From ed35f9edcc420b4f8c1f909bc7cfb002a54f437b Mon Sep 17 00:00:00 2001

From: Paolo Bonzini <pbonzini@redhat.com>

Date: Fri, 20 Sep 2013 16:57:50 +0200

Subject: [PATCH] virtio-bus: remove vdev field

The vdev field is complicated to synchronize.  Just access the

BusState's list of children.

Cc: qemu-stable@nongnu.org

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

---

 hw/virtio/virtio-bus.c         | 67 ++++++++++++++++++++++++------------------

 hw/virtio/virtio-mmio.c        |  9 +++---

 hw/virtio/virtio-pci.c         |  2 +-

 include/hw/virtio/virtio-bus.h | 16 +++++++---

 4 files changed, 57 insertions(+), 37 deletions(-)

diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c

index 6849a01..669ce38 100644

--- a/hw/virtio/virtio-bus.c

+++ b/hw/virtio/virtio-bus.c

@@ -46,8 +46,6 @@ int virtio_bus_plug_device(VirtIODevice *vdev)

     VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);

     DPRINTF("%s: plug device.\n", qbus->name);

-    bus->vdev = vdev;

-

     if (klass->device_plugged != NULL) {

         klass->device_plugged(qbus->parent);

     }

@@ -58,75 +56,84 @@ int virtio_bus_plug_device(VirtIODevice *vdev)

 /* Reset the virtio_bus */

 void virtio_bus_reset(VirtioBusState *bus)

 {

+    VirtIODevice *vdev = virtio_bus_get_device(bus);

+

     DPRINTF("%s: reset device.\n", qbus->name);

-    if (bus->vdev != NULL) {

-        virtio_reset(bus->vdev);

+    if (vdev != NULL) {

+        virtio_reset(vdev);

     }

 }

 /* Destroy the VirtIODevice */

 void virtio_bus_destroy_device(VirtioBusState *bus)

 {

-    DeviceState *qdev;

     BusState *qbus = BUS(bus);

     VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);

+    VirtIODevice *vdev = virtio_bus_get_device(bus);

+

     DPRINTF("%s: remove device.\n", qbus->name);

-    if (bus->vdev != NULL) {

+    if (vdev != NULL) {

         if (klass->device_unplug != NULL) {

             klass->device_unplug(qbus->parent);

         }

-        qdev = DEVICE(bus->vdev);

-        qdev_free(qdev);

-        bus->vdev = NULL;

+        qdev_free(DEVICE(vdev));

     }

 }

 /* Get the device id of the plugged device. */

 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus)

 {

-    assert(bus->vdev != NULL);

-    return bus->vdev->device_id;

+    VirtIODevice *vdev = virtio_bus_get_device(bus);

+    assert(vdev != NULL);

+    return vdev->device_id;

 }

 /* Get the config_len field of the plugged device. */

 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)

 {

-    assert(bus->vdev != NULL);

-    return bus->vdev->config_len;

+    VirtIODevice *vdev = virtio_bus_get_device(bus);

+    assert(vdev != NULL);

+    return vdev->config_len;

 }

 /* Get the features of the plugged device. */

 uint32_t virtio_bus_get_vdev_features(VirtioBusState *bus,

                                     uint32_t requested_features)

 {

+    VirtIODevice *vdev = virtio_bus_get_device(bus);

     VirtioDeviceClass *k;

-    assert(bus->vdev != NULL);

-    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);

+

+    assert(vdev != NULL);

+    k = VIRTIO_DEVICE_GET_CLASS(vdev);

     assert(k->get_features != NULL);

-    return k->get_features(bus->vdev, requested_features);

+    return k->get_features(vdev, requested_features);

 }

 /* Set the features of the plugged device. */

 void virtio_bus_set_vdev_features(VirtioBusState *bus,

                                       uint32_t requested_features)

 {

+    VirtIODevice *vdev = virtio_bus_get_device(bus);

     VirtioDeviceClass *k;

-    assert(bus->vdev != NULL);

-    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);

+

+    assert(vdev != NULL);

+    k = VIRTIO_DEVICE_GET_CLASS(vdev);

     if (k->set_features != NULL) {

-        k->set_features(bus->vdev, requested_features);

+        k->set_features(vdev, requested_features);

