Re: [Qemu-devel] [PATCH v6 3/4] guest agent: add guest agent commands schema file

[Luiz Capitulino <lcapitulino@redhat.com>]

On Tue,  5 Jul 2011 08:21:39 -0500
Michael Roth <mdroth@linux.vnet.ibm.com> wrote:

> 
> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
> ---
>  qapi-schema-guest.json |  204 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 204 insertions(+), 0 deletions(-)
>  create mode 100644 qapi-schema-guest.json

I think this should be folded in the next patch.

More comments below.

> 
> diff --git a/qapi-schema-guest.json b/qapi-schema-guest.json
> new file mode 100644
> index 0000000..367b42d
> --- /dev/null
> +++ b/qapi-schema-guest.json
> @@ -0,0 +1,204 @@
> +# *-*- Mode: Python -*-*
> +
> +##
> +# @guest-sync:
> +#
> +# Echo back a unique integer value
> +#
> +# This is used by clients talking to the guest agent over the
> +# wire to ensure the stream is in sync and doesn't contain stale
> +# data from previous client. All guest agent responses should be
> +# ignored until the provided unique integer value is returned,
> +# and it is up to the client to handle stale whole or
> +# partially-delivered JSON text in such a way that this response
> +# can be obtained.
> +#
> +# Such clients should also preceed this command
> +# with a 0xFF byte to make such the guest agent flushes any
> +# partially read JSON data from a previous session.
> +#
> +# @id: randomly generated 64-bit integer
> +#
> +# Returns: The unique integer id passed in by the client
> +#
> +# Since: 0.15.0
> +##
> +{ 'command': 'guest-sync'
> +  'data':    { 'id': 'int' },
> +  'returns': 'int' }
> +
> +##
> +# @guest-ping:
> +#
> +# Ping the guest agent, a non-error return implies success
> +#
> +# Since: 0.15.0
> +##
> +{ 'command': 'guest-ping' }
> +
> +##
> +# @guest-info:
> +#
> +# Get some information about the guest agent.
> +#
> +# Since: 0.15.0
> +##
> +{ 'type': 'GuestAgentInfo', 'data': {'version': 'str'} }
> +{ 'command': 'guest-info',
> +  'returns': 'GuestAgentInfo' }
> +
> +##
> +# @guest-shutdown:
> +#
> +# Initiate guest-activated shutdown. Note: this is an asynchronous
> +# shutdown request, with no guaruntee of successful shutdown. Errors
> +# will be logged to guest's syslog.
> +#
> +# @mode: "halt", "powerdown", or "reboot"
> +#
> +# Returns: Nothing on success
> +#
> +# Since: 0.15.0
> +##
> +{ 'command': 'guest-shutdown', 'data': { 'mode': 'str' } }

Shouldn't 'mode' be optional?

> +
> +##
> +# @guest-file-open:
> +#
> +# Open a file in the guest and retrieve a file handle for it
> +#
> +# @filepath: Full path to the file in the guest to open.
> +#
> +# @mode: #optional open mode, as per fopen(), "r" is the default.
> +#
> +# Returns: Guest file handle on success.
> +#          If @filepath cannot be opened, OpenFileFailed
> +#
> +# Since: 0.15.0
> +##
> +{ 'command': 'guest-file-open',
> +  'data':    { 'filepath': 'str', '*mode': 'str' },
> +  'returns': 'int' }

You can use 'file-path'. Actually, I'd use just 'path'.

> +
> +##
> +# @guest-file-read:
> +#
> +# Read from an open file in the guest
> +#
> +# @filehandle: filehandle returned by guest-file-open
> +#
> +# @count: maximum number of bytes to read
> +#
> +# Returns: GuestFileRead on success.
> +#          If @filehandle is not open, OpenFileFailed
> +#
> +# Since: 0.15.0
> +##
> +{ 'type': 'GuestFileRead',
> +  'data': { 'count': 'int', 'buf': 'str', 'eof': 'bool' } }
> +
> +{ 'command': 'guest-file-read',
> +  'data':    { 'filehandle': 'int', 'count': 'int' },
> +  'returns': 'GuestFileRead' }

file-handle. Also, we have to say that the returned data is base64-encoded.

