Patchwork [3/3] chardev: add hotplug support.

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Submitter Gerd Hoffmann
Date Oct. 17, 2012, 10:09 a.m.
Message ID <1350468595-5238-4-git-send-email-kraxel@redhat.com>
Download mbox | patch
Permalink /patch/191999/
State New
Headers show

Comments

Gerd Hoffmann - Oct. 17, 2012, 10:09 a.m.
This patch adds chardev_add and chardev_remove monitor commands.

They work similar to the netdev_{add,del} commands.  The hmp version of
chardev_add accepts like the -chardev command line option does.  The qmp
version expects the arguments being passed as named parameters.

chardev_del just takes an id argument and zaps the chardev specified.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hmp-commands.hx  |   32 ++++++++++++++++++++++++++++
 hmp.c            |   23 ++++++++++++++++++++
 hmp.h            |    2 +
 qapi-schema.json |   47 +++++++++++++++++++++++++++++++++++++++++
 qemu-char.c      |   44 ++++++++++++++++++++++++++++++++++++++
 qemu-char.h      |    1 +
 qmp-commands.hx  |   61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 7 files changed, 210 insertions(+), 0 deletions(-)
Eric Blake - Oct. 17, 2012, 3:26 p.m.
On 10/17/2012 04:09 AM, Gerd Hoffmann wrote:
> This patch adds chardev_add and chardev_remove monitor commands.
> 
> They work similar to the netdev_{add,del} commands.  The hmp version of
> chardev_add accepts like the -chardev command line option does.  The qmp
> version expects the arguments being passed as named parameters.
> 
> chardev_del just takes an id argument and zaps the chardev specified.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---

> +##
> +# @chardev-add:
> +#
> +# Add a chardev
> +#
> +# @id: the chardev's ID, must be unique
> +# @backend: the chardev backend: "file", "socket", ...

This still needs to be an enum.

> +# @path: file / device / unix socket path
> +# @name: spice channel name
> +# @host: host name
> +# @port: port number
> +# @server: create socket in server mode
> +# @wait: wait for connect
> +# @ipv4: force ipv4-only
> +# @ipv6: force ipv6-only
> +# @telnet: telnet negotiation

But this part looks nicer.
Paolo Bonzini - Oct. 17, 2012, 4:28 p.m.
Il 17/10/2012 17:26, Eric Blake ha scritto:
> On 10/17/2012 04:09 AM, Gerd Hoffmann wrote:
>> This patch adds chardev_add and chardev_remove monitor commands.
>>
>> They work similar to the netdev_{add,del} commands.  The hmp version of
>> chardev_add accepts like the -chardev command line option does.  The qmp
>> version expects the arguments being passed as named parameters.
>>
>> chardev_del just takes an id argument and zaps the chardev specified.
>>
>> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
>> ---
> 
>> +##
>> +# @chardev-add:
>> +#
>> +# Add a chardev
>> +#
>> +# @id: the chardev's ID, must be unique
>> +# @backend: the chardev backend: "file", "socket", ...
> 
> This still needs to be an enum.
> 
>> +# @path: file / device / unix socket path
>> +# @name: spice channel name
>> +# @host: host name
>> +# @port: port number
>> +# @server: create socket in server mode
>> +# @wait: wait for connect
>> +# @ipv4: force ipv4-only
>> +# @ipv6: force ipv6-only
>> +# @telnet: telnet negotiation
> 
> But this part looks nicer.

Note that this schema is just for documentation.  It is not used at QEMU
build time.

Paolo

Patch

diff --git a/hmp-commands.hx b/hmp-commands.hx
index e0b537d..5207383 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1404,6 +1404,38 @@  passed since 1970, i.e. unix epoch.
 ETEXI
 
     {
+        .name       = "chardev_add",
+        .args_type  = "args:s",
+        .params     = "args",
+        .help       = "add chardev",
+        .mhandler.cmd = hmp_chardev_add,
+    },
+
+STEXI
+@item chardev_add args
+@findex chardev_add
+
+chardev_add accepts the same parameters as the -chardev command line switch.
+
+ETEXI
+
+    {
+        .name       = "chardev_remove",
+        .args_type  = "id:s",
+        .params     = "id",
+        .help       = "remove chardev",
+        .mhandler.cmd = hmp_chardev_remove,
+    },
+
+STEXI
+@item chardev_remove id
+@findex chardev_remove
+
+Removes the chardev @var{id}.
+
+ETEXI
+
+    {
         .name       = "info",
         .args_type  = "item:s?",
         .params     = "[subcommand]",
diff --git a/hmp.c b/hmp.c
index 70bdec2..fc9d7bc 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1209,3 +1209,26 @@  void hmp_screen_dump(Monitor *mon, const QDict *qdict)
     qmp_screendump(filename, &err);
     hmp_handle_error(mon, &err);
 }
+
+void hmp_chardev_add(Monitor *mon, const QDict *qdict)
+{
+    const char *args = qdict_get_str(qdict, "args");
+    Error *err = NULL;
+    QemuOpts *opts;
+
+    opts = qemu_opts_parse(qemu_find_opts("chardev"), args, 1);
+    if (opts == NULL) {
+        error_setg(&err, "Parsing chardev args failed\n");
+    } else {
+        qemu_chr_new_from_opts(opts, NULL, &err);
+    }
+    hmp_handle_error(mon, &err);
+}
+
+void hmp_chardev_remove(Monitor *mon, const QDict *qdict)
+{
+    Error *err = NULL;
+    qmp_chardev_remove(qdict_get_str(qdict, "id"),
+                       &err);
+    hmp_handle_error(mon, &err);
+}
diff --git a/hmp.h b/hmp.h
index 71ea384..cabe944 100644
--- a/hmp.h
+++ b/hmp.h
@@ -75,5 +75,7 @@  void hmp_getfd(Monitor *mon, const QDict *qdict);
 void hmp_closefd(Monitor *mon, const QDict *qdict);
 void hmp_send_key(Monitor *mon, const QDict *qdict);
 void hmp_screen_dump(Monitor *mon, const QDict *qdict);
+void hmp_chardev_add(Monitor *mon, const QDict *qdict);
+void hmp_chardev_remove(Monitor *mon, const QDict *qdict);
 
