Commit f1a1a356 authored by Gerd Hoffmann's avatar Gerd Hoffmann
Browse files

chardev: add qmp hotplug commands, with null chardev support 



Add chardev-add and chardev-remove qmp commands.  Hotplugging
a null chardev is supported for now, more will be added later.

Signed-off-by: default avatarGerd Hoffmann <kraxel@redhat.com>
parent e551498e

qapi-schema.json

+49 −0
Original line number Diff line number Diff line
@@ -3017,3 +3017,52 @@ 
# Since: 1.3.0

##

{ 'command': 'nbd-server-stop' }



##

# @ChardevBackend:

#

# Configuration info for the new chardev backend.

#

# Since: 1.4

##

{ 'type': 'ChardevDummy', 'data': { } }



{ 'union': 'ChardevBackend', 'data': { 'null' : 'ChardevDummy' } }



##

# @ChardevReturn:

#

# Return info about the chardev backend just created.

#

# Since: 1.4

##

{ 'type' : 'ChardevReturn', 'data': { } }



##

# @chardev-add:

#

# Add a file chardev

#

# @id: the chardev's ID, must be unique

# @backend: backend type and parameters

#

# Returns: chardev info.

#

# Since: 1.4

##

{ 'command': 'chardev-add', 'data': {'id'      : 'str',

                                     'backend' : 'ChardevBackend' },

  'returns': 'ChardevReturn' }



##

# @chardev-remove:

#

# Remove a chardev

#

# @id: the chardev's ID, must exist and not be in use

#

# Returns: Nothing on success

#

# Since: 1.4

##

{ 'command': 'chardev-remove', 'data': {'id': 'str'} }

qemu-char.c

+53 −0
Original line number Diff line number Diff line
@@ -3010,3 +3010,56 @@ QemuOptsList qemu_chardev_opts = { 
        { /* end of list */ }

    },

};



ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,

                               Error **errp)

{

    ChardevReturn *ret = g_new0(ChardevReturn, 1);

    CharDriverState *chr = NULL;



    chr = qemu_chr_find(id);

    if (chr) {

        error_setg(errp, "Chardev '%s' already exists", id);

        g_free(ret);

        return NULL;

    }



    switch (backend->kind) {

    case CHARDEV_BACKEND_KIND_NULL:

        chr = qemu_chr_open_null(NULL);

        break;

    default:

        error_setg(errp, "unknown chardev backend (%d)", backend->kind);

        break;

    }



    if (chr == NULL && !error_is_set(errp)) {

        error_setg(errp, "Failed to create chardev");

    }

    if (chr) {

        chr->label = g_strdup(id);

        chr->avail_connections = 1;

        QTAILQ_INSERT_TAIL(&chardevs, chr, next);

        return ret;

    } else {

        g_free(ret);

        return NULL;

    }

}



void qmp_chardev_remove(const char *id, Error **errp)

{

    CharDriverState *chr;



    chr = qemu_chr_find(id);

    if (NULL == chr) {

        error_setg(errp, "Chardev '%s' not found", id);

        return;

    }

    if (chr->chr_can_read || chr->chr_read ||

        chr->chr_event || chr->handler_opaque) {

        error_setg(errp, "Chardev '%s' is busy", id);

        return;

    }

    qemu_chr_delete(chr);

}

qmp-commands.hx

+50 −0
Original line number Diff line number Diff line
@@ -2654,3 +2654,53 @@ EQMP 
        .args_type  = "",

        .mhandler.cmd_new = qmp_marshal_input_query_target,

    },



    {

        .name       = "chardev-add",

        .args_type  = "id:s,backend:q",

        .mhandler.cmd_new = qmp_marshal_input_chardev_add,

    },



SQMP

chardev-add

----------------



Add a chardev.



Arguments:



- "id": the chardev's ID, must be unique (json-string)

- "backend": chardev backend type + parameters



Example:



-> { "execute" : "chardev-add",

     "arguments" : { "id" : "foo",

                     "backend" : { "type" : "null", "data" : {} } } }

<- { "return": {} }



EQMP



    {

        .name       = "chardev-remove",

        .args_type  = "id:s",

        .mhandler.cmd_new = qmp_marshal_input_chardev_remove,

    },





SQMP

chardev-remove

--------------



Remove a chardev.



Arguments:



- "id": the chardev's ID, must exist and not be in use (json-string)



Example:



-> { "execute": "chardev-remove", "arguments": { "id" : "foo" } }

<- { "return": {} }



EQMP