qemu_domain.c: post parse pSeries NVDIMM align with PARSE_ABI_UPDATE

A previous patch removed the pSeries NVDIMM align that wasn't
being done properly. This patch reintroduces it in the right
fashion, making it reliant on VIR_DOMAIN_DEF_PARSE_ABI_UPDATE.
This makes it complying with the intended design defined by
commit c7d7ba85a6.

Since the PARSE_ABI_UPDATE is more restrictive than checking for
!migrate && !snapshot, like is being currently done with
qemuDomainAlignMemorySizes(), this means that we'll align the
pSeries NVDIMMs in two places - in post parse time for new
guests, and in qemuDomainAlignMemorySizes() for all guests
that aren't migrating or in a snapshot.

Another difference is that the logic is now in the QEMU driver
instead of domain_conf.c. This was necessary because all
considerations made about the PARSE_ABI_UPDATE flag were done
under QEMU. Given that no other driver supports ppc64 there is no
impact in this change.

A new test was added to exercise what we're doing. It consists
of a a copy of the existing 'memory-hotplug-nvdimm-ppc64' xml2xml
test, called with the PARSE_ABI_UPDATE flag. As intended, we're
not changing QEMU command line or any XML without the flag,
while the pseries NVDIMM memory is being aligned when the
flag is used.

Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

src/qemu/qemu_domain.c

@@ -5341,6 +5341,33 @@ qemuDomainTPMDefPostParse(virDomainTPMDefPtr tpm,
 }
 
 
+static int
+qemuDomainMemoryDefPostParse(virDomainMemoryDefPtr mem, virArch arch,
+                             unsigned int parseFlags)
+{
+    /* Memory alignment can't be done for migration or snapshot
+     * scenarios. This logic was defined by commit c7d7ba85a624.
+     *
+     * There is no easy way to replicate at this point the same conditions
+     * used to call qemuDomainAlignMemorySizes(), which means checking if
+     * we're not migrating and not in a snapshot.
+     *
+     * We can use the PARSE_ABI_UPDATE flag, which is more strict -
+     * existing guests will not activate the flag to avoid breaking
+     * boot ABI. This means that any alignment done here will be replicated
+     * later on by qemuDomainAlignMemorySizes() to contemplate existing
+     * guests as well. */
+    if (parseFlags & VIR_DOMAIN_DEF_PARSE_ABI_UPDATE) {
+        if (ARCH_IS_PPC64(arch) &&
+            mem->model == VIR_DOMAIN_MEMORY_MODEL_NVDIMM &&
+            virDomainNVDimmAlignSizePseries(mem) < 0)
+            return -1;
+    }
+
+    return 0;
+}
+
+
 static int
 qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
                              const virDomainDef *def,
@@ -5398,6 +5425,11 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
         ret = qemuDomainTPMDefPostParse(dev->data.tpm, def->os.arch);
         break;
 
+    case VIR_DOMAIN_DEVICE_MEMORY:
+        ret = qemuDomainMemoryDefPostParse(dev->data.memory, def->os.arch,
+                                           parseFlags);
+        break;
+
     case VIR_DOMAIN_DEVICE_LEASE:
     case VIR_DOMAIN_DEVICE_FS:
     case VIR_DOMAIN_DEVICE_INPUT:
@@ -5410,7 +5442,6 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
     case VIR_DOMAIN_DEVICE_MEMBALLOON:
     case VIR_DOMAIN_DEVICE_NVRAM:
     case VIR_DOMAIN_DEVICE_RNG:
-    case VIR_DOMAIN_DEVICE_MEMORY:
     case VIR_DOMAIN_DEVICE_IOMMU:
     case VIR_DOMAIN_DEVICE_AUDIO:
         ret = 0;

tests/qemuxml2argvdata/memory-hotplug-nvdimm-ppc64-abi-update.args

@@ -0,0 +1,30 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-ppc64 \
+-name QEMUGuest1 \
+-S \
+-machine pseries,accel=tcg,usb=off,dump-guest-core=off,nvdimm=on \
+-m size=1048576k,slots=16,maxmem=1099511627776k \
+-realtime mlock=off \
+-smp 2,sockets=2,cores=1,threads=1 \
+-numa node,nodeid=0,cpus=0-1,mem=1024 \
+-object memory-backend-file,id=memnvdimm0,mem-path=/tmp/nvdimm,prealloc=yes,\
+size=537001984 \
+-device nvdimm,node=0,label-size=131072,\
+uuid=49545eb3-75e1-2d0a-acdd-f0294406c99e,memdev=memnvdimm0,id=nvdimm0,slot=0 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/lib/domain--1-QEMUGuest1/monitor.sock,\
+server,nowait \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown

