From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:47999) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TRkO0-0002s8-AX for qemu-devel@nongnu.org; Fri, 26 Oct 2012 09:55:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TRkNt-0001eB-Qp for qemu-devel@nongnu.org; Fri, 26 Oct 2012 09:55:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44106) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TRkNt-0001dy-Ie for qemu-devel@nongnu.org; Fri, 26 Oct 2012 09:55:37 -0400 Date: Fri, 26 Oct 2012 11:56:13 -0200 From: Luiz Capitulino Message-ID: <20121026115613.5b666998@doriath.home> In-Reply-To: <5089964E.3060207@linux.vnet.ibm.com> References: <1350838081-6351-1-git-send-email-lilei@linux.vnet.ibm.com> <1350838081-6351-6-git-send-email-lilei@linux.vnet.ibm.com> <20121022165928.65ef9602@doriath.home> <50879601.1090609@linux.vnet.ibm.com> <20121024105536.2bc9a9bf@doriath.home> <5089964E.3060207@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 5/5] HMP: Introduce console command List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Lei Li Cc: blauwirbel@gmail.com, aliguori@us.ibm.com, qemu-devel@nongnu.org On Fri, 26 Oct 2012 03:43:10 +0800 Lei Li wrote: > On 10/24/2012 08:55 PM, Luiz Capitulino wrote: > > On Wed, 24 Oct 2012 15:17:21 +0800 > > Lei Li wrote: > > > >> On 10/23/2012 02:59 AM, Luiz Capitulino wrote: > >>> On Mon, 22 Oct 2012 00:48:01 +0800 > >>> Lei Li wrote: > >>> > >>>> Signed-off-by: Lei Li > >>>> --- > >>>> hmp-commands.hx | 23 +++++++++++++++++++++++ > >>>> hmp.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > >>>> hmp.h | 1 + > >>>> monitor.c | 15 +++++++++++++++ > >>>> monitor.h | 3 +++ > >>>> 5 files changed, 95 insertions(+), 0 deletions(-) > >>>> > >>>> diff --git a/hmp-commands.hx b/hmp-commands.hx > >>>> index 5f91428..f862a53 100644 > >>>> --- a/hmp-commands.hx > >>>> +++ b/hmp-commands.hx > >>>> @@ -868,7 +868,30 @@ char device and return @var{size} of the data. > >>>> that specifies behavior when the queue is full/empty. By default is > >>>> 'drop'. Note that the 'block' option is not supported now. > >>>> -b for 'block' option. None for 'drop' option. > >>>> +ETEXI > >>>> + > >>>> + { > >>>> + .name = "console", > >>>> + .args_type = "chardev:s", > >>>> + .params = "chardev", > >>>> + .help = "Connect to the serial console from within the" > >>>> + "monitor, allow to write data to memchardev" > >>>> + "'chardev'. Exit from the console and return back" > >>>> + "to monitor by typing 'ctrl-]'", > >>>> + .mhandler.cmd = hmp_console, > >>>> + }, > >>>> > >>>> +STEXI > >>>> +@item console @var{device} > >>>> +@findex console > >>>> + > >>>> +Connect to the serial console from within the monitor, allow to write data > >>>> +to memchardev @var{chardev}. Exit from the console and return back to > >>>> +monitor by typing 'ctrl-]'. > >>>> +@example > >>>> +(qemu) console foo > >>>> +foo: data string... > >>>> +@end example > >>>> ETEXI > >>>> > >>>> { > >>>> diff --git a/hmp.c b/hmp.c > >>>> index fa858c4..bc245f4 100644 > >>>> --- a/hmp.c > >>>> +++ b/hmp.c > >>>> @@ -1245,3 +1245,56 @@ void hmp_screen_dump(Monitor *mon, const QDict *qdict) > >>>> qmp_screendump(filename, &err); > >>>> hmp_handle_error(mon, &err); > >>>> } > >>>> + > >>>> +enum escape_char > >>>> +{ > >>>> + ESCAPE_CHAR_CTRL_GS = 0x1d /* ctrl-] used for escape */ > >>>> +}; > >>>> + > >>>> +static void hmp_read_console(Monitor *mon, const char *data, > >>>> + void *opaque) > >>>> +{ > >>>> + CharDriverState *chr = opaque; > >>>> + uint32_t size = strlen(data); > >>>> + enum DataFormat format = DATA_FORMAT_UTF8; > >>>> + enum CongestionControl control = CONGESTION_CONTROL_DROP; > >>>> + enum escape_char console_escape = ESCAPE_CHAR_CTRL_GS; > >>>> + > >>>> + Error *err = NULL; > >>>> + > >>>> + if (*data == console_escape) { > >>>> + monitor_resume(mon); > >>>> + return; > >>>> + } > >>>> + > >>>> + qmp_memchar_write(chr->label, size, data, 0, format, > >>>> + 0, control, &err); > >>>> + if (err) { > >>>> + monitor_printf(mon, "%s\n", error_get_pretty(err)); > >>>> + error_free(err); > >>>> + return; > >>>> + } > >>> Shouldn't