     }

 }

 /* Get bad features of the plugged device. */

 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)

 {

+    VirtIODevice *vdev = virtio_bus_get_device(bus);

     VirtioDeviceClass *k;

-    assert(bus->vdev != NULL);

-    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);

+

+    assert(vdev != NULL);

+    k = VIRTIO_DEVICE_GET_CLASS(vdev);

     if (k->bad_features != NULL) {

-        return k->bad_features(bus->vdev);

+        return k->bad_features(vdev);

     } else {

         return 0;

     }

@@ -135,22 +142,26 @@ uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)

 /* Get config of the plugged device. */

 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config)

 {

+    VirtIODevice *vdev = virtio_bus_get_device(bus);

     VirtioDeviceClass *k;

-    assert(bus->vdev != NULL);

-    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);

+

+    assert(vdev != NULL);

+    k = VIRTIO_DEVICE_GET_CLASS(vdev);

     if (k->get_config != NULL) {

-        k->get_config(bus->vdev, config);

+        k->get_config(vdev, config);

     }

 }

 /* Set config of the plugged device. */

 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config)

 {

+    VirtIODevice *vdev = virtio_bus_get_device(bus);

     VirtioDeviceClass *k;

-    assert(bus->vdev != NULL);

-    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);

+

+    assert(vdev != NULL);

+    k = VIRTIO_DEVICE_GET_CLASS(vdev);

     if (k->set_config != NULL) {

-        k->set_config(bus->vdev, config);

+        k->set_config(vdev, config);

     }

 }

diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c

index 4bd2953..8f7b764 100644

--- a/hw/virtio/virtio-mmio.c

+++ b/hw/virtio/virtio-mmio.c

@@ -94,7 +94,7 @@ static void virtio_mmio_bus_new(VirtioBusState *bus, VirtIOMMIOProxy *dev);

 static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)

 {

     VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;

-    VirtIODevice *vdev = proxy->bus.vdev;

+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);

     DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset);

@@ -184,7 +184,7 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,

                               unsigned size)

 {

     VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;

-    VirtIODevice *vdev = proxy->bus.vdev;

+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);

     DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n",

             (int)offset, value);

@@ -297,12 +297,13 @@ static const MemoryRegionOps virtio_mem_ops = {

 static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)

 {

     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);

+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);

     int level;

-    if (!proxy->bus.vdev) {

+    if (!vdev) {

         return;

     }

-    level = (proxy->bus.vdev->isr != 0);

+    level = (vdev->isr != 0);

     DPRINTF("virtio_mmio setting IRQ %d\n", level);

     qemu_set_irq(proxy->irq, level);

 }

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c

index 41b96ce..55617a6 100644

--- a/hw/virtio/virtio-pci.c

+++ b/hw/virtio/virtio-pci.c

@@ -942,7 +942,7 @@ static void virtio_pci_device_plugged(DeviceState *d)

     uint8_t *config;

     uint32_t size;

-    proxy->vdev = bus->vdev;

+    proxy->vdev = virtio_bus_get_device(bus);

     config = proxy->pci_dev.config;

     if (proxy->class_code) {

diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h

index 9217f85..ba0f86a 100644

--- a/include/hw/virtio/virtio-bus.h

+++ b/include/hw/virtio/virtio-bus.h

@@ -72,10 +72,6 @@ typedef struct VirtioBusClass {

 struct VirtioBusState {

     BusState parent_obj;

-    /*

-     * Only one VirtIODevice can be plugged on the bus.

-     */

-    VirtIODevice *vdev;

 };

 int virtio_bus_plug_device(VirtIODevice *vdev);

@@ -98,4 +94,16 @@ void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config);

 /* Set config of the plugged device. */

 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config);

+static inline VirtIODevice *virtio_bus_get_device(VirtioBusState *bus)

+{

+    BusState *qbus = &bus->parent_obj;

+    BusChild *kid = QTAILQ_FIRST(&qbus->children);

+    DeviceState *qdev = kid ? kid->child : NULL;

+

+    /* This is used on the data path, the cast is guaranteed

+     * to succeed by the qdev machinery.

+     */

+    return (VirtIODevice *)qdev;

+}

+

 #endif /* VIRTIO_BUS_H */