virtio_mmio currently lacks generation support which makes multi-byte field access racy. Fix by getting the value at offset 0xfc for version 2 devices. Nothing we can do for version 1, so return generation id 0.
Unified · Split
| @@ -174,6 +174,16 @@ static void vm_set(struct virtio_device *vdev, unsigned offset, · 173 unmodified lines | ||
| 174 | 174 | writeb(ptr[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i); |
| 175 | 175 | } |
| 176 | 176 | |
| 177 | +static u32 vm_generation(struct virtio_device *vdev) | |
| 178 | +{ | |
| 179 | + struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); | |
| 180 | + | |
| 181 | + if (vm_dev->version == 1) | |
| 182 | + return 0; | |
| 183 | + else | |
| 184 | + return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION); | |
| 185 | +} | |
| 186 | + | |
| 177 | 187 | static u8 vm_get_status(struct virtio_device *vdev) |
| 178 | 188 | { |
| 179 | 189 | struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); |
| @@ -440,6 +450,7 @@ static const char *vm_bus_name(struct virtio_device *vdev) · 260 unmodified lines | ||
| 440 | 450 | static const struct virtio_config_ops virtio_mmio_config_ops = { |
| 441 | 451 | .get = vm_get, |
| 442 | 452 | .set = vm_set, |
| 453 | + .generation = vm_generation, | |
| 443 | 454 | .get_status = vm_get_status, |
| 444 | 455 | .set_status = vm_set_status, |
| 445 | 456 | .reset = vm_reset, |