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

[Laurent Vivier]

On 11/09/2017 14:04, Dr. David Alan Gilbert wrote:
> * Daniel P. Berrange (address@hidden) 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" <address@hidden> 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?

BTW, I'm not sure it is really useful to dump memory of a machine
without CPU.

Laurent