Re: [PATCH v3 3/7] arm/virt: Use virtio-md-pci (un)plug functions

[David Hildenbrand]

On 11.07.23 10:47, Michael S. Tsirkin wrote:
> On Tue, Jul 11, 2023 at 10:32:31AM +0200, David Hildenbrand wrote:
> > On 10.07.23 23:40, Michael S. Tsirkin wrote:
> > > > @@ -2855,12 +2796,11 @@ static void virt_machine_device_plug_cb(HotplugHandler 
> > > > *hotplug_dev,
> > > >                                         SYS_BUS_DEVICE(dev));
> > > >            }
> > > >        }
> > > > +
> > > >        if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > > >            virt_memory_plug(hotplug_dev, dev, errp);
> > > > -    }
> > > > -
> > > > -    if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
> > > > -        virt_virtio_md_pci_plug(hotplug_dev, dev, errp);
> > > > +    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MD_PCI)) {
> > > > +        virtio_md_pci_plug(VIRTIO_MD_PCI(dev), MACHINE(hotplug_dev), errp);
> > > >        }
> > > >        if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
> > >
> > >
> > > How is this supposed to link if virtio-md is disabled at compile time?
> >
> > Good point.
> >
> > The old code unconditionally enabled MEM_DEVICE, so we never required subs
> > for that.
> >
> > We either need stubs or have to wrap this in #ifdef.
> >
> > Stubs sound cleaner.
>
> That is what we usually do, yes.

I'm testing with the following:


diff --git a/stubs/meson.build b/stubs/meson.build
index a56645e2f7..160154912c 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -65,3 +65,4 @@ else
 endif
 stub_ss.add(files('semihost-all.c'))
 stub_ss.add(when: 'CONFIG_VFIO_USER_SERVER', if_false: 
files('vfio-user-obj.c'))
+stub_ss.add(when: 'CONFIG_VIRTIO_MD', if_false: files('virtio_md_pci.c'))
diff --git a/stubs/virtio_md_pci.c b/stubs/virtio_md_pci.c
new file mode 100644
index 0000000000..ce5bba0c9d
--- /dev/null
+++ b/stubs/virtio_md_pci.c
@@ -0,0 +1,24 @@
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/virtio/virtio-md-pci.h"
+
+void virtio_md_pci_pre_plug(VirtIOMDPCI *vmd, MachineState *ms, Error **errp)
+{
+    error_setg(errp, "virtio based memory devices not supported");
+}
+
+void virtio_md_pci_plug(VirtIOMDPCI *vmd, MachineState *ms, Error **errp)
+{
+    error_setg(errp, "virtio based memory devices not supported");
+}
+
+void virtio_md_pci_unplug_request(VirtIOMDPCI *vmd, MachineState *ms,
+                                  Error **errp)
+{
+    error_setg(errp, "virtio based memory devices not supported");
+}
+
+void virtio_md_pci_unplug(VirtIOMDPCI *vmd, MachineState *ms, Error **errp)
+{
+    error_setg(errp, "virtio based memory devices not supported");
+}


For now (not having virtio-md-ccw or virtio-md-mmio) this should do the trick I 
think.

--
Cheers,

David / dhildenb