Re: [Qemu-devel] [PATCH] configure: Relax check for libseccomp

[Thomas Huth]

On 04/04/2019 03.53, Peter Maydell wrote:
> On Wed, 3 Apr 2019 at 23:27, Daniel P. Berrangé <address@hidden> wrote:
>>
>> On Wed, Apr 03, 2019 at 02:49:48PM +0200, Helge Deller wrote:
>>> diff --git a/configure b/configure
>>> index 1c563a7027..8632267049 100755
>>> --- a/configure
>>> +++ b/configure
>>> @@ -2389,7 +2389,6 @@ if test "$seccomp" != "no" ; then
>>>          libseccomp_minver="2.3.0"
>>>          ;;
>>>      *)
>>> -        libseccomp_minver=""
>>>          ;;
>>>      esac
>>
>> This makes sense to me. From a QEMU source POV we are able to build with
>> libseccomp >= 2.2.0, which our default libseccomp_minver= env expresses
>> a few lines earlier.
>>
>> If libseccomp isn't supported on a platform, then I think we should just
>> assume that libseccomp won't be present in the OS install we are building
>> against. I don't think QEMU needs to second-guess whether or not it is
>> supported on the given architecture.
> 
> If we want to do this then we should handle all the archs which
> don't need to special case the seccomp version identically, ie
> remove the x86/mips case which with this patch would be the
> same as the default case.
> 
>> In fact I'd go as far as to say we
>> could probably just remove all this per-arch checking and just have a
>> generic >= 2.2.0 check, and just rely on fact libseccomp won't exist
>> on a s390/ppc/etc host if the distro had version < 2.3.0
> 
> The arm case at least is present because libseccomp 2.2.0 was
> being built but didn't actually work for us. See commit ae6e8ef11e6cb43ec83.

Looking at https://repology.org/project/libseccomp/versions it seems
like all major distro versions that we want to support feature at least
version 2.3.0 ... so I think we can simplify the check here for all
architectures and only test for a version >= 2.3.0.

 Thomas