On 26.09.2017 18:20, Cornelia Huck wrote:
> d32bd032d8 ("s390x/ccw: create s390 phb conditionally") made
> creating the s390 phb dependant on the zpci facility. This broke
> migration from pre-cpu model machines which was fixed with
> 8ad9087c4a ("s390x/ccw: create s390 phb for compat reasons as well").
> However, that is not enough: Migration from 2.10 with -cpu z13
> breaks as well.
>
> Let's create a phb for all pre-2.11 compat machines to fix this.
> We leave the zpci facility off to avoid a guest-visible change
> with cpu models on.
>
> Reported-by: Christian Borntraeger <borntrae...@de.ibm.com>
> Fixes: d32bd032d8 ("s390x/ccw: create s390 phb conditionally")
> Signed-off-by: Cornelia Huck <coh...@redhat.com>
> ---
> hw/s390x/s390-virtio-ccw.c | 8 +++++++-
> include/hw/s390x/s390-virtio-ccw.h | 1 +
> 2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 1bcb7000ab..981f1c4336 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -247,6 +247,8 @@ static void s390_create_virtio_net(BusState *bus, const
> char *name)
> }
> }
>
> +static S390CcwMachineClass *get_machine_class(void);
> +
> static void ccw_init(MachineState *machine)
> {
> int ret;
> @@ -266,7 +268,7 @@ static void ccw_init(MachineState *machine)
> machine->initrd_filename, "s390-ccw.img",
> "s390-netboot.img", true);
>
> - if (s390_has_feat(S390_FEAT_ZPCI)) {
> + if (s390_has_feat(S390_FEAT_ZPCI) || get_machine_class()->phb_compat) {
> DeviceState *dev = qdev_create(NULL, TYPE_S390_PCI_HOST_BRIDGE);
> object_property_add_child(qdev_get_machine(),
> TYPE_S390_PCI_HOST_BRIDGE,
> @@ -407,6 +409,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void
> *data)
> s390mc->cpu_model_allowed = true;
> s390mc->css_migration_enabled = true;
> s390mc->gs_allowed = true;
> + s390mc->phb_compat = false;
> mc->init = ccw_init;
> mc->reset = s390_machine_reset;
> mc->hot_add_cpu = s390_hot_add_cpu;
> @@ -716,6 +719,9 @@ static void
> ccw_machine_2_10_instance_options(MachineState *machine)
>
> static void ccw_machine_2_10_class_options(MachineClass *mc)
> {
> + S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc);
> +
> + s390mc->phb_compat = pci_available;
> ccw_machine_2_11_class_options(mc);
> SET_MACHINE_COMPAT(mc, CCW_COMPAT_2_10);
> }
> diff --git a/include/hw/s390x/s390-virtio-ccw.h
> b/include/hw/s390x/s390-virtio-ccw.h
> index a9a90c2022..fb717afe92 100644
> --- a/include/hw/s390x/s390-virtio-ccw.h
> +++ b/include/hw/s390x/s390-virtio-ccw.h
> @@ -41,6 +41,7 @@ typedef struct S390CcwMachineClass {
> bool cpu_model_allowed;
> bool css_migration_enabled;
> bool gs_allowed;
> + bool phb_compat;
> } S390CcwMachineClass;
>
> /* runtime-instrumentation allowed by the machine */
>
I'd really really really (did I mention really?) favor something like a
dummy device, because we could easily handle the !CONFIG_PCI case then.
All these compat options and conditions will kill us someday... we're
already patching around that whole stuff way too much.
If we ever unconditionally created a device, we should keep doing so.
--
Thanks,
David
