Re: [Qemu-devel] [PATCH 3/5] QAPI: Introduce memchar-write QMP command

[Blue Swirl]

On Wed, Sep 12, 2012 at 11:57 AM, Lei Li <address@hidden> wrote:
> Signed-off-by: Lei Li <address@hidden>
> ---
>  hmp-commands.hx  |   23 ++++++++++++++++++
>  hmp.c            |   19 +++++++++++++++
>  hmp.h            |    1 +
>  qapi-schema.json |   69 
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  qemu-char.c      |   48 +++++++++++++++++++++++++++++++++++++
>  qmp-commands.hx  |   39 ++++++++++++++++++++++++++++++
>  6 files changed, 199 insertions(+), 0 deletions(-)
>
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index ed67e99..fe11926 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -796,6 +796,29 @@ Inject an NMI on the given CPU (x86 only).
>  ETEXI
>
>      {
> +        .name       = "memchar_write",
> +        .args_type  = "chardev:s,size:i,data:s,format:s?,control:s?",
> +        .params     = "chardev size data [format] [control]",
> +        .help       = "Provide writing interface for CirMemCharDriver. Write"
> +                      "'data' to it with size 'size'",
> +        .mhandler.cmd = hmp_memchar_write,
> +    },
> +
> +STEXI
> address@hidden memchar_write @var{chardev} @var{size} @var{data} 
> address@hidden address@hidden
> address@hidden memchar_write
> +Provide writing interface for CirMemCharDriver. Write @var{data}
> +to cirmemchr char device with size @var{size}.
> +
> address@hidden is the format of the data write to CirMemCharDriver.
> +Support 'utf8' and 'base64', by default is 'utf8'.
> +
> address@hidden is option('block', 'drop') for read and write command
> +that specifies behavior when the queue is full/empty. By default is
> +'drop'. Note that the 'block' option is not supported now.
> +ETEXI
> +
> +    {
>          .name       = "migrate",
>          .args_type  = "detach:-d,blk:-b,inc:-i,uri:s",
>          .params     = "[-d] [-b] [-i] uri",
> diff --git a/hmp.c b/hmp.c
> index ba6fbd3..97f5058 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -671,6 +671,25 @@ void hmp_pmemsave(Monitor *mon, const QDict *qdict)
>      hmp_handle_error(mon, &errp);
>  }
>
> +void hmp_memchar_write(Monitor *mon, const QDict *qdict)
> +{
> +    uint32_t size = qdict_get_int(qdict, "size");
> +    const char *chardev = qdict_get_str(qdict, "chardev");
> +    const char *data = qdict_get_str(qdict, "data");
> +    int val = qdict_get_try_bool(qdict, "base64", 0);
> +    enum DataFormat format;
> +    int con = qdict_get_try_bool(qdict, "block", 0);
> +    enum CongestionControl control;
> +    Error *errp = NULL;
> +
> +    format = val ? DATA_FORMAT_BASE64 : DATA_FORMAT_UTF8;
> +    control = con ? CONGESTION_CONTROL_BLOCK : CONGESTION_CONTROL_DROP;
> +    qmp_memchar_write(chardev, size, data, true, format,
> +                      true, control, &errp);
> +
> +    hmp_handle_error(mon, &errp);
> +}
> +
>  static void hmp_cont_cb(void *opaque, int err)
>  {
>      if (!err) {
> diff --git a/hmp.h b/hmp.h
> index 48b9c59..44b6463 100644
> --- a/hmp.h
> +++ b/hmp.h
> @@ -43,6 +43,7 @@ void hmp_system_powerdown(Monitor *mon, const QDict *qdict);
>  void hmp_cpu(Monitor *mon, const QDict *qdict);
>  void hmp_memsave(Monitor *mon, const QDict *qdict);
>  void hmp_pmemsave(Monitor *mon, const QDict *qdict);
> +void hmp_memchar_write(Monitor *mon, const QDict *qdict);
>  void hmp_cont(Monitor *mon, const QDict *qdict);
>  void hmp_system_wakeup(Monitor *mon, const QDict *qdict);
>  void hmp_inject_nmi(Monitor *mon, const QDict *qdict);
> diff --git a/qapi-schema.json b/qapi-schema.json
> index a9f465a..371239a 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -236,6 +236,75 @@
>  { 'command': 'query-chardev', 'returns': ['ChardevInfo'] }
>
>  ##
> +# @DataFormat:
> +#
> +# An enumeration of data format write to or read from
> +# memchardev. The default value would be utf8.
> +#
> +# @utf8: The data format is 'utf8'.
> +#
> +# @base64: The data format is 'base64'.
> +#
> +# Note: The data format start with 'utf8' and 'base64', will support
> +#       other data format as well.
> +#
> +# Since: 1.3
> +##
> +{ 'enum': 'DataFormat'
> +  'data': [ 'utf8', 'base64' ] }
> +
> +##
> +# @CongestionControl
> +#
> +# An enumeration of options for the read and write command that
> +# specifies behavior when the queue is full/empty. The default
> +# option would be dropped.
> +#
> +# @drop: Would result in reads returning empty strings and writes
> +#        dropping queued data.
> +#
> +# @block: Would make the session block until data was available
> +#         or the queue had space available.
> +#
> +# Note: The option 'block' is not supported now due to the miss
> +#       feature in qmp. Will add it later when we gain the necessary
> +#       infrastructure enhancement.
> +#
> +# Since: 1.3
> +##
> +{'enum': 'CongestionControl'
> + 'data': [ 'drop', 'block' ] }
> +
> +##
> +# @memchar-write:
> +#
> +# Provide writing interface for CirMemCharDriver. Write data to cirmemchar
> +# char device.
> +#
> +# @chardev: the name of the cirmemchar char device.
> +#
> +# @size: the size to write in bytes.
> +#
> +# @data: the source data write to cirmemchar.
> +#
> +# @format: #optional the format of the data write to cirmemchar, by
> +#          default is 'utf8'.
> +#
> +# @control: #optional options for read and write command that specifies
> +#           behavior when the queue is full/empty.
> +#
> +# Returns: Nothing on success
> +#          If @chardev is not a valid cirmemchr device, DeviceNotFound
> +#          If an I/O error occurs while writing, IOError
> +#
> +# Since: 1.3
> +##
> +{ 'command': 'memchar-write',
> +  'data': {'chardev': 'str', 'size': 'int', 'data': 'str',
> +           '*format': 'DataFormat',
> +           '*control': 'CongestionControl'} }
> +
> +##
>  # @CommandInfo:
>  #
>  # Information about a QMP command
> diff --git a/qemu-char.c b/qemu-char.c
> index 6e84acc..be1d79a 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -2700,6 +2700,54 @@ static CharDriverState 
> *qemu_chr_open_cirmemchr(QemuOpts *opts)
>      return chr;
>  }
>
> +void qmp_memchar_write(const char *chardev, int64_t size,
> +                       const char *data, bool has_format,
> +                       enum DataFormat format, bool has_control,
> +                       enum CongestionControl control,
> +                       Error **errp)
> +{
> +    CharDriverState *chr;
> +    guchar *write_data;
> +    int ret;
> +    gsize write_count;
> +
> +    chr = qemu_chr_find(chardev);
> +
> +    if(!chr) {

