From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60576) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dx8wB-0003t0-DK for qemu-devel@nongnu.org; Wed, 27 Sep 2017 05:47:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dx8w8-0003Tf-9g for qemu-devel@nongnu.org; Wed, 27 Sep 2017 05:47:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51966) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dx8w8-0003TF-0S for qemu-devel@nongnu.org; Wed, 27 Sep 2017 05:47:24 -0400 Date: Wed, 27 Sep 2017 11:47:17 +0200 From: Cornelia Huck Message-ID: <20170927114717.72bd69f8.cohuck@redhat.com> In-Reply-To: <338c8565-691e-a8bc-d8a6-3637ce13701d@redhat.com> References: <20170926162058.30772-1-cohuck@redhat.com> <20170926162058.30772-2-cohuck@redhat.com> <338c8565-691e-a8bc-d8a6-3637ce13701d@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/1] s390x: create a compat s390 phb for <=2.10 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Hildenbrand Cc: qemu-devel@nongnu.org, borntraeger@de.ibm.com, agraf@suse.de, zyimin@linux.vnet.ibm.com, pasic@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, dgilbert@redhat.com On Tue, 26 Sep 2017 20:40:25 +0200 David Hildenbrand wrote: > 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 > > Fixes: d32bd032d8 ("s390x/ccw: create s390 phb conditionally") > > Signed-off-by: Cornelia Huck > > --- > > 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. Yes, that whole thing is horrible, especially interaction with compat machines. Do you have an idea on how to create such a dummy device (without having to effectively copy a lot of configured-out code)?