[Qemu-devel] [RFC PATCH v3 0/2] Introduce virtio-bus.

[Qemu-devel] [RFC PATCH v3 0/2] Introduce virtio-bus.

[fred.konrad]

From: KONRAD Frederic <fred.konrad@greensocs.com>

As said on IRC, I send only VirtioBus as old implementation of VirtioPCI is not longer making sense after the changes on VirtioBus.

As anthony said, the better way to do this refactoring is :

    * Introducing a virtio-bus which extends bus-state.
    * Implementing a virtio-pci-bus which extends virtio-bus.
    * Implementing virtio-device which extends device-states.

This patch introduce virtio-bus, which is abstract and extends bus-state.

The VirtioBusClass still has init and exit methods, which must be called by the
VirtIODevice, and have all the VirtioBindings methods. The futur virtio-x-bus,
will have to implement this methods to be a virtio-bus.

The second patch is a modification of qdev-monitor.c, it forces the function
qbus_find_recursive(..) to return a non full bus, and return an error if the
desired bus ( with "bus=" option ) is full. It add a max_dev field to the
bus_state structure. If max_dev=0 it has no limitation, if not the maximum
amount of device connected to the bus is max_dev.

Changes v2 -> v3:
    * Added VirtioBusClass.
    * Renamed VirtioBus -> VirtioBusState.
    * Renamed qbus -> parent_obj.
    * Plug the device only in a non-full bus.

Changes v1 -> v2:

    * All the little fix you suggest ( License, Debug printf, naming convention,
      ...)
    * Added get_virtio_device_id(), and remove the pci_id* from the VirtioBus
      structure.
    * Added virtio_bus_reset().
    * Added cast macros VIRTIO_BUS.
    * Added virtio_bus_plug_device.
    * Replaced the old-style "bus->qbus" by BUS() macro.

Fred

KONRAD Frederic (2):
  virtio-bus : Introduce virtio-bus
  qbus : add a maximum device.

 hw/qdev-core.h    |    1 +
 hw/qdev-monitor.c |   12 +++++
 hw/virtio-bus.c   |  118 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/virtio-bus.h   |   74 +++++++++++++++++++++++++++++++++
 4 files changed, 205 insertions(+), 0 deletions(-)
 create mode 100644 hw/virtio-bus.c
 create mode 100644 hw/virtio-bus.h

[Qemu-devel] [RFC PATCH v3 1/2] virtio-bus : Introduce virtio-bus

[fred.konrad]

From: KONRAD Frederic <fred.konrad@greensocs.com>

This patch create VirtioBus which is abstract, we can create virtio-x-bus which
extends this virtio-bus.

The virtio-x-bus need to implement all the methods from the VirtioBusClass.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
---
 hw/virtio-bus.c |  118 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/virtio-bus.h |   74 ++++++++++++++++++++++++++++++++++
 2 files changed, 192 insertions(+), 0 deletions(-)
 create mode 100644 hw/virtio-bus.c
 create mode 100644 hw/virtio-bus.h

