virtio_mmio: generation support (87e7bf14) · Commits · 戴 / test

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>

drivers/virtio/virtio_mmio.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -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,

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