machine: Replace has_dynamic_sysbus with list of allowed devices

The existing has_dynamic_sysbus flag makes the machine accept
every user-creatable sysbus device type on the command-line.
Replace it with a list of allowed device types, so machines can
easily accept some sysbus devices while rejecting others.

To keep exactly the same behavior as before, the existing
has_dynamic_sysbus=true assignments are replaced with a
TYPE_SYS_BUS_DEVICE entry on the allowed list.  Other patches
will replace the TYPE_SYS_BUS_DEVICE entries with more specific
lists of devices.

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: qemu-arm@nongnu.org
Cc: qemu-ppc@nongnu.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20171125151610.20547-2-ehabkost@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

hw/arm/virt.c

@@ -1591,7 +1591,8 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
      * configuration of the particular instance.
      */
     mc->max_cpus = 255;
-    mc->has_dynamic_sysbus = true;
+    /*TODO: allow only sysbus devices that really work with this machine */
+    machine_class_allow_dynamic_sysbus_dev(mc, TYPE_SYS_BUS_DEVICE);
     mc->block_default_type = IF_VIRTIO;
     mc->no_cdrom = 1;
     mc->pci_allow_0_address = true;

hw/core/machine.c

@@ -334,29 +334,44 @@ static bool machine_get_enforce_config_section(Object *obj, Error **errp)
     return ms->enforce_config_section;
 }
 
-static void error_on_sysbus_device(SysBusDevice *sbdev, void *opaque)
+void machine_class_allow_dynamic_sysbus_dev(MachineClass *mc, const char *type)
 {
-    error_report("Option '-device %s' cannot be handled by this machine",
+    strList *item = g_new0(strList, 1);
-                 object_class_get_name(object_get_class(OBJECT(sbdev))));
+
-    exit(1);
+    item->value = g_strdup(type);
+    item->next = mc->allowed_dynamic_sysbus_devices;
+    mc->allowed_dynamic_sysbus_devices = item;
+}
+
+static void validate_sysbus_device(SysBusDevice *sbdev, void *opaque)
+{
+    MachineState *machine = opaque;
+    MachineClass *mc = MACHINE_GET_CLASS(machine);
+    bool allowed = false;
+    strList *wl;
+
+    for (wl = mc->allowed_dynamic_sysbus_devices;
+         !allowed && wl;
+         wl = wl->next) {
+        allowed |= !!object_dynamic_cast(OBJECT(sbdev), wl->value);
+    }
+
+    if (!allowed) {
+        error_report("Option '-device %s' cannot be handled by this machine",
+                     object_class_get_name(object_get_class(OBJECT(sbdev))));
+        exit(1);
+    }
 }
 
 static void machine_init_notify(Notifier *notifier, void *data)
 {
-    Object *machine = qdev_get_machine();
+    MachineState *machine = MACHINE(qdev_get_machine());
-    ObjectClass *oc = object_get_class(machine);
-    MachineClass *mc = MACHINE_CLASS(oc);
-
-    if (mc->has_dynamic_sysbus) {
-        /* Our machine can handle dynamic sysbus devices, we're all good */
-        return;
-    }
 
     /*
-     * Loop through all dynamically created devices and check whether there
+     * Loop through all dynamically created sysbus devices and check if they are
-     * are sysbus devices among them. If there are, error out.
+     * all allowed.  If a device is not allowed, error out.
      */
-    foreach_dynamic_sysbus_device(error_on_sysbus_device, NULL);
+    foreach_dynamic_sysbus_device(validate_sysbus_device, machine);
 }
 
 HotpluggableCPUList *machine_query_hotpluggable_cpus(MachineState *machine)

hw/i386/pc_q35.c

@@ -299,7 +299,8 @@ static void pc_q35_machine_options(MachineClass *m)
     m->default_machine_opts = "firmware=bios-256k.bin";
     m->default_display = "std";
     m->no_floppy = 1;
-    m->has_dynamic_sysbus = true;
+    /*TODO: allow only sysbus devices that really work with this machine */
+    machine_class_allow_dynamic_sysbus_dev(m, TYPE_SYS_BUS_DEVICE);
     m->max_cpus = 288;
 }
 

hw/ppc/e500plat.c

@@ -15,6 +15,7 @@
 #include "hw/boards.h"
 #include "sysemu/device_tree.h"
 #include "sysemu/kvm.h"
+#include "hw/sysbus.h"
 #include "hw/pci/pci.h"
 #include "hw/ppc/openpic.h"
 #include "kvm_ppc.h"
@@ -63,7 +64,8 @@ static void e500plat_machine_init(MachineClass *mc)
     mc->desc = "generic paravirt e500 platform";
     mc->init = e500plat_init;
     mc->max_cpus = 32;
-    mc->has_dynamic_sysbus = true;
+    /*TODO: allow only sysbus devices that really work with this machine */
+    machine_class_allow_dynamic_sysbus_dev(mc, TYPE_SYS_BUS_DEVICE);
     mc->default_cpu_type = POWERPC_CPU_TYPE_NAME("e500v2_v30");
 }
 

hw/ppc/spapr.c

@@ -3843,7 +3843,8 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     mc->default_boot_order = "";
     mc->default_ram_size = 512 * M_BYTE;
     mc->kvm_type = spapr_kvm_type;
-    mc->has_dynamic_sysbus = true;
+    /*TODO: allow only sysbus devices that really work with this machine */
+    machine_class_allow_dynamic_sysbus_dev(mc, TYPE_SYS_BUS_DEVICE);
     mc->pci_allow_0_address = true;
     mc->get_hotplug_handler = spapr_get_hotplug_handler;
     hc->pre_plug = spapr_machine_device_pre_plug;

hw/xen/xen_backend.c

@@ -564,7 +564,12 @@ static void xen_set_dynamic_sysbus(void)
     ObjectClass *oc = object_get_class(machine);
     MachineClass *mc = MACHINE_CLASS(oc);
 
-    mc->has_dynamic_sysbus = true;
+    /*
+     * Emulate old mc->has_dynamic_sysbus=true assignment
+     *
+     *TODO: add only Xen devices to the list
+     */
+    machine_class_allow_dynamic_sysbus_dev(mc, TYPE_SYS_BUS_DEVICE);
 }
 
 int xen_be_register(const char *type, struct XenDevOps *ops)

include/hw/boards.h

@@ -76,6 +76,9 @@ void machine_set_cpu_numa_node(MachineState *machine,
                                const CpuInstanceProperties *props,
                                Error **errp);
 
+void machine_class_allow_dynamic_sysbus_dev(MachineClass *mc, const char *type);
+
+
 /**
  * CPUArchId:
  * @arch_id - architecture-dependent CPU ID of present or possible CPU
@@ -179,7 +182,6 @@ struct MachineClass {
         no_floppy:1,
         no_cdrom:1,
         no_sdcard:1,
-        has_dynamic_sysbus:1,
         pci_allow_0_address:1,
         legacy_fw_cfg_order:1;
     int is_default;
@@ -197,6 +199,7 @@ struct MachineClass {
     bool ignore_memory_transaction_failures;
     int numa_mem_align_shift;
     const char **valid_cpu_types;
+    strList *allowed_dynamic_sysbus_devices;
     bool auto_enable_numa_with_memhp;
     void (*numa_auto_assign_ram)(MachineClass *mc, NodeInfo *nodes,
                                  int nb_nodes, ram_addr_t size);