (k->set_guest_notifiers) {
>> - ret = k->set_guest_notifiers(qbus->parent,
>> - b->dev.nvqs, false);
>> - if (ret < 0) {
>> - error_report("vhost guest notifier cleanup failed: %d", ret);
>> - }
>> + if (k->set_guest_notifiers &&
>> + k->set_guest_notifiers(qbus->parent, b->dev.nvqs, false)< 0) {
>
> coding style violation.
>
>> + error_report("vhost guest notifier cleanup failed: %d", ret);
>> + return -1;
>> }
>> - assert(ret >= 0);
>>
>> vhost_dev_disable_notifiers(&b->dev, b->vdev);
>> b->started = false;
>> + return ret;
>> }
>>
>> static void set_chardev(Object *obj, const char *value, Error **errp)
>> diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
>> index ae42327cf8..f355459123 100644
>> --- a/hw/block/vhost-user-blk.c
>> +++ b/hw/block/vhost-user-blk.c
>> @@ -204,7 +204,7 @@ err_host_notifiers:
>> return ret;
>> }
>>
>> -static void vhost_user_blk_stop(VirtIODevice *vdev)
>> +static int vhost_user_blk_stop(VirtIODevice *vdev)
>> {
>> VHostUserBlk *s = VHOST_USER_BLK(vdev);
>> BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
>> @@ -212,26 +212,26 @@ static void vhost_user_blk_stop(VirtIODevice *vdev)
>> int ret;
>>
>> if (!s->started_vu) {
>> - return;
>> + return 0;
>> }
>> s->started_vu = false;
>>
>> if (!k->set_guest_notifiers) {
>> - return;
>> + return 0;
>> }
>>
>> - vhost_dev_stop(&s->dev, vdev, true);
>> + ret = vhost_dev_stop(&s->dev, vdev, true);
>>
>> - ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
>> - if (ret < 0) {
>> + if (k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false) < 0) {
>> error_report("vhost guest notifier cleanup failed: %d", ret);
>> - return;
>> + return -1;
>> }
>>
>> vhost_dev_disable_notifiers(&s->dev, vdev);
>> + return ret;
>> }
>>
>> -static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int 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);
>> @@ -239,11 +239,11 @@ static void vhost_user_blk_set_status(VirtIODevice
>> *vdev, uint8_t status)
>> int ret;
>>
>> if (!s->connected) {
>> - return;
>> + return -1;
>> }
>>
>> if (vhost_dev_is_started(&s->dev) == should_start) {
>> - return;
>> + return 0;
>> }
>>
>> if (should_start) {
>> @@ -253,9 +253,12 @@ static void vhost_user_blk_set_status(VirtIODevice
>> *vdev, uint8_t status)
>> qemu_chr_fe_disconnect(&s->chardev);
>> }
>> } else {
>> - vhost_user_blk_stop(vdev);
>> + ret = vhost_user_blk_stop(vdev);
>> + if (ret < 0) {
>> + return ret;
>> + }
>> }
>> -
>> + return 0;
>> }
>>
>> static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
>> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
>> index 4a48a16790..4244ee3410 100644
>> --- a/hw/block/virtio-blk.c
>> +++ b/hw/block/virtio-blk.c
>> @@ -1269,7 +1269,7 @@ static uint64_t virtio_blk_get_features(VirtIODevice
>> *vdev, uint64_t features,
>> return features;
>> }
>>
>> -static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VirtIOBlock *s = VIRTIO_BLK(vdev);
>>
>> @@ -1278,7 +1278,7 @@ static void virtio_blk_set_status(VirtIODevice *vdev,
>> uint8_t status)
>> }
>>
>> if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
>> - return;
>> + return 0;
>> }
>>
>> /* A guest that supports VIRTIO_BLK_F_CONFIG_WCE must be able to send
>> @@ -1301,6 +1301,7 @@ static void virtio_blk_set_status(VirtIODevice *vdev,
>> uint8_t status)
>> virtio_vdev_has_feature(vdev,
>>
>> VIRTIO_BLK_F_WCE));
>> }
>> + return 0;
>> }
>>
>> static void virtio_blk_save_device(VirtIODevice *vdev, QEMUFile *f)
>> diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
>> index b6d2743a9c..22accfd8e4 100644
>> --- a/hw/char/virtio-serial-bus.c
>> +++ b/hw/char/virtio-serial-bus.c
>> @@ -622,7 +622,7 @@ static void guest_reset(VirtIOSerial *vser)
>> }
>> }
>>
>> -static void set_status(VirtIODevice *vdev, uint8_t status)
>> +static int set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VirtIOSerial *vser;
>> VirtIOSerialPort *port;
>> @@ -650,6 +650,7 @@ static void set_status(VirtIODevice *vdev, uint8_t
>> status)
>> vsc->enable_backend(port, vdev->vm_running);
>> }
>> }
>> + return 0;
>> }
>>
>> static void vser_reset(VirtIODevice *vdev)
>> diff --git a/hw/display/vhost-user-gpu.c b/hw/display/vhost-user-gpu.c
>> index 2aed6243f6..d7d159ecd9 100644
>> --- a/hw/display/vhost-user-gpu.c
>> +++ b/hw/display/vhost-user-gpu.c
>> @@ -513,7 +513,7 @@ vhost_user_gpu_set_config(VirtIODevice *vdev,
>> }
>> }
>>
>> -static void
>> +static int
>> vhost_user_gpu_set_status(VirtIODevice *vdev, uint8_t val)
>> {
>> VhostUserGPU *g = VHOST_USER_GPU(vdev);
>> @@ -522,18 +522,24 @@ vhost_user_gpu_set_status(VirtIODevice *vdev, uint8_t
>> val)
>> if (val & VIRTIO_CONFIG_S_DRIVER_OK && vdev->vm_running) {
>> if (!vhost_user_gpu_do_set_socket(g, &err)) {
>> error_report_err(err);
>> - return;
>> + return 0;
>> }
>> vhost_user_backend_start(g->vhost);
>> } else {
>> + int ret;
>> +
>> /* unblock any wait and stop processing */
>> if (g->vhost_gpu_fd != -1) {
>> vhost_user_gpu_update_blocked(g, true);
>> qemu_chr_fe_deinit(&g->vhost_chr, true);
>> g->vhost_gpu_fd = -1;
>> }
>> - vhost_user_backend_stop(g->vhost);
>> + ret = vhost_user_backend_stop(g->vhost);
>> + if (ret < 0) {
>> + return ret;
>> + }
>> }
>> + return 0;
>> }
>>
>> static bool
>> diff --git a/hw/input/virtio-input.c b/hw/input/virtio-input.c
>> index 1394d99c6b..7ce53b7449 100644
>> --- a/hw/input/virtio-input.c
>> +++ b/hw/input/virtio-input.c
>> @@ -189,7 +189,7 @@ static uint64_t virtio_input_get_features(VirtIODevice
>> *vdev, uint64_t f,
>> return f;
>> }
>>
>> -static void virtio_input_set_status(VirtIODevice *vdev, uint8_t val)
>> +static int virtio_input_set_status(VirtIODevice *vdev, uint8_t val)
>> {
>> VirtIOInputClass *vic = VIRTIO_INPUT_GET_CLASS(vdev);
>> VirtIOInput *vinput = VIRTIO_INPUT(vdev);
>> @@ -202,6 +202,7 @@ static void virtio_input_set_status(VirtIODevice *vdev,
>> uint8_t val)
>> }
>> }
>> }
>> + return 0;
>> }
>>
>> static void virtio_input_reset(VirtIODevice *vdev)
>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
>> index de87cfadff..b7de824baa 100644
>> --- a/hw/net/virtio-net.c
>> +++ b/hw/net/virtio-net.c
>> @@ -382,7 +382,7 @@ static void virtio_net_drop_tx_queue_data(VirtIODevice
>> *vdev, VirtQueue *vq)
>> }
>> }
>>
>> -static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
>> +static int virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
>> {
>> VirtIONet *n = VIRTIO_NET(vdev);
>> VirtIONetQueue *q;
>> @@ -437,6 +437,7 @@ static void virtio_net_set_status(struct VirtIODevice
>> *vdev, uint8_t status)
>> }
>> }
>> }
>> + return 0;
>> }
>>
>> static void virtio_net_set_link_status(NetClientState *nc)
>> diff --git a/hw/scsi/vhost-scsi-common.c b/hw/scsi/vhost-scsi-common.c
>> index 4c8637045d..43525ba46d 100644
>> --- a/hw/scsi/vhost-scsi-common.c
>> +++ b/hw/scsi/vhost-scsi-common.c
>> @@ -101,24 +101,25 @@ err_host_notifiers:
>> return ret;
