Re: [PATCH v12 2/7] s390x/cpu topology: reporting the CPU topology to the guest

From: Pierre Morel <pmorel@linux.ibm.com>
To: qemu-s390x@nongnu.org
Cc: qemu-devel@nongnu.org, borntraeger@de.ibm.com,
	pasic@linux.ibm.com, richard.henderson@linaro.org,
	david@redhat.com, thuth@redhat.com, cohuck@redhat.com,
	mst@redhat.com, pbonzini@redhat.com, kvm@vger.kernel.org,
	ehabkost@redhat.com, marcel.apfelbaum@gmail.com,
	eblake@redhat.com, armbru@redhat.com, seiden@linux.ibm.com,
	nrb@linux.ibm.com, scgl@linux.ibm.com, frankja@linux.ibm.com,
	berrange@redhat.com, clg@kaod.org
Subject: Re: [PATCH v12 2/7] s390x/cpu topology: reporting the CPU topology to the guest
Date: Tue, 6 Dec 2022 15:44:24 +0100	[thread overview]
Message-ID: <8c6ae27d-ac83-505f-cf2f-df30c3612e6f@linux.ibm.com> (raw)
In-Reply-To: <20221129174206.84882-3-pmorel@linux.ibm.com>

On 11/29/22 18:42, Pierre Morel wrote:
> The guest uses the STSI instruction to get information on the
> CPU topology.
> 
> Let us implement the STSI instruction for the basis CPU topology
> level, level 2.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>   target/s390x/cpu.h          |  77 +++++++++++++++
>   hw/s390x/s390-virtio-ccw.c  |  12 +--
>   target/s390x/cpu_topology.c | 186 ++++++++++++++++++++++++++++++++++++
>   target/s390x/kvm/kvm.c      |   6 +-
>   target/s390x/meson.build    |   1 +
>   5 files changed, 274 insertions(+), 8 deletions(-)
>   create mode 100644 target/s390x/cpu_topology.c
> 

> + */
> +static void s390_topology_add_cpu(S390Topology *topo, S390CPU *cpu)
> +{
> +    int core_id = cpu->env.core_id;
> +    int bit, origin;
> +    int socket_id;
> +
> +    cpu->machine_data = topo;

Sorry this wrong machine_data is already used as a pointer to the 
S390CcwMachineState machine.

> +    socket_id = core_id / topo->num_cores;
> +    /*

...snip...

> +
> +static int setup_stsi(S390CPU *cpu, SysIB_151x *sysib, int level)
> +{
> +    S390Topology *topo = (S390Topology *)cpu->machine_data;

Sorry, wrong too this must be:

     S390CcwMachineState *s390ms = cpu->machine_data;
     S390Topology *topo = S390_CPU_TOPOLOGY(s390ms->topology);

> +    char *p = sysib->tle;
> +
> +    sysib->mnest = level;
> +    switch (level) {
> +    case 2:
> +        sysib->mag[S390_TOPOLOGY_MAG2] = topo->num_sockets;
> +        sysib->mag[S390_TOPOLOGY_MAG1] = topo->num_cores;
> +        p = s390_top_set_level2(topo, p);
> +        break;
> +    }
> +
> +    return p - (char *)sysib;
> +}
> +

Regards,
Pierre

-- 
Pierre Morel
IBM Lab Boeblingen