Please add a space between 'if' and '('.

> +        error_set(errp, QERR_DEVICE_NOT_FOUND, chardev);
> +        return;
> +    }
> +
> +    /* XXX: For the sync command as 'block', waiting for the qmp
> + *      * to support necessary feature. Now just act as 'drop'. */
> +    if (cirmem_chr_is_full(chr)) {
> +        if (has_control && (control == CONGESTION_CONTROL_BLOCK)) {
> +            g_free((char *)data);
> +            return;
> +        } else {
> +            g_free((char *)data);
> +            error_setg(errp, "Failed to write to memchr %s", chardev);
> +            return;
> +        }
> +    }
> +
> +    write_count = (gsize)size;
> +
> +    if (has_format && (format == DATA_FORMAT_BASE64)) {
> +        write_data = g_base64_decode(data, &write_count);
> +    } else {
> +        write_data = (uint8_t *)data;
> +    }
> +
> +    ret = cirmem_chr_write(chr, write_data, write_count);
> +    /* */

Missing comment contents.

> +    if (ret <= 0) {
> +        error_setg(errp, "Failed to write to memchr %s", chardev);
> +    }
> +
> +    g_free(write_data);
> +}
> +
>  QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
>  {
>      char host[65], port[33], width[8], height[8];
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 6e21ddb..5a1b86b 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -466,6 +466,45 @@ Note: inject-nmi fails when the guest doesn't support 
> injecting.
>  EQMP
>
>      {
> +        .name       = "memchar-write",
> +        .args_type  = "chardev:s,size:i,data:s,format:s?,control:s?",
> +        .mhandler.cmd_new = qmp_marshal_input_memchar_write,
> +    },
> +
> +SQMP
> +memchar-write
> +-------------
> +
> +Provide writing interface for CirMemCharDriver. Write data to cirmemchar
> +char device.
> +
> +Arguments:
> +
> +- "chardev": the name of the char device, must be unique (json-string)
> +- "size": the memory size, in bytes (json-int)
> +- "data": the source data writed to cirmemchar (json-string)
> +- "format": the data format write to CirMemCharDriver, default is
> +            utf8. (json-string, optional)
> +          - Possible values: "utf8", "base64"
> +
> +- "control": options for read and write command that specifies
> +             behavior when the queue is full/empty, default is
> +             drop. (json-string, optional)
> +          - Possible values: "drop", "block"
> +
> +Example:
> +
> +-> { "execute": "memchar-write",
> +                "arguments": { "chardev": foo,
> +                               "size": 7,
> +                               "data": "abcdefg",
> +                               "format": "utf8",
> +                               "control": "drop" } }
> +<- { "return": {} }
> +
> +EQMP
> +
> +    {
>          .name       = "xen-save-devices-state",
>          .args_type  = "filename:F",
>      .mhandler.cmd_new = qmp_marshal_input_xen_save_devices_state,
> --
> 1.7.7.6
>
>