From 62658bbf060784c757f96c9de3935f27885834aa Mon Sep 17 00:00:00 2001
From: Collin Walling <walling@linux.ibm.com>
Date: Mon, 16 Dec 2024 18:03:58 -0500
Subject: [PATCH] conf: add deprecated_features attribute

Add a new a attribute, deprecated_features='on|off' to the <cpu>
element.  This is used to toggle features flagged as deprecated on the
CPU model on or off.  When this attribute is paired with 'on',
deprecated features will not be filtered.  When paired with 'off', any
CPU features that are flagged as deprecated will be listed under the
CPU model with the 'disable' policy.

Example:

  <cpu mode='host-model' check='partial' deprecated_features='off'/>

The absence of this attribute is equivalent to the 'on' option.

The deprecated features that will populate the domain XML are the same
features that result in the virsh domcapabilities command with the
--disable-deprecated-features argument present.

It is recommended to define a domain XML with this attribute set to
'off' to ensure migration to machines that may outright drop these
features in the future.

Signed-off-by: Collin Walling <walling@linux.ibm.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/conf/cpu_conf.c                           | 11 +++++++
 src/conf/cpu_conf.h                           |  1 +
 src/conf/schemas/cputypes.rng                 |  5 +++
 src/qemu/qemu_process.c                       | 11 +++++++
 ...el-deprecated-features-off.s390x-8.2.0.err |  1 +
 ...el-deprecated-features-off.s390x-8.2.0.xml | 25 +++++++++++++++
 ...-deprecated-features-off.s390x-latest.args | 32 +++++++++++++++++++
 ...l-deprecated-features-off.s390x-latest.xml | 25 +++++++++++++++
 .../cpu-model-deprecated-features-off.xml     | 15 +++++++++
 tests/qemuxmlconftest.c                       |  3 ++
 10 files changed, 129 insertions(+)
 create mode 100644 tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-8.2.0.err
 create mode 100644 tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-8.2.0.xml
 create mode 100644 tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-latest.args
 create mode 100644 tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-latest.xml
 create mode 100644 tests/qemuxmlconfdata/cpu-model-deprecated-features-off.xml

diff --git a/src/conf/cpu_conf.c b/src/conf/cpu_conf.c
index dcc164d165..31425783ba 100644
--- a/src/conf/cpu_conf.c
+++ b/src/conf/cpu_conf.c
@@ -238,6 +238,7 @@ virCPUDefCopyWithoutModel(const virCPUDef *cpu)
     copy->mode = cpu->mode;
     copy->match = cpu->match;
     copy->check = cpu->check;
+    copy->deprecated_feats = cpu->deprecated_feats;
     copy->fallback = cpu->fallback;
     copy->sockets = cpu->sockets;
     copy->dies = cpu->dies;
@@ -450,6 +451,11 @@ virCPUDefParseXML(xmlXPathContextPtr ctxt,
         if (virXMLPropEnum(ctxt->node, "check", virCPUCheckTypeFromString,
                            VIR_XML_PROP_NONE, &def->check) < 0)
             return -1;
+
+        if (virXMLPropTristateSwitch(ctxt->node, "deprecated_features",
+                                     VIR_XML_PROP_NONE,
+                                     &def->deprecated_feats) < 0)
+            return -1;
     }
 
     if (def->type == VIR_CPU_TYPE_HOST) {
@@ -748,6 +754,11 @@ virCPUDefFormatBufFull(virBuffer *buf,
             virBufferAsprintf(&attributeBuf, " migratable='%s'",
                               virTristateSwitchTypeToString(def->migratable));
         }
+
+        if (def->deprecated_feats) {
+            virBufferAsprintf(&attributeBuf, " deprecated_features='%s'",
+                              virTristateSwitchTypeToString(def->deprecated_feats));
+        }
     }
 
     /* Format children */
diff --git a/src/conf/cpu_conf.h b/src/conf/cpu_conf.h
index f71d942ce6..28e26303ef 100644
--- a/src/conf/cpu_conf.h
+++ b/src/conf/cpu_conf.h
@@ -161,6 +161,7 @@ struct _virCPUDef {
     virCPUMaxPhysAddrDef *addr;
     virHostCPUTscInfo *tsc;
     virTristateSwitch migratable; /* for host-passthrough mode */
+    virTristateSwitch deprecated_feats;
 };
 
 virCPUDef *virCPUDefNew(void);
diff --git a/src/conf/schemas/cputypes.rng b/src/conf/schemas/cputypes.rng
index 3a8910e09f..8edf1d14e3 100644
--- a/src/conf/schemas/cputypes.rng
+++ b/src/conf/schemas/cputypes.rng
@@ -439,6 +439,11 @@
       <optional>
         <ref name="cpuCheck"/>
       </optional>
+      <optional>
+        <attribute name="deprecated_features">
+          <ref name="virOnOff"/>
+        </attribute>
+      </optional>
       <optional>
         <attribute name="migratable">
           <ref name="virOnOff"/>
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index bee7a39e4e..5f2e278156 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -6399,6 +6399,17 @@ qemuProcessUpdateGuestCPU(virDomainDef *def,
                                 &def->os.arch) < 0)
         return -1;
 
