diff mbox series

[v10,06/14] vfio-user: instantiate vfio-user context

Message ID 38676caf167ae5205a4179e6a1256d2586b801af.1653404595.git.jag.raman@oracle.com
State New
Headers show
Series vfio-user server in QEMU | expand

Commit Message

Jag Raman May 24, 2022, 3:30 p.m. UTC
create a context with the vfio-user library to run a PCI device

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>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/remote/vfio-user-obj.c | 96 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
diff mbox series

Patch

diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
index bc49adcc27..68aac0c2b9 100644
--- a/hw/remote/vfio-user-obj.c
+++ b/hw/remote/vfio-user-obj.c
@@ -40,6 +40,9 @@ 
 #include "hw/remote/machine.h"
 #include "qapi/error.h"
 #include "qapi/qapi-visit-sockets.h"
+#include "qemu/notify.h"
+#include "sysemu/sysemu.h"
+#include "libvfio-user.h"
 
 #define TYPE_VFU_OBJECT "x-vfio-user-server"
 OBJECT_DECLARE_TYPE(VfuObject, VfuObjectClass, VFU_OBJECT)
@@ -73,8 +76,14 @@  struct VfuObject {
     char *device;
 
     Error *err;
+
+    Notifier machine_done;
+
+    vfu_ctx_t *vfu_ctx;
 };
 
+static void vfu_object_init_ctx(VfuObject *o, Error **errp);
+
 static bool vfu_object_auto_shutdown(void)
 {
     bool auto_shutdown = true;
@@ -107,6 +116,11 @@  static void vfu_object_set_socket(Object *obj, Visitor *v, const char *name,
 {
     VfuObject *o = VFU_OBJECT(obj);
 
+    if (o->vfu_ctx) {
+        error_setg(errp, "vfu: Unable to set socket property - server busy");
+        return;
+    }
+
     qapi_free_SocketAddress(o->socket);
 
     o->socket = NULL;
@@ -122,17 +136,83 @@  static void vfu_object_set_socket(Object *obj, Visitor *v, const char *name,
     }
 
     trace_vfu_prop("socket", o->socket->u.q_unix.path);
+
+    vfu_object_init_ctx(o, errp);
 }
 
 static void vfu_object_set_device(Object *obj, const char *str, Error **errp)
 {
     VfuObject *o = VFU_OBJECT(obj);
 
+    if (o->vfu_ctx) {
+        error_setg(errp, "vfu: Unable to set device property - server busy");
+        return;
+    }
+
     g_free(o->device);
 
     o->device = g_strdup(str);
 
     trace_vfu_prop("device", str);
+
+    vfu_object_init_ctx(o, errp);
+}
+
+/*
+ * TYPE_VFU_OBJECT depends on the availability of the 'socket' and 'device'
+ * properties. It also depends on devices instantiated in QEMU. These
+ * dependencies are not available during the instance_init phase of this
+ * object's life-cycle. As such, the server is initialized after the
+ * machine is setup. machine_init_done_notifier notifies TYPE_VFU_OBJECT
+ * when the machine is setup, and the dependencies are available.
+ */
+static void vfu_object_machine_done(Notifier *notifier, void *data)
+{
+    VfuObject *o = container_of(notifier, VfuObject, machine_done);
+    Error *err = NULL;
+
+    vfu_object_init_ctx(o, &err);
+
+    if (err) {
+        error_propagate(&error_abort, err);
+    }
+}
+
+/**
+ * vfu_object_init_ctx: Create and initialize libvfio-user context. Add
+ *   an unplug blocker for the associated PCI device. Setup a FD handler
+ *   to process incoming messages in the context's socket.
+ *
+ *   The socket and device properties are mandatory, and this function
+ *   will not create the context without them - the setters for these
+ *   properties should call this function when the property is set. The
+ *   machine should also be ready when this function is invoked - it is
+ *   because QEMU objects are initialized before devices, and the
+ *   associated PCI device wouldn't be available at the object
+ *   initialization time. Until these conditions are satisfied, this
+ *   function would return early without performing any task.
+ */
+static void vfu_object_init_ctx(VfuObject *o, Error **errp)
+{
+    ERRP_GUARD();
+
+    if (o->vfu_ctx || !o->socket || !o->device ||
+            !phase_check(PHASE_MACHINE_READY)) {
+        return;
+    }
+
+    if (o->err) {
+        error_propagate(errp, o->err);
+        o->err = NULL;
+        return;
+    }
+
+    o->vfu_ctx = vfu_create_ctx(VFU_TRANS_SOCK, o->socket->u.q_unix.path, 0,
+                                o, VFU_DEV_TYPE_PCI);
+    if (o->vfu_ctx == NULL) {
+        error_setg(errp, "vfu: Failed to create context - %s", strerror(errno));
+        return;
+    }
 }
 
 static void vfu_object_init(Object *obj)
@@ -147,6 +227,12 @@  static void vfu_object_init(Object *obj)
                    TYPE_VFU_OBJECT, TYPE_REMOTE_MACHINE);
         return;
     }
+
+    if (!phase_check(PHASE_MACHINE_READY)) {
+        o->machine_done.notify = vfu_object_machine_done;
+        qemu_add_machine_init_done_notifier(&o->machine_done);
+    }
+
 }
 
 static void vfu_object_finalize(Object *obj)
@@ -160,6 +246,11 @@  static void vfu_object_finalize(Object *obj)
 
     o->socket = NULL;
 
+    if (o->vfu_ctx) {
+        vfu_destroy_ctx(o->vfu_ctx);
+        o->vfu_ctx = NULL;
+    }
+
     g_free(o->device);
 
     o->device = NULL;
@@ -167,6 +258,11 @@  static void vfu_object_finalize(Object *obj)
     if (!k->nr_devs && vfu_object_auto_shutdown()) {
         qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
     }
+
+    if (o->machine_done.notify) {
+        qemu_remove_machine_init_done_notifier(&o->machine_done);
+        o->machine_done.notify = NULL;
+    }
 }
 
 static void vfu_object_class_init(ObjectClass *klass, void *data)