Re: [Qemu-devel] [PATCH v8] s390x/cpu: expose the guest crash information

[Cornelia Huck <cohuck@redhat.com>]

On Mon, 12 Feb 2018 11:51:37 -0600
Eric Blake <eblake@redhat.com> wrote:

> On 02/09/2018 06:25 AM, Christian Borntraeger wrote:
> > This patch is the s390 implementation of guest crash information,
> > similar to commit d187e08dc4 ("i386/cpu: add crash-information QOM
> > property") and the related commits. We will detect several crash
> > reasons, with the "disabled wait" being the most important one, since
> > this is used by all s390 guests as a "panic like" notification.
> >   
> ...
> > 
> > Co-authored-by: Jing Liu <liujbjl@linux.vnet.ibm.com>
> > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> > ---  
> 
> > +##
> > +# @GuestPanicInformationS390:
> > +#
> > +# S390 specific guest panic information (PSW)
> > +#
> > +# @core: core id of the CPU that crashed
> > +# @psw-mask: control fields of guest PSW
> > +# @psw-addr: guest instruction address
> > +# @reason: guest crash reason in human readable form  
> 
> This description is stale, now that it is an enum (and thus also 
> machine-readable).  I'd shorten it to just
> 
> # @reason: guest crash reason

Agreed, folded in.

> 
> > +#
> > +# Since: 2.12
> > +##
> > +{'struct': 'GuestPanicInformationS390',
> > + 'data': { 'core': 'uint32',
> > +           'psw-mask': 'uint64',
> > +           'psw-addr': 'uint64',
> > +           'reason': 'S390CrashReason' } }  
> 
> > +static GuestPanicInformation *s390_cpu_get_crash_info(CPUState *cs)
> > +{
> > +    GuestPanicInformation *panic_info;
> > +    S390CPU *cpu = S390_CPU(cs);
> > +
> > +    cpu_synchronize_state(cs);
> > +    panic_info = g_malloc0(sizeof(GuestPanicInformation));
> > +
> > +    panic_info->type = GUEST_PANIC_INFORMATION_TYPE_S390;
> > +#if !defined(CONFIG_USER_ONLY)
> > +    panic_info->u.s390.core = cpu->env.core_id;
> > +#else
> > +    panic_info->u.s390.core = 0; /* sane default for non system emulation */  
> 
> Redundant assignment thanks to the g_malloc0() above, but the comment 
> makes it explicit why you did that, so I can live with it.

I actually prefer it this way, as it preempts questions about user-only
handling.

> 
> With the qapi comment tweak,
> Reviewed-by: Eric Blake <eblake@redhat.com>

Thanks!