[PATCH 7/7] cpu: Add `machine` parameter to query-cpu-definitions

[Eduardo Habkost]

The new parameter can be used by management software to query for
CPU model alias information for multiple machines without
restarting QEMU.

Signed-off-by: Eduardo Habkost <address@hidden>
---
 qapi/machine-target.json                   | 14 +++++++-
 target/arm/helper.c                        |  4 ++-
 target/i386/cpu.c                          | 16 +++++++--
 target/mips/helper.c                       |  4 ++-
 target/ppc/translate_init.inc.c            |  4 ++-
 target/s390x/cpu_models.c                  |  4 ++-
 tests/acceptance/x86_cpu_model_versions.py | 42 ++++++++++++++++++++++
 7 files changed, 81 insertions(+), 7 deletions(-)

diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index 55310a6aa2..7bff3811fe 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -281,6 +281,10 @@
 #
 # @alias-of: Name of CPU model this model is an alias for.  The target of the
 #            CPU model alias may change depending on the machine type.
+#            If the @machine argument was provided to query-cpu-definitions,
+#            alias information that machine type will be returned.
+#            If @machine is not provided, alias information for
+#            the current machine will be returned.
 #            Management software is supposed to translate CPU model aliases
 #            in the VM configuration, because aliases may stop being
 #            migration-safe in the future (since 4.1)
@@ -317,9 +321,17 @@
 #
 # Return a list of supported virtual CPU definitions
 #
+# @machine: Name of machine type.  The command returns some data
+#           that machine-specific.  This overrides the machine type
+#           used to look up that information.  This can be used,
+#           for example, to query machine-specific CPU model aliases
+#           without restarting QEMU (since 4.2)
+#
 # Returns: a list of CpuDefInfo
 #
 # Since: 1.2.0
 ##
-{ 'command': 'query-cpu-definitions', 'returns': ['CpuDefinitionInfo'],
+{ 'command': 'query-cpu-definitions',
+  'data': { '*machine': 'str' },
+  'returns': ['CpuDefinitionInfo'],
   'if': 'defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_I386) || 
defined(TARGET_S390X) || defined(TARGET_MIPS)' }
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 0d9a2d2ab7..96f9fe7fff 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6965,7 +6965,9 @@ static void arm_cpu_add_definition(gpointer data, 
gpointer user_data)
     *cpu_list = entry;
 }
 
-CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
+CpuDefinitionInfoList *qmp_query_cpu_definitions(bool has_machine,
+                                                 const char *machine,
+                                                 Error **errp)
 {
     CpuDefinitionInfoList *cpu_list = NULL;
     GSList *list;
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 67d1eca4ed..ae633793ed 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -4078,11 +4078,23 @@ static void x86_cpu_definition_entry(gpointer data, 
gpointer user_data)
     args->cpu_list = entry;
 }
 
-CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
+CpuDefinitionInfoList *qmp_query_cpu_definitions(bool has_machine,
+                                                 const char *machine,
+                                                 Error **errp)
 {
     X86CPUDefinitionArgs args = { .cpu_list = NULL };
     GSList *list;
-    MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
+    MachineClass *mc;
+
+    if (!has_machine) {
+        mc = MACHINE_GET_CLASS(qdev_get_machine());
+    } else {
+        mc = machine_find_class(machine);
+        if (!mc) {
+            error_setg(errp, "Machine type '%s' not found", machine);
+            return NULL;
+        }
+    }
 
     args.default_version = default_cpu_version_for_machine(mc);
     list = get_sorted_cpu_model_list();
diff --git a/target/mips/helper.c b/target/mips/helper.c
index a2b6459b05..a73c767462 100644
--- a/target/mips/helper.c
+++ b/target/mips/helper.c
@@ -1481,7 +1481,9 @@ static void mips_cpu_add_definition(gpointer data, 
gpointer user_data)
     *cpu_list = entry;
 }
 
-CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
+CpuDefinitionInfoList *qmp_query_cpu_definitions(bool has_machine,
+                                                 const char *machine,
+                                                 Error **errp)
 {
     CpuDefinitionInfoList *cpu_list = NULL;
     GSList *list;
diff --git a/target/ppc/translate_init.inc.c b/target/ppc/translate_init.inc.c
index ba726dec4d..4493309c4c 100644
--- a/target/ppc/translate_init.inc.c
+++ b/target/ppc/translate_init.inc.c
@@ -10350,7 +10350,9 @@ static void ppc_cpu_defs_entry(gpointer data, gpointer 
user_data)
     *first = entry;
 }
 
-CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
+CpuDefinitionInfoList *qmp_query_cpu_definitions(bool has_machine,
+                                                 const char *machine,
+                                                 Error **errp)
 {
     CpuDefinitionInfoList *cpu_list = NULL;
     GSList *list;
diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
index 7e92fb2e15..e40f1f6bec 100644
--- a/target/s390x/cpu_models.c
+++ b/target/s390x/cpu_models.c
@@ -456,7 +456,9 @@ static void create_cpu_model_list(ObjectClass *klass, void 
*opaque)
     *cpu_list = entry;
 }
 
-CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
+CpuDefinitionInfoList *qmp_query_cpu_definitions(bool has_machine,
+                                                 const char *machine,
+                                                 Error **errp)
 {
     struct CpuDefinitionInfoListData list_data = {
         .list = NULL,
diff --git a/tests/acceptance/x86_cpu_model_versions.py 
b/tests/acceptance/x86_cpu_model_versions.py
index 5fc9ca4bc6..79c5250243 100644
--- a/tests/acceptance/x86_cpu_model_versions.py
+++ b/tests/acceptance/x86_cpu_model_versions.py
@@ -234,6 +234,48 @@ class X86CPUModelAliases(avocado_qemu.Test):
 
         self.validate_aliases(cpus)
 
+    def test_machine_arg_none(self):
+        """Check if unversioned CPU model is an alias pointing to right 
version"""
+        vm1 = self.get_vm()
+        vm1.add_args('-S')
+        vm1.set_machine('pc-i440fx-4.0')
+        vm1.launch()
+        cpus1 = dict((m['name'], m.get('alias-of')) for m in 
vm1.command('query-cpu-definitions', machine='none'))
+        vm1.shutdown()
+
+        vm2 = self.get_vm()
+        vm2.add_args('-S')
+        vm2.set_machine('none')
+        vm2.launch()
+        cpus2 = dict((m['name'], m.get('alias-of')) for m in 
vm2.command('query-cpu-definitions'))
+        vm1.shutdown()
+
+        self.assertEquals(cpus1, cpus2)
+
+    def test_machine_arg_4_1(self):
+        """Check if unversioned CPU model is an alias pointing to right 
version"""
+        vm1 = self.get_vm()
+        vm1.add_args('-S')
+        vm1.set_machine('pc-i440fx-4.0')
+        vm1.launch()
+        cpus1 = dict((m['name'], m.get('alias-of')) for m in 
vm1.command('query-cpu-definitions', machine='pc-i440fx-4.1'))
+        vm1.shutdown()
+
+        vm2 = self.get_vm()
+        vm2.add_args('-S')
+        vm2.set_machine('pc-i440fx-4.1')
+        vm2.launch()
+        cpus2 = dict((m['name'], m.get('alias-of')) for m in 
vm2.command('query-cpu-definitions'))
+        vm1.shutdown()
+
+        self.assertEquals(cpus1, cpus2)
+
+    def test_invalid_machine(self):
+        self.vm.add_args('-S')
+        self.vm.launch()
+        r = self.vm.qmp('query-cpu-definitions', machine='invalid-machine-123')
+        self.assertIn('error', r)
+
 
 class CascadelakeArchCapabilities(avocado_qemu.Test):
     """
-- 
2.21.0