>> }
>>
>> -void vhost_scsi_common_stop(VHostSCSICommon *vsc)
>> +int vhost_scsi_common_stop(VHostSCSICommon *vsc)
>> {
>> VirtIODevice *vdev = VIRTIO_DEVICE(vsc);
>> BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
>> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
>> int ret = 0;
>>
>> - vhost_dev_stop(&vsc->dev, vdev, true);
>> + ret = vhost_dev_stop(&vsc->dev, vdev, true);
>>
>> if (k->set_guest_notifiers) {
>> - ret = k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, false);
>> - if (ret < 0) {
>> - error_report("vhost guest notifier cleanup failed: %d",
>> ret);
>> + int r = k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, false);
>> + if (r < 0) {
>> + error_report("vhost guest notifier cleanup failed: %d", ret);
>> + return r;
>> }
>> }
>> - assert(ret >= 0);
>>
>> vhost_dev_disable_notifiers(&vsc->dev, vdev);
>> + return ret;
>> }
>>
>> uint64_t vhost_scsi_common_get_features(VirtIODevice *vdev, uint64_t
>> features,
>> diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
>> index 8039d13fd9..19d5261019 100644
>> --- a/hw/scsi/vhost-scsi.c
>> +++ b/hw/scsi/vhost-scsi.c
>> @@ -114,7 +114,7 @@ static void vhost_scsi_stop(VHostSCSI *s)
>> vhost_scsi_common_stop(vsc);
>> }
>>
>> -static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
>> +static int vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
>> {
>> VHostSCSI *s = VHOST_SCSI(vdev);
>> VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
>> @@ -125,7 +125,7 @@ static void vhost_scsi_set_status(VirtIODevice *vdev,
>> uint8_t val)
>> }
>>
>> if (vhost_dev_is_started(&vsc->dev) == start) {
>> - return;
>> + return 0;
>> }
>>
>> if (start) {
>> @@ -139,6 +139,7 @@ static void vhost_scsi_set_status(VirtIODevice *vdev,
>> uint8_t val)
>> } else {
>> vhost_scsi_stop(s);
>> }
>> + return 0;
>> }
>>
>> static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
>> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
>> index adb41b9816..aba9fb82d2 100644
>> --- a/hw/scsi/vhost-user-scsi.c
>> +++ b/hw/scsi/vhost-user-scsi.c
>> @@ -52,19 +52,19 @@ static int vhost_user_scsi_start(VHostUserSCSI *s, Error
>> **errp)
>> return ret;
>> }
>>
>> -static void vhost_user_scsi_stop(VHostUserSCSI *s)
>> +static int vhost_user_scsi_stop(VHostUserSCSI *s)
>> {
>> VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
>>
>> if (!s->started_vu) {
>> - return;
>> + return 0;
>> }
>> s->started_vu = false;
>>
>> - vhost_scsi_common_stop(vsc);
>> + return vhost_scsi_common_stop(vsc);
>> }
>>
>> -static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VHostUserSCSI *s = (VHostUserSCSI *)vdev;
>> DeviceState *dev = DEVICE(vdev);
>> @@ -75,11 +75,11 @@ static void vhost_user_scsi_set_status(VirtIODevice
>> *vdev, uint8_t status)
>> int ret;
>>
>> if (!s->connected) {
>> - return;
>> + return -1;
>> }
>>
>> if (vhost_dev_is_started(&vsc->dev) == should_start) {
>> - return;
>> + return 0;
>> }
>>
>> if (should_start) {
>> @@ -91,8 +91,12 @@ static void vhost_user_scsi_set_status(VirtIODevice
>> *vdev, uint8_t status)
>> qemu_chr_fe_disconnect(&vs->conf.chardev);
>> }
>> } else {
>> - vhost_user_scsi_stop(s);
>> + ret = vhost_user_scsi_stop(s);
>> + if (ret) {
>> + return ret;
>> + }
>> }
>> + return 0;
>> }
>>
>> static void vhost_user_scsi_handle_output(VirtIODevice *vdev, VirtQueue *vq)
>> diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
>> index a7e73b1c99..d80d46baed 100644
