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) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [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 <peter.maydell@linaro.org>

1 files changed, 67 insertions, 0 deletions

diff --git a/util/module.c b/util/module.c
index e48d9aacc0..32b0547b82 100644
--- a/util/module.c
+++ b/util/module.c
@@ -245,3 +245,70 @@ bool module_load_one(const char *prefix, const char *lib_name)
 #endif
     return success;
 }
+
+/*
+ * Building devices and other qom objects modular is mostly useful in
+ * case they have dependencies to external shared libraries, so we can
+ * cut down the core qemu library dependencies.  Which is the case for
+ * only a very few devices & objects.
+ *
+ * So with the expectation that this will be rather the exception than
+ * to rule and the list will not gain that many entries go with a
+ * simple manually maintained list for now.
+ */
+static struct {
+    const char *type;
+    const char *prefix;
+    const char *module;
+} const qom_modules[] = {
+    { "ccid-card-passthru",    "hw-", "usb-smartcard"         },
+    { "ccid-card-emulated",    "hw-", "usb-smartcard"         },
+    { "usb-redir",             "hw-", "usb-redirect"          },
+    { "qxl-vga",               "hw-", "display-qxl"           },
+    { "qxl",                   "hw-", "display-qxl"           },
+    { "virtio-gpu-device",     "hw-", "display-virtio-gpu"    },
+    { "virtio-gpu-pci",        "hw-", "display-virtio-gpu"    },
+    { "virtio-vga",            "hw-", "display-virtio-gpu"    },
+    { "vhost-user-gpu-device", "hw-", "display-virtio-gpu"    },
+    { "vhost-user-gpu-pci",    "hw-", "display-virtio-gpu"    },
+    { "vhost-user-vga",        "hw-", "display-virtio-gpu"    },
+    { "chardev-braille",       "chardev-", "baum"             },
+};
+
+static bool module_loaded_qom_all;
+
+void module_load_qom_one(const char *type)
+{
+    int i;
+
+    if (module_loaded_qom_all) {
+        return;
+    }
+    for (i = 0; i < ARRAY_SIZE(qom_modules); i++) {
+        if (strcmp(qom_modules[i].type, type) == 0) {
+            module_load_one(qom_modules[i].prefix,
+                            qom_modules[i].module);
+            return;
+        }
+    }
+}
+
+void module_load_qom_all(void)
+{
+    int i;
+
+    if (module_loaded_qom_all) {
+        return;
+    }
+    for (i = 0; i < ARRAY_SIZE(qom_modules); i++) {
+        if (i > 0 && (strcmp(qom_modules[i - 1].module,
+                             qom_modules[i].module) == 0 &&
+                      strcmp(qom_modules[i - 1].prefix,
+                             qom_modules[i].prefix) == 0)) {
+            /* one module implementing multiple types -> load only once */
+            continue;
+        }
+        module_load_one(qom_modules[i].prefix, qom_modules[i].module);
+    }
+    module_loaded_qom_all = true;
+}