Merge remote-tracking branch 'remotes/kraxel/tags/modules-20200707-pull-request' into staging

qom: add support for qom objects in modules.
build some devices (qxl, virtio-gpu, ccid, usb-redir) as modules.
build braille chardev as module.

v2: more verbose comment for "build: fix device module builds" patch.

note: qemu doesn't rebuild objects on cflags changes (specifically
      -fPIC being added when code is switched from builtin to module).
      Workaround for resulting build errors: "make clean", rebuild.

# gpg: Signature made Tue 07 Jul 2020 14:42:16 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <[email protected]>" [full]
# gpg:                 aka "Gerd Hoffmann <[email protected]>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <[email protected]>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/modules-20200707-pull-request:
  chardev: enable modules, use for braille
  vga: build virtio-gpu as module
  vga: build virtio-gpu only once
  vga: build qxl as module
  usb: build usb-redir as module
  ccid: build smartcard as module
  build: fix device module builds
  qdev: device module support
  object: qom module support
  module: qom module support

Signed-off-by: Peter Maydell <[email protected]>

Author: pm215

Makefile.objs

@@ -59,6 +59,7 @@ common-obj-y += migration/
 common-obj-y += audio/
 common-obj-m += audio/
 common-obj-y += hw/
+common-obj-m += hw/
 
 common-obj-y += replay/
 
@@ -70,6 +71,7 @@ common-obj-$(CONFIG_TPM) += tpm.o
 
 common-obj-y += backends/
 common-obj-y += chardev/
+common-obj-m += chardev/
 
 common-obj-$(CONFIG_SECCOMP) += qemu-seccomp.o
 qemu-seccomp.o-cflags := $(SECCOMP_CFLAGS)

Makefile.target

@@ -179,6 +179,20 @@ endif # CONFIG_SOFTMMU
 dummy := $(call unnest-vars,,obj-y)
 all-obj-y := $(obj-y)
 
+#
+# common-obj-m has some crap here, probably as side effect from
+# unnest-vars recursing into target directories to fill obj-y and not
+# properly handling the -m case.
+#
+# Clear common-obj-m as workaround.  Fixes suspious dependency errors
+# when building devices as modules.  A bit hackish, but should be ok
+# as long as we do not have any target-specific modules.
+#
+# The meson-based build system currently in development doesn't need
+# unnest-vars and will obsolete this workaround.
+#
+common-obj-m :=
+
 include $(SRC_PATH)/Makefile.objs
 dummy := $(call unnest-vars,.., \
                authz-obj-y \

chardev/Makefile.objs

@@ -18,8 +18,11 @@ chardev-obj-$(CONFIG_WIN32) += char-win.o
 chardev-obj-$(CONFIG_WIN32) += char-win-stdio.o
 
 common-obj-y += msmouse.o wctablet.o testdev.o
-common-obj-$(CONFIG_BRLAPI) += baum.o
+
+ifeq ($(CONFIG_BRLAPI),y)
+common-obj-m += baum.o
 baum.o-cflags := $(SDL_CFLAGS)
 baum.o-libs := $(BRLAPI_LIBS)
+endif
 
 common-obj-$(CONFIG_SPICE) += spice.o

chardev/char.c

@@ -527,7 +527,7 @@ static const ChardevClass *char_get_class(const char *driver, Error **errp)
     const ChardevClass *cc;
     char *typename = g_strdup_printf("chardev-%s", driver);
 
-    oc = object_class_by_name(typename);
+    oc = module_object_class_by_name(typename);
     g_free(typename);
 
     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {

hw/Makefile.objs

@@ -43,4 +43,6 @@ devices-dirs-y += smbios/
 endif
 
 common-obj-y += $(devices-dirs-y)
+common-obj-m += display/
+common-obj-m += usb/
 obj-y += $(devices-dirs-y)

hw/core/qdev.c

@@ -137,6 +137,9 @@ void qdev_set_parent_bus(DeviceState *dev, BusState *bus)
  */
 DeviceState *qdev_new(const char *name)
 {
+    if (!object_class_by_name(name)) {
+        module_load_qom_one(name);
+    }
     return DEVICE(object_new(name));
 }
 
@@ -147,10 +150,9 @@ DeviceState *qdev_new(const char *name)
  */
 DeviceState *qdev_try_new(const char *name)
 {
-    if (!object_class_by_name(name)) {
+    if (!module_object_class_by_name(name)) {
         return NULL;
     }
-
     return DEVICE(object_new(name));
 }
 