>> --- a/hw/virtio/vdpa-dev.c
>> +++ b/hw/virtio/vdpa-dev.c
>> @@ -312,7 +312,7 @@ static void vhost_vdpa_device_stop(VirtIODevice *vdev)
>> vhost_dev_disable_notifiers(&s->dev, vdev);
>> }
>>
>> -static void vhost_vdpa_device_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int vhost_vdpa_device_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
>> bool should_start = virtio_device_started(vdev, status);
>> @@ -324,7 +324,7 @@ static void vhost_vdpa_device_set_status(VirtIODevice
>> *vdev, uint8_t status)
>> }
>>
>> if (s->started == should_start) {
>> - return;
>> + return 0;
>> }
>>
>> if (should_start) {
>> @@ -335,6 +335,7 @@ static void vhost_vdpa_device_set_status(VirtIODevice
>> *vdev, uint8_t status)
>> } else {
>> vhost_vdpa_device_stop(vdev);
>> }
>> + return 0;
>> }
>>
>> static const Property vhost_vdpa_device_properties[] = {
>> diff --git a/hw/virtio/vhost-user-base.c b/hw/virtio/vhost-user-base.c
>> index 2bc3423326..37718653bd 100644
>> --- a/hw/virtio/vhost-user-base.c
>> +++ b/hw/virtio/vhost-user-base.c
>> @@ -66,7 +66,7 @@ err_host_notifiers:
>> vhost_dev_disable_notifiers(&vub->vhost_dev, vdev);
>> }
>>
>> -static void vub_stop(VirtIODevice *vdev)
>> +static int vub_stop(VirtIODevice *vdev)
>> {
>> VHostUserBase *vub = VHOST_USER_BASE(vdev);
>> BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
>> @@ -74,34 +74,39 @@ static void vub_stop(VirtIODevice *vdev)
>> int ret;
>>
>> if (!k->set_guest_notifiers) {
>> - return;
>> + return 0;
>> }
>>
>> - vhost_dev_stop(&vub->vhost_dev, vdev, true);
>> + ret = vhost_dev_stop(&vub->vhost_dev, vdev, true);
>>
>> - ret = k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, false);
>> - if (ret < 0) {
>> + if (k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, false) <
>> 0) {
>> error_report("vhost guest notifier cleanup failed: %d", ret);
>> - return;
>> + return -1;
>> }
>>
>> vhost_dev_disable_notifiers(&vub->vhost_dev, vdev);
>> + return ret;
>> }
>>
>> -static void vub_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int vub_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VHostUserBase *vub = VHOST_USER_BASE(vdev);
>> bool should_start = virtio_device_should_start(vdev, status);
>>
>> if (vhost_dev_is_started(&vub->vhost_dev) == should_start) {
>> - return;
>> + return 0;
>> }
>>
>> if (should_start) {
>> vub_start(vdev);
>> } else {
>> - vub_stop(vdev);
>> + int ret;
>> + ret = vub_stop(vdev);
>> + if (ret < 0) {
>> + return ret;
>> + }
>> }
>> + return 0;
>> }
>>
>> /*
>> diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
>> index 3f00d79ed0..266c179671 100644
>> --- a/hw/virtio/vhost-user-fs.c
>> +++ b/hw/virtio/vhost-user-fs.c
>> @@ -100,7 +100,7 @@ err_host_notifiers:
>> vhost_dev_disable_notifiers(&fs->vhost_dev, vdev);
>> }
>>
>> -static void vuf_stop(VirtIODevice *vdev)
>> +static int vuf_stop(VirtIODevice *vdev)
>> {
>> VHostUserFS *fs = VHOST_USER_FS(vdev);
>> BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
>> @@ -108,34 +108,39 @@ static void vuf_stop(VirtIODevice *vdev)
>> int ret;
>>
>> if (!k->set_guest_notifiers) {
>> - return;
>> + return 0;
>> }
>>
>> - vhost_dev_stop(&fs->vhost_dev, vdev, true);
>> + ret = vhost_dev_stop(&fs->vhost_dev, vdev, true);
>>
>> - ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false);
>> - if (ret < 0) {
>> + if (k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false) <
>> 0) {
