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

[Cornelia Huck <cohuck@redhat.com>]

On Mon, 11 Sep 2017 14:10:14 +0200
Laurent Vivier <lvivier@redhat.com> 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:  

> >>> 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?

We have several combinations that can fail here... (cf. the problem
with no memory and no filter above).

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

Even so, it should not segfault (and neither should dumping a guest
with no memory, even if it doesn't make sense).