hw/display/Makefile.objs

@@ -44,18 +44,24 @@ common-obj-$(CONFIG_ARTIST) += artist.o
 
 obj-$(CONFIG_VGA) += vga.o
 
-common-obj-$(CONFIG_QXL) += qxl.o qxl-logger.o qxl-render.o
-
-obj-$(CONFIG_VIRTIO_GPU) += virtio-gpu-base.o virtio-gpu.o virtio-gpu-3d.o
-obj-$(CONFIG_VHOST_USER_GPU) += vhost-user-gpu.o
-obj-$(call land,$(CONFIG_VIRTIO_GPU),$(CONFIG_VIRTIO_PCI)) += virtio-gpu-pci.o
-obj-$(call land,$(CONFIG_VHOST_USER_GPU),$(CONFIG_VIRTIO_PCI)) += vhost-user-gpu-pci.o
-obj-$(CONFIG_VIRTIO_VGA) += virtio-vga.o
-obj-$(CONFIG_VHOST_USER_VGA) += vhost-user-vga.o
-virtio-gpu.o-cflags := $(VIRGL_CFLAGS)
-virtio-gpu.o-libs += $(VIRGL_LIBS)
-virtio-gpu-3d.o-cflags := $(VIRGL_CFLAGS)
-virtio-gpu-3d.o-libs += $(VIRGL_LIBS)
+ifeq ($(CONFIG_QXL),y)
+common-obj-m += qxl.mo
+qxl.mo-objs = qxl.o qxl-logger.o qxl-render.o
+endif
+
+ifeq ($(CONFIG_VIRTIO_GPU),y)
+common-obj-m += virtio-gpu.mo
+virtio-gpu-obj-$(CONFIG_VIRTIO_GPU) += virtio-gpu-base.o virtio-gpu.o virtio-gpu-3d.o
+virtio-gpu-obj-$(CONFIG_VHOST_USER_GPU) += vhost-user-gpu.o
+virtio-gpu-obj-$(call land,$(CONFIG_VIRTIO_GPU),$(CONFIG_VIRTIO_PCI)) += virtio-gpu-pci.o
+virtio-gpu-obj-$(call land,$(CONFIG_VHOST_USER_GPU),$(CONFIG_VIRTIO_PCI)) += vhost-user-gpu-pci.o
+virtio-gpu-obj-$(CONFIG_VIRTIO_VGA) += virtio-vga.o
+virtio-gpu-obj-$(CONFIG_VHOST_USER_VGA) += vhost-user-vga.o
+virtio-gpu.mo-objs := $(virtio-gpu-obj-y)
+virtio-gpu.mo-cflags := $(VIRGL_CFLAGS)
+virtio-gpu.mo-libs := $(VIRGL_LIBS)
+endif
+
 common-obj-$(CONFIG_DPCD) += dpcd.o
 common-obj-$(CONFIG_XLNX_ZYNQMP_ARM) += xlnx_dp.o
 

hw/usb/Makefile.objs

@@ -29,21 +29,26 @@ common-obj-$(CONFIG_USB_NETWORK)      += dev-network.o
 
 ifeq ($(CONFIG_USB_SMARTCARD),y)
 common-obj-y                          += dev-smartcard-reader.o
-common-obj-$(CONFIG_SMARTCARD)        += smartcard.mo
+ifeq ($(CONFIG_SMARTCARD),y)
+common-obj-m                          += smartcard.mo
 smartcard.mo-objs := ccid-card-passthru.o ccid-card-emulated.o
 smartcard.mo-cflags := $(SMARTCARD_CFLAGS)
 smartcard.mo-libs := $(SMARTCARD_LIBS)
 endif
+endif
 
 ifeq ($(CONFIG_POSIX),y)
 common-obj-$(CONFIG_USB_STORAGE_MTP)  += dev-mtp.o
 endif
 
 # usb redirection
 ifeq ($(CONFIG_USB),y)
-common-obj-$(CONFIG_USB_REDIR) += redirect.o quirks.o
-redirect.o-cflags = $(USB_REDIR_CFLAGS)
-redirect.o-libs = $(USB_REDIR_LIBS)
+ifeq ($(CONFIG_USB_REDIR),y)
+common-obj-m += redirect.mo
+redirect.mo-objs = redirect.o quirks.o
+redirect.mo-cflags = $(USB_REDIR_CFLAGS)
+redirect.mo-libs = $(USB_REDIR_LIBS)
+endif
 endif
 
 # usb pass-through

include/qemu/module.h

@@ -70,5 +70,7 @@ void register_dso_module_init(void (*fn)(void), module_init_type type);
 
 void module_call_init(module_init_type type);
 bool module_load_one(const char *prefix, const char *lib_name);
+void module_load_qom_one(const char *type);
+void module_load_qom_all(void);
 
 #endif

include/qom/object.h

@@ -994,6 +994,18 @@ bool object_class_is_abstract(ObjectClass *klass);
  */
 ObjectClass *object_class_by_name(const char *typename);
 
+/**
+ * module_object_class_by_name:
+ * @typename: The QOM typename to obtain the class for.
+ *
+ * For objects which might be provided by a module.  Behaves like
+ * object_class_by_name, but additionally tries to load the module
+ * needed in case the class is not available.
+ *
+ * Returns: The class for @typename or %NULL if not found.
+ */
+ObjectClass *module_object_class_by_name(const char *typename);
+
 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
                           const char *implements_type, bool include_abstract,
                           void *opaque);