>> error_report("vhost guest notifier cleanup failed: %d", ret);
>> - return;
>> + return -1;
>> }
>>
>> vhost_dev_disable_notifiers(&fs->vhost_dev, vdev);
>> + return ret;
>> }
>>
>> -static void vuf_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int vuf_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VHostUserFS *fs = VHOST_USER_FS(vdev);
>> bool should_start = virtio_device_should_start(vdev, status);
>>
>> if (vhost_dev_is_started(&fs->vhost_dev) == should_start) {
>> - return;
>> + return 0;
>> }
>>
>> if (should_start) {
>> vuf_start(vdev);
>> } else {
>> - vuf_stop(vdev);
>> + int ret;
>> + ret = vuf_stop(vdev);
>> + if (ret < 0) {
>> + return ret;
>> + }
>> }
>> + return 0;
>> }
>>
>> static uint64_t vuf_get_features(VirtIODevice *vdev,
>> diff --git a/hw/virtio/vhost-user-scmi.c b/hw/virtio/vhost-user-scmi.c
>> index 410a936ca7..a9778f1f4b 100644
>> --- a/hw/virtio/vhost-user-scmi.c
>> +++ b/hw/virtio/vhost-user-scmi.c
>> @@ -83,7 +83,7 @@ err_host_notifiers:
>> return ret;
>> }
>>
>> -static void vu_scmi_stop(VirtIODevice *vdev)
>> +static int vu_scmi_stop(VirtIODevice *vdev)
>> {
>> VHostUserSCMI *scmi = VHOST_USER_SCMI(vdev);
>> BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
>> @@ -93,41 +93,46 @@ static void vu_scmi_stop(VirtIODevice *vdev)
>>
>> /* vhost_dev_is_started() check in the callers is not fully reliable. */
>> if (!scmi->started_vu) {
>> - return;
>> + return 0;
>> }
>> scmi->started_vu = false;
>>
>> if (!k->set_guest_notifiers) {
>> - return;
>> + return 0;
>> }
>>
>> - vhost_dev_stop(vhost_dev, vdev, true);
>> + ret = vhost_dev_stop(vhost_dev, vdev, true);
>>
>> - ret = k->set_guest_notifiers(qbus->parent, vhost_dev->nvqs, false);
>> - if (ret < 0) {
>> + if (k->set_guest_notifiers(qbus->parent, vhost_dev->nvqs, false) < 0) {
>> error_report("vhost guest notifier cleanup failed: %d", ret);
>> - return;
>> + return -1;
>> }
>> vhost_dev_disable_notifiers(vhost_dev, vdev);
>> + return ret;
>> }
>>
>> -static void vu_scmi_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int vu_scmi_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VHostUserSCMI *scmi = VHOST_USER_SCMI(vdev);
>> bool should_start = virtio_device_should_start(vdev, status);
>>
>> if (!scmi->connected) {
>> - return;
>> + return -1;
>> }
>> if (vhost_dev_is_started(&scmi->vhost_dev) == should_start) {
>> - return;
>> + return 0;
>> }
>>
>> if (should_start) {
>> vu_scmi_start(vdev);
>> } else {
>> - vu_scmi_stop(vdev);
>> + int ret;
>> + ret = vu_scmi_stop(vdev);
>> + if (ret < 0) {
>> + return ret;
>> + }
>> }
>> + return 0;
>> }
>>
>> static uint64_t vu_scmi_get_features(VirtIODevice *vdev, uint64_t features,
>> diff --git a/hw/virtio/vhost-user-vsock.c b/hw/virtio/vhost-user-vsock.c
>> index 293273080b..7a4aec7bf4 100644
>> --- a/hw/virtio/vhost-user-vsock.c
>> +++ b/hw/virtio/vhost-user-vsock.c
>> @@ -54,23 +54,28 @@ const VhostDevConfigOps vsock_ops = {
>> .vhost_dev_config_notifier = vuv_handle_config_change,
>> };
>>
>> -static void vuv_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int vuv_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
>> bool should_start = virtio_device_should_start(vdev, status);
>> + int ret;
>>
>> if (vhost_dev_is_started(&vvc->vhost_dev) == should_start) {
>> - return;
>> + return 0;
>> }
>>
>> if (should_start) {
>> - int ret = vhost_vsock_common_start(vdev);
>> + ret = vhost_vsock_common_start(vdev);
>> if (ret < 0) {
>> - return;
