Re: [Qemu-devel] [PATCH v18 19/21] replay: replay blockers for devices

[Eric Blake <eblake@redhat.com>]

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On 09/17/2015 10:25 AM, Pavel Dovgalyuk wrote:
> Some devices are not supported by record/replay subsystem.
> This patch introduces replay blocker which denies starting record/replay
> if such devices are included into the configuration.
> 
> Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
> ---
>  hw/bt/hci.c               |    7 +++++++
>  include/qapi/qmp/qerror.h |    3 +++
>  qapi/common.json          |    6 +++++-
>  replay/replay.c           |   13 +++++++++++++
>  replay/replay.h           |    3 +++
>  vl.c                      |   10 ++++++++++
>  6 files changed, 41 insertions(+), 1 deletions(-)
> 

> @@ -2189,6 +2193,9 @@ struct HCIInfo *bt_new_hci(struct bt_scatternet_s *net)
>  
>      s->device.handle_destroy = bt_hci_destroy;
>  
> +    error_set(&s->replay_blocker, ERROR_CLASS_REPLAY_NOT_SUPPORTED, "bt hci");

New code should favor error_setg().

> +++ b/include/qapi/qmp/qerror.h
> @@ -106,4 +106,7 @@
>  #define QERR_UNSUPPORTED \
>      "this feature or command is not currently supported"
>  
> +#define QERR_REPLAY_NOT_SUPPORTED \
> +    ERROR_CLASS_GENERIC_ERROR, "Record/replay feature is not supported for '%s'"

We very strongly discourage the addition of new error classes.  Most new
errors should be part of ERROR_CLASS_GENERIC_ERROR, in which case
error_setg() should be used with the message directly inline instead of
hidden behind a macro.

> +
>  #endif /* QERROR_H */
> diff --git a/qapi/common.json b/qapi/common.json
> index bad56bf..d80e3d4 100644
> --- a/qapi/common.json
> +++ b/qapi/common.json
> @@ -22,11 +22,15 @@
>  # @KVMMissingCap: the requested operation can't be fulfilled because a
>  #                 required KVM capability is missing
>  #
> +# @ReplayNotSupported: the requested feature is not supported with
> +#                      record/replay mode enabled
> +#

Again, this should not be added.  But even if it were acceptable to add,
it is missing a 'since 2.5' designation.

>  # Since: 1.2
>  ##
>  { 'enum': 'ErrorClass',
>    'data': [ 'GenericError', 'CommandNotFound', 'DeviceEncrypted',
> -            'DeviceNotActive', 'DeviceNotFound', 'KVMMissingCap' ] }
> +            'DeviceNotActive', 'DeviceNotFound', 'KVMMissingCap',
> +            'ReplayNotSupported' ] }


-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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