> +
> +##
> +# @guest-file-write:
> +#
> +# Write to an open file in the guest
> +#
> +# @filehandle: filehandle returned by guest-file-open
> +#
> +# @data_b64: base64-encoded string representing data to be written
> +#
> +# @count: bytes to write (actual bytes, after b64-decode)
> +#
> +# Returns: GuestFileWrite on success.
> +#          If @filehandle is not opened, OpenFileFailed
> +#
> +# Since: 0.15.0
> +##
> +{ 'type': 'GuestFileWrite',
> +  'data': { 'count': 'int', 'eof': 'bool' } }
> +{ 'command': 'guest-file-write',
> +  'data':    { 'filehandle': 'int', 'data_b64': 'str', 'count': 'int' },
> +  'returns': 'GuestFileWrite' }

data-b64

> +
> +##
> +# @guest-file-seek:
> +#
> +# Seek to a position in the file, as with fseek(), and return the
> +# current file position afterward. Also encapsulates ftell()'s
> +# functionality, just Set offset=0, whence=SEEK_CUR.
> +#
> +# @filehandle: filehandle returned by guest-file-open
> +#
> +# @offset: bytes to skip over in the file stream
> +#
> +# @whence: SEEK_SET, SEEK_CUR, or SEEK_END, as with fseek()
> +#
> +# Returns: GuestFileSeek on success.
> +#          If @filehandle is not opened, OpenFileFailed
> +#
> +# Since: 0.15.0
> +##
> +{ 'type': 'GuestFileSeek',
> +  'data': { 'position': 'int', 'eof': 'bool' } }
> +
> +{ 'command': 'guest-file-seek',
> +  'data':    { 'filehandle': 'int', 'offset': 'int', 'whence': 'int' },
> +  'returns': 'GuestFileSeek' }
> +
> +##
> +# @guest-file-close:
> +#
> +# Close an open file in the guest
> +#
> +# @filehandle: filehandle returned by guest-file-open
> +#
> +# Returns: Nothing on success.
> +#          If @filehandle is not opened, OpenFileFailed
> +#
> +# Since: 0.15.0
> +##
> +{ 'command': 'guest-file-close',
> +  'data': { 'filehandle': 'int' } }
> +
> +##
> +# @guest-fsfreeze-status:
> +#
> +# get guest fsfreeze state
> +#
> +# Returns: GuestFsfreezeStatus (enumeration starts at 1)
> +#
> +# Since: 0.15.0
> +##
> +{ 'enum': 'GuestFsfreezeStatus',
> +  'data': [ 'thawed', 'inprogress', 'frozen', 'error' ] }
> +{ 'command': 'guest-fsfreeze-status',
> +  'returns': 'GuestFsfreezeStatus' }

hmm, I thought a qapi command implementation would return an enum (ie. int),
but the qapi would translate it to a string and return the string to the
client. However, this returns an int (as explained above).

Did I misunderstand how the qapi handles enums then?

> +
> +##
> +# @guest-fsfreeze-freeze:
> +#
> +# Sync and freeze all non-network guest filesystems
> +#
> +# Returns: Number of file systems frozen
> +#          If error, -1 (unknown error) or -errno
> +#
> +# Since: 0.15.0
> +##
> +{ 'command': 'guest-fsfreeze-freeze',
> +  'returns': 'int' }
> +
> +##
> +# @guest-fsfreeze-thaw:
> +#
> +# Unfreeze frozen guest fileystems
> +#
> +# Returns: Number of file systems thawed
> +#          If error, -1 (unknown error) or -errno
> +#
> +# Since: 0.15.0
> +##
> +{ 'command': 'guest-fsfreeze-thaw',
> +  'returns': 'int' }