Hi Cédric,
On 5/14/24 17:31, Cédric Le Goater wrote:
> Add an Error** argument to vfio_migration_set_state() and adjust
> callers, including vfio_save_setup(). The error will be propagated up
> to qemu_savevm_state_setup() where the save_setup() handler is
> executed.
>
> Modify vfio_vmstate_change_prepare() and vfio_vmstate_change() to
> store a reported error under the migration stream if a migration is in
> progress.
>
> Signed-off-by: Cédric Le Goater <c...@redhat.com>
> ---
>
> Changes in v6:
>
> - Commit log improvements (Avihai)
> - vfio_migration_set_state() : Dropped the error_setg_errno() change
> when setting device in recover state fails (Avihai)
> - vfio_migration_state_notifier() : report local error (Avihai)
>
> Changes in v5:
>
> - Replaced error_setg() by error_setg_errno() in vfio_migration_set_state()
> - Rebased on 20c64c8a51a4 ("migration: migration_file_set_error")
>
> hw/vfio/migration.c | 77 ++++++++++++++++++++++++++++-----------------
> 1 file changed, 48 insertions(+), 29 deletions(-)
>
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> index
> bf2fd0759ba6e4fb103cc5c1a43edb180a3d0de4..bf11135167ebb162dd41415656bdacfa0e1ca550
> 100644
> --- a/hw/vfio/migration.c
> +++ b/hw/vfio/migration.c
> @@ -82,7 +82,8 @@ static const char *mig_state_to_str(enum
> vfio_device_mig_state state)
>
> static int vfio_migration_set_state(VFIODevice *vbasedev,
> enum vfio_device_mig_state new_state,
> - enum vfio_device_mig_state recover_state)
> + enum vfio_device_mig_state recover_state,
> + Error **errp)
> {
> VFIOMigration *migration = vbasedev->migration;
> uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) +
> @@ -102,18 +103,19 @@ static int vfio_migration_set_state(VFIODevice
> *vbasedev,
> ret = -errno;
>
> if (recover_state == VFIO_DEVICE_STATE_ERROR) {
> - error_report("%s: Failed setting device state to %s, err: %s. "
> - "Recover state is ERROR. Resetting device",
> - vbasedev->name, mig_state_to_str(new_state),
> - strerror(errno));
> + error_setg_errno(errp, errno,
> + "%s: Failed setting device state to %s. "
> + "Recover state is ERROR. Resetting device",
> + vbasedev->name, mig_state_to_str(new_state));
nit: this may be simplified
with a first unconditional msg saying Failed setting device state to %s.
Recover state is %s.
and not duplicating the msg.
In the reset label you can prepend "resetting the device ..."
>
> goto reset_device;
> }
>
> - error_report(
> - "%s: Failed setting device state to %s, err: %s. Setting device
> in recover state %s",
> - vbasedev->name, mig_state_to_str(new_state),
> - strerror(errno), mig_state_to_str(recover_state));
> + error_setg_errno(errp, errno,
> + "%s: Failed setting device state to %s. "
> + "Setting device in recover state %s",
> + vbasedev->name, mig_state_to_str(new_state),
> + mig_state_to_str(recover_state));>
> mig_state->device_state = recover_state;
> if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) {
in case you fail setting the device in recover state, your simply
error_report() and do not prepend any other msg in the error handle. Is
it what you want? In the positive, maybe worth a comment.
> @@ -137,7 +139,7 @@ static int vfio_migration_set_state(VFIODevice *vbasedev,
> * This can happen if the device is asynchronously reset and
> * terminates a data transfer.
> */
> - error_report("%s: data_fd out of sync", vbasedev->name);
> + error_setg(errp, "%s: data_fd out of sync", vbasedev->name);
> close(mig_state->data_fd);
>
> return -EBADF;
> @@ -168,10 +170,11 @@ reset_device:
> */
> static int
> vfio_migration_set_state_or_reset(VFIODevice *vbasedev,
> - enum vfio_device_mig_state new_state)
> + enum vfio_device_mig_state new_state,
> + Error **errp)
> {
> return vfio_migration_set_state(vbasedev, new_state,
> - VFIO_DEVICE_STATE_ERROR);
> + VFIO_DEVICE_STATE_ERROR, errp);
> }
>
> static int vfio_load_buffer(QEMUFile *f, VFIODevice *vbasedev,
> @@ -399,10 +402,8 @@ static int vfio_save_setup(QEMUFile *f, void *opaque,
> Error **errp)
> switch (migration->device_state) {
> case VFIO_DEVICE_STATE_RUNNING:
> ret = vfio_migration_set_state(vbasedev,
> VFIO_DEVICE_STATE_PRE_COPY,
> - VFIO_DEVICE_STATE_RUNNING);
> + VFIO_DEVICE_STATE_RUNNING, errp);
> if (ret) {
> - error_setg(errp, "%s: Failed to set new PRE_COPY state",
> - vbasedev->name);
> return ret;
> }
>
> @@ -435,13 +436,20 @@ static void vfio_save_cleanup(void *opaque)
> {
> VFIODevice *vbasedev = opaque;
> VFIOMigration *migration = vbasedev->migration;
> + Error *local_err = NULL;
> + int ret;
>
> /*
> * Changing device state from STOP_COPY to STOP can take time. Do it
> here,
> * after migration has completed, so it won't increase downtime.
