Re: [Qemu-devel] [PATCH 1/2] qga: add guest-get-time command

[Lei Li <lilei@linux.vnet.ibm.com>]

On 03/02/2013 01:02 AM, Eric Blake wrote:
> On 03/01/2013 02:32 AM, Lei Li wrote:
>> Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
>> ---
>>   qga/commands-posix.c | 16 ++++++++++++++++
>>   qga/qapi-schema.json | 16 ++++++++++++++++
>>   2 files changed, 32 insertions(+)
>>
>> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
>> index 0ad73f3..f159e25 100644
>> --- a/qga/commands-posix.c
>> +++ b/qga/commands-posix.c
>> @@ -119,6 +119,22 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err)
>>       /* succeded */
>>   }
>>   
>> +int64_t qmp_guest_get_time(Error **errp)
>> +{
>> +   int ret;
>> +   qemu_timeval tq;
>> +   int64_t time_ns;
>> +
>> +   ret = qemu_gettimeofday(&tq);
>> +   if (ret < 0) {
>> +       error_setg_errno(errp, errno, "Failed to get time");
>> +       return -1;
>> +   }
>> +
>> +   time_ns = tq.tv_sec * 1000000000LL + tq.tv_usec * 1000;
> Is it worth a sanity check that the tv_sec scaling doesn't overflow?  Of
> course, that won't happen until far into the future (well beyond the
> 2038 overflow of 32-bit seconds since Epoch), so it won't hit in OUR
> lifetime, so I can look the other way.
>>   
>>   ##
>> +# @guest-get-time:
>> +#
>> +# Get the information about guest time relative to the Epoch
>> +# of 1970-01-01 in UTC/GMT.
> UTC and GMT are not the same thing.  I'd drop the '/GMT'.
> http://www.diffen.com/difference/GMT_vs_UTC

Oh, good to know! :)
Thanks.

>> +#
>> +# This command try to get the guest's notion of the current
>> +# time.
> This sentence is redundant with the first one, and has grammar issues.
> Drop it.

Sure.

>
>> +#
>> +# Returns: Time in nanoseconds on success.
>> +#
>> +# Since 1.5
>> +##
>> +{ 'command': 'guest-get-time',
>> +  'returns': 'int' }
>> +
>> +##
>>   # @GuestAgentCommandInfo:
>>   #
>>   # Information about guest agent commands.
>>


-- 
Lei