 #endif
diff --git a/qapi-schema.json b/qapi-schema.json
index f9dbdae..fab6bbc 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2796,3 +2796,50 @@ 
 # Since: 0.14.0
 ##
 { 'command': 'screendump', 'data': {'filename': 'str'} }
+
+##
+# @chardev-add:
+#
+# Add a chardev
+#
+# @id: the chardev's ID, must be unique
+# @backend: the chardev backend: "file", "socket", ...
+# @path: file / device / unix socket path
+# @name: spice channel name
+# @host: host name
+# @port: port number
+# @server: create socket in server mode
+# @wait: wait for connect
+# @ipv4: force ipv4-only
+# @ipv6: force ipv6-only
+# @telnet: telnet negotiation
+#
+# Returns: Nothing on success
+#
+# Since: 1.3.0
+##
+{ 'command': 'chardev-add', 'data': {'id'      : 'str',
+                                     'backend' : 'str',
+                                     '*path'   : 'str',
+                                     '*name'   : 'str',
+                                     '*host'   : 'str',
+                                     '*port'   : 'str',
+                                     '*server' : 'bool',
+                                     '*wait'   : 'bool',
+                                     '*ipv4'   : 'bool',
+                                     '*ipv6'   : 'bool',
+                                     '*telnet' : 'bool' },
+  'gen': 'no' }
+
+##
+# @chardev-remove:
+#
+# Remove a chardev
+#
+# @id: the chardev's ID, must exist and not be in use
+#
+# Returns: Nothing on success
+#
+# Since: 1.3.0
+##
+{ 'command': 'chardev-remove', 'data': {'id': 'str'} }
diff --git a/qemu-char.c b/qemu-char.c
index be4ec61..cbfa24e 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2911,3 +2911,47 @@  CharDriverState *qemu_char_get_next_serial(void)
     return serial_hds[next_serial++];
 }
 
+int qmp_chardev_add(Monitor *mon, const QDict *qdict, QObject **ret)
+{
+    Error *err = NULL;
+    QemuOptsList *opts_list;
+    QemuOpts *opts;
+
+    opts_list = qemu_find_opts_err("chardev", &err);
+    if (error_is_set(&err)) {
+        goto exit_err;
+    }
+
+    opts = qemu_opts_from_qdict(opts_list, qdict, &err);
+    if (error_is_set(&err)) {
+        goto exit_err;
+    }
+
+    qemu_chr_new_from_opts(opts, NULL, &err);
+    if (error_is_set(&err)) {
+        goto exit_err;
+    }
+    return 0;
+
+exit_err:
+    qerror_report_err(err);
+    error_free(err);
+    return -1;
+}
+
+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\n", id);
+        return;
+    }
+    if (chr->chr_can_read || chr->chr_read ||
+        chr->chr_event || chr->handler_opaque) {
+        error_setg(errp, "Chardev '%s' is busy\n", id);
+        return;
+    }
+    qemu_chr_delete(chr);
+}
diff --git a/qemu-char.h b/qemu-char.h
index 99bc132..407e0fe 100644
--- a/qemu-char.h
+++ b/qemu-char.h
@@ -238,6 +238,7 @@  void qemu_chr_info(Monitor *mon, QObject **ret_data);
 CharDriverState *qemu_chr_find(const char *name);
 
 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename);
+int qmp_chardev_add(Monitor *mon, const QDict *qdict, QObject **ret);
 
 /* add an eventfd to the qemu devices that are polled */
 CharDriverState *qemu_chr_open_eventfd(int eventfd);
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 2f8477e..ea5fc71 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2576,3 +2576,64 @@  EQMP
         .args_type  = "",
         .mhandler.cmd_new = qmp_marshal_input_query_target,
     },
+
+    {
+        .name       = "chardev-add",
+        .args_type  = "",
+        .mhandler.cmd_new = qmp_chardev_add,
+    },
+
+SQMP
+chardev-add
+-----------
+
+Add a chardev.
+
+Arguments:
+
+- "id": the chardev's ID, must be unique (json-string)
+- "backend": the chardev backend: "file", "socket", ... (json-string)
+- "path": file / device / unix socket path (json-string, optional)
+- "name": spice channel name (json-string, optional)
+- "host": host name (json-string, optional)
+- "port": port number (json-string, optional)
+- "server": create socket in server mode (json-bool, optional)
+- "wait": wait for connect (json-bool, optional)
+- "ipv4": force ipv4-only (json-bool, optional)
+- "ipv6": force ipv6-only (json-bool, optional)
+- "telnet": telnet negotiation (json-bool, optional)
+
+Example:
+
+-> { "execute": "chardev-add", "arguments": { "id"      : "foo",
+                                              "backend" : "socket",
+                                              "path"    : "/tmp/foo",
+                                              "server"  : true,
+                                              "wait"    : false } }
+<- { "return": {} }
+
+EQMP
+
+    {
+        .name       = "chardev-remove",
+        .args_type  = "",
+        .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