+    if (def->cpu->deprecated_feats &&
+        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_QUERY_CPU_MODEL_EXPANSION_DEPRECATED_PROPS)) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("toggling deprecated features for CPU model is unsupported"));
+        return -1;
+    }
+
+    if (def->cpu->deprecated_feats == VIR_TRISTATE_SWITCH_OFF) {
+        virQEMUCapsUpdateCPUDeprecatedFeatures(qemuCaps, def->virtType, def->cpu);
+    }
+
     return 0;
 }
 
diff --git a/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-8.2.0.err b/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-8.2.0.err
new file mode 100644
index 0000000000..936d1d5a46
--- /dev/null
+++ b/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-8.2.0.err
@@ -0,0 +1 @@
+unsupported configuration: toggling deprecated features for CPU model is unsupported
diff --git a/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-8.2.0.xml b/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-8.2.0.xml
new file mode 100644
index 0000000000..e1f7ba3857
--- /dev/null
+++ b/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-8.2.0.xml
@@ -0,0 +1,25 @@
+<domain type='kvm'>
+  <name>guest</name>
+  <uuid>22782664-6b93-46bf-9595-317220dd2d1c</uuid>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='s390x' machine='s390-ccw-virtio-8.2'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-model' check='partial' deprecated_features='off'/>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-s390x</emulator>
+    <controller type='pci' index='0' model='pci-root'/>
+    <audio id='1' type='none'/>
+    <memballoon model='virtio'>
+      <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0000'/>
+    </memballoon>
+    <panic model='s390'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-latest.args b/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-latest.args
new file mode 100644
index 0000000000..ba6e7c5304
--- /dev/null
+++ b/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-latest.args
@@ -0,0 +1,32 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/var/lib/libvirt/qemu/domain--1-guest \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/var/lib/libvirt/qemu/domain--1-guest/.local/share \
+XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain--1-guest/.cache \
+XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-guest/.config \
+/usr/bin/qemu-system-s390x \
+-name guest=guest,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain--1-guest/master-key.aes"}' \
+-machine s390-ccw-virtio,usb=off,dump-guest-core=off,memory-backend=s390.ram \
+-accel kvm \
+-cpu gen16a-base,nnpa=on,aen=on,cmmnt=on,vxpdeh=on,aefsi=on,diag318=on,csske=off,mepoch=on,msa9=on,msa8=on,msa7=on,msa6=on,msa5=on,msa4=on,msa3=on,msa2=on,msa1=on,sthyi=on,edat=on,ri=on,deflate=on,edat2=on,etoken=on,vx=on,ipter=on,pai=on,paie=on,mepochptff=on,ap=on,vxeh=on,vxpd=on,esop=on,msa9_pckmo=on,vxeh2=on,esort=on,appv=on,apqi=on,apft=on,els=on,iep=on,appvi=on,apqci=on,cte=off,ais=on,bpb=off,ctop=on,gs=on,ppa15=on,zpci=on,rdp=on,sea_esop2=on,beareh=on,te=off,cmm=on,vxpdeh2=on \
+-m size=219136k \
+-object '{"qom-type":"memory-backend-ram","id":"s390.ram","size":224395264}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid 22782664-6b93-46bf-9595-317220dd2d1c \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,fd=1729,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-boot strict=on \
+-audiodev '{"id":"audio1","driver":"none"}' \
+-device '{"driver":"virtio-balloon-ccw","id":"balloon0","devno":"fe.0.0000"}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on
diff --git a/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-latest.xml b/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-latest.xml
new file mode 100644
index 0000000000..fdd87acb1d
--- /dev/null
+++ b/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.s390x-latest.xml
@@ -0,0 +1,25 @@
+<domain type='kvm'>
+  <name>guest</name>
+  <uuid>22782664-6b93-46bf-9595-317220dd2d1c</uuid>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='s390x' machine='s390-ccw-virtio'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-model' check='partial' deprecated_features='off'/>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-s390x</emulator>
+    <controller type='pci' index='0' model='pci-root'/>
+    <audio id='1' type='none'/>
+    <memballoon model='virtio'>
+      <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0000'/>
+    </memballoon>
+    <panic model='s390'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.xml b/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.xml
new file mode 100644
index 0000000000..67950715ec
--- /dev/null
+++ b/tests/qemuxmlconfdata/cpu-model-deprecated-features-off.xml
@@ -0,0 +1,15 @@
+<domain type='kvm'>
+  <name>guest</name>
+  <uuid>22782664-6b93-46bf-9595-317220dd2d1c</uuid>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='s390x' machine='s390-ccw-virtio'>hvm</type>
+  </os>
+  <cpu mode='host-model' check='partial' deprecated_features='off'/>
+  <clock offset='utc'/>
+  <devices>
+    <emulator>/usr/bin/qemu-system-s390x</emulator>
+  </devices>
+</domain>
diff --git a/tests/qemuxmlconftest.c b/tests/qemuxmlconftest.c
index f3c8d0ae34..23f1d9eab7 100644
--- a/tests/qemuxmlconftest.c
+++ b/tests/qemuxmlconftest.c
@@ -2295,6 +2295,9 @@ mymain(void)
     DO_TEST_CAPS_ARCH_LATEST("cpu-s390-zEC12", "s390x");
     DO_TEST_CAPS_ARCH_LATEST("cpu-s390-features", "s390x");
 
+    DO_TEST_CAPS_ARCH_VER_FAILURE("cpu-model-deprecated-features-off", "s390x", "8.2.0");
+    DO_TEST_CAPS_ARCH_LATEST("cpu-model-deprecated-features-off", "s390x");
+
     DO_TEST_CAPS_ARCH_LATEST_FULL("cpu-Haswell", "x86_64", ARG_CAPS_HOST_CPU_MODEL, QEMU_CPU_DEF_HASWELL);
     DO_TEST_CAPS_ARCH_LATEST_FULL("cpu-Haswell2", "x86_64", ARG_CAPS_HOST_CPU_MODEL, QEMU_CPU_DEF_HASWELL);
     DO_TEST_CAPS_ARCH_LATEST_FULL("cpu-Haswell3", "x86_64", ARG_CAPS_HOST_CPU_MODEL, QEMU_CPU_DEF_HASWELL);