virtio_mmio: generation support

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.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Michael S. Tsirkin 2015-03-12 12:56:43 +10:30 коммит произвёл Rusty Russell
Родитель 71e4b8bf04
Коммит 87e7bf1450
1 изменённых файлов: 11 добавлений и 0 удалений

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@ -174,6 +174,16 @@ static void vm_set(struct virtio_device *vdev, unsigned offset,
writeb(ptr[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
}
static u32 vm_generation(struct virtio_device *vdev)
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
if (vm_dev->version == 1)
return 0;
else
return readl(vm_dev->base + VIRTIO_MMIO_CONFIG_GENERATION);
}
static u8 vm_get_status(struct virtio_device *vdev)
{
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)
static const struct virtio_config_ops virtio_mmio_config_ops = {
.get = vm_get,
.set = vm_set,
.generation = vm_generation,
.get_status = vm_get_status,
.set_status = vm_set_status,
.reset = vm_reset,