For virtio-1 devices, the driver must not attempt to set feature bits after it set FEATURES_OK in the device status. Simply reject it in that case.
Signed-off-by: Cornelia Huck <cornelia.h...@de.ibm.com> --- hw/virtio/virtio.c | 17 +++++++++++++++-- include/hw/virtio/virtio.h | 2 ++ 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 2c6bb91..8cdc0cb 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -982,7 +982,8 @@ void virtio_save(VirtIODevice *vdev, QEMUFile *f) vmstate_save_state(f, &vmstate_virtio, vdev); } -int virtio_set_features(VirtIODevice *vdev, unsigned int index, uint32_t val) +static int __virtio_set_features(VirtIODevice *vdev, unsigned int index, + uint32_t val) { BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); VirtioBusClass *vbusk = VIRTIO_BUS_GET_CLASS(qbus); @@ -998,6 +999,18 @@ int virtio_set_features(VirtIODevice *vdev, unsigned int index, uint32_t val) return bad ? -1 : 0; } +int virtio_set_features(VirtIODevice *vdev, unsigned int index, uint32_t val) +{ + /* + * The driver must not attempt to set features after feature negotiation + * has finished. + */ + if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { + return -EINVAL; + } + return __virtio_set_features(vdev, index, val); +} + int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) { int i, ret; @@ -1030,7 +1043,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) qemu_get_be32s(f, &features); /* XXX features >= 32 */ - if (virtio_set_features(vdev, 0, features) < 0) { + if (__virtio_set_features(vdev, 0, features) < 0) { supported_features = k->get_features(qbus->parent, 0); error_report("Features 0x%x unsupported. Allowed features: 0x%x", features, supported_features); diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index f840320..ec1be3b 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -32,6 +32,8 @@ #define VIRTIO_CONFIG_S_DRIVER 2 /* Driver has used its parts of the config, and is happy */ #define VIRTIO_CONFIG_S_DRIVER_OK 4 +/* Driver has finished configuring features */ +#define VIRTIO_CONFIG_S_FEATURES_OK 8 /* We've given up on this device. */ #define VIRTIO_CONFIG_S_FAILED 0x80 -- 1.7.9.5