>> + return ret;
>> }
>> } else {
>> - vhost_vsock_common_stop(vdev);
>> + ret = vhost_vsock_common_stop(vdev);
>> + if (ret < 0) {
>> + return ret;
>> + }
>> }
>> + return 0;
>> }
>>
>> static uint64_t vuv_get_features(VirtIODevice *vdev,
>> diff --git a/hw/virtio/vhost-vsock-common.c b/hw/virtio/vhost-vsock-common.c
>> index 9ac587d20c..bbfbbdb317 100644
>> --- a/hw/virtio/vhost-vsock-common.c
>> +++ b/hw/virtio/vhost-vsock-common.c
>> @@ -95,7 +95,7 @@ err_host_notifiers:
>> return ret;
>> }
>>
>> -void vhost_vsock_common_stop(VirtIODevice *vdev)
>> +int vhost_vsock_common_stop(VirtIODevice *vdev)
>> {
>> VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
>> BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
>> @@ -103,18 +103,18 @@ void vhost_vsock_common_stop(VirtIODevice *vdev)
>> int ret;
>>
>> if (!k->set_guest_notifiers) {
>> - return;
>> + return 0;
>> }
>>
>> - vhost_dev_stop(&vvc->vhost_dev, vdev, true);
>> + ret = vhost_dev_stop(&vvc->vhost_dev, vdev, true);
>>
>> - ret = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false);
>> - if (ret < 0) {
>> + if (k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false) <
>> 0) {
>> error_report("vhost guest notifier cleanup failed: %d", ret);
>> - return;
>> + return -1;
>> }
>>
>> vhost_dev_disable_notifiers(&vvc->vhost_dev, vdev);
>> + return ret;
>> }
>>
>>
>> diff --git a/hw/virtio/vhost-vsock.c b/hw/virtio/vhost-vsock.c
>> index 940b30fa27..62b36b28f5 100644
>> --- a/hw/virtio/vhost-vsock.c
>> +++ b/hw/virtio/vhost-vsock.c
>> @@ -67,37 +67,38 @@ static int vhost_vsock_set_running(VirtIODevice *vdev,
>> int start)
>> }
>>
>>
>> -static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
>> bool should_start = virtio_device_should_start(vdev, status);
>> int ret;
>>
>> if (vhost_dev_is_started(&vvc->vhost_dev) == should_start) {
>> - return;
>> + return 0;
>> }
>>
>> if (should_start) {
>> ret = vhost_vsock_common_start(vdev);
>> if (ret < 0) {
>> - return;
>> + return 0;
>> }
>>
>> ret = vhost_vsock_set_running(vdev, 1);
>> if (ret < 0) {
>> vhost_vsock_common_stop(vdev);
>> error_report("Error starting vhost vsock: %d", -ret);
>> - return;
>> + return 0;
>> }
>> } else {
>> ret = vhost_vsock_set_running(vdev, 0);
>> if (ret < 0) {
>> error_report("vhost vsock set running failed: %d", ret);
>> - return;
>> + return 0;
>> }
>>
>> vhost_vsock_common_stop(vdev);
>> }
>> + return 0;
>> }
>>
>> static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
>> diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
>> index 2eb5a14fa2..e719c078aa 100644
>> --- a/hw/virtio/virtio-balloon.c
>> +++ b/hw/virtio/virtio-balloon.c
>> @@ -958,7 +958,7 @@ static void virtio_balloon_device_reset(VirtIODevice
>> *vdev)
>> s->poison_val = 0;
>> }
>>
>> -static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
>>
>> @@ -988,6 +988,7 @@ static void virtio_balloon_set_status(VirtIODevice
>> *vdev, uint8_t status)
>> qemu_mutex_unlock(&s->free_page_lock);
>> }
>> }
>> + return 0;
>> }
>>
>> static ResettableState *virtio_balloon_get_reset_state(Object *obj)
>> diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c
>> index a1b3c90618..626279dc5b 100644
>> --- a/hw/virtio/virtio-crypto.c
>> +++ b/hw/virtio/virtio-crypto.c
>> @@ -1197,11 +1197,12 @@ static void virtio_crypto_vhost_status(VirtIOCrypto
>> *c, uint8_t status)
>> }
>> }
>>