tests/qemuxml2argvdata/memory-hotplug-nvdimm-ppc64-abi-update.xml

@@ -0,0 +1 @@
+memory-hotplug-nvdimm-ppc64.xml

tests/qemuxml2argvtest.c

@@ -3014,6 +3014,13 @@ mymain(void)
     DO_TEST("memory-hotplug-nvdimm-ppc64", QEMU_CAPS_DEVICE_SPAPR_PCI_HOST_BRIDGE,
                                            QEMU_CAPS_OBJECT_MEMORY_FILE,
                                            QEMU_CAPS_DEVICE_NVDIMM);
+    DO_TEST_FULL("memory-hotplug-nvdimm-ppc64-abi-update",
+                 ARG_PARSEFLAGS, VIR_DOMAIN_DEF_PARSE_ABI_UPDATE,
+                 ARG_QEMU_CAPS,
+                 QEMU_CAPS_DEVICE_SPAPR_PCI_HOST_BRIDGE,
+                 QEMU_CAPS_OBJECT_MEMORY_FILE,
+                 QEMU_CAPS_DEVICE_NVDIMM,
+                 QEMU_CAPS_LAST);
 
     DO_TEST("machine-aeskeywrap-on-caps",
             QEMU_CAPS_AES_KEY_WRAP,

tests/qemuxml2xmloutdata/memory-hotplug-nvdimm-ppc64-abi-update.xml

@@ -0,0 +1,46 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <maxMemory slots='16' unit='KiB'>1099511627776</maxMemory>
+  <memory unit='KiB'>1572992</memory>
+  <currentMemory unit='KiB'>1267710</currentMemory>
+  <vcpu placement='static' cpuset='0-1'>2</vcpu>
+  <os>
+    <type arch='ppc64' machine='pseries'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu>
+    <topology sockets='2' dies='1' cores='1' threads='1'/>
+    <numa>
+      <cell id='0' cpus='0-1' memory='1048576' unit='KiB'/>
+    </numa>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-ppc64</emulator>
+    <controller type='usb' index='0' model='none'/>
+    <controller type='pci' index='0' model='pci-root'>
+      <model name='spapr-pci-host-bridge'/>
+      <target index='0'/>
+    </controller>
+    <memballoon model='none'/>
+    <panic model='pseries'/>
+    <memory model='nvdimm'>
+      <uuid>49545eb3-75e1-2d0a-acdd-f0294406c99e</uuid>
+      <source>
+        <path>/tmp/nvdimm</path>
+      </source>
+      <target>
+        <size unit='KiB'>524416</size>
+        <node>0</node>
+        <label>
+          <size unit='KiB'>128</size>
+        </label>
+      </target>
+      <address type='dimm' slot='0'/>
+    </memory>
+  </devices>
+</domain>

tests/qemuxml2xmltest.c

@@ -1244,6 +1244,13 @@ mymain(void)
     DO_TEST("memory-hotplug-nvdimm-ppc64", QEMU_CAPS_DEVICE_SPAPR_PCI_HOST_BRIDGE,
                                            QEMU_CAPS_OBJECT_MEMORY_FILE,
                                            QEMU_CAPS_DEVICE_NVDIMM);
+    DO_TEST_FULL("memory-hotplug-nvdimm-ppc64-abi-update", WHEN_BOTH,
+                 ARG_PARSEFLAGS, VIR_DOMAIN_DEF_PARSE_ABI_UPDATE,
+                 ARG_QEMU_CAPS,
+                 QEMU_CAPS_DEVICE_SPAPR_PCI_HOST_BRIDGE,
+                 QEMU_CAPS_OBJECT_MEMORY_FILE,
+                 QEMU_CAPS_DEVICE_NVDIMM,
+                 QEMU_CAPS_LAST);
 
     DO_TEST("net-udp", NONE);