[PATCH v2 02/11] hw/boards: Introduce machine_class_valid_for_accelerator()

[Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>]

Introduce the valid_accelerators[] field to express the list
of valid accelators a machine can use, and add the
machine_class_valid_for_current_accelerator() and
machine_class_valid_for_accelerator() methods.

Signed-off-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
---
 include/hw/boards.h | 24 ++++++++++++++++++++++++
 hw/core/machine.c   | 26 ++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/include/hw/boards.h b/include/hw/boards.h
index 68d3d10f6b0..4d08bc12093 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -36,6 +36,24 @@ void machine_set_cpu_numa_node(MachineState *machine,
                                const CpuInstanceProperties *props,
                                Error **errp);
 
+/**
+ * machine_class_valid_for_accelerator:
+ * @mc: the machine class
+ * @acc_name: accelerator name
+ *
+ * Returns %true if the accelerator is valid for the machine, %false
+ * otherwise. See #MachineClass.valid_accelerators.
+ */
+bool machine_class_valid_for_accelerator(MachineClass *mc, const char 
*acc_name);
+/**
+ * machine_class_valid_for_current_accelerator:
+ * @mc: the machine class
+ *
+ * Returns %true if the accelerator is valid for the current machine,
+ * %false otherwise. See #MachineClass.valid_accelerators.
+ */
+bool machine_class_valid_for_current_accelerator(MachineClass *mc);
+
 void machine_class_allow_dynamic_sysbus_dev(MachineClass *mc, const char 
*type);
 /*
  * Checks that backend isn't used, preps it for exclusive usage and
@@ -125,6 +143,11 @@ typedef struct {
  *    should instead use "unimplemented-device" for all memory ranges where
  *    the guest will attempt to probe for a device that QEMU doesn't
  *    implement and a stub device is required.
+ * @valid_accelerators:
+ *    If this machine supports a specific set of virtualization accelerators,
+ *    this contains a NULL-terminated list of the accelerators that can be
+ *    used. If this field is not set, any accelerator is valid. The QTest
+ *    accelerator is always valid.
  * @kvm_type:
  *    Return the type of KVM corresponding to the kvm-type string option or
  *    computed based on other criteria such as the host kernel capabilities
@@ -166,6 +189,7 @@ struct MachineClass {
     const char *alias;
     const char *desc;
     const char *deprecation_reason;
+    const char *const *valid_accelerators;
 
     void (*init)(MachineState *state);
     void (*reset)(MachineState *state);
diff --git a/hw/core/machine.c b/hw/core/machine.c
index 970046f4388..c42d8e382b1 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -518,6 +518,32 @@ static void machine_set_nvdimm_persistence(Object *obj, 
const char *value,
     nvdimms_state->persistence_string = g_strdup(value);
 }
 
+bool machine_class_valid_for_accelerator(MachineClass *mc, const char 
*acc_name)
+{
+    const char *const *name = mc->valid_accelerators;
+
+    if (!name) {
+        return true;
+    }
+    if (strcmp(acc_name, "qtest") == 0) {
+        return true;
+    }
+
+    for (unsigned i = 0; name[i]; i++) {
+        if (strcasecmp(acc_name, name[i]) == 0) {
+            return true;
+        }
+    }
+    return false;
+}
+
+bool machine_class_valid_for_current_accelerator(MachineClass *mc)
+{
+    AccelClass *ac = ACCEL_GET_CLASS(current_accel());
+
+    return machine_class_valid_for_accelerator(mc, ac->name);
+}
+
 void machine_class_allow_dynamic_sysbus_dev(MachineClass *mc, const char *type)
 {
     QAPI_LIST_PREPEND(mc->allowed_dynamic_sysbus_devices, g_strdup(type));
-- 
2.26.2