>> -static void virtio_crypto_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int virtio_crypto_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VirtIOCrypto *vcrypto = VIRTIO_CRYPTO(vdev);
>>
>> virtio_crypto_vhost_status(vcrypto, status);
>> + return 0;
>> }
>>
>> static void virtio_crypto_guest_notifier_mask(VirtIODevice *vdev, int idx,
>> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
>> index b6e7e01ef7..63ec12014f 100644
>> --- a/hw/virtio/virtio-iommu.c
>> +++ b/hw/virtio/virtio-iommu.c
>> @@ -1522,9 +1522,10 @@ static void virtio_iommu_device_reset_exit(Object
>> *obj, ResetType type)
>> NULL, NULL, virtio_iommu_put_endpoint);
>> }
>>
>> -static void virtio_iommu_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int virtio_iommu_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> trace_virtio_iommu_device_status(status);
>> + return 0;
>> }
>>
>> static void virtio_iommu_instance_init(Object *obj)
>> diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c
>> index a515fc5cd9..4748d039f9 100644
>> --- a/hw/virtio/virtio-rng.c
>> +++ b/hw/virtio/virtio-rng.c
>> @@ -159,17 +159,18 @@ static void check_rate_limit(void *opaque)
>> vrng->activate_timer = true;
>> }
>>
>> -static void virtio_rng_set_status(VirtIODevice *vdev, uint8_t status)
>> +static int virtio_rng_set_status(VirtIODevice *vdev, uint8_t status)
>> {
>> VirtIORNG *vrng = VIRTIO_RNG(vdev);
>>
>> if (!vdev->vm_running) {
>> - return;
>> + return 0;
>> }
>> vdev->status = status;
>>
>> /* Something changed, try to process buffers */
>> virtio_rng_process(vrng);
>> + return 0;
>> }
>>
>> static void virtio_rng_device_realize(DeviceState *dev, Error **errp)
>> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
>> index 202a052053..8d292b45c5 100644
>> --- a/hw/virtio/virtio.c
>> +++ b/hw/virtio/virtio.c
>> @@ -2221,12 +2221,12 @@ int virtio_set_status(VirtIODevice *vdev, uint8_t
>> val)
>> {
>> VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
>> trace_virtio_set_status(vdev, val);
>> + int ret = 0;
>>
>> if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
>> if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) &&
>> val & VIRTIO_CONFIG_S_FEATURES_OK) {
>> - int ret = virtio_validate_features(vdev);
>> -
>> + ret = virtio_validate_features(vdev);
>> if (ret) {
>> return ret;
>> }
>> @@ -2239,11 +2239,15 @@ int virtio_set_status(VirtIODevice *vdev, uint8_t
>> val)
>> }
>>
>> if (k->set_status) {
>> - k->set_status(vdev, val);
>> + ret = k->set_status(vdev, val);
>> + if (ret) {
>> + qemu_log("set %s status to %d failed, old status: %d\n",
>> + vdev->name, val, vdev->status);
>> + }
>> }
>> vdev->status = val;
>>
>> - return 0;
>> + return ret;
>> }
>>
>> static enum virtio_device_endian virtio_default_endian(void)
>> @@ -3419,7 +3423,7 @@ void virtio_cleanup(VirtIODevice *vdev)
>> qemu_del_vm_change_state_handler(vdev->vmstate);
>> }
>>
>> -static void virtio_vmstate_change(void *opaque, bool running, RunState
>> state)
>> +static int virtio_vmstate_change(void *opaque, bool running, RunState state)
>> {
>> VirtIODevice *vdev = opaque;
>> BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
>> @@ -3436,8 +3440,13 @@ static void virtio_vmstate_change(void *opaque, bool
>> running, RunState state)
>> }
>>
>> if (!backend_run) {
>> - virtio_set_status(vdev, vdev->status);
>> + // the return value was used for stopping VM during migration
>
> this style of comment violates the qemu coding style
> besides, no idea what it means.
