Re: [Qemu-devel] [PATCH v7 07/13] vfio: Add migration state change notifier

[Kirti Wankhede <kwankhede@nvidia.com>]

On 7/17/2019 7:55 AM, Yan Zhao wrote:
> On Tue, Jul 09, 2019 at 05:49:14PM +0800, Kirti Wankhede wrote:
>> Added migration state change notifier to get notification on migration state
>> change. These states are translated to VFIO device state and conveyed to vendor
>> driver.
>>
>> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
>> Reviewed-by: Neo Jia <cjia@nvidia.com>
>> ---
>>  hw/vfio/migration.c           | 54 +++++++++++++++++++++++++++++++++++++++++++
>>  hw/vfio/trace-events          |  1 +
>>  include/hw/vfio/vfio-common.h |  1 +
>>  3 files changed, 56 insertions(+)
>>
>> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
>> index c01f08b659d0..e4a89a6f9bc7 100644
>> --- a/hw/vfio/migration.c
>> +++ b/hw/vfio/migration.c
>> @@ -132,6 +132,53 @@ static void vfio_vmstate_change(void *opaque, int running, RunState state)
>>      }
>>  }
>>  
>> +static void vfio_migration_state_notifier(Notifier *notifier, void *data)
>> +{
>> +    MigrationState *s = data;
>> +    VFIODevice *vbasedev = container_of(notifier, VFIODevice, migration_state);
>> +    int ret;
>> +
>> +    trace_vfio_migration_state_notifier(vbasedev->name, s->state);
>> +
>> +    switch (s->state) {
>> +    case MIGRATION_STATUS_ACTIVE:
>> +        if (vbasedev->device_state & VFIO_DEVICE_STATE_RUNNING) {
>> +            if (vbasedev->vm_running) {
>> +                ret = vfio_migration_set_state(vbasedev,
>> +                          VFIO_DEVICE_STATE_RUNNING | VFIO_DEVICE_STATE_SAVING);
>> +                if (ret) {
>> +                    error_report("%s: Failed to set state RUNNING and SAVING",
>> +                                  vbasedev->name);
>> +                }
>> +            } else {
>> +                ret = vfio_migration_set_state(vbasedev,
>> +                                               VFIO_DEVICE_STATE_SAVING);
>> +                if (ret) {
>> +                    error_report("%s: Failed to set state STOP and SAVING",
>> +                                 vbasedev->name);
>> +                }
>> +            }
>> +        } else {
>> +            ret = vfio_migration_set_state(vbasedev,
>> +                                           VFIO_DEVICE_STATE_RESUMING);
>> +            if (ret) {
>> +                error_report("%s: Failed to set state RESUMING",
>> +                             vbasedev->name);
>> +            }
>> +        }
>> +        return;
>> +
> hi Kirti
> currently, migration state notifiers are only notified in below 3 interfaces:
> migrate_fd_connect, migrate_fd_cleanup, postcopy_start, where
> MIGRATION_STATUS_ACTIVE is not an valid state.
> Have you tested the above code? what's the purpose of the code?
> 

Sorry for delayed response.

migration_iteration_finish() -> qemu_bh_schedule(s->cleanup_bh) which is
migrate_fd_cleanup().

migration_iteration_finish() can be called with MIGRATION_STATUS_ACTIVE
state. So migration state notifiers can be called with
MIGRATION_STATUS_ACTIVE. So handled that case here.


Thanks,
Kirti


> Thanks
> Yan
> 
>> +    case MIGRATION_STATUS_CANCELLING:
>> +    case MIGRATION_STATUS_CANCELLED:
>> +    case MIGRATION_STATUS_FAILED:
>> +        ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RUNNING);
>> +        if (ret) {
>> +            error_report("%s: Failed to set state RUNNING", vbasedev->name);
>> +        }
>> +        return;
>> +    }
>> +}
>> +
>>  static int vfio_migration_init(VFIODevice *vbasedev,
>>                                 struct vfio_region_info *info)
>>  {
>> @@ -152,6 +199,9 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>>      vbasedev->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
>>                                                            vbasedev);
>>  
>> +    vbasedev->migration_state.notify = vfio_migration_state_notifier;
>> +    add_migration_state_change_notifier(&vbasedev->migration_state);
>> +
>>      return 0;
>>  }
>>  
>> @@ -194,6 +244,10 @@ void vfio_migration_finalize(VFIODevice *vbasedev)
>>          return;
>>      }
>>  
>> +    if (vbasedev->migration_state.notify) {
>> +        remove_migration_state_change_notifier(&vbasedev->migration_state);
>> +    }
>> +
>>      if (vbasedev->vm_state) {
>>          qemu_del_vm_change_state_handler(vbasedev->vm_state);
>>      }
>> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
>> index 3d15bacd031a..69503228f20e 100644
>> --- a/hw/vfio/trace-events
>> +++ b/hw/vfio/trace-events
>> @@ -148,3 +148,4 @@ vfio_display_edid_write_error(void) ""
>>  vfio_migration_probe(char *name, uint32_t index) " (%s) Region %d"
>>  vfio_migration_set_state(char *name, uint32_t state) " (%s) state %d"
>>  vfio_vmstate_change(char *name, int running, const char *reason, uint32_t dev_state) " (%s) running %d reason %s device state %d"
>> +vfio_migration_state_notifier(char *name, int state) " (%s) state %d"
>> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
>> index f6c70db3a9c1..a022484d2636 100644
>> --- a/include/hw/vfio/vfio-common.h
>> +++ b/include/hw/vfio/vfio-common.h
>> @@ -128,6 +128,7 @@ typedef struct VFIODevice {
>>      uint32_t device_state;
>>      VMChangeStateEntry *vm_state;
>>      int vm_running;
>> +    Notifier migration_state;
>>  } VFIODevice;
>>  
>>  struct VFIODeviceOps {
>> -- 
>> 2.7.0
>>