qemu: Format nested-hv feature on the command line

Signed-off-by: Andrea Bolognani <abologna@redhat.com>

src/qemu/qemu_command.c

@@ -7468,6 +7468,26 @@ qemuBuildMachineCommandLine(virCommandPtr cmd,
         virBufferAsprintf(&buf, ",cap-htm=%s", str);
     }
 
+    if (def->features[VIR_DOMAIN_FEATURE_NESTED_HV] != VIR_TRISTATE_SWITCH_ABSENT) {
+        const char *str;
+
+        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MACHINE_PSERIES_CAP_NESTED_HV)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("Nested HV configuration is not supported by "
+                             "this QEMU binary"));
+            goto cleanup;
+        }
+
+        str = virTristateSwitchTypeToString(def->features[VIR_DOMAIN_FEATURE_NESTED_HV]);
+        if (!str) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("Invalid setting for nested HV state"));
+            goto cleanup;
+        }
+
+        virBufferAsprintf(&buf, ",cap-nested-hv=%s", str);
+    }
+
     if (cpu && cpu->model &&
         cpu->mode == VIR_CPU_MODE_HOST_MODEL &&
         qemuDomainIsPSeries(def) &&

tests/qemuxml2argvdata/pseries-features.args

@@ -8,7 +8,7 @@ QEMU_AUDIO_DRV=none \
 -name guest \
 -S \
 -machine pseries,accel=tcg,usb=off,dump-guest-core=off,resize-hpt=required,\
-cap-hpt-max-page-size=1048576k,cap-htm=on \
+cap-hpt-max-page-size=1048576k,cap-htm=on,cap-nested-hv=off \
 -m 512 \
 -smp 1,sockets=1,cores=1,threads=1 \
 -uuid 1ccfd97d-5eb4-478a-bbe6-88d254c16db7 \