[Qemu-devel] [PATCH v3] numa: we don't implement NUMA for s390x

[Qemu-devel] [PATCH v3] numa: we don't implement NUMA for s390x

[David Hildenbrand]

Right now it is possible to crash QEMU for s390x by providing e.g.
    -numa node,nodeid=0,cpus=0-1

Problem is, that numa.c uses mc->cpu_index_to_instance_props as an
indicator whether NUMA is supported by a machine type. We don't
implement NUMA for s390x ("topology") yet. However we need
mc->cpu_index_to_instance_props for query-cpus.

So let's fix this case by also checking for mc->get_default_cpu_node_id,
which will be needed by machine_set_cpu_numa_node().

qemu-system-s390x: -numa node,nodeid=0,cpus=0-1: NUMA is not supported by
                   this machine-type

While at it, make s390_cpu_index_to_props() look like on other
architectures.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 hw/s390x/s390-virtio-ccw.c | 8 +++++---
 numa.c                     | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 4abbe89847..1eff4a6274 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -388,12 +388,14 @@ static void s390_machine_device_unplug_request(HotplugHandler *hotplug_dev,
     }
 }
 
-static CpuInstanceProperties s390_cpu_index_to_props(MachineState *machine,
+static CpuInstanceProperties s390_cpu_index_to_props(MachineState *ms,
                                                      unsigned cpu_index)
 {
-    g_assert(machine->possible_cpus && cpu_index < machine->possible_cpus->len);
+    MachineClass *mc = MACHINE_GET_CLASS(ms);
+    const CPUArchIdList *possible_cpus = mc->possible_cpu_arch_ids(ms);
 
-    return machine->possible_cpus->cpus[cpu_index].props;
+    assert(cpu_index < possible_cpus->len);
+    return possible_cpus->cpus[cpu_index].props;
 }
 
 static const CPUArchIdList *s390_possible_cpu_arch_ids(MachineState *ms)
diff --git a/numa.c b/numa.c
index 7e0e789b02..103b93f5cb 100644
--- a/numa.c
+++ b/numa.c
@@ -80,7 +80,7 @@ static void parse_numa_node(MachineState *ms, NumaNodeOptions *node,
         return;
     }
 
-    if (!mc->cpu_index_to_instance_props) {
+    if (!mc->cpu_index_to_instance_props || !mc->get_default_cpu_node_id) {
         error_report("NUMA is not supported by this machine-type");
         exit(1);
     }
-- 
2.14.3

Re: [Qemu-devel] [PATCH v3] numa: we don't implement NUMA for s390x

[Christian Borntraeger]

On 02/27/2018 12:02 PM, David Hildenbrand wrote:
> Right now it is possible to crash QEMU for s390x by providing e.g.
>     -numa node,nodeid=0,cpus=0-1
> 
> Problem is, that numa.c uses mc->cpu_index_to_instance_props as an
> indicator whether NUMA is supported by a machine type. We don't
> implement NUMA for s390x ("topology") yet. However we need
> mc->cpu_index_to_instance_props for query-cpus.
> 
> So let's fix this case by also checking for mc->get_default_cpu_node_id,
> which will be needed by machine_set_cpu_numa_node().
> 
> qemu-system-s390x: -numa node,nodeid=0,cpus=0-1: NUMA is not supported by
>                    this machine-type
> 
> While at it, make s390_cpu_index_to_props() look like on other
> architectures.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>


> ---
>  hw/s390x/s390-virtio-ccw.c | 8 +++++---
>  numa.c                     | 2 +-
>  2 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 4abbe89847..1eff4a6274 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -388,12 +388,14 @@ static void s390_machine_device_unplug_request(HotplugHandler *hotplug_dev,
>      }
>  }
> 
> -static CpuInstanceProperties s390_cpu_index_to_props(MachineState *machine,
> +static CpuInstanceProperties s390_cpu_index_to_props(MachineState *ms,
>                                                       unsigned cpu_index)
>  {
> -    g_assert(machine->possible_cpus && cpu_index < machine->possible_cpus->len);
> +    MachineClass *mc = MACHINE_GET_CLASS(ms);
> +    const CPUArchIdList *possible_cpus = mc->possible_cpu_arch_ids(ms);
> 
> -    return machine->possible_cpus->cpus[cpu_index].props;
> +    assert(cpu_index < possible_cpus->len);
> +    return possible_cpus->cpus[cpu_index].props;
>  }
> 
>  static const CPUArchIdList *s390_possible_cpu_arch_ids(MachineState *ms)
> diff --git a/numa.c b/numa.c
> index 7e0e789b02..103b93f5cb 100644
> --- a/numa.c
> +++ b/numa.c
> @@ -80,7 +80,7 @@ static void parse_numa_node(MachineState *ms, NumaNodeOptions *node,
>          return;
>      }
> 
> -    if (!mc->cpu_index_to_instance_props) {
> +    if (!mc->cpu_index_to_instance_props || !mc->get_default_cpu_node_id) {
>          error_report("NUMA is not supported by this machine-type");
>          exit(1);
>      }
> 

Re: [Qemu-devel] [PATCH v3] numa: we don't implement NUMA for s390x

[Cornelia Huck]

On Tue, 27 Feb 2018 12:02:55 +0100
David Hildenbrand <david@redhat.com> wrote:

> Right now it is possible to crash QEMU for s390x by providing e.g.
>     -numa node,nodeid=0,cpus=0-1
> 
> Problem is, that numa.c uses mc->cpu_index_to_instance_props as an
> indicator whether NUMA is supported by a machine type. We don't
> implement NUMA for s390x ("topology") yet. However we need
> mc->cpu_index_to_instance_props for query-cpus.
> 
> So let's fix this case by also checking for mc->get_default_cpu_node_id,
> which will be needed by machine_set_cpu_numa_node().
> 
> qemu-system-s390x: -numa node,nodeid=0,cpus=0-1: NUMA is not supported by
>                    this machine-type
> 
> While at it, make s390_cpu_index_to_props() look like on other
> architectures.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  hw/s390x/s390-virtio-ccw.c | 8 +++++---
>  numa.c                     | 2 +-
>  2 files changed, 6 insertions(+), 4 deletions(-)

Thanks, applied.