> */
> if (migration->device_state == VFIO_DEVICE_STATE_STOP_COPY) {
> - vfio_migration_set_state_or_reset(vbasedev, VFIO_DEVICE_STATE_STOP);
> + ret = vfio_migration_set_state_or_reset(vbasedev,
> + VFIO_DEVICE_STATE_STOP,
> + &local_err);
> + if (ret) {
> + error_report_err(local_err);
> + }
> }
>
> g_free(migration->data_buffer);
> @@ -549,11 +557,13 @@ static int vfio_save_complete_precopy(QEMUFile *f, void
> *opaque)
> VFIODevice *vbasedev = opaque;
> ssize_t data_size;
> int ret;
> + Error *local_err = NULL;
>
> /* We reach here with device state STOP or STOP_COPY only */
> ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP_COPY,
> - VFIO_DEVICE_STATE_STOP);
> + VFIO_DEVICE_STATE_STOP, &local_err);
> if (ret) {
> + error_report_err(local_err);
> return ret;
> }
>
> @@ -591,14 +601,9 @@ static void vfio_save_state(QEMUFile *f, void *opaque)
> static int vfio_load_setup(QEMUFile *f, void *opaque, Error **errp)
> {
> VFIODevice *vbasedev = opaque;
> - int ret;
>
> - ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RESUMING,
> - vbasedev->migration->device_state);
> - if (ret) {
> - error_setg(errp, "%s: Failed to set RESUMING state", vbasedev->name);
> - }
> - return ret;
> + return vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RESUMING,
> + vbasedev->migration->device_state, errp);
> }
>
> static int vfio_load_cleanup(void *opaque)
> @@ -714,19 +719,20 @@ static void vfio_vmstate_change_prepare(void *opaque,
> bool running,
> VFIODevice *vbasedev = opaque;
> VFIOMigration *migration = vbasedev->migration;
> enum vfio_device_mig_state new_state;
> + Error *local_err = NULL;
> int ret;
>
> new_state = migration->device_state == VFIO_DEVICE_STATE_PRE_COPY ?
> VFIO_DEVICE_STATE_PRE_COPY_P2P :
> VFIO_DEVICE_STATE_RUNNING_P2P;
>
> - ret = vfio_migration_set_state_or_reset(vbasedev, new_state);
> + ret = vfio_migration_set_state_or_reset(vbasedev, new_state, &local_err);
> if (ret) {
> /*
> * Migration should be aborted in this case, but vm_state_notify()
> * currently does not support reporting failures.
> */
> - migration_file_set_error(ret, NULL);
> + migration_file_set_error(ret, local_err);
> }
>
> trace_vfio_vmstate_change_prepare(vbasedev->name, running,
> @@ -738,6 +744,7 @@ static void vfio_vmstate_change(void *opaque, bool
> running, RunState state)
> {
> VFIODevice *vbasedev = opaque;
> enum vfio_device_mig_state new_state;
> + Error *local_err = NULL;
> int ret;
>
> if (running) {
> @@ -750,13 +757,13 @@ static void vfio_vmstate_change(void *opaque, bool
> running, RunState state)
> VFIO_DEVICE_STATE_STOP;
> }
>
> - ret = vfio_migration_set_state_or_reset(vbasedev, new_state);
> + ret = vfio_migration_set_state_or_reset(vbasedev, new_state, &local_err);
> if (ret) {
> /*
> * Migration should be aborted in this case, but vm_state_notify()
> * currently does not support reporting failures.
> */
> - migration_file_set_error(ret, NULL);
> + migration_file_set_error(ret, local_err);
> }
>
> trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state),
> @@ -769,11 +776,23 @@ static int
> vfio_migration_state_notifier(NotifierWithReturn *notifier,
> VFIOMigration *migration = container_of(notifier, VFIOMigration,
> migration_state);
> VFIODevice *vbasedev = migration->vbasedev;
> + Error *local_err = NULL;
> + int ret = 0;
>
> trace_vfio_migration_state_notifier(vbasedev->name, e->type);
>
> if (e->type == MIG_EVENT_PRECOPY_FAILED) {
> - vfio_migration_set_state_or_reset(vbasedev,
> VFIO_DEVICE_STATE_RUNNING);
> + /*
> + * MigrationNotifyFunc may return an error code and an Error
> + * object only for MIG_EVENT_PRECOPY_SETUP. Hence, report the
> + * error locally and ignore the errp argument.
> + */
> + ret = vfio_migration_set_state_or_reset(vbasedev,
> + VFIO_DEVICE_STATE_RUNNING,
> + &local_err);
> + if (ret) {
> + error_report_err(local_err);
> + }
> }
> return 0;
> }
Thanks
Eric
