conf: Introduce <address/> for virtio-mem and virtio-pmem

Both virtio-mem and virtio-pmem devices have '.memaddr' attribute
which controls the address where they are mapped in the guest
memory. Ideally, users do not need to specify this as QEMU does
the right thing and computes addresses automatically on startup.

But soon, we will need to record this address as it is part of
guest ABI. And also, there might be some users that want to
control this value. Now, we are in a bit of a pickle, because
both these device types already have a PCI address, therefore we
can't just use <address/> blindly. But what we can do, is
introduce <address/> under the <target/> element. This is also
more conceptual, as knobs under <target/> control guest visible
config of memory device (and .memaddr surely falls into that
category).

NB, SgxEPCDeviceInfo struct in QMP definition also has .memaddr
attribute, but because of the way we build cmd line there's no
(easy) way to set the attribute. So ignore that for now.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>

docs/formatdomain.rst

@@ -8129,6 +8129,7 @@ Example: usage of the memory devices
        </source>
        <target>
          <size unit='KiB'>524288</size>
+         <address base='0x140000000'/>
        </target>
      </memory>
      <memory model='virtio-mem'>
@@ -8142,6 +8143,7 @@ Example: usage of the memory devices
          <block unit='KiB'>2048</block>
          <requested unit='KiB'>1048576</requested>
          <current unit='KiB'>524288</current>
+         <address base='0x150000000'/>
        </target>
      </memory>
      <memory model='sgx-epc'>
@@ -8285,6 +8287,11 @@ Example: usage of the memory devices
      element is formatted into live XML and never parsed, i.e. it is
      output-only element.
 
+   ``address``
+     For ``virtio-mem`` and ``virtio-pmem`` only.
+     The physical address in memory, where device is mapped. :since:`Since
+     9.4.0`
+
 
 IOMMU devices
 ~~~~~~~~~~~~~

src/conf/domain_conf.c

@@ -13318,6 +13318,7 @@ virDomainMemoryTargetDefParseXML(xmlNodePtr node,
                                  virDomainMemoryDef *def)
 {
     VIR_XPATH_NODE_AUTORESTORE(ctxt)
+    xmlNodePtr addrNode = NULL;
     int rv;
 
     ctxt->node = node;
@@ -13363,16 +13364,27 @@ virDomainMemoryTargetDefParseXML(xmlNodePtr node,
         if (virDomainParseMemory("./requested", "./requested/@unit", ctxt,
                                  &def->requestedsize, false, false) < 0)
             return -1;
+
+        addrNode = virXPathNode("./address", ctxt);
+        break;
+
+    case VIR_DOMAIN_MEMORY_MODEL_VIRTIO_PMEM:
+        addrNode = virXPathNode("./address", ctxt);
         break;
 
     case VIR_DOMAIN_MEMORY_MODEL_NONE:
     case VIR_DOMAIN_MEMORY_MODEL_DIMM:
-    case VIR_DOMAIN_MEMORY_MODEL_VIRTIO_PMEM:
     case VIR_DOMAIN_MEMORY_MODEL_SGX_EPC:
     case VIR_DOMAIN_MEMORY_MODEL_LAST:
         break;
     }
 
+    if (addrNode &&
+        virXMLPropULongLong(addrNode, "base", 16,
+                            VIR_XML_PROP_NONE, &def->address) < 0) {
+        return -1;
+    }
+
     return 0;
 }
 
@@ -20952,6 +20964,13 @@ virDomainMemoryDefCheckABIStability(virDomainMemoryDef *src,
         return false;
     }
 
+    if (src->address != dst->address) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("Target memory device address '0x%1$llx' doesn't match source memory device address '0x%2$llx'"),
+                       dst->address, src->address);
+        return false;
+    }
+
     if (src->model == VIR_DOMAIN_MEMORY_MODEL_NVDIMM) {
         if (src->labelsize != dst->labelsize) {
             virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
@@ -25120,6 +25139,9 @@ virDomainMemoryTargetDefFormat(virBuffer *buf,
         }
     }
 
+    if (def->address)
+        virBufferAsprintf(&childBuf, "<address base='0x%llx'/>\n", def->address);
+
     virXMLFormatElement(buf, "target", NULL, &childBuf);
 }
 

src/conf/domain_conf.h

@@ -2652,6 +2652,8 @@ struct _virDomainMemoryDef {
     unsigned long long currentsize; /* kibibytes, valid for VIRTIO_MEM and
                                        active domain only, only to report never
                                        parse */
+    unsigned long long address; /* address where memory is mapped, valid for
+                                   VIRTIO_PMEM and VIRTIO_MEM only. */
     bool readonly; /* valid only for NVDIMM */
 
     /* required for QEMU NVDIMM ppc64 support */

src/conf/domain_validate.c

@@ -2355,6 +2355,12 @@ virDomainMemoryDefValidate(const virDomainMemoryDef *mem,
                            _("requested size must be an integer multiple of block size"));
             return -1;
         }
+
+        if (mem->address % mem->blocksize != 0) {
+            virReportError(VIR_ERR_XML_DETAIL, "%s",
+                           _("memory device address must be aligned to blocksize"));
+            return -1;
+        }
         break;
 
     case VIR_DOMAIN_MEMORY_MODEL_DIMM:

src/conf/schemas/domaincommon.rng

@@ -7177,6 +7177,13 @@
             <empty/>
           </element>
         </optional>
+        <optional>
+          <element name="address">
+            <attribute name="base">
+              <ref name="hexuint"/>
+            </attribute>
+          </element>
+        </optional>
       </interleave>
     </element>
   </define>

tests/qemuxml2argvdata/memory-hotplug-virtio-mem.xml

@@ -65,6 +65,7 @@
         <node>0</node>
         <block unit='KiB'>2048</block>
         <requested unit='KiB'>1048576</requested>
+        <address base='0x150000000'/>
       </target>
       <address type='pci' domain='0x0000' bus='0x01' slot='0x01' function='0x0'/>
     </memory>

tests/qemuxml2argvdata/memory-hotplug-virtio-pmem.xml

@@ -47,6 +47,7 @@
       </source>
       <target>
         <size unit='KiB'>524288</size>
+        <address base='0x140000000'/>
       </target>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
     </memory>