Re: [Qemu-devel] [PATCH] hmp: fix "dump-quest-memory" segfault (ppc)

[Thomas Huth <thuth@redhat.com>]

On 11.09.2017 14:15, Laurent Vivier wrote:
> On 11/09/2017 14:13, Daniel P. Berrange wrote:
>> On Mon, Sep 11, 2017 at 02:10:14PM +0200, Laurent Vivier wrote:
>>> On 11/09/2017 14:04, Dr. David Alan Gilbert wrote:
>>>> * Daniel P. Berrange (berrange@redhat.com) wrote:
>>>>> On Mon, Sep 11, 2017 at 01:41:58PM +0200, Cornelia Huck wrote:
>>>>>> On Mon, 11 Sep 2017 12:06:15 +0100
>>>>>> "Daniel P. Berrange" <berrange@redhat.com> wrote:
>>>>>>
>>>>>>> On Mon, Sep 11, 2017 at 01:00:37PM +0200, Laurent Vivier wrote:
>>>>>>>> Commit fd5d23babf (hmp: fix "dump-quest-memory" segfault)
>>>>>>>> fixes the problem for i386, do the same for ppc.  
>>>>>>>
>>>>>>> What about all the other targets QEMU supports ?  Have you checked if they
>>>>>>> are similarly affected, as we don't want to wait another 6 months to get a
>>>>>>> bug report that s390 or aarch64 crash in exactly the same way too.
>>>>>>
>>>>>> This patch actually prompted me to check s390, and the mentioned
>>>>>> command line works fine.
>>>>>>
>>>>>> However, if we start a qemu with no guest memory defined and then call
>>>>>> dump-guest-memory without filtering, we get a core dump instead of a
>>>>>> guest dump (s390x or x86_64, machine none).
>>>>>>
>>>>>> I can take a stab at fixing that, unless someone beats me to it.
>>>>>
>>>>> I wonder if someone wants to write a qtest job to run dump-guest-memory
>>>>> across all machine types, on all targets. Seems we have enough crashiness
>>>>> in this code to make it worthwhile to test
>>>>
>>>> We do have - that's how we found this case;  it's part of test-hmp.
>>>
>>> The test-hmp runs by default with 0 MB of memory, the problem can only
>>> be found with some memory added to the machine.
>>>
>>> Perhaps we can simply update the test to add memory?
>>
>> Probably best to run it twice, 0MB and with say 2MB, as they're both
>> fairly magic values.
> 
> OK, I'm going to update the test.

Thanks! But please note that it is only the "none" machine which is
started without memory and CPU by default - all the other boards should
have a default set of memory and at least one CPU. So we should only add
an additional tests for the "none" machine here.

 Thomas