drm/virtio: use virtio_max_dma_size (9b2a0a1e) · Commits · 戴 / test

We must make sure our scatterlist segments are not too big, otherwise we might see swiotlb failures (happens with sev, also reproducable with swiotlb=force). Suggested-by:

Laszlo Ersek <lersek@redhat.com> Signed-off-by:

Gerd Hoffmann <kraxel@redhat.com> Reviewed-by:

Laszlo Ersek <lersek@redhat.com> Link: http://patchwork.freedesktop.org/patch/msgid/20190821111210.27165-1-kraxel@redhat.com

drivers/gpu/drm/virtio/virtgpu_object.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -204,6 +204,7 @@ int virtio_gpu_object_get_sg_table(struct virtio_gpu_device *qdev,
		.interruptible = false,
		.no_wait_gpu = false
		};
		size_t max_segment;

		/* wtf swapping */
		if (bo->pages)
		@@ -215,8 +216,13 @@ int virtio_gpu_object_get_sg_table(struct virtio_gpu_device *qdev,
		if (!bo->pages)
		goto out;

		ret = sg_alloc_table_from_pages(bo->pages, pages, nr_pages, 0,
		nr_pages << PAGE_SHIFT, GFP_KERNEL);
		max_segment = virtio_max_dma_size(qdev->vdev);
		max_segment &= PAGE_MASK;
		if (max_segment > SCATTERLIST_MAX_SEGMENT)
		max_segment = SCATTERLIST_MAX_SEGMENT;
		ret = __sg_alloc_table_from_pages(bo->pages, pages, nr_pages, 0,
		nr_pages << PAGE_SHIFT,
		max_segment, GFP_KERNEL);
		if (ret)
		goto out;
		return 0;

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