you also read from the device? > >> The use-case for this console command is just allow the user to > >> write data to each memchar device as in a signal terminal. Then > >> type escape sequences to take you back to the monitor. So I don't > >> think it is also need to read from the device in this command. > >> > >> BTW, we can read from the device by hmp_memchar_read. :) > > And how is the console command better than the hmp_memchar_write one? > > > > Could you please give examples? > > Sure. The "console" command behaves like: > > (qemu) console foo > foo: hello world > (qemu) > > you can input data, then put enter or ctrl-] to return back to > the monitor. The data input from console would be written to the > CirMemCharDriver backend, which provide a more friendly and nice > HMP command as Anthony suggested. Maybe I'm missing something, but I don't understand how this is better than the hmp_memchar_write command. > >>>> + > >>>> + monitor_read_command(mon, 1); > >>>> +} > >>>> + > >>>> +void hmp_console(Monitor *mon, const QDict *qdict) > >>>> +{ > >>>> + const char *device = qdict_get_str(qdict, "chardev"); > >>>> + CharDriverState *chr; > >>>> + Error *err = NULL; > >>>> + > >>>> + chr = qemu_chr_find(device); > >>>> + > >>>> + if (!chr) { > >>>> + error_set(&err, QERR_DEVICE_NOT_FOUND, device); > >>>> + goto out; > >>>> + } > >>> No need to do this here as the QMP command will do it too. > >>> > >> I think we should do this check here, otherwise would > >> cause core dump when 'console' to a chardev that does not > >> exist. Wepass parameterchr->label by qmp_memchar_write() > >> in the handler hmp_read_console. > > Do you need the chr object? Why don't you just pass 'device' to > > monitor_read_console()? > > Yes, we need 'device' and 'chr' both here. 'device' pass to monitor_read_console > for the friendly prompt. 'chr' pass to handler hmp_read_console, the reason did not > pass 'device' directly to it is the limitation of argument for the handler > hmp_read_console. What limitation? It takes 'data' and 'opaque' (which is a bit weird). > Also it's better to give the prompt before the user enter the input > console if the device not found, the use-case as I post above. Why? > > >>>> + > >>>> + if (monitor_read_console(mon, device, hmp_read_console, chr) < 0) { > >>>> + monitor_printf(mon, "Connect to console %s failed\n", device); > >>>> + } > >>>> + > >>>> +out: > >>>> + hmp_handle_error(mon, &err); > >>>> +} > >>>> diff --git a/hmp.h b/hmp.h > >>>> index a5a0cfe..5b54a79 100644 > >>>> --- a/hmp.h > >>>> +++ b/hmp.h > >>>> @@ -77,5 +77,6 @@ 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_console(Monitor *mon, const QDict *qdict); > >>>> > >>>> #endif > >>>> diff --git a/monitor.c b/monitor.c > >>>> index 131b325..453c084 100644 > >>>> --- a/monitor.c > >>>> +++ b/monitor.c > >>>> @@ -256,6 +256,21 @@ int monitor_read_password(Monitor *mon, ReadLineFunc *readline_func, > >>>> } > >>>> } > >>>> > >>>> +int monitor_read_console(Monitor *mon, const char *device, > >>>> + ReadLineFunc *readline_func, void *opaque) > >>>> +{ > >>>> + char prompt[60]; > >>>> + > >>>> + if (!mon->rs) { > >>>> + return -1; > >>>> + } > >>>> + > >>>> + snprintf(prompt, sizeof(prompt), "%s: ", device); > >>>> + readline_start(mon->rs, prompt, 0, readline_func, opaque); > >>>> + > >>>> + return 0; > >>>> +} > >>>> + > >>>> void monitor_flush(Monitor *mon) > >>>> { > >>>> if (mon && mon->outbuf_index != 0 && !mon->mux_out) { > >>>> diff --git a/monitor.h b/monitor.h > >>>> index b6e7d95..735bd1b 100644 > >>>> --- a/monitor.h > >>>> +++ b/monitor.h > >>>> @@ -86,6 +86,9 @@ ReadLineState *monitor_get_rs(Monitor *mon); > >>>> int monitor_read_password(Monitor *mon, ReadLineFunc *readline_func, > >>>> void *opaque); > >>>> > >>>> +int monitor_read_console(Monitor *mon, const char *device, > >>>> + ReadLineFunc *readline_func, void *opaque); > >>>> + > >>>> int qmp_qom_set(Monitor *mon, const QDict *qdict, QObject **ret); > >>>> > >>>> int qmp_qom_get(Monitor *mon, const QDict *qdict, QObject **ret); > >> > > > >