From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:43016) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TT8yl-0004hC-BB for qemu-devel@nongnu.org; Tue, 30 Oct 2012 06:23:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TT8yi-0005o3-I8 for qemu-devel@nongnu.org; Tue, 30 Oct 2012 06:23:27 -0400 Received: from e28smtp08.in.ibm.com ([122.248.162.8]:40161) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TT8yh-0005n9-KV for qemu-devel@nongnu.org; Tue, 30 Oct 2012 06:23:24 -0400 Received: from /spool/local by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 30 Oct 2012 15:53:20 +0530 Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q9UANG1W27263224 for ; Tue, 30 Oct 2012 15:53:16 +0530 Received: from d28av04.in.ibm.com (loopback [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q9UFr7Zn022292 for ; Wed, 31 Oct 2012 02:53:07 +1100 Message-ID: <508FAA64.4070507@linux.vnet.ibm.com> Date: Tue, 30 Oct 2012 18:22:28 +0800 From: Lei Li MIME-Version: 1.0 References: <1351250512-6386-1-git-send-email-lilei@linux.vnet.ibm.com> <1351250512-6386-3-git-send-email-lilei@linux.vnet.ibm.com> <20121026151716.37b78de8@doriath.home> <508E01B0.3030200@linux.vnet.ibm.com> <20121029112302.3bf84418@doriath.home> In-Reply-To: <20121029112302.3bf84418@doriath.home> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/4] QAPI: Introduce memchar-write QMP command List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luiz Capitulino Cc: blauwirbel@gmail.com, aliguori@us.ibm.com, qemu-devel@nongnu.org On 10/29/2012 09:23 PM, Luiz Capitulino wrote: > On Mon, 29 Oct 2012 12:10:24 +0800 > Lei Li wrote: > >> On 10/27/2012 01:17 AM, Luiz Capitulino wrote: >>> On Fri, 26 Oct 2012 19:21:50 +0800 >>> Lei Li wrote: >>> >>>> Signed-off-by: Lei Li >>>> --- >>>> hmp-commands.hx | 17 +++++++++++++++++ >>>> hmp.c | 15 +++++++++++++++ >>>> hmp.h | 1 + >>>> qapi-schema.json | 47 +++++++++++++++++++++++++++++++++++++++++++++++ >>>> qemu-char.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ >>>> qmp-commands.hx | 34 ++++++++++++++++++++++++++++++++++ >>>> 6 files changed, 158 insertions(+), 0 deletions(-) >>>> >>>> diff --git a/hmp-commands.hx b/hmp-commands.hx >>>> index e0b537d..a37b8e9 100644 >>>> --- a/hmp-commands.hx >>>> +++ b/hmp-commands.hx >>>> @@ -825,6 +825,23 @@ Inject an NMI on the given CPU (x86 only). >>>> ETEXI >>>> >>>> { >>>> + .name = "memchar_write", >>>> + .args_type = "chardev:s,data:s", >>>> + .params = "chardev data", >>>> + .mhandler.cmd = hmp_memchar_write, >>>> + }, >>>> + >>>> +STEXI >>>> +@item memchar_write @var{chardev} @var{data} >>>> +@findex memchar_write >>>> +Provide writing interface for CirMemCharDriver. Write @var{data} >>>> +to cirmemchr char device. Note that we will add 'control' options >>>> +for read and write command that specifies behavior when the queue >>>> +is full/empty, for now just assume a drop behaver in these two commands. >>> You can drop everything after "Note". >>> >> ok >> >>>> + >>>> +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 2b97982..082985b 100644 >>>> --- a/hmp.c >>>> +++ b/hmp.c >>>> @@ -683,6 +683,21 @@ 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; >>>> + const char *chardev = qdict_get_str(qdict, "chardev"); >>>> + const char *data = qdict_get_str(qdict, "data"); >>>> + enum DataFormat format; >>> Why do you need this variable? >> Sure, I will drop this. >> >>>> + Error *errp = NULL; >>>> + >>>> + size = strlen(data); >>>> + format = DATA_FORMAT_UTF8; >>>> + qmp_memchar_write(chardev, size, data, true, format, &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 71ea384..406ebb1 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 c615ee2..43ef6bc 100644 >>>> --- a/qapi-schema.json >>>> +++ b/qapi-schema.json >>>> @@ -325,6 +325,53 @@ >>>> { 'command': 'query-chardev', 'returns': ['ChardevInfo'] } >>>> >>>> ## >>>> +# @DataFormat: >>>> +# >>>> +# An enumeration of data format. The default value would >>>> +# be utf8. >>> Please, remove the "default value" part. This is decided by the command >>> using this type. >> Now the option format is optional, if it's not set then default by 'utf8'. >> I think it's a reasonable behaver. :) > What I meant is that the right place to say what the value is is in > the command documentation, not in @DataFormat doc. Here, only having > "An enumeration of data encodings" is fine. OK, done. >>>> +# >>>> +# @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. >>> Please, drop this note. It's not needed. >>> >> ok >> >>>> +# >>>> +# Since: 1.3 >>>> +## >>>> +{ 'enum': 'DataFormat' >>>> + 'data': [ 'utf8', 'base64' ] } >>>> + >>>> +## >>>> +# @memchar-write: >>>> +# >>>> +# Provide writing interface for memchardev. Write data to memchar >>>> +# char