pc-dimm: assign and verify the "addr" property during pre_plug

We can assign and verify the address before realizing and trying to plug.
reading/writing the address property should never fail for DIMMs, so let's
reduce error handling a bit by using &error_abort. Getting access to the
memory region now might however fail. So forward errors from
get_memory_region() properly.

As all memory devices should use the alignment of the underlying memory
region for guest physical address asignment, do detection of the
alignment in pc_dimm_pre_plug(), but allow pc.c to overwrite the
alignment for compatibility handling.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180801133444.11269-5-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 5 insertions, 11 deletions

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index b31610c..0314845 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1679,7 +1679,9 @@ static void pc_memory_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
                                Error **errp)
 {
     const PCMachineState *pcms = PC_MACHINE(hotplug_dev);
+    const PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
     const bool is_nvdimm = object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM);
+    const uint64_t legacy_align = TARGET_PAGE_SIZE;
 
     /*
      * When -no-acpi is used with Q35 machine type, no ACPI is built,
@@ -1697,7 +1699,8 @@ static void pc_memory_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
         return;
     }
 
-    pc_dimm_pre_plug(dev, MACHINE(hotplug_dev), errp);
+    pc_dimm_pre_plug(dev, MACHINE(hotplug_dev),
+                     pcmc->enforce_aligned_dimm ? NULL : &legacy_align, errp);
 }
 
 static void pc_memory_plug(HotplugHandler *hotplug_dev,
@@ -1706,18 +1709,9 @@ static void pc_memory_plug(HotplugHandler *hotplug_dev,
     HotplugHandlerClass *hhc;
     Error *local_err = NULL;
     PCMachineState *pcms = PC_MACHINE(hotplug_dev);
-    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
-    PCDIMMDevice *dimm = PC_DIMM(dev);
-    PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
-    MemoryRegion *mr = ddc->get_memory_region(dimm, &error_abort);
-    uint64_t align = TARGET_PAGE_SIZE;
     bool is_nvdimm = object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM);
 
-    if (pcmc->enforce_aligned_dimm) {
-        align = memory_region_get_alignment(mr);
-    }
-
-    pc_dimm_plug(dev, MACHINE(pcms), align, &local_err);
+    pc_dimm_plug(dev, MACHINE(pcms), &local_err);
     if (local_err) {
         goto out;
     }