virtio: move host_features

Move host_features from the individual transport proxies into
the virtio device. Transports may continue to add feature bits
during device plugging.

This should it make easier to offer different sets of host features
for virtio-1/transitional support.
Tested-by: NShannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/s390x/s390-virtio-bus.c

@@ -139,8 +139,6 @@ static void s390_virtio_device_init(VirtIOS390Device *dev,
 
     bus->dev_offs += dev_len;
 
-    dev->host_features = virtio_bus_get_vdev_features(&dev->bus,
-                                                      dev->host_features);
     s390_virtio_device_sync(dev);
     s390_virtio_reset_idx(dev);
     if (dev->qdev.hotplugged) {
@@ -433,7 +431,8 @@ void s390_virtio_device_sync(VirtIOS390Device *dev)
     cur_offs += num_vq * VIRTIO_VQCONFIG_LEN;
 
     /* Sync feature bitmap */
-    address_space_stl_le(&address_space_memory, cur_offs, dev->host_features,
+    address_space_stl_le(&address_space_memory, cur_offs,
+                         dev->vdev->host_features,
                          MEMTXATTRS_UNSPECIFIED, NULL);
 
     dev->feat_offs = cur_offs + dev->feat_len;
@@ -528,12 +527,6 @@ static void virtio_s390_notify(DeviceState *d, uint16_t vector)
     s390_virtio_irq(0, token);
 }
 
-static unsigned virtio_s390_get_features(DeviceState *d)
-{
-    VirtIOS390Device *dev = to_virtio_s390_device(d);
-    return dev->host_features;
-}
-
 /**************** S390 Virtio Bus Device Descriptions *******************/
 
 static void s390_virtio_net_class_init(ObjectClass *klass, void *data)
@@ -626,16 +619,10 @@ static void s390_virtio_busdev_reset(DeviceState *dev)
     virtio_reset(_dev->vdev);
 }
 
-static Property virtio_s390_properties[] = {
-    DEFINE_VIRTIO_COMMON_FEATURES(VirtIOS390Device, host_features),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void virtio_s390_device_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
-    dc->props = virtio_s390_properties;
     dc->realize = s390_virtio_busdev_realize;
     dc->bus_type = TYPE_S390_VIRTIO_BUS;
     dc->reset = s390_virtio_busdev_reset;
@@ -733,7 +720,6 @@ static void virtio_s390_bus_class_init(ObjectClass *klass, void *data)
     BusClass *bus_class = BUS_CLASS(klass);
     bus_class->max_dev = 1;
     k->notify = virtio_s390_notify;
-    k->get_features = virtio_s390_get_features;
 }
 
 static const TypeInfo virtio_s390_bus_info = {

hw/s390x/s390-virtio-bus.h

@@ -92,7 +92,6 @@ struct VirtIOS390Device {
     ram_addr_t feat_offs;
     uint8_t feat_len;
     VirtIODevice *vdev;
-    uint32_t host_features;
     VirtioBusState bus;
 };
 

hw/s390x/virtio-ccw.c

@@ -381,8 +381,8 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
                                                 + sizeof(features.features),
                                                 MEMTXATTRS_UNSPECIFIED,
                                                 NULL);
-            if (features.index < ARRAY_SIZE(dev->host_features)) {
-                features.features = dev->host_features[features.index];
+            if (features.index == 0) {
+                features.features = vdev->host_features;
             } else {
                 /* Return zeroes if the guest supports more feature bits. */
                 features.features = 0;
@@ -417,7 +417,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
                                                      ccw.cda,
                                                      MEMTXATTRS_UNSPECIFIED,
                                                      NULL);
-            if (features.index < ARRAY_SIZE(dev->host_features)) {
+            if (features.index == 0) {
                 virtio_set_features(vdev, features.features);
             } else {
                 /*
@@ -1071,14 +1071,6 @@ static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
     }
 }
 
-static unsigned virtio_ccw_get_features(DeviceState *d)
-{
-    VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
-
-    /* Only the first 32 feature bits are used. */
-    return dev->host_features[0];
-}
-
 static void virtio_ccw_reset(DeviceState *d)
 {
     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
@@ -1390,14 +1382,12 @@ static void virtio_ccw_device_plugged(DeviceState *d)
 {
     VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
     SubchDev *sch = dev->sch;
+    VirtIODevice *vdev = virtio_ccw_get_vdev(sch);
 
     sch->id.cu_model = virtio_bus_get_vdev_id(&dev->bus);
 
