Re: [PATCH 1/2] libxl, Introduce the command line handler for the new qemu.

[Anthony PERARD <anthony.perard@citrix.com>]

Stefano Stabellini wrote:
> On Wed, 4 Aug 2010, anthony.perard@citrix.com wrote:
>> From: Anthony PERARD <anthony.perard@citrix.com>
>>
>> This patch adds a function to check the version of the device model.
>> Depending on the version of the DM, the command line arguments will be
>> built differently.
>>
>> Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
>> ---
>>  tools/libxl/libxl.c       |  163 ++++++++++++++++++++++++++++++++++++++++++++-
>>  tools/libxl/libxl_utils.c |   73 ++++++++++++++++++++
>>  tools/libxl/libxl_utils.h |    5 ++
>>  3 files changed, 240 insertions(+), 1 deletions(-)
 >>
 >> [...]
 >>
>> +    // Search for the new version or the old version:
>> +    // QEMU emulator version 0.12.50, ...
>> +    // QEMU PC emulator version 0.10.2, ...
>> +    if (strncmp("QEMU", buf, 4) == 0) {
>> +        char *v = strstr(buf, "version ");
>> +        if (v) {
>> +            int major, minor;
>> +            char *endptr = NULL;
>> +
>> +            v += strlen("version ");
>> +            major = strtol(v, &endptr, 10);
>> +            if (major == 0 && endptr && *endptr == '.') {
>> +                v = endptr + 1;
>> +                minor = strtol(v, &endptr, 10);
>> +                if (minor >= 12)
>> +                    return 1;
>> +            }
>> +            return 0;
>> +        }
>> +    }
>> +    return 0;
>> +}
> 
> I think Gianni is right about the string to search: it is probably
> better to add a Xen specific string to qemu-dm, like "QEMU-DM", and rely
> on that and the version (0.10.2 or older) to distinguish between the
> two.

I can do something better by run "qemu -M ?" and check if "xenfv" 
machine is supported. This work with both versions.

-- 
Anthony PERARD