device. >>>> +# >>>> +# @chardev: the name of the memchar char device. >>>> +# >>>> +# @size: the size to write in bytes. Should be power of 2. >>>> +# >>>> +# @data: the source data write to memchar. >>>> +# >>>> +# @format: #optional the format of the data write to memchardev, by >>>> +# default is 'utf8'. >>>> +# >>>> +# Returns: Nothing on success >>>> +# If @chardev is not a valid memchr device, DeviceNotFound >>>> +# >>>> +# Notes: 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. For now just assume 'drop' behaver >>>> +# for this command. >>> Please, replace this note with an explanation of the current behavior. No >>> need to talk about the future. >> Sure. >> >>>> +# >>>> +# Since: 1.3 >>>> +## >>>> +{ 'command': 'memchar-write', >>>> + 'data': {'chardev': 'str', 'size': 'int', 'data': 'str', >>>> + '*format': 'DataFormat'} } >>>> + >>>> +## >>>> # @CommandInfo: >>>> # >>>> # Information about a QMP command >>>> diff --git a/qemu-char.c b/qemu-char.c >>>> index c3ec43d..6114e29 100644 >>>> --- a/qemu-char.c >>>> +++ b/qemu-char.c >>>> @@ -2717,6 +2717,50 @@ fail: >>>> return NULL; >>>> } >>>> >>>> +void qmp_memchar_write(const char *chardev, int64_t size, >>>> + const char *data, bool has_format, >>>> + enum DataFormat format, >>>> + Error **errp) >>>> +{ >>>> + CharDriverState *chr; >>>> + guchar *write_data; >>>> + int ret; >>>> + gsize write_count; >>>> + >>>> + chr = qemu_chr_find(chardev); >>>> + if (!chr) { >>>> + error_set(errp, QERR_DEVICE_NOT_FOUND, chardev); >>>> + return; >>>> + } >>>> + >>>> + if (strcmp(chr->filename, "memchr") != 0) { >>>> + error_setg(errp,"%s is not memory char device\n", chardev); >>>> + return; >>>> + } >>> This is wrong, as it's unreliable. A hackish (but hopefully correct) way >>> of doing this would be to check chr->init against the circmem init function. >>> But please, put this behind a function because it's ugly. >> Hmm, I guess it's because the chr->filename could be NULL. but we can still >> get it since CharDriverState keeps the inited type of backend. I am not sure >> that check chr->init against the cirmem init funciton could work, I'll have >> a try. >> >>>> + >>>> + /* XXX: For the sync command as 'block', waiting for the qmp >>>> + * to support necessary feature. Now just act as 'drop' */ >>> Please, replace this note with an explanation of the current behavior. >> ok. >> >>>> + if (cirmem_chr_is_full(chr)) { >>>> + 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); >>> IIRC circmem_chr_write() doesn't check if write_count if a power of two, >>> what happens if it isn't? >> I have considered your suggestion on this in v4. The reason why I did not >> add the assert is that I think we have already check with this when cirmem >> init, so there is no need to check it again. Correct me if I am wrong. :) > I was actually asking an honest question: does cirmem_chr_write() assume > that len is a power of two? If yes, what if the user doesn't pass a > power of two value to qmp_memchar_write()? Ah, there must be some misunderstanding here... :) We let the size of ring buffer inited as power of 2, not the write_count. And it has already been checked when we init the CirMemCharDriver. That's why I did not add the assert in the function cirmem_chr_write. > >>>> + >>>> + if (ret < 0) { >>>> + error_setg(errp, "Failed to write to memchr %s", chardev); >>>> + return; >>>> + } >>>> +} >>>> + >>>> 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 5ba8c48..7548b9b 100644 >>>> --- a/qmp-commands.hx >>>> +++ b/qmp-commands.hx >>>> @@ -466,6 +466,40 @@ 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?", >>> You've dropped 'control', haven't you? >> Yes, sorry I forgot to drop here.. :( >> >>>> + .help = "write size of data to memchar chardev", >>>> + .mhandler.cmd_new = qmp_marshal_input_memchar_write, >>>> + }, >>>> + >>>> +SQMP >>>> +memchar-write >>>> +------------- >>>> + >>>> +Provide writing interface for memchardev. Write data to memchar >>>> +char device. >>>> + >>>> +Arguments: >>>> + >>>> +- "chardev": the name of the char device, must be unique (json-string) >>>> +- "size": the memory size, in bytes, should be power of 2 (json-int) >>>> +- "data": the source data writed to memchar (json-string) >>>> +- "format": the data format write to memchardev, default is >>>> + utf8. (json-string, optional) >>>> + - Possible values: "utf8", "base64" >>>> + >>>> +Example: >>>> + >>>> +-> { "execute": "memchar-write", >>>> + "arguments": { "chardev": foo, >>>> + "size": 8, >>>> + "data": "abcdefgh", >>>> + "format": "utf8" } } >>>> +<- { "return": {} } >>>> + >>>> +EQMP >>>> + >>>> + { >>>> .name = "xen-save-devices-state", >>>> .args_type = "filename:F", >>>> .mhandler.cmd_new = qmp_marshal_input_xen_save_devices_state, >> -- Lei