-    /* Only the first 32 feature bits are used. */
-    virtio_add_feature(&dev->host_features[0], VIRTIO_F_NOTIFY_ON_EMPTY);
-    virtio_add_feature(&dev->host_features[0], VIRTIO_F_BAD_FEATURE);
-    dev->host_features[0] = virtio_bus_get_vdev_features(&dev->bus,
-                                                         dev->host_features[0]);
+    virtio_add_feature(&vdev->host_features, VIRTIO_F_NOTIFY_ON_EMPTY);
+    virtio_add_feature(&vdev->host_features, VIRTIO_F_BAD_FEATURE);
 
     css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid,
                           d->hotplugged, 1);
@@ -1648,16 +1638,10 @@ static void virtio_ccw_busdev_unplug(HotplugHandler *hotplug_dev,
     object_unparent(OBJECT(dev));
 }
 
-static Property virtio_ccw_properties[] = {
-    DEFINE_VIRTIO_COMMON_FEATURES(VirtioCcwDevice, host_features[0]),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void virtio_ccw_device_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
-    dc->props = virtio_ccw_properties;
     dc->realize = virtio_ccw_busdev_realize;
     dc->exit = virtio_ccw_busdev_exit;
     dc->bus_type = TYPE_VIRTUAL_CSS_BUS;
@@ -1722,7 +1706,6 @@ static void virtio_ccw_bus_class_init(ObjectClass *klass, void *data)
 
     bus_class->max_dev = 1;
     k->notify = virtio_ccw_notify;
-    k->get_features = virtio_ccw_get_features;
     k->vmstate_change = virtio_ccw_vmstate_change;
     k->query_guest_notifiers = virtio_ccw_query_guest_notifiers;
     k->set_host_notifier = virtio_ccw_set_host_notifier;

hw/s390x/virtio-ccw.h

@@ -68,9 +68,6 @@ typedef struct VirtIOCCWDeviceClass {
     int (*exit)(VirtioCcwDevice *dev);
 } VirtIOCCWDeviceClass;
 
-/* Change here if we want to support more feature bits. */
-#define VIRTIO_CCW_FEATURE_SIZE 1
-
 /* Performance improves when virtqueue kick processing is decoupled from the
  * vcpu thread using ioeventfd for some devices. */
 #define VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT 1
@@ -88,7 +85,6 @@ struct VirtioCcwDevice {
     DeviceState parent_obj;
     SubchDev *sch;
     char *bus_id;
-    uint32_t host_features[VIRTIO_CCW_FEATURE_SIZE];
     VirtioBusState bus;
     bool ioeventfd_started;
     bool ioeventfd_disabled;

hw/virtio/virtio-bus.c

@@ -44,12 +44,17 @@ int virtio_bus_device_plugged(VirtIODevice *vdev)
     BusState *qbus = BUS(qdev_get_parent_bus(qdev));
     VirtioBusState *bus = VIRTIO_BUS(qbus);
     VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
+
     DPRINTF("%s: plug device.\n", qbus->name);
 
     if (klass->device_plugged != NULL) {
         klass->device_plugged(qbus->parent);
     }
 
+    /* Get the features of the plugged device. */
+    assert(vdc->get_features != NULL);
+    vdev->host_features = vdc->get_features(vdev, vdev->host_features);
     return 0;
 }
 
@@ -96,19 +101,6 @@ size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
     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(vdev != NULL);
-    k = VIRTIO_DEVICE_GET_CLASS(vdev);
-    assert(k->get_features != NULL);
-    return k->get_features(vdev, requested_features);
-}
-
 /* Get bad features of the plugged device. */
 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
 {

hw/virtio/virtio-mmio.c

@@ -80,7 +80,6 @@ typedef struct {
     SysBusDevice parent_obj;
     MemoryRegion iomem;
     qemu_irq irq;
-    uint32_t host_features;
     /* Guest accessible state needing migration and reset */
     uint32_t host_features_sel;
     uint32_t guest_features_sel;
@@ -147,7 +146,7 @@ static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
         if (proxy->host_features_sel) {
             return 0;
         }
-        return proxy->host_features;
+        return vdev->host_features;
     case VIRTIO_MMIO_QUEUENUMMAX:
         if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
             return 0;
@@ -306,13 +305,6 @@ static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
     qemu_set_irq(proxy->irq, level);
 }
 