diff --git a/hw/virtio-bus.c b/hw/virtio-bus.c
new file mode 100644
index 0000000..c6aa02a
--- /dev/null
+++ b/hw/virtio-bus.c
@@ -0,0 +1,118 @@
+/*
+ * VirtioBus
+ *
+ *  Copyright (C) 2012 : GreenSocs Ltd
+ *      http://www.greensocs.com/ , email: info@greensocs.com
+ *
+ *  Developed by :
+ *  Frederic Konrad   <fred.konrad@greensocs.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "hw.h"
+#include "qemu-error.h"
+#include "qdev.h"
+#include "virtio-bus.h"
+#include "virtio.h"
+
+#define DEBUG_VIRTIO_BUS
+
+#ifdef DEBUG_VIRTIO_BUS
+#define DPRINTF(fmt, ...) \
+do { printf("virtio_bus: " fmt , ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) do { } while (0)
+#endif
+
+/* Is the bus used ? */
+static inline int virtio_bus_in_use(VirtioBusState *bus)
+{
+    return (bus->vdev != NULL);
+}
+
+/* Plug the VirtIODevice */
+int virtio_bus_plug_device(VirtioBusState *bus, VirtIODevice *vdev)
+{
+    BusState *qbus = BUS(bus);
+    VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
+    DPRINTF("plug device into %s.\n", qbus->name);
+    if (virtio_bus_in_use(bus)) {
+        /* that couldn't be reached if we modify qdev-monitor.c */
+        error_report("%s in use.\n", qbus->name);
+        return -1;
+    }
+
+    /* keep the VirtIODevice in the VirtioBus. */
+    bus->vdev = vdev;
+
+    /* call the "transport" callback. */
+    if (klass->init != NULL) {
+        klass->init(qbus->parent);
+    }
+    return 0;
+}
+
+/* Bind the VirtIODevice to the VirtioBus. */
+void virtio_bus_bind_device(VirtioBusState *bus)
+{
+    BusState *qbus = BUS(bus);
+    VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
+    assert(bus != NULL);
+    assert(bus->vdev != NULL);
+    /*
+     * Can we do that this way ?
+     */
+    bus->bindings.notify = klass->notify;
+    bus->bindings.save_config = klass->save_config;
+    bus->bindings.save_queue = klass->save_queue;
+    bus->bindings.load_config = klass->load_config;
+    bus->bindings.load_queue = klass->load_queue;
+    bus->bindings.load_done = klass->load_done;
+    bus->bindings.get_features = klass->get_features;
+    bus->bindings.query_guest_notifiers = klass->query_guest_notifiers;
+    bus->bindings.set_guest_notifiers = klass->set_guest_notifiers;
+    bus->bindings.set_host_notifier = klass->set_host_notifier;
+    bus->bindings.vmstate_change = klass->vmstate_change;
+    virtio_bind_device(bus->vdev, &(bus->bindings), qbus->parent);
+}
+
+/* Return the virtio device id of the plugged device. */
+uint16_t get_virtio_device_id(VirtioBusState *bus)
+{
+    return bus->vdev->device_id;
+}
+
+static void virtio_bus_class_init(ObjectClass *klass, void *data)
+{
+    /* Set the default value here. */
+}
+
+static TypeInfo virtio_bus_info = {
+    .name = TYPE_VIRTIO_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(VirtioBusState),
+    /* Abstract the VIRTIO-BUS */
+    .class_init = virtio_bus_class_init,
+    .abstract = true,
+    .class_size = sizeof(VirtioBusClass),
+};
+
+static void virtio_register_types(void)
+{
+    type_register_static(&virtio_bus_info);
+}
+
+type_init(virtio_register_types)
diff --git a/hw/virtio-bus.h b/hw/virtio-bus.h
new file mode 100644
index 0000000..f79276c
--- /dev/null
+++ b/hw/virtio-bus.h
@@ -0,0 +1,74 @@
+/*
+ * VirtioBus
+ *
+ *  Copyright (C) 2012 : GreenSocs Ltd
+ *      http://www.greensocs.com/ , email: info@greensocs.com
+ *
+ *  Developed by :
+ *  Frederic Konrad   <fred.konrad@greensocs.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef VIRTIO_BUS_H
+#define VIRTIO_BUS_H
+
+#include "qdev.h"
+#include "sysemu.h"
+#include "virtio.h"
+
+#define TYPE_VIRTIO_BUS "virtio-bus"
+#define VIRTIO_BUS_GET_CLASS(obj) \
+        OBJECT_GET_CLASS(VirtioBusClass, obj, TYPE_VIRTIO_BUS)
+#define VIRTIO_BUS_CLASS(klass) \
+        OBJECT_CLASS_CHECK(VirtioBusClass, klass, TYPE_VIRTIO_BUS)
+#define VIRTIO_BUS(obj) OBJECT_CHECK(VirtioBusState, (obj), TYPE_VIRTIO_BUS)
+
+typedef struct VirtioBusState VirtioBusState;
+
+typedef struct VirtioBusClass {
+    /* This is what a VirtioBus must implement */
+    BusClass parent;
+    /* Old VirtioBindings */
+    void (*notify)(void * opaque, uint16_t vector);
+    void (*save_config)(void * opaque, QEMUFile *f);
+    void (*save_queue)(void * opaque, int n, QEMUFile *f);
+    int (*load_config)(void * opaque, QEMUFile *f);
+    int (*load_queue)(void * opaque, int n, QEMUFile *f);
+    int (*load_done)(void * opaque, QEMUFile *f);
+    unsigned (*get_features)(void * opaque);
+    bool (*query_guest_notifiers)(void * opaque);
+    int (*set_guest_notifiers)(void * opaque, bool assigned);
+    int (*set_host_notifier)(void * opaque, int n, bool assigned);
+    void (*vmstate_change)(void * opaque, bool running);
+    /* transport independent init function. */
+    void (*init)(void *opaque);
+    /* transport independent exit function. */
+    void (*exit)(void *opaque);
+} VirtioBusClass;
+
+struct VirtioBusState {
+    BusState parent_obj;
+    /* Only one VirtIODevice can be plugged on the bus. */
+    VirtIODevice *vdev;
+    /* VirtIOBindings for bindings the VirtIODevice. */
+    VirtIOBindings bindings;
+};
+
+void virtio_bus_bind_device(VirtioBusState *bus);
+int virtio_bus_plug_device(VirtioBusState *bus, VirtIODevice *vdev);
+uint16_t get_virtio_device_id(VirtioBusState *bus);
+
+#endif /* VIRTIO_BUS_H */
-- 
1.7.1

[Qemu-devel] [RFC PATCH v3 2/2] qbus : add a maximum device.

[fred.konrad]

From: KONRAD Frederic <fred.konrad@greensocs.com>

Only one device can be connected to virtio-bus.
This patch add a field max_dev which is :
    * the maximum amount of devices connected on the bus ( when
    * max_dev!=0 ).
    * have no effect ( when max_dev=0 ).

The function qbus_find_recursive is modified :
    * to return a non full bus when the "bus=" option is not present.
    * to give an error when the "bus=" option is pointing a full bus.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
---
 hw/qdev-core.h    |    1 +
 hw/qdev-monitor.c |   12 ++++++++++++
 2 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/hw/qdev-core.h b/hw/qdev-core.h
index fce9e22..15161f7 100644
--- a/hw/qdev-core.h
+++ b/hw/qdev-core.h
@@ -118,6 +118,7 @@ struct BusState {
     bool qom_allocated;
     bool glib_allocated;
     int max_index;
+    int max_dev;
     QTAILQ_HEAD(ChildrenHead, BusChild) children;
     QLIST_ENTRY(BusState) sibling;
 };
diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 479eecd..66d8e59 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -293,6 +293,18 @@ static BusState *qbus_find_recursive(BusState *bus, const char *name,
         (strcmp(object_get_typename(OBJECT(bus)), bus_typename) != 0)) {
         match = 0;
     }
+
+    /* Check if max_dev is reached */
+    if ((bus->max_dev != 0) && (bus->max_dev <= bus->max_index)) {
+        if (name != NULL) {
+            error_report("maximum amount of devices reached for %s\n", 
+                         bus->name);
+            return NULL;
+        } else {
+            match = 0;
+        }
+    }
+
     if (match) {
         return bus;
     }
-- 
1.7.1