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@xxxxxxxxxx>
---
Pawel, you mentioned you have a working virtio 1.0
hypervisor, can you pls confirm this works correctly?
drivers/virtio/virtio_mmio.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 0375456..69b2e4d 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -237,6 +237,16 @@ static void vm_set(struct virtio_device *vdev, unsigned offset,
}
}
+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);
@@ -503,6 +513,8 @@ 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,
.get_status = vm_get_status,
.set_status = vm_set_status,
.reset = vm_reset,
--
MST
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