-static unsigned int virtio_mmio_get_features(DeviceState *opaque)
-{
-    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
-
-    return proxy->host_features;
-}
-
 static int virtio_mmio_load_config(DeviceState *opaque, QEMUFile *f)
 {
     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
@@ -348,10 +340,9 @@ static void virtio_mmio_reset(DeviceState *d)
 static void virtio_mmio_device_plugged(DeviceState *opaque)
 {
     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
-    virtio_add_feature(&proxy->host_features, VIRTIO_F_NOTIFY_ON_EMPTY);
-    proxy->host_features = virtio_bus_get_vdev_features(&proxy->bus,
-                                                        proxy->host_features);
+    virtio_add_feature(&vdev->host_features, VIRTIO_F_NOTIFY_ON_EMPTY);
 }
 
 static void virtio_mmio_realizefn(DeviceState *d, Error **errp)
@@ -367,16 +358,10 @@ static void virtio_mmio_realizefn(DeviceState *d, Error **errp)
     sysbus_init_mmio(sbd, &proxy->iomem);
 }
 
-static Property virtio_mmio_properties[] = {
-    DEFINE_VIRTIO_COMMON_FEATURES(VirtIOMMIOProxy, host_features),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void virtio_mmio_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
-    dc->props = virtio_mmio_properties;
     dc->realize = virtio_mmio_realizefn;
     dc->reset = virtio_mmio_reset;
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
@@ -399,7 +384,6 @@ static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data)
     k->notify = virtio_mmio_update_irq;
     k->save_config = virtio_mmio_save_config;
     k->load_config = virtio_mmio_load_config;
-    k->get_features = virtio_mmio_get_features;
     k->device_plugged = virtio_mmio_device_plugged;
     k->has_variable_vring_alignment = true;
     bus_class->max_dev = 1;

hw/virtio/virtio-pci.c

@@ -306,7 +306,7 @@ static uint32_t virtio_ioport_read(VirtIOPCIProxy *proxy, uint32_t addr)
 
     switch (addr) {
     case VIRTIO_PCI_HOST_FEATURES:
-        ret = proxy->host_features;
+        ret = vdev->host_features;
         break;
     case VIRTIO_PCI_GUEST_FEATURES:
         ret = vdev->guest_features;
@@ -434,12 +434,6 @@ static void virtio_write_config(PCIDevice *pci_dev, uint32_t address,
     }
 }
 
-static unsigned virtio_pci_get_features(DeviceState *d)
-{
-    VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
-    return proxy->host_features;
-}
-
 static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy *proxy,
                                         unsigned int queue_no,
                                         unsigned int vector,
@@ -924,6 +918,7 @@ static void virtio_pci_device_plugged(DeviceState *d)
     VirtioBusState *bus = &proxy->bus;
     uint8_t *config;
     uint32_t size;
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
     config = proxy->pci_dev.config;
     if (proxy->class_code) {
@@ -958,10 +953,8 @@ static void virtio_pci_device_plugged(DeviceState *d)
         proxy->flags &= ~VIRTIO_PCI_FLAG_USE_IOEVENTFD;
     }
 
