Re: [Qemu-devel] [RFC v6 06/14] configure: Use slow-path for atomic only when the softmmu is enabled

[Laurent Vivier <lvivier@redhat.com>]

On 15/12/2015 15:31, Paolo Bonzini wrote:
> 
> 
> On 15/12/2015 15:23, alvise rigo wrote:
>> Hi,
>>
>> On Mon, Dec 14, 2015 at 11:14 AM, Laurent Vivier <lvivier@redhat.com> wrote:
>>>
>>>
>>> On 14/12/2015 09:41, Alvise Rigo wrote:
>>>> Use the new slow path for atomic instruction translation when the
>>>> softmmu is enabled.
>>>>
>>>> Suggested-by: Jani Kokkonen <jani.kokkonen@huawei.com>
>>>> Suggested-by: Claudio Fontana <claudio.fontana@huawei.com>
>>>> Signed-off-by: Alvise Rigo <a.rigo@virtualopensystems.com>
>>>> ---
>>>>  configure | 4 ++++
>>>>  1 file changed, 4 insertions(+)
>>>>
>>>> diff --git a/configure b/configure
>>>> index b9552fd..cc3891a 100755
>>>> --- a/configure
>>>> +++ b/configure
>>>> @@ -4794,6 +4794,7 @@ echo "Install blobs     $blobs"
>>>>  echo "KVM support       $kvm"
>>>>  echo "RDMA support      $rdma"
>>>>  echo "TCG interpreter   $tcg_interpreter"
>>>> +echo "use ld/st excl    $softmmu"
>>>>  echo "fdt support       $fdt"
>>>>  echo "preadv support    $preadv"
>>>>  echo "fdatasync         $fdatasync"
>>>> @@ -5186,6 +5187,9 @@ fi
>>>>  if test "$tcg_interpreter" = "yes" ; then
>>>>    echo "CONFIG_TCG_INTERPRETER=y" >> $config_host_mak
>>>>  fi
>>>> +if test "$softmmu" = "yes" ; then
>>>> +  echo "CONFIG_TCG_USE_LDST_EXCL=y" >> $config_host_mak
>>>> +fi
>>>
>>> why is this "$softmmu" and not "$target_softmmu" ?
>>
>> I see now that is $target_softmmu setting CONFIG_SOFTMMU=y.
>> So for my understanding, which are the cases where $softmmu is set
>> while $target_softmmu is not?
> 
> When compiling foo-linux-user.

In fact, after having asked the question, I've found that it is right to
use softmmu which is a host parameter (while target_softmmu is guest
parameter) and softmmu is set to true if there is at least one *-softmmu
target.

Laurent