Devices may support different sets of feature bits depending on which
revision they're operating at. Let's give the transport a way to
re-query the device about its features when the revision has been
changed.
Signed-off-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
---
hw/s390x/virtio-ccw.c | 12 ++++++++++--
hw/virtio/virtio-bus.c | 14 ++++++++++++--
include/hw/virtio/virtio-bus.h | 3 +++
include/hw/virtio/virtio.h | 3 +++
4 files changed, 28 insertions(+), 4 deletions(-)
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index a55e851..8b6b2ab 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -699,6 +699,10 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
}
ret = 0;
dev->revision = revinfo.revision;
+ /* Re-evaluate which features the device wants to offer. */
+ dev->host_features =
+ virtio_bus_get_vdev_features_rev(&dev->bus, dev->host_features,
+ dev->revision >= 1 ? 1 : 0);
break;
default:
ret = -ENOSYS;
@@ -712,6 +716,9 @@ static void virtio_sch_disable_cb(SubchDev *sch)
VirtioCcwDevice *dev = sch->driver_data;
dev->revision = -1;
+ /* Reset the device's features to legacy. */
+ dev->host_features =
+ virtio_bus_get_vdev_features_rev(&dev->bus, dev->host_features, 0);
}
static int virtio_ccw_device_init(VirtioCcwDevice *dev, VirtIODevice *vdev)
@@ -853,8 +860,9 @@ static int virtio_ccw_device_init(VirtioCcwDevice *dev, VirtIODevice *vdev)
virtio_add_feature(&dev->host_features, VIRTIO_F_NOTIFY_ON_EMPTY);
virtio_add_feature(&dev->host_features, VIRTIO_F_BAD_FEATURE);
- dev->host_features = virtio_bus_get_vdev_features(&dev->bus,
- dev->host_features);
+ /* All devices start in legacy mode. */
+ dev->host_features =
+ virtio_bus_get_vdev_features_rev(&dev->bus, dev->host_features, 0);
css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid,
parent->hotplugged, 1);
diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
index 32e3fab..a30826c 100644
--- a/hw/virtio/virtio-bus.c
+++ b/hw/virtio/virtio-bus.c
@@ -97,18 +97,28 @@ size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
}
/* Get the features of the plugged device. */
-uint64_t virtio_bus_get_vdev_features(VirtioBusState *bus,
- uint64_t requested_features)
+uint64_t virtio_bus_get_vdev_features_rev(VirtioBusState *bus,
+ uint64_t requested_features,
+ unsigned int revision)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioDeviceClass *k;
assert(vdev != NULL);
k = VIRTIO_DEVICE_GET_CLASS(vdev);
+ if (revision > 0 && k->get_features_rev) {
+ return k->get_features_rev(vdev, requested_features, revision);
+ }
assert(k->get_features != NULL);
return k->get_features(vdev, requested_features);
}
+uint64_t virtio_bus_get_vdev_features(VirtioBusState *bus,
+ uint64_t requested_features)
+{
+ return virtio_bus_get_vdev_features_rev(bus, requested_features, 0);
+}
+
/* Get bad features of the plugged device. */
uint64_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
{
diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h
index 0a4dde1..f0916ef 100644
--- a/include/hw/virtio/virtio-bus.h
+++ b/include/hw/virtio/virtio-bus.h
@@ -84,6 +84,9 @@ size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus);
/* Get the features of the plugged device. */
uint64_t virtio_bus_get_vdev_features(VirtioBusState *bus,
uint64_t requested_features);
+uint64_t virtio_bus_get_vdev_features_rev(VirtioBusState *bus,
+ uint64_t requested_features,
+ unsigned int revision);
/* Get bad features of the plugged device. */
uint64_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus);
/* Get config of the plugged device. */
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 068211e..1338540 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -147,6 +147,9 @@ typedef struct VirtioDeviceClass {
DeviceRealize realize;
DeviceUnrealize unrealize;
uint64_t (*get_features)(VirtIODevice *vdev, uint64_t requested_features);
+ uint64_t (*get_features_rev)(VirtIODevice *vdev,
+ uint64_t requested_features,
+ unsigned int revision);
uint64_t (*bad_features)(VirtIODevice *vdev);
void (*set_features)(VirtIODevice *vdev, uint64_t val);
int (*validate_features)(VirtIODevice *vdev);
--
1.7.9.5
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