-    virtio_add_feature(&proxy->host_features, VIRTIO_F_NOTIFY_ON_EMPTY);
-    virtio_add_feature(&proxy->host_features, VIRTIO_F_BAD_FEATURE);
-    proxy->host_features = virtio_bus_get_vdev_features(bus,
-                                                      proxy->host_features);
+    virtio_add_feature(&vdev->host_features, VIRTIO_F_NOTIFY_ON_EMPTY);
+    virtio_add_feature(&vdev->host_features, VIRTIO_F_BAD_FEATURE);
 }
 
 static void virtio_pci_device_unplugged(DeviceState *d)
@@ -999,7 +992,6 @@ static void virtio_pci_reset(DeviceState *qdev)
 static Property virtio_pci_properties[] = {
     DEFINE_PROP_BIT("virtio-pci-bus-master-bug-migration", VirtIOPCIProxy, flags,
                     VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT, false),
-    DEFINE_VIRTIO_COMMON_FEATURES(VirtIOPCIProxy, host_features),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -1469,7 +1461,6 @@ static void virtio_pci_bus_class_init(ObjectClass *klass, void *data)
     k->load_config = virtio_pci_load_config;
     k->save_queue = virtio_pci_save_queue;
     k->load_queue = virtio_pci_load_queue;
-    k->get_features = virtio_pci_get_features;
     k->query_guest_notifiers = virtio_pci_query_guest_notifiers;
     k->set_host_notifier = virtio_pci_set_host_notifier;
     k->set_guest_notifiers = virtio_pci_set_guest_notifiers;

hw/virtio/virtio-pci.h

@@ -91,7 +91,6 @@ struct VirtIOPCIProxy {
     uint32_t flags;
     uint32_t class_code;
     uint32_t nvectors;
-    uint32_t host_features;
     bool ioeventfd_disabled;
     bool ioeventfd_started;
     VirtIOIRQFD *vector_irqfd;

hw/virtio/virtio.c

@@ -970,13 +970,10 @@ void virtio_save(VirtIODevice *vdev, QEMUFile *f)
 
 int virtio_set_features(VirtIODevice *vdev, uint32_t val)
 {
-    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
-    VirtioBusClass *vbusk = VIRTIO_BUS_GET_CLASS(qbus);
     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
-    uint32_t supported_features = vbusk->get_features(qbus->parent);
-    bool bad = (val & ~supported_features) != 0;
+    bool bad = (val & ~(vdev->host_features)) != 0;
 
-    val &= supported_features;
+    val &= vdev->host_features;
     if (k->set_features) {
         k->set_features(vdev, val);
     }
@@ -990,7 +987,6 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)
     int32_t config_len;
     uint32_t num;
     uint32_t features;
-    uint32_t supported_features;
     BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
@@ -1016,9 +1012,8 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)
     qemu_get_be32s(f, &features);
 
     if (virtio_set_features(vdev, features) < 0) {
-        supported_features = k->get_features(qbus->parent);
         error_report("Features 0x%x unsupported. Allowed features: 0x%x",
-                     features, supported_features);
+                     features, vdev->host_features);
         return -1;
     }
     config_len = qemu_get_be32(f);
@@ -1351,6 +1346,11 @@ static void virtio_device_unrealize(DeviceState *dev, Error **errp)
     vdev->bus_name = NULL;
 }
 
+static Property virtio_properties[] = {
+    DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void virtio_device_class_init(ObjectClass *klass, void *data)
 {
     /* Set the default value here. */
@@ -1359,6 +1359,7 @@ static void virtio_device_class_init(ObjectClass *klass, void *data)
     dc->realize = virtio_device_realize;
     dc->unrealize = virtio_device_unrealize;
     dc->bus_type = TYPE_VIRTIO_BUS;
+    dc->props = virtio_properties;
 }
 
 static const TypeInfo virtio_device_info = {

include/hw/virtio/virtio-bus.h

@@ -47,7 +47,6 @@ typedef struct VirtioBusClass {
     int (*load_config)(DeviceState *d, QEMUFile *f);
     int (*load_queue)(DeviceState *d, int n, QEMUFile *f);
     int (*load_done)(DeviceState *d, QEMUFile *f);
-    unsigned (*get_features)(DeviceState *d);
     bool (*query_guest_notifiers)(DeviceState *d);
     int (*set_guest_notifiers)(DeviceState *d, int nvqs, bool assign);
     int (*set_host_notifier)(DeviceState *d, int n, bool assigned);

include/hw/virtio/virtio.h

@@ -74,6 +74,7 @@ struct VirtIODevice
     uint8_t isr;
     uint16_t queue_sel;
     uint32_t guest_features;
+    uint32_t host_features;
     size_t config_len;
     void *config;
     uint16_t config_vector;