[PATCH 1/4] iommu: Add virtio-iommu driver

Tian, Kevin
Wed, 21 Mar 2018 06:43:35 -0000

> From: Jean-Philippe Brucker [mailto:jean-philippe.brucker at arm.com]
> Sent: Wednesday, February 14, 2018 10:54 PM
>
> The virtio IOMMU is a para-virtualized device, allowing to send IOMMU
> requests such as map/unmap over virtio-mmio transport without
> emulating
> page tables. This implementation handles ATTACH, DETACH, MAP and
> UNMAP
> requests.
>
> The bulk of the code transforms calls coming from the IOMMU API into
> corresponding virtio requests. Mappings are kept in an interval tree
> instead of page tables.
>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker at
arm.com>

[...]
> diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
> new file mode 100644
> index 000000000000..a9c9245e8ba2
> --- /dev/null
> +++ b/drivers/iommu/virtio-iommu.c
> @@ -0,0 +1,960 @@
> +/*
> + * Virtio driver for the paravirtualized IOMMU
> + *
> + * Copyright (C) 2018 ARM Limited
> + * Author: Jean-Philippe Brucker <jean-philippe.brucker at arm.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/amba/bus.h>
> +#include <linux/delay.h>
> +#include <linux/dma-iommu.h>
> +#include <linux/freezer.h>
> +#include <linux/interval_tree.h>
> +#include <linux/iommu.h>
> +#include <linux/module.h>
> +#include <linux/of_iommu.h>
> +#include <linux/of_platform.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/virtio.h>
> +#include <linux/virtio_config.h>
> +#include <linux/virtio_ids.h>
> +#include <linux/wait.h>
> +
> +#include <uapi/linux/virtio_iommu.h>
> +
> +#define MSI_IOVA_BASE			0x8000000
> +#define MSI_IOVA_LENGTH			0x100000

this is ARM specific, and according to virtio-iommu spec isn't it
better probed on the endpoint instead of hard-coding here?

Thanks
Kevin