Maybe we can remove the comment here, and I will fix the style error ASAP.
Thanks,
Haoqian
>
>> + int ret = virtio_set_status(vdev, vdev->status);
>> + if (ret) {
>> + return ret;
>> + }
>> }
>> + return 0;
>> }
>>
>> void virtio_instance_init_common(Object *proxy_obj, void *data,
>> @@ -3489,7 +3498,7 @@ void virtio_init(VirtIODevice *vdev, uint16_t
>> device_id, size_t config_size)
>> vdev->config = NULL;
>> }
>> vdev->vmstate = qdev_add_vm_change_state_handler(DEVICE(vdev),
>> - virtio_vmstate_change, NULL, vdev);
>> + NULL, virtio_vmstate_change, vdev);
>> vdev->device_endian = virtio_default_endian();
>> vdev->use_guest_notifier_mask = true;
>> }
>> diff --git a/include/hw/virtio/vhost-scsi-common.h
>> b/include/hw/virtio/vhost-scsi-common.h
>> index c5d2c09455..d54d9c916f 100644
>> --- a/include/hw/virtio/vhost-scsi-common.h
>> +++ b/include/hw/virtio/vhost-scsi-common.h
>> @@ -40,7 +40,7 @@ struct VHostSCSICommon {
>> };
>>
>> int vhost_scsi_common_start(VHostSCSICommon *vsc, Error **errp);
>> -void vhost_scsi_common_stop(VHostSCSICommon *vsc);
>> +int vhost_scsi_common_stop(VHostSCSICommon *vsc);
>> char *vhost_scsi_common_get_fw_dev_path(FWPathProvider *p, BusState *bus,
>> DeviceState *dev);
>> void vhost_scsi_common_set_config(VirtIODevice *vdev, const uint8_t *config);
>> diff --git a/include/hw/virtio/vhost-vsock-common.h
>> b/include/hw/virtio/vhost-vsock-common.h
>> index 75a74e8a99..01bf6062af 100644
>> --- a/include/hw/virtio/vhost-vsock-common.h
>> +++ b/include/hw/virtio/vhost-vsock-common.h
>> @@ -42,7 +42,7 @@ struct VHostVSockCommon {
>> };
>>
>> int vhost_vsock_common_start(VirtIODevice *vdev);
>> -void vhost_vsock_common_stop(VirtIODevice *vdev);
>> +int vhost_vsock_common_stop(VirtIODevice *vdev);
>> int vhost_vsock_common_pre_save(void *opaque);
>> int vhost_vsock_common_post_load(void *opaque, int version_id);
>> void vhost_vsock_common_realize(VirtIODevice *vdev);
>> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
>> index 6386910280..a7ee9bec75 100644
>> --- a/include/hw/virtio/virtio.h
>> +++ b/include/hw/virtio/virtio.h
>> @@ -186,7 +186,7 @@ struct VirtioDeviceClass {
>> void (*get_config)(VirtIODevice *vdev, uint8_t *config);
>> void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
>> void (*reset)(VirtIODevice *vdev);
>> - void (*set_status)(VirtIODevice *vdev, uint8_t val);
>> + int (*set_status)(VirtIODevice *vdev, uint8_t val);
>> /* Device must validate queue_index. */
>> void (*queue_reset)(VirtIODevice *vdev, uint32_t queue_index);
>> /* Device must validate queue_index. */
>> diff --git a/include/system/vhost-user-backend.h
>> b/include/system/vhost-user-backend.h
>> index 327b0b84f1..87765a1218 100644
>> --- a/include/system/vhost-user-backend.h
>> +++ b/include/system/vhost-user-backend.h
>> @@ -43,6 +43,6 @@ struct VhostUserBackend {
>> int vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev,
>> unsigned nvqs, Error **errp);
>> void vhost_user_backend_start(VhostUserBackend *b);
>> -void vhost_user_backend_stop(VhostUserBackend *b);
>> +int vhost_user_backend_stop(VhostUserBackend *b);
>>
>> #endif
>> --
>> 2.44.0
