Re: [Qemu-devel] [PATCH v2] test: port postcopy test to ppc64

[Thomas Huth <thuth@redhat.com>]

On 26.07.2016 11:23, Laurent Vivier wrote:
> 
> 
> On 23/07/2016 08:30, David Gibson wrote:
>> On Fri, Jul 22, 2016 at 09:28:58AM +0200, Laurent Vivier wrote:
>>>
>>>
>>> On 22/07/2016 08:43, David Gibson wrote:
>>>> On Thu, Jul 21, 2016 at 06:47:56PM +0200, Laurent Vivier wrote:
>>>>> As userfaultfd syscall is available on powerpc, migration
>>>>> postcopy can be used.
>>>>>
>>>>> This patch adds the support needed to test this on powerpc,
>>>>> instead of using a bootsector to run code to modify memory,
>>>>> we use a FORTH script in "boot-command" property.
>>>>>
>>>>> As spapr machine doesn't support "-prom-env" argument
>>>>> (the nvram is initialized by SLOF and not by QEMU),
>>>>> "boot-command" is provided to SLOF via a file mapped nvram
>>>>> (with "-drive file=...,if=pflash")
>>>>>
>>>>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>>>>> ---
>>>>> v2: move FORTH script directly in sprintf()
>>>>>     use openbios_firmware_abi.h
>>>>>     remove useless "default" case
>>>>>
>>>>>  tests/Makefile.include |   1 +
>>>>>  tests/postcopy-test.c  | 116 +++++++++++++++++++++++++++++++++++++++++--------
>>>>>  2 files changed, 98 insertions(+), 19 deletions(-)
>>>>
>>>> There's a mostly cosmetic problem with this.  If you run make check
>>>> for a ppc64 target on an x86 machine, you get:
>>>>
>>>> GTESTER check-qtest-ppc64
>>>> "kvm" accelerator not found.
>>>> "kvm" accelerator not found.
>>>
>>> I think this is because of "-machine accel=kvm:tcg", it tries to use kvm
>>> and fall back to tcg.
>>>
>>> accel.c:
>>>
>>>      80 void configure_accelerator(MachineState *ms)
>>>      81 {
>>> ...
>>>     100         acc = accel_find(buf);
>>>     101         if (!acc) {
>>>     102             fprintf(stderr, "\"%s\" accelerator not found.\n", buf);
>>>     103             continue;
>>>     104         }
>>>
>>> We can remove the "-machine" argument to use the default instead (tcg or
>>> kvm).
>>
>> That sounds like a good option for a general test.
> 
> In fact, we can't: we need to add a "-machine accel=XXXX" to our command
> line to override the "-machine accel=qtest" provided by the qtest
> framework. If we don't override it, the machine doesn't start.

Would it work if you'd added some magic with "#ifdef CONFIG_KVM" here?

 Thomas