[PATCH RFC server v2 02/11] vfio-user: define vfio-user object

[Jagannathan Raman <jag.raman@oracle.com>]

Define vfio-user object which is remote process server for QEMU. Setup
object initialization functions and properties necessary to instantiate
the object

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
---
 qapi/qom.json             |  20 ++++++-
 hw/remote/vfio-user-obj.c | 145 ++++++++++++++++++++++++++++++++++++++++++++++
 MAINTAINERS               |   1 +
 hw/remote/meson.build     |   1 +
 hw/remote/trace-events    |   3 +
 5 files changed, 168 insertions(+), 2 deletions(-)
 create mode 100644 hw/remote/vfio-user-obj.c

diff --git a/qapi/qom.json b/qapi/qom.json
index a25616b..3e941ee 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -689,6 +689,20 @@
   'data': { 'fd': 'str', 'devid': 'str' } }
 
 ##
+# @VfioUserProperties:
+#
+# Properties for vfio-user objects.
+#
+# @socket: path to be used as socket by the libvfiouser library
+#
+# @devid: the id of the device to be associated with the file descriptor
+#
+# Since: 6.0
+##
+{ 'struct': 'VfioUserProperties',
+  'data': { 'socket': 'str', 'devid': 'str' } }
+
+##
 # @RngProperties:
 #
 # Properties for objects of classes derived from rng.
@@ -812,7 +826,8 @@
     'tls-creds-psk',
     'tls-creds-x509',
     'tls-cipher-suites',
-    'x-remote-object'
+    'x-remote-object',
+    'vfio-user'
   ] }
 
 ##
@@ -868,7 +883,8 @@
       'tls-creds-psk':              'TlsCredsPskProperties',
       'tls-creds-x509':             'TlsCredsX509Properties',
       'tls-cipher-suites':          'TlsCredsProperties',
-      'x-remote-object':            'RemoteObjectProperties'
+      'x-remote-object':            'RemoteObjectProperties',
+      'vfio-user':                  'VfioUserProperties'
   } }
 
 ##
diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
new file mode 100644
index 0000000..4a1e297
--- /dev/null
+++ b/hw/remote/vfio-user-obj.c
@@ -0,0 +1,145 @@
+/**
+ * QEMU vfio-user server object
+ *
+ * Copyright © 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL-v2, version 2 or later.
+ *
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+/**
+ * Usage: add options:
+ *     -machine x-remote
+ *     -device <PCI-device>,id=<pci-dev-id>
+ *     -object vfio-user,id=<id>,socket=<socket-path>,devid=<pci-dev-id>
+ *
+ * Note that vfio-user object must be used with x-remote machine only. This
+ * server could only support PCI devices for now.
+ *
+ * socket is path to a file. This file will be created by the server. It is
+ * a required option
+ *
+ * devid is the id of a PCI device on the server. It is also a required option.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "qom/object.h"
+#include "qom/object_interfaces.h"
+#include "qemu/error-report.h"
+#include "trace.h"
+#include "sysemu/runstate.h"
+
+#define TYPE_VFU_OBJECT "vfio-user"
+OBJECT_DECLARE_TYPE(VfuObject, VfuObjectClass, VFU_OBJECT)
+
+struct VfuObjectClass {
+    ObjectClass parent_class;
+
+    unsigned int nr_devs;
+
+    /* Maximum number of devices the server could support */
+    unsigned int max_devs;
+};
+
+struct VfuObject {
+    /* private */
+    Object parent;
+
+    char *socket;
+    char *devid;
+};
+
+static void vfu_object_set_socket(Object *obj, const char *str, Error **errp)
+{
+    VfuObject *o = VFU_OBJECT(obj);
+
+    g_free(o->socket);
+
+    o->socket = g_strdup(str);
+
+    trace_vfu_prop("socket", str);
+}
+
+static void vfu_object_set_devid(Object *obj, const char *str, Error **errp)
+{
+    VfuObject *o = VFU_OBJECT(obj);
+
+    g_free(o->devid);
+
+    o->devid = g_strdup(str);
+
+    trace_vfu_prop("devid", str);
+}
+
+static void vfu_object_init(Object *obj)
+{
+    VfuObjectClass *k = VFU_OBJECT_GET_CLASS(obj);
+
+    if (!object_dynamic_cast(OBJECT(current_machine), TYPE_REMOTE_MACHINE)) {
+        error_report("vfu: %s only compatible with %s machine",
+                     TYPE_VFU_OBJECT, TYPE_REMOTE_MACHINE);
+        return;
+    }
+
+    if (k->nr_devs >= k->max_devs) {
+        error_report("Reached maximum number of vfio-user devices: %u",
+                     k->max_devs);
+        return;
+    }
+
+    k->nr_devs++;
+}
+
+static void vfu_object_finalize(Object *obj)
+{
+    VfuObjectClass *k = VFU_OBJECT_GET_CLASS(obj);
+    VfuObject *o = VFU_OBJECT(obj);
+
+    k->nr_devs--;
+
+    g_free(o->socket);
+    g_free(o->devid);
+
+    if (k->nr_devs == 0) {
+        qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
+    }
+}
+
+static void vfu_object_class_init(ObjectClass *klass, void *data)
+{
+    VfuObjectClass *k = VFU_OBJECT_CLASS(klass);
+
+    /* Limiting maximum number of devices to 1 until IOMMU support is added */
+    k->max_devs = 1;
+    k->nr_devs = 0;
+
+    object_class_property_add_str(klass, "socket", NULL,
+                                  vfu_object_set_socket);
+    object_class_property_add_str(klass, "devid", NULL,
+                                  vfu_object_set_devid);
+}
+
+static const TypeInfo vfu_object_info = {
+    .name = TYPE_VFU_OBJECT,
+    .parent = TYPE_OBJECT,
+    .instance_size = sizeof(VfuObject),
+    .instance_init = vfu_object_init,
+    .instance_finalize = vfu_object_finalize,
+    .class_size = sizeof(VfuObjectClass),
+    .class_init = vfu_object_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_USER_CREATABLE },
+        { }
+    }
+};
+
+static void vfu_register_types(void)
+{
+    type_register_static(&vfu_object_info);
+}
+
+type_init(vfu_register_types);
diff --git a/MAINTAINERS b/MAINTAINERS
index 0c5a18e..f9d8092 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3391,6 +3391,7 @@ F: hw/remote/proxy-memory-listener.c
 F: include/hw/remote/proxy-memory-listener.h
 F: hw/remote/iohub.c
 F: include/hw/remote/iohub.h
+F: hw/remote/vfio-user-obj.c
 
 EBPF:
 M: Jason Wang <jasowang@redhat.com>
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
index fb35fb8..cd44dfc 100644
--- a/hw/remote/meson.build
+++ b/hw/remote/meson.build
@@ -6,6 +6,7 @@ remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('message.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('remote-obj.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('proxy.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('iohub.c'))
+remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('vfio-user-obj.c'))
 
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: vfiouser)
 
diff --git a/hw/remote/trace-events b/hw/remote/trace-events
index 0b23974..7da12f0 100644
--- a/hw/remote/trace-events
+++ b/hw/remote/trace-events
@@ -2,3 +2,6 @@
 
 mpqemu_send_io_error(int cmd, int size, int nfds) "send command %d size %d, %d file descriptors to remote process"
 mpqemu_recv_io_error(int cmd, int size, int nfds) "failed to receive %d size %d, %d file descriptors to remote process"
+
+# vfio-user-obj.c
+vfu_prop(const char *prop, const char *val) "vfu: setting %